TW201007116A - Film thickness measuring apparatus - Google Patents

Abstract

The present invention provides a film thickness measuring apparatus, wherein cycle of reflectivity waveform of the object under test becomes longer if a longer wavelength of measuring light is used. Array elements of InGaAs are configured with equal interval in terms wavelength, thus, when the wave number decreases, the configured interval of the array elements corresponding to the wave number gets larger. In order to correctly sample the reflectivity waveform which corresponds to the wave number and varies with a preset cycle, configuration interval of the array elements (i.e. wavelength resolution Δλ) must satisfy the Nyquist sampling theorem. By satisfying the sampling theorem, the upper bound dmax of the measurement range in film thickness is determined.

Description

201007116 IV. Designation of the representative representative: (1) The representative representative of the case is: figure (6). (2) A brief description of the component symbols of this representative figure: 64~ detection part. 5. If there is a chemical formula, please disclose the chemical formula that best shows the characteristics of the hairpin. Description of the invention: Measuring device and film thickness measuring method, especially the film thickness of the test object with multiple layers [Technology of the invention] FIELD OF THE INVENTION The present invention relates to film thicknesses that are formed on substrates, structures and methods. [Prior Art] In recent years, in order to achieve low power consumption and high speed in a complementary metal oxide semiconductor (c〇mplemenhry oxide Semiconduct〇r, CM〇s) circuit, the insulating layer is covered with silicon (silicon 〇n insulat〇r, The substrate structure of s〇i) is noticed. The s〇I substrate is connected to two 矽ic〇n,) an insulating layer (germanium layer) such as cerium oxide (Si〇2) is disposed between the substrates, so that a germanium joint surface formed in one of the germanium layers is The parasitic diode (diode) and electrostatic capacitance generated between the other layer (substrate) can be reduced. Conventionally, the manufacturing method of the SOI substrate is formed by forming an acidified film on the surface of a silicon wafer, and adhering to other germanium wafers to refresh the acidified film in 201007116, and between the blood and the blood- Step 'grinding the dream wafer forming the circuit component to a predetermined thickness. According to this polishing process, in order to control the thickness of the germanium wafer, the film thickness needs to be continuously monitored. Japanese Patent Special Opened G5_Write (4) and special Kaiping. 5. In the observation bulletin, a method for measuring the film thickness of the polishing process, that is, a method using a Fourier transform infrared spectrophotometer (F(10) core transform infrared spectr〇sc〇py, FTIR) is disclosed. Further, a method of measuring a reflection spectrum by a dispersion type multi-channel spectroscope is disclosed in Japanese Laid-Open Patent Publication No. 2G() No. 5-992G. In the above-mentioned Japanese Patent Application Laid-Open No. Hei No. Hei. No. Hei. Further, in the Japanese Patent Laid-Open Publication No. 2-221-2842, the infrared rays above the wavelength of m (micrometer) are irradiated toward the surface of the stone film, and then the light reflected from the surface of the stone film and the interference light reflected in the dream film are interfering. The results are based on the method for measuring the film thickness of the film. Further, in Japanese Patent Laid-Open Publication No. 2〇〇3_1141〇7, the light interference type film thickness measuring device using infrared rays as the measuring light is used. However, the Japanese Patent Application No. 5_3〇691〇 In the film thickness measuring method disclosed in Japanese Laid-Open Patent Publication No. Hei 5-3-96, the film thickness relative value of the sample based on the standard cannot be measured, and thus the film thickness cannot be measured absolutely. "Measurement disclosed in the 20th bulletin 201007116 In the method of determining 'the refractive index does not depend on the wavelength and the period is estimated according to the self-regressive model (1„0(161), and the rooting rate has wavelength dependence, Therefore, it is impossible to rule out the mistakes of the fold. From the Q ^ *, the child wavelength dependence' In addition, the measurement method of the Japanese Patent Laid-Open No. 2003_114107 has the same problem. In the test method towel disclosed in the 2nd bulletin, it is necessary to continuously measure the film thickness in a non-destructive manner on the sample of the target object. 73..., method [Summary of the Invention] To solve this problem, the object of the present invention In ^ The film thickness measuring method 'is used for film thickness with higher precision, and the film thickness measuring device of the present invention includes a light source, which has a predetermined wavelength range of light, and b forms at least a layer or more on the substrate. The object to be tested; the spectroscopic part, the root enthalpy is: fine 丨 &# s U , according to the light reflected by the object or the light penetrating the object to be tested 'to obtain the wavelength of reflectivity or transmittance The distribution characteristic; and the determining unit, according to the large wave number component of the amplitude value included in the wave number distribution characteristic, is used to determine the film thickness of each layer constituting the object to be tested. The spectrometry portion can be detected by the wavelength resolution 包含 included in the predetermined wavelength range. The wavelength distribution characteristic of the upper limit wavelength Wi of the lower limit wavelength U disk. The spectroscopic measurement and the thickness of the target layer which may be measured by the film thickness measuring device are the longest = & nax, and the upper limit wavelength of seven nax is satisfied. : 201007116 . * "Δ;ί 幺Amax 2 /2(乂继+ 2 . «祖.ί/颜) Better, the lower limit wavelength jlmin of the spectrometric part, and the film that may be measured by the film thickness measuring device Thick minimum, satisfying the following Relation: ^min - ^min * ^max /^(^max * ^min ~ meaning min * Wmax ) where wmin is the lower limit wavelength & ii of the target layer refractive index. More preferably, the coefficient α (0<α; $ n, so that the wavelength resolution Δ; ι is as follows: • ΔΑ < a X λ 2 /ΐ(λ + 2 · w rl , zero max /^V^max «max ' Ctmax ) Better The ground 'coefficient α is less than 1 / 2. According to the present invention, it is possible to measure the film thickness of the test object having higher accuracy. The above described objects, features, and advantages of the invention will be apparent from the description and appended claims appended claims

[Embodiment] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition

In the drawings, the same or similar elements are denoted by the same or like numerals, and the repeated description is omitted. <<Device Architecture>> Fig. 1 is a schematic block diagram showing an embodiment of the present invention. Film Thickness Measuring Apparatus 100 The film thickness measuring apparatus of the present embodiment is generally used in the case of a test object, and the thickness of each layer is determined for a single layer or a laminated structure. In the fifth embodiment, the film thickness measuring device 100 of 201007116 is particularly suitable for measuring the film thickness of the test object in a thick layer (usually 2 μm..., the film thickness measuring device 1 〇 is a microscopic spectroscopic measuring device) The light is irradiated onto the object to be tested, and the film thickness of each layer constituting the object to be tested can be measured according to the wavelength distribution characteristic of the reflected light reflected by the object to be tested (hereinafter also referred to as "spectrum (10)). Further, the measurement is not limited to the film thickness, and can be used for the measurement of the reflectance of each layer (absolute and relative) and the analysis of the layer structure. Progress can also use the spectrum of the light that penetrates the object under test (the spectrum of the transmitted light) to replace the spectrum of the reflected light. In the specification, a case is described in which a substrate or a substrate as a substrate to be tested is formed with one or more layers. In the embodiment, the object to be tested is a substrate having a laminated structure such as a thick substrate of a bismuth (Si) substrate, a glass substrate, and a sapphire substrate, and an SOI substrate. In particular, the film thickness measuring device of the present embodiment is suitable for measuring the thickness of the germanium substrate after the cutting and polishing, the thickness of the germanium layer (active layer) of the SOI substrate, and chemical mechanical polishing (CMP). The thickness of the substrate is the thickness of the substrate. Referring to Fig. 1, the film thickness measuring apparatus 100 includes a measuring light source 10, a collimating lens 12' cutting filter 14, imaging lenses 16 and 36, a diaphragm 18, and a beam splitter (20). 30. Observation light source 22, optical fiber 24, injection portion 26, pinhole mirror 32, axis conversion mirror 34, camera 38, display portion 39, and data processing portion 201007116 In order to obtain the reflectance spectrum of the test object, the light source for measurement is used to generate a light source having a predetermined wavelength range, and particularly has a wavelength component in the infrared light field (for example, 900 nm (nano) to 16 A light source of 〇〇nm, or 147〇nm~i 600nm). A Hierogen lamp is usually used as a light source for measurement. The focus lens 12, the filter 14, the imaging lens 16, and the diaphragm 18 are disposed on the optical axis m for connecting the measurement light source 1G and the beam splitter 3 ().

The measurement light emitted from the measurement light source 1 is optically adjusted. Specifically, the focus lens 12 is an optical light at which the measurement light of the measurement light source 1 is initially incident, and the measurement light that propagates as the diffusion light is refracted into parallel light. The measurement light that has passed through the focus lens 12 is incident on the filter 14. The filter 14 is for blocking unwanted wavelength components in the measurement light. The filter Η is usually formed of a multilayer film deposited on a glass substrate or the like. To adjust the measurement 2 = beam diameter, the imaging lens 16 converts the measured light passing through the filter 14 from parallel rays to concentrated rays. The light passing through the imaging lens 16 is incident on the diaphragm 18. The aperture 18 adjusts the amount of light of the measurement light to a predetermined amount for emission to the beam splitter 30. More preferably, the aperture 18 is arranged in accordance with the measured light imaging position converted by the imaging lens 16. Further, the aperture amount of the diaphragm 18 is appropriately set to correspond to the depth of field of the incident light incident to the object to be tested, the necessary light intensity, and the like. In other respects, the observation light source 22 is a light source for generating observation light, and is used for households to focus and confirm the measurement position. And select the observation source Μ, the raw observation light to include the wavelength that the object to be tested may reflect. The observation light source 22 is connected to the emission portion 26 via the optical fiber 24 so that the observation light generated by the observation light source 7 201007116 is propagated through the optical fiber 24 as the optical waveguide, and then emitted from the emission portion 26 toward the spectroscopic mirror 2. The injection portion 26 includes a mask portion 26a for masking the flaw observation light generated by the observation light source 22 to project a predetermined observation reference image onto the object to be tested. The observation reference image is also easy to focus on the surface without the (four) pattern (the material to be tested (usually a transparent glass substrate, etc.). Further, any shape of the reticle can be used. For example, a concentric circular shape and a cross-shaped pattern can be used. In other words, in the beam cross section of the observation light generated by the observation light source 22, the light intensity (light amount) is approximately the same, and the _ partial observation light is obscured. After the mask portion 26a is masked (shaded), the observation light forms an area (shaded area) where the light intensity is about zero on the beam section. The shadow area is projected as an observation reference image on the object to be tested. 50 is a sample stage on which the object to be tested is placed, and its placement surface is flat. For example, 'the stage 50 is a mechanically coupled movable mechanism', which can be in three directions () [direction, γ direction, and z The direction is freely driven. The movable mechanism 51 is usually composed of a three-axis servo motor and a servo driver for driving each of the servo motors. Further, the movable mechanism 51 is driven by a user or a control device not shown. use In response to the command of the position of the stage, the driving relationship of the stage 50 is used to change the positional relationship between the object to be tested and the objective lens 40 to be described later. The objective lens 40, the beam splitter 30 and the pinhole mirror 32 are used. The light beam splitter 30 disposed in the direction perpendicular to the flat surface of the stage 50 reflects the measurement light generated by the measurement light source 1 for 201007116. • The direction of propagation is converted to the lower side of the paper surface toward the optical axis AX1. Further, the dichroic mirror 30 transmits the reflected light of the object to be detected which propagates over the plane of the optical axis. On the other hand, the spectroscope 20 reflects the observation light generated by the observation light source 22, and converts the propagation direction into To the right of the paper surface of the optical axis Αχ2, that is, the beam splitter 30 has a function of a light injection portion, from the measuring light source 10 to the optical path of the objective lens 40 of the collecting optical system, for viewing light. The measurement light and the observation light synthesized by the beam splitter 20 are reflected by the spectroscope 30 and then incident on the objective lens 4, in particular, since the measurement light has a wavelength component of an infrared light field, and the observation light has can Seeing the wavelength component of the optical region, the spectroscopes 20 and 30 are capable of maintaining the target value of the transmission/reflection characteristics from the visible light to the infrared region. The objective lens 40 is a collecting optical system for moving toward The measuring light and the observation light propagating below the optical axis of the optical axis are collected, that is, the objective lens 4 会 converges the measuring light and the observation light for imaging on the object to be tested or its adjacent position. In addition, the objective lens 40 is attached. It is a magnifying lens having a predetermined magnification (for example, 1 〇, 2 〇, 30 倍, 40 倍, etc.). Therefore, the magnifying lens can make optical properties of the measuring light compared to the beam section incident on the objective lens 40. In addition, the measurement light and the observation light incident on the object to be tested through the objective lens 40 are reflected by the object to be tested, and propagate toward the upper side of the optical axis. After the reflected light passes through the objective lens 40, it is then passed through the beam splitter 3 to the pinhole mirror 32. 201007116 The pinhole mirror 32 has a function of a light separating portion, and separates the measured reflected light and the observed reflected light from the reflected light generated by the object to be tested. Specifically, the pinhole mirror 32 includes a reflecting surface for reflecting the reflected light from the object to be tested and propagating toward the upper side of the paper sleeve AX1 and forming a hole at the center of the intersection of the reflecting surface and the optical axis AX1. Part (pinhole) 32a. The measured reflected light generated after the measurement light of the measuring light source 10 is reflected by the object to be tested is smaller than the diameter of the beam at the position of the pinhole mirror 32, and the diameter of the pinhole 32a formed becomes smaller. . In addition, the pinhole mirror 32 is configured to make the measurement light and the observation light coincide with the imaging position of the reflected light reflected by the object to be detected and the reflected light. In this configuration, the reflected light generated by the object to be tested is incident on the spectrometry unit 60 through the pinhole 32a. On the other hand, the propagation direction of the remaining reflected light is converted to be incident on the axis conversion mirror 34. The spectrometry portion 6 is used to measure the reflectance spectrum of the reflected light measured by the pinhole mirror 32 and output the measurement result to the data processing portion 70 °. In more detail, the spectroscopic portion 60 includes diffraction The grating (forbearance 1:1 叩) 62, the detecting portion 64, the filter 66 and the shutter (311111^61〇68. The filter 'light mirror 66, the shutter 68 and the diffraction grating 62 are arranged on the light sleeve Αχι The calender mirror 66 is an optical boring mirror for detecting the reflected light outside the measurement range contained by the person through the pinhole 32a to the spectrophotometry &amp; I 60 &lt; The wavelength component outside the measurement range is blocked. When the reset portion 64 is reset or the like, the shutter 68 is used to block the light incident on the detection port 64. The shutter 68 is usually driven by electromagnetic force. Shutter composition 10 201007116 The diffraction grating determines the reflected light to perform the splitting waveguide to the detecting portion (4). Specifically, the diffracted light ... the reflective diffraction grating 'reflects each of the diffracted waves to a corresponding direction at a predetermined wavelength interval In this scheme, the diffraction grating 62 When the ingredients contained in the respective wavelength is reflected to a corresponding direction, and then enters into the detecting portion 64. ⑽ detection area. Furthermore, the wavelength interval rather

The wavelength resolution of the split _ part 6 。. The diffraction grating 62 is usually composed of a spherical grating of a flat f0cus type. Among the measured reflected light split by the diffraction grating 62, an electronic signal corresponding to the light intensity of each wavelength component is output from the detecting portion 64 for measuring the reflectance spectrum of the object to be tested. The detecting portion 64 is composed of an indium gal arsenide (W-like array) having an infrared light-domain sensitivity. The data processing unit 〇 is a characteristic of the present invention related to the reflectance spectrum of the detecting portion #64. The program is used to determine the film thickness of each layer constituting the object to be tested. Further, the data processing portion 7Q can also be used to analyze the reflectance and layer structure of each layer of the object to be tested. Further, the procedure will be described in detail below. Thereafter, the data processing portion 70 rotates to determine the optical characteristics of the film thickness of the object to be tested. On the other hand, the reflected light reflected by the pinhole mirror 32 propagates along the optical axis AX1, and then is incident on the axis conversion reflection. The mirror 34 observes that the propagation of the reflected light is converted from the optical axis AX3 to the optical axis Αχ 4. In this way, the observed reflected light propagates along the optical axis ΑΧ 4 and then enters the observation camera 38. The observation camera 38 is the image capturing portion. Used to obtain reflected light from observations. 201007116 Reflected image 'usually by charged-coupled device (-CCD) and complementary metal oxide semiconductor (CMOS) Further, the observation camera 38 usually has a visible light range sensitivity, and in many cases, the sensitivity characteristic is different from the detection portion having a sensitivity of a predetermined measurement range of 64°, followed by 'observation The video signal 38 is outputted to the display portion 39 by the camera 38 after observing the reflected image obtained by the reflected light. The display portion 39 displays the reflected image on the screen based on the video signal of the observation camera 38. The user sees After the reflected image displayed on the display portion 39, the focus of the object to be tested and the position of the measurement are confirmed. The display portion 39 is usually composed of a liquid crystal display (LCD). Further, a viewfinder can be provided. (finder), allowing the user to directly see the reflected image' instead of the observation camera 38 and the display portion 39. "Analytical examination of reflected light" First, in the case where the measurement light is irradiated to the object to be tested, The observed reflected light is subjected to mathematical and physical examination. Fig. 2 is a view showing the measurement of the film thickness measuring device ι〇〇 as an embodiment of the present invention. The cross-sectional view of the object to be tested 〇Bj. Referring to Fig. 2, the SO I substrate is taken as a representative example of the object to be tested 。Bj. That is to say, the object to be tested 〇Bj is configured with a three-layer structure: 矽(s丨) layer 1. Base plate 3 (substrate layer) and cerium oxide (Si 〇〇 layer 2 (BOX layer) between the two. Further, the film thickness measuring device illuminates the light from the paper surface The upper side is incident on the object to be tested 〇BJ. In other words, the measurement light is initially incident on the Si layer 1. 12 201007116 For the sake of easy understanding, the measurement light incident on the object to be tested 〇BJ is then considered, and the interface between the Si layer 1 and the Si Oh layer 2 is considered. The reflected light produced after reflection. In the following description, each layer is represented by i. That is to say, "〇" means the atmosphere such as air and vacuum, "Si" means the Si layer 1 of the object to be tested 〇BJ, and the layer 2 of Si 〇2 is represented by r2. In addition to this, the refractive index of each layer is expressed by i, that is, the refractive index ni. Since the reflection of light is generated at the interface of each layer having different refractive indices (1), the amplitude of the L-polarized light into the $ and s polarized components can be reflected at each interface between the ith layer and the i+1th layer having different refractive indices. The rate (Frensnei coefficient) r ζ·, ζ·+1 and r zV+i are expressed as follows: r(P) _ nM COS^ -n. cos M+1 nM cos^. +«. cos^i+1 r( S) _ % COS do c〇s us, M+1 'cos 戎+«i+1cos0,'+1

Here, the angle of incidence of the i-th layer is indicated. According to the Snell method described below, the incident angle can be calculated from the incident angle of the uppermost atmosphere (layer 0): Λ^〇sin = Nf sin φι In the film thickness layer with optical interference, the reflectivity shown by the above formula is reflected There are many round trips in the light poetry layer. For this reason, the light directly reflected by the interface of the adjacent layer and the light after multiple reflections in the layer, due to the different lengths of the optical paths between the two, make the phases different from each other, and the light interferes with the surface of i. It It shows the light interference effect in each layer'. The optical phase angle A· in the first layer can be expressed as follows: A = 2π , cos dt λ 13 201007116 Here, the film thickness of the i-th layer is reported, and A Indicates the wavelength of the incident light. In order to be more simplistic, when the light is irradiated perpendicularly to the object to be tested, that is, when the incident is "=〇, there is no difference between the p-polarized light and the s-polarized light, and the amplitude reflectance and the film phase angle of the interface between the layers are as follows. Shown as: «0+«! r M2-- + n2 Α =2π\ γ Λι

Person J

Further, in the three-layer system shown in Fig. 2, the reflectance of the object to be tested aBJ is expressed as follows: ff_ rii+rn+2rMr„cos2B, 1 + + 2r0, r12 cos in the above equation, regarding the phase angle The frequency conversion of the burn (Fourier transform), the phase factor (^2 is about nonlinear to the reflectivity and then nonlinear. Then, the phase factor 0〇82&gt;^ is converted into a linear function.

In the example, the reflectivity is converted; the following equation is converted and defined as an independent variable "wavenumber converted reflectivity" and ': R'

R Α + τί

❶s2A 2πη\ Propagation where 'one' is the light (electromagnetic wave) in the matter, ie the wave number in the layer ^&quot;(propagation number). The wavenumber conversion reflectance W is a linear expression of the phase factor cos2/?i, so it is linear. Here, in the formula, α represents the wave number conversion reflectance and the slice, and sum) represents the inclination of the wave number conversion reflectance. In other words, for 14 201007116 • The phase factor associated with frequency conversion is about 32, which is a function used to linearize the reflectivity and value of each wavelength. Alternatively, the function 1/(1 - and ) can be used as a function of the phase factor linearization. Therefore, the wave number in the Si layer 1 can be defined as follows: a 2^r scale, which is the wavelength in the Si layer 1; the i-speed is s, and the wavelength in the vacuum is the light velocity C. In addition, the refractive index is expressed as Φ Μ χ μ 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用 利用- Insignia + In other words, the propagation characteristics of electromagnetic waves in Si layer 1 depend on the wavenumber. Through these relationships, it is known that there is wavelength-dependent light in a vacuum, and as the speed of light decreases in the layer, the wavelength also increases from 乂/«1. Considering this wavelength dispersion phenomenon, the wave number conversion reflectance brother can be defined as follows: and '(&amp;) = &amp;+ do cos 2昊岣# by this relationship, when the wave number converts the reflectivity and In the frequency conversion (Fourier transform) in which the number is particularly relevant, the peak thickness appears in the periodic component corresponding to the film thickness umbrella, and the position of the peak is specified to calculate the film thickness ή. In other words, the correspondence between the reflectance spectrum measured by the test object OBJ and the reflectance of each wavelength is converted into the wave number calculated by each wavelength and the wave number converted reflectance calculated by the above relational expression. After the relationship, the wave number conversion reflectance 疋 function including the wave number A: is particularly relevant to the wave number. 15 201007116 After the frequency conversion 'after' is based on the peak appearing in the characteristic after the frequency conversion, the composition can be calculated. The thickness of the Si layer 1 of the object OBJ. This is because the amplitude value of each wavenumber component included in the wave number distribution characteristic is obtained, and then the film thickness of the Si layer 1 is calculated based on the large wavenumber component of the amplitude value. Furthermore, as described below, a method of using a discrete Fourier transform such as a fast Fourier transform (FFT) or an optimization method using a maximum entropy method (hereinafter also referred to as "MEM") For analyzing the large wavenumber component of the amplitude value from the wave number distribution characteristics. In the definition of the wavenumber conversion reflectance ruler, the value of the interference phenomenon in the layer is irrelevant, but it depends on the amplitude reflectance of the refractive index q of the Si layer 1 in the interface between the layers. For this reason, when the refractive index 波长 has a wavelength dispersion, the value is a function value depending on the wavelength (that is, the wave number 夂), and therefore, it is related to the wave number [cannot be a fixed value. Then, the Fourier transform m々心钱河 is represented by 〕, and the wave number [after Fourier transform] is used as a function, and the power spectrum is set to P, Pa, pb, and F, respectively, and the following formula holds: p =&gt;pa+(Pb*F) where * indicates a convolution (conv〇luti〇n). In the formula, the composition of the film thickness is relatively small, and the power spectrum has independent peaks, so that the power spectrum F is not affected. Another

Because the Pb in the equation is decomposed with the power spectrum F, the film thickness component of the ' is added to the film thickness of the power spectrum F. However, Pb is independent of the intra-layer interference phenomenon because it is only folded by the adjacent two layers 16 201007116 Points =: The number of work waves is one, for example, it will be as small as a thick film medium, and can be ignored to a lesser extent. ^ The periodic function of the 卞 膜 厚 q 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 透过 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期 周期』 or 『(四)』, and because ^ is small, the influence on the peak position d is small.

When Fourier transform is performed, the maximum film thickness of the measurement layer is considered as follows. According to the Nyquist sampling theorem, the wave number rotation and the reflectance Θ are sampled at an appropriate sampling interval and number of samples. The film thickness reflectance V′ sampled by this method is smaller than the film thickness resolution r of the calculated power spectrum, and the film thickness component q of Pb may be smaller U<lt;!〇, so it can be said that the film is hardly The measurement result of the thickness d has an influence. In this way, the calculated reflectance spectrum is converted to a wave number correlation. Considering the wavelength dispersion of the film, the Fourier transform is performed, and the film thickness of the film can be accurately calculated. Furthermore, in the above description, the reflectance spectrum is used to illustrate that the kernel can also utilize the transmittance spectrum. In this case, the measured penetration rate is 7 and the "wavenumber conversion transmittance" is expressed, and the relationship is expressed as follows: T' = Y = Ta + Tb cos 2Kdx Even if the transmittance spectrum is used, penetration The rate 亦 is also non-linear with respect to the phase factor c 〇 s 2 . For this reason, for the above reasons, the phase factor c〇s2A is used, and the linear wavenumber conversion transmittance is based on the above formula, and the wave number is converted to 17 201007116. The transmissivity r is a phase factor cos2 approximately once, The film thickness of the film can be accurately calculated in the same manner as described above. That is, for the phase factor cos] associated with the frequency conversion, the wavenumber conversion transmittance 7, which is a function for linearizing the transmittance values of the respective wavelengths. Referring again to Fig. 2, the reflected light generated by the interface between the Si 〇 2 layer 2 and the base layer 3 is considered. The 折射率 indicates the refractive index of 51 layers 1 , 4 indicates the film thickness, % indicates the refractive index of the Si 〇 2 layer 2, and when the film thickness is expressed, the wave number conversion reflectance can be expressed as follows:

R' = Ra+Rb cos2Κλ dx + Rc cos2K2 d2 + Rd cos2{KX dx +K2d2) + Re cos2(jfiTj d.^ — K2 d2) where 2π ηλ ~λ~ Ξ 2π η2 ~λ~ Wavenumber conversion reflectance and 1 (especially 1) and 2 (especially 2) converted by wavenumbers of 1 and 2, respectively, for separating and calculating Si layer 1

The film thickness in the film thickness and the Si 〇2 layer 2 are thick. Specifically, as follows: (-^1 )~Ra+Rbcos^1 + Rc cos2^i d'2 + Rd cos2KX{άλ+ά'2) + Reco?, 2Kx{dl-d'2) and 2 ([2)= and a + and &lt;&gt; c〇s 2 especially 2 4 + and c cos 2 especially 2 4 + and ac〇s 2 especially 2 ( &quot;1 + 4) + Re cos 1K2 (d[ - d2) where «2 d'2 = —d2 «1 18 201007116 In these equations, the strict tube 4 and 4 are not the correct film thickness, but the wavenumber conversion reflectivity and (10)) of the second term In the corresponding power spectrum, the original film thickness can be obtained from the peak, and the wavenumber conversion reflectance and the power spectrum corresponding to the third term of 2) can be obtained from the peak by the peak. Further, in actuality, the refractive indices of the Si layer 1 and the Si eh layer 2 are similar, and in most cases, the reflectance at the interface is relatively small compared to the reflectance at other interfaces. As a result, compared with the function of the wavenumber conversion reflectance, the values of 々' and c are small, so in many cases, it is difficult to confirm the third of the wavenumber conversion reflectance from the power spectrum. The peak corresponding to the item. In this case, first calculate the wavenumber conversion reflectance and the peak position of the power spectrum corresponding to the fourth term of 2 (foot 2), and the second term of the wave number, g reflectance, and 2 C^2 ). The peak position of the corresponding power spectrum (^lj, after which the difference between the two is obtained, the film thickness can be calculated. "About wavelength range and wavelength resolution" Fig. 3 shows the film thickness using the embodiment of the present invention. The measurement result of the measurement apparatus 1 〇〇 _ after measuring the SO I substrate. Furthermore, in the measurement example shown in FIG. 3 , in the case of the third (a) diagram, the measurement light has a wavelength range of 90 〇 nm. ~1 600 nm, and in the case of the third (b), the wavelength range is 134 〇 nm to 1600 nm. Further, corresponding to the measurement wavelength, the diffraction grating 62 having appropriate characteristics is selected so that the reflected light is incident on the detection portion. After 64, the number of detection points (p〇i ηΐ) of the detection portion 64 (the number of detection channels) is the same (for example, 512 channels). In other words, the narrower the wavelength range, the wavelength interval of each detection point ( That is, the smaller the wavelength resolution. 19 201007116 According to the aforementioned analytical test Check the length 'should have a periodic change. 'The measured reflectance is relative to the measurement result shown in the 3(a) diagram. Although it can be seen that the reflectivity has a periodic change with respect to the wavelength, it cannot be (4) Very accurate film thickness measurement. In this case, the peaks and troughs (vaUey) of the reflectance are clearly shown in the measurement and results shown in Fig. 3(b), and the change in reflectance can also be measured. Cycle. Figure 3(c) shows the measurement result (reflectance spectrum) shown in Figure 3 (8) converted to the function of the wavenumber conversion reflectance ,, _ used to display the frequency conversion associated with the wave scale As a result, as shown in Fig. 3, the value corresponding to the main peak can be used as the film thickness of the 51-layer crucible. The fourth step and the fifth graph show the other measurement results of the s〇I substrate. A schematic diagram showing another measurement result after measuring the SO I substrate by using the film thickness measuring device of the embodiment of the present invention. In the measurement example of Fig. 4, the film thickness of the Si layer 1 is 10.0 um (design value),膜 2 layer 2 film thickness is 0.3Um (design value). Further, in the 4th (a) figure, the system shows The measurement light having a wavelength component of the visible light region (330 nm to llOO nm) is used, and in the fourth (b) diagram, the measurement is performed by using a wavelength having an infrared light region (9 〇〇 nm to 1 60 nm). In addition, as described above, the number of detection points (the number of detection channels) of the detection portion 64 (Fig. 1) is the same. As shown in Fig. 4(a), when the wavelength component having the visible light region is used, the measurement is performed. In the case of light, in the wavelength region larger than 860 nm, the periodic variation of the reflectance is exhibited, but in the shorter visible light region, it is known that 20 201007116 does not occur. On the other hand, as shown in Fig. 4(b), when the measurement light having the wavelength component of the infrared light region is used, it is known that a significant change in the periodicity of the reflectance occurs. Fig. 5 is a view showing another measurement result after measuring the SOI substrate by using the film thickness measuring device ι of the embodiment of the present invention. In the measurement example of Fig. 5, the film thickness of the 'Si layer 1 is 8 〇. 〇 ym (design value), and the film thickness of the layer 2 of the Si 〇 2 layer is 0.1 μmη (design value). Further, in the fifth (a) diagram, measurement light having a wavelength component having an infrared light domain (900 nm to 1600 nm) is used, and in the fifth (b) diagram, it is shown that a light source having a narrower infrared light is used ( 147〇(10)~1 600ηιη) Measurement of wavelength components. Further, as described above, the number of detection points (the number of detection channels) of the detection portion 6 4 (Fig. 1) is the same. As shown in Fig. 5(a), there is no significant periodic change in the reflectance measured by the measurement light having the wavelength component of the infrared light region. Conversely, as shown in Fig. 5(b), when the measurement light having a narrower wavelength component of the infrared light region is used, it is known that a significant change in the periodicity of the reflectance occurs. φ According to the above measurement example, in order to measure the film thickness of the thick layer with high accuracy, it is necessary to appropriately set the wavelength range and wavelength resolution of the measurement light. Since this is a measurement method using the intra-layer light interference object, and the detection portion 64 has a limited wavelength resolution for the reflected light, a more appropriate measurement light wavelength can be set according to the method described below. In the following inspection, the lower limit of the wavelength detection of the detecting portion 64 is Amin, and the upper limit of the wavelength detecting portion of the detecting portion 64 is; Further, the range of the measurement light wavelength to be irradiated by the measurement light source 1 (Fig. 1) may be any range if the wavelength detection range of the detection portion 64 is included. Further, 21, 201007116, the number of detection points (the number of detection channels) is one step, and the detection portion 64 (Sp. Fig. 6 is a schematic view) for explaining the film according to the embodiment of the present invention.

The thickness measurement range and the detection wavelength range of the detection portion of 64 仏, 丨, * i π HP Ο 4, and the relationship with the number of detection points. ~ (1) The lower limit of the film thickness measurement range "The relationship with the detection wavelength range. 0 According to the film thickness measurement method described above, the detection portion 64 needs to have the energy because it is necessary to find the wavelength of the light interference generated in the object to be tested. The wavelength range in which the light @ interference is generated "that is, as shown in Fig. 6(a), in the detection wavelength range of the detecting portion 64, the reflectance waveform measured by the object is required to have a change of more than one cycle. This is because the detection wavelength range of the detecting portion 64 is changed from the lower limit value to the upper limit value Amax, which means that the change in the optical distance generated is sufficient to carry out the film thickness of the object to be tested. ❹ Therefore, the film thickness measurement range is The relationship between the lower limit jmin and the wavelength range of the measured light is required to satisfy the following conditional expression (1):

乂min .also η

(1) where %iin represents the refractive index of the wavelength Ληώ, and ^ represents the refractive index of the wavelength Ληβχ. (2) The relationship between the upper limit of the film thickness and the number of detection points. As shown in Fig. 6(b), the longer the wavelength of the measurement light is, the longer the period of the reflectance waveform measured by the object to be tested is. The reflectance shown in Fig. 6(c) 22 201007116 waveform, the reflectance waveform shown in f 6(b) is converted to the coordinates of wavenumber 〇/f). In this case, the array elements such as InGaAs are arranged at equal intervals for the wavelength. As a result, the smaller the wave number, the larger the arrangement interval of the array elements corresponding to the wave number.

Therefore, in order to correctly sample the reflectance waveform corresponding to the wave number and change with a predetermined period, the arrangement interval (wavelength resolution ΔΑ) of each array element needs to satisfy the Nyquist sampling theorem, by satisfying the sampling theorem, It is used to determine the upper limit i/max of the film thickness measurement range. The wavelength resolution ΔΑ of the detection portion 64 is represented by the number of detection points (the number of detected channels) $/?, which can be expressed as Δ==(乂max — /imin. The longer the wavelength of the measurement light, the reflectance waveform The period is shorter and shorter. Therefore, in the reflectance waveform, when the upper limit value of the light is measured; the extreme value (peak or valley) is generated, the extreme value adjacent to the extreme value is generated. The wavelength is expressed as meaning 1, and the following conditions are satisfied between the upper limit i/max of the film thickness measurement range: d — _Kax — max − 2 (Amax.Wl−V«眶) Here, when the film of the target layer is measured When the thickness is large, it is assumed that % n is therefore expressed as the following conditional expression (2):

\ '^max 2 . &quot;max (max) — (2) At this point, the wavelength resolution does not need to meet the following conditions:

Substituting the relationship of the upper limit value dmax into the above-mentioned wavelength resolution 23 23 23 201007116 In the system, after 'elimination and another 1 ', it can be expressed as the following conditional expression (3 ): ΔΑ = - and again min ^ _乂max__.. (3) SP 2(^max+2*«max-^max) The above is the result of the inspection. If you want to determine the film thickness required for the test object in advance, the lower limit άγ(\χγ\~ The upper limit value i/max) 'in order to satisfy the above conditional expressions (1) and (2) 'must determine the wavelength range of the measurement light (lower limit value; Ijnin to upper limit value; ^ shape) and the number of detection points. In the SOI substrate shown in Fig. 2, when the film thickness of the Si layer 1 is measured, the calculation of the necessary conditions is as follows. In this calculation example, the upper limit of the si layer 1 of the SOI substrate is ^ The shape is l〇〇um ' and the refractive index is constant (n = 3. 5) without depending on the wavelength. Furthermore, in this calculation example, the lower limit of the Si layer of the s〇I substrate is not considered. ^匕. By substituting the above set values into the above conditional expressions (2) and (3), the upper limit value can be calculated; Imax = 1424. Onm, and the wavelength resolution △ is again = 1.445375, so 'when there are 512 frequencies The detecting portion 64 is used to measure the film thickness of the object to be tested having a maximum film thickness of 100. If the measuring light used covers a wavelength range of about 684 to 1424 nm, the detecting portion 64 can detect the range. The reflected light (wavelength resolution △ = 1. 4453125 nm). The 'cloudy mountain' and the long resolution calculated according to the above conditional formula are used to explain the theoretical minimum specification. Compared with the calculated wavelength resolution Δ!, it is better to 'know the accuracy. Moreover, the attack is several times (for example, 2 to 4 times). In addition, 'improve the accuracy, meaning 201007116 refers to the wavelength resolution △; [the value is set to be smaller. That is, in the actual film thickness measuring device, the influence of the incident light angle of the object to be tested, and the opening angle when using the lens collecting system The influence, etc., will cause the spectral accuracy to decrease. In this case, the peak height in the power spectrum becomes smaller, and it becomes difficult to calculate the film thickness. Furthermore, the discrete frequency conversion is performed by FFT or the like with a limited sampling value. Feelings Under affected distortion (aliasing), is also produced when will the wave number conversion

The conversion error of the hygienist becomes larger. Further, the refractive index dispersion of the test object may be drastically changed depending on the wavelength range of the light to be measured, or some conditions may not be satisfied. Fig. 7 is a view showing a simulation result of a measurement result using a film thickness measuring device having a wavelength resolution close to a theoretical value.帛8 is a schematic diagram showing the simulation results of the measurement results without using a wavelength measurement device having a wavelength resolution higher than the theoretical value. Further, the film thickness of the object to be tested as a target is l〇〇Jjm. More specifically, in Fig. 7(a), the result of measuring the reflectance spectrum (wavelength resolution of 12.7343751^) in the range of 900 nm to 16 〇〇 nm by the detecting portion 64 having 512 channels is shown. In the figure, the power spectrum after frequency conversion (here, m conversion) of the reflectance spectrum shown in Fig. 7(a) is shown. As shown in Fig. 7(b), in this case, although there is a peak near __, the level is smaller than that of the film side (ghost), and it is difficult to determine the film thickness. On the other hand, in the 8th U) diagram, in the case where the wavelength range is determined, the accuracy of the wavelength resolution of the detecting portion 64 becomes twice the theoretical value, and in the eighth (b) diagram, The system displays the power spectrum after frequency conversion (in this case, m conversion) of the reflectance spectrum of 25 201007116 shown in Fig. 8u). In this embodiment, it is determined that the wavelength resolution of the detection point 64 and the wavelength range detecting portion 64 becomes 1 3671875, as shown in the figure, in which case the original thickness is 1 〇〇 near the pole. A strong peak means that the film thickness of the analyte can be accurately measured. <<Overview of Film Thickness Calculation Program>> m As described above, the film thickness of the object can be calculated from the periodicity of the reflectance spectrum. In other words, the detected reflectance spectrum is frequency-converted to obtain the power spectrum, and the peak appearing in the power spectrum can be used to calculate the film thickness. In fact, this power spectrum is obtained by using the m-isolation: Fourier transform method. However, there is a case where the milk cannot be used to fully reflect the periodic power spectrum. For this reason, the thick-thickness device 100 of the present embodiment can perform a method of optimizing the MEM or the like as a method of calculating the power spectrum, in addition to the discrete Fourier transform such as FFT. That is, the film thickness measuring apparatus 1 of the present embodiment performs the method of performing the Fourier transform and the optimization selectively or in combination corresponding to the detected reflectance spectrum. In addition, the details of the surface program are detailed on the micro-computer/PC utilization technology of the d-quantity system, the first version of the exam' August 992! Japanese Laid-Open, CQ Press, hereby provides, as a further step, the film thickness measuring apparatus 1 of the present embodiment, in addition to the film thickness calculated analytically from the above-described reflectance spectrum, Strip β #精田, the physical model calculated by the image, theoretically calculate the reflectance 26 201007116 spectrum, compare the reflectance spectrum of the actually detected lift, and explore the deviation between the two. The adaptive (1) uing method for measurement is calculated. The optical characteristic value of Μ, that is, the other method as shown in Fig. 2, such as the mm ^ ^ , the substrate, compared with the second layer Si 〇 2 : thick, the thickness of the layer 1 of the first layer is More than 2 digits, in terms of the object to be tested, 'the fit is suitable (the thickness of each layer of the fitting ^ degree. Μ has the charge accurate [9 2 shows the reflectance spectrum of the S0I substrate: the intention. In Figure 9 In the measurement example, the second layer: the film thickness of the second layer 2 is in the range of 48 _:, and the interval varies. As shown in Fig. 9, even if the second layer is large, the second change occurs. It will not cause the measured reflectance spectrum to be too much... The reflectance spectrum measured from this object to be tested, the influence of ❹ layer == US1 layer 1, means that the 2nd (10) parameter cannot be charged even if it changes. Fitting the parts. ^To 'For the sample with different complex layers, the film thickness is measured, and the film thickness measurement device i WO performs one of the above-mentioned Fourier transform method, the appropriate method or is appropriately grouped to separate Each layer has a thick film thickness and can be accurately analyzed. Hereinafter, in the embodiment, the film thickness measurement program of the film thickness measurement device is calculated. Correlation = arithmetic, using the data processing part 7 (Fig. 1) to perform this - film thickness calculation procedure. "Structure of data processing part" - Fig. 10 shows a data processing part according to an embodiment of the present invention 70 27 201007116 A schematic hardware diagram. Referring to Figure 10, a data processing portion 70 is generally implemented by a computer, comprising: a central processing unit (CPU) 200 for executing an operating system (OS) And a memory portion 212 for temporarily storing necessary data when the CPU 200 executes the program; and a hard disk drive (HDD) 21〇 for storing the CPU 200 non-volatilely In addition, in the hard disk portion 210, a program for realizing a program to be described later is stored in advance through a floppy disk drive (FDD) 216 or a CD-ROM drive (CD-ROM). The drive 214 is read from the floppy disk 216a or the compact disk-read only memory (CD-R〇M) 214a. The input portion 208 is composed of a keyboard and a mouse. ' CPU 200 receives from the user At the same time, the execution of the program is used to output the measured measurement results and the like to the display portion 2〇4. The respective portions are connected to each other through the bus bar 200.

The calculus program structure, the data processing part 70 of the present embodiment, corresponding to the parameter de- fading coefficient of each layer of the object to be tested, etc., can be obtained from the following program type (material, film thickness, film thickness range, refractive index). , the type and quantity, and the accuracy of the analysis, etc., one of (Pattern) 1 to 6 is selected for execution. In addition, in the following, the SOI substrate shown in Fig. 2 is calculated independently. Since the film thickness is taken as an example, then the same method can be used to separate the film thicknesses of each layer. 28 201007116 - (1) Program pattern l Program pattern 1, which is known as the first layer and The film thickness calculation procedure that can be performed when the refractive index and the decay coefficient of the second layer are performed. In the program pattern, the film thickness of each layer is determined by the fitting method. Further, in one embodiment, the minimum can be utilized. The second multiplication method is used as the adaptation method. Fig. 11 is a block diagram showing the control structure for executing the film thickness calculation program related to the program pattern 1 according to the embodiment of the present invention. In the block diagram of the second figure, the CPU 200 will pre-store the program 4 stored in the hard disk part 21, etc. The portion 212 is then executed. Referring to item 11, the data processing portion 70 (i) includes a buffer portion 71, a model (m〇del) portion 721, and a matching portion). 722. The buffer portion 71. is used for temporarily storing the measured reflectance spectrum R (again) outputted by the spectrometry portion 6〇. More specifically, the spectrometry section 6 outputs the reflectance value according to each of the predetermined wavelength resolutions, and therefore, the buffer portion 71 stores the wavelength and the reflectance of the wavelength correspondingly. The modeling portion 721 receives parameters related to the object to be tested, determines a model (function) for representing the theoretical reflectance of the object to be tested based on the received parameters, and then calculates a theoretical reflection of each wavelength by using the determined function. Rate (spectrum). The calculated theoretical reflectance of each wavelength is output to the fitting portion 722. More specifically, the modeled portion 721 receives the refractive index of the first layer and the attenuation coefficient ki, and the refractive index m and the attenuation coefficient 第 of the second layer, while receiving the initial value of the film thickness of the first layer and The film thickness dz initial value of the second layer. Furthermore, the parameters may be input by the user, or the parameters of the standard material 29 201007116 may be stored in advance as a standard, and then read if necessary. Further, if necessary, the refractive index m and the attenuation coefficient ke of the atmosphere may be input. The model for displaying the theoretical reflectance is the same as the object to be tested of the above three-layer system, and the reflectance is the same as that of at least the film thickness value of each layer. Furthermore, the modeled partial injury 721 is updated according to the parameter update of the following adaptive part 722 to update the function of the apparent theoretical reflectance, and then the theoretical reflectance (spectrum) of each wavelength is calculated according to the function of updating 彳4. . More specifically, the 'modeling part 721 is updated sequentially as the parameter! The film thickness of the layer (L and the thickness of the film of the second layer. The reflectance spectrum theory output by the modeled portion 721 after the reference portion 722 reads the reflectance spectrum of the buffer portion 71 The value is used to sequentially calculate the squared deviation value of each wavelength between the two. Then, the matching portion 722 calculates the residual 'from the deviation value of each wavelength' and then determines whether the residual is below a predetermined critical value. The appropriate portion 722 determines whether or not the current parameter is convergent. The appropriate portion 722 outputs the current film thickness di of the first layer and the film thickness d2 of the second layer as analytical values.

When the residual is not at the established threshold, the instruction is updated to the modeled portion 721 rate spectrum is output. On the other hand, the matching portion 722 transmits the parameter 'and then waits until the new reflection'. When the residual is below the predetermined threshold, the 12th figure shows the calculated medium thickness associated with the program type 1 according to the embodiment of the present invention. Flow chart of the method of the program. Referring to the 12th lap, the user places the object to be tested (sample) on the stage 5 (Fig. 1) (step s100). Thereafter, when the user issues the measurement preparation 30 201007116 command, the observation light source (the first drawing) starts to refer to the observation camera 38 for taking _', ..., and shooting. The display portion 39 is turned off and the stage position command is issued to the movable mechanism 51 for adjusting the adjustment and focusing of the measurement range (step S102). After the measurement range is adjusted and the 隹徭^ „ ..., the user releases the measurement start, the measurement light source 10 (i-th image) is opened # ”. The reflected light of the object to be tested is received, and the base light is received. The spectrum is measured by the data processing part of the 7G (step-shooting rate - O.CPO 4; 1 ^ ± 彳疋 伤 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 The CPU of the resource processing section 70 executes the film thickness calculation program described below. The CPU 200 displays the input screen on the display part of the game, and asks the user to input parameters (step sm). ::: input screen, etc., input the refractive index m and the attenuation number of the first layer of the object to be tested and the refractive index of the second layer of the object to be tested and the attenuation coefficient ^, the same as the film of the first layer The initial value of the film thickness d2 of the thickness dl and the second layer (step 11 0 ) ° Further, the CPU 200 calculates the theoretical value of the inverse spectrum according to the parameter input by the user (step S112). Next, for the memory portion, etc. The stored reflectance spectrum measured value and the reflectance spectrum theoretical value, pU 200 sequentially calculates the wavelength between the two The second multiplied deviation value is used to calculate the residual of the two (step S114) e further, cpu 2〇. It is determined whether the calculated residual 疋 is below the predetermined threshold (step S116). The calculated residual is not established. When the threshold value is equal to or less (in the case of NO in step 31, 201007116 and S116), the CPU 200 changes the film thickness d1 of the i-th layer and the current value of the film thickness ch of the second layer (step S118). Further, the film thickness di and The extent to which the film thickness th is to be changed depends on the degree of occurrence of the residual. Then, it returns to step SU2 of the procedure. Conversely, when the calculated residual is below the predetermined threshold ( In the case of YES in step S116, the CPU 200 sets the film thickness d1 of the first layer and the film thickness of the second layer &amp; the film thickness (analytical value) of each layer of the object to be tested (step S120). Further, in the block diagram shown in Fig. 11, although the refractive indices ηι, η2 are referenced = the attenuation coefficient k!, kz is input at a fixed value, a refractive index considering the wavelength of the knife can be used. And the coefficient of decay. For example, the following Cauchy model can be considered The refractive index and the decay coefficient of wavelength dispersion: n(^) = ~ + -~+c where a, 0, c, c?, e, / represent the correlation coefficient in each layer. The coefficients in the middle can also be input with the preset initial 已 or A value, and these coefficients can also be used as the matching objects. Alternatively, the following Sel lmeier model can be used: , , medium, /, capacity, and SeUmeier coefficient. (2) Program type 2 Anti-feeding pattern 2 is a film thickness calculation program that can be performed when the refractive index of the second layer and the second layer is known and the coefficient of the layer is reduced. In the procedure pattern 2, the film thickness of each layer was determined by the fitting method. The frequency conversion by discrete Fourier transform is used to obtain a third film having a large film thickness, and the film thickness of the i-th layer is a fixed value, and the film thickness of the second layer is determined by a suitable method. Furthermore, in an embodiment, the least squares method can generally be used as the fitting method. Figure 13 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program pattern 2 according to an embodiment of the present invention. In the block diagram of Fig. 13, the CPU 2GG reads out the program previously stored in the hard disk portion 21G or the like to the memory portion 212' and then executes it. Referring to the 13th 'data processing section 7' (i-th image) including the buffer portion 71, the wave number conversion portion 731, the buffer portion 7 guilt, the Fourier transform portion 733, the peak search portion 734, the model Part 735 and fitting part 736. The buffer damage 7 is used to temporarily store the measured reflectance spectrum rq) outputted by the spectrometry section 60. Furthermore, the specific architecture and processing contents have been described above, and will not be described here. The ▲ wave number conversion portion 731 receives the Uth parameter (refractive index (1) and the nuisance coefficient k1), and performs the wave number conversion on the reflectance spectrum RU of the temporary field buffer portion 71 according to the received parameter. In other words, the wave number transition portion 731 converts the correspondence between each wavelength in the reflectance spectrum D and the reflectance of each wavelength into gold ^e ^ , the wave number Κι ( λ ) associated with each wavelength, and utilization. Correspondence between the turbid wave number conversion reflectance configuration calculated by the above relational expression. More specifically, for each wavelength stored in the buffer portion 71, the wave number conversion portion 731 is sequentially 篡'number (ι(λ) and the wave number conversion reflectivity 33 201007116 巧(4)(=雄)/(ι- Male))), then, output to the buffer part. The buffer portion 732 converts the wave number, the wave number ΚΚ λ of the output portion 731, and the wave number conversion reflectance are stored correspondingly. That is to say, in relation to the wave number KK A ), the wave number conversion reflectance of the wave number conversion reflectance is particularly the second, that is, the wave number conversion reflectance (especially 1) is stored in the buffer portion. Fourier transform, part 733, converts the stored value of the buffer portion to the reflectance _), and performs the Fourier transform associated with the wave number: used to calculate the power spectrum P1. Furthermore, a fast Fourier transform (FFT) ^^^^(discrete c〇slne transf〇rm, DCT)^ can be utilized as a method of Fourier transform. The wave bee explores the power spectrum 算出 calculated by the partial m, ^ Fourier transform portion 733, and explores the wave thickness of the ^, which is used as the film thickness of the uth and is output. The film receiving portion 735 corresponding to the peak receives the parameter related to the object to be tested, and determines the model formula for the theoretical reflectance of the object (four) according to the connected number (determined by the use of the heart) Function, calculate each spectrum). Calculated ^ 4 Calculate the theoretical reflectance of each wavelength (the theoretical reflectivity of each wavelength of the frequency (four), is output to the appropriate part of the output, more specifically, the modeled part 735, the receiving part from the peak exploration (10) k2, at the same time, the refractive index of the 1st and 2nd layers is used to reduce the initial value of the media thickness d2 of the 2nd layer. In addition, the parameter can be saved in advance or the standard can be used. The parameters of the material are read in the same way as the above two. If necessary, the model is used to display the theoretical reflectivity, including the film of each layer: the layer of the object to be tested 0β: the reflectivity is the same, including at least the film thickness of each layer. The function of the value. 34 201007116 Furthermore, the modeling part 735 updates the function of displaying the theoretical reflectivity according to the parameter update instruction of the fitting part 736, and then calculates the wavelength according to the updated function ' Theoretical reflectivity (spectrum). More specifically, the modeled portion 735 sequentially updates the film thickness d2 of the second layer as a parameter, and the matching portion 736 reads the reflectance spectrum of the buffer portion 71. 'Using the modeled part 735 to output The theoretical value of the reflectance spectrum is used to sequentially calculate the squared deviation value of each wavelength between the two. Then, the fitting portion 736 calculates the residual from the deviation value of each wavelength, and then determines whether the residual is below a predetermined critical value. That is to say, 'matching some coffee to judge whether the current parameter is convergence. § The residual is not at the established threshold ^. 丨, T77 〖Get the parameter update instruction to the model part 735, and then wait until the new reflectivity The spectrum is output. On the other hand, when the residual is below the predetermined threshold value: = 736, the current film thickness dl of the first layer and the film thickness Φ2 of the second layer are used as analytical values and output. A flowchart of a method for calculating a program-type film thickness according to an embodiment of the present invention. In the fourth embodiment, the steps of steps S100 to S108 are denoted by the same reference numerals as the steps of the flowchart. The flow chart not shown here is different from the flowchart shown in the figure. The needle thickness calculation program will be described below. In step S132, the user enters the test according to the display (4) i. Layer refraction Ηι„(4)1^pictures etc. 'Transform 1 and the object to be tested 35th 201007116 The refractive index nz of the 2nd layer and the initial value of the attenuation coefficient d2. At the same time, the thickness of the 2nd layer is rounded, and then the CPU_. K1' is stored in the memory Zhao et al.: shot = wave number conversion (step S134). Then the M rate spectrum is transmitted, and the norm converted reflectance obtained after the wave number conversion is stored in the memory portion. 212, etc. (Step § wave step, talk 2〇0 to convert the wave number conversion reflectance to the wave number ^ correlation: leaf conversion 'to calculate the power spectrum (step S138). Further, the cpu takes the power spectrum to appear The peak and the peak correspond to the film thickness of the first layer and are output (step sl4). Next, the CPU 200 calculates the theoretical value of the reflectance spectrum based on d of the first layer obtained in step _ and the second layer parameter input by the user (step SU2). Next, for the measured value of the reflectance spectrum and the theoretical value of the reflectance spectrum stored in the memory portion 212 and the like, cpu 2〇〇 sequentially calculates the squared deviation value of each wavelength between the two, and calculates the difference between the two. The residual (step S144). Further, the CPU 200 determines whether or not the calculated residual is equal to or lower than a predetermined threshold (step S146). _ When the calculated residual is not below the predetermined threshold (in the case of (10) in step S146), the CPU 200 changes the current value of the thickness of the second layer &amp; (step S148). Further, the extent to which the film thickness i is to be changed depends on the degree of occurrence of the residual. After that, return to step S142 of the program. On the other hand, when the calculated residual is below the predetermined threshold (in the case of YES in step S146), the CPU 200 treats the film thickness of the first layer and the current value of the thickness i of the 36th 201007116 layer as The film thickness (analytical value) of each layer of the object is measured and output (step S150). After that, the program ends. Further, 'the same as the above-described program type I i' can also be used in consideration of the refractive index and the attenuation coefficient of the wavelength knife. The detailed function has been explained above and will not be described here. (3) Program type 3

▲ Program pattern 3 is a film thickness calculation program that can be performed when the refractive index and the attenuation coefficient of the i-th layer and the second layer are known. In the program pattern 3, compared with the above-mentioned program record 2, the difference is that when the film thickness of the first layer is calculated, 'the Fourier transform is not performed, but the method of optimization is used. The other programs are the same as the above-described program pattern 2. Fig. 15 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 3 according to the embodiment of the present invention. In the block diagram of Fig. 15, the cPU 2GG reads out the program previously stored in the hard disk portion 2iq and the like to the memory portion 212, and then executes it. The back nr1, the data processing part 70 (Fig. 1) includes a buffer: an optimization calculation part 741, a modeled part W, and an adaptation part: ΠΓ71' is used for temporarily storing the output of the spectrometry part 60 The spectrum Ru). Furthermore, the specific architecture and processing contents have been described above, and will not be described here.匕孑 Optimizing the calculation part m, using the _ _ optimization optimization of the 锾 器 部份 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 The 'Optimization Calculus Part 741 uses the 37 201007116 self-regression model to obtain a self-correlation function relative to the measured values of the reflectance spectrum, and the values used to describe the self-regressive coefficients of the self-regression model. The optimization calculation section 741 performs frequency analysis in this manner to obtain the thickness corresponding to the wavelength of the principal component, and uses it as the film thickness d of the first layer, and outputs it. Furthermore, optimize the calculus before performing the optimization method

The portion 741 receives the search range of the film thickness of the first layer, the Z-rate (1) of the second layer, the decay coefficient kl, the refractive index n2 of the second layer, and the decay coefficient, and simultaneously receives the film thickness of the second layer. Heart tentative value. Furthermore, the parameters may be input by the user ,, or the parameters of the standard material may be stored in advance by using a standard or the like, and then read out if necessary. The modeled portion 742 and the matching portion 743 receive the film thickness &amp; and the parameters related to the object to be tested calculated by the optimization algorithm, and determine the film of the second layer by using the fit. Thick heart. The procedures for modeling part (4) and fitting part 743 are the same as those of modeled part 5 and fitting part 736 of the above-mentioned program type 2, and are not described here. Fig. 16 is a flow chart showing the method of calculating the film thickness associated with the program type 3 according to the embodiment of the present invention. In the steps of the flow (4) shown in the figure, the procedure of the steps _~S1G6 and the flowchart shown in Fig. 12 indicate the same steps, and the details are not described herein. Hereinafter, a film thickness calculation program which is different from the flowchart shown in Fig. 2, that is, after step S162 will be described. In step S162, the user inputs the search range of the film thickness dl of the first layer of the test object, the fold of the first layer of the object to be tested, the ηι and the decay coefficient kl, according to the displayed input surface or the like. The refractive index of the second layer of the object to be tested... and the attenuation 38 201007116 The coefficient k2. The analysis buffer portion is used to calculate the first layer. Then, the CPU 200 uses the frequency component of the reflectance spectrum stored by the optimization method 212, and the film thickness d1 (step S164). Then '(10)200 calculates the reflectance spectrum from the wave si(6). Next, for the memory portion 212 and the like, the stored ❿ = value and the reflectance spectrum theoretical value, cpu 2. . (4) Calculating both: Bay: Multiplying the deviation value to calculate the residual between the two (step further, the CPU 200 determines whether the calculated residual is below the predetermined threshold (step S170). The calculated residual is not established. When the threshold value is less than or equal to the value of NO in the step (the case of NO in the Chuanxiong), the CPU 2〇〇 changes the current value of the film thickness of the second layer (step S1 72). Further, in which direction the film thickness is to be carried out The degree of change depends on the degree of occurrence of the residual. Then, it returns to step S166 of the program. 相对 Relatively when the calculated residual is below the predetermined threshold (YES in step S170), cpu 200, the current value of the film thickness of the first layer &amp; and the film thickness dz of the second layer is used as the film thickness (analytical value) of each layer of the object to be tested (step S174). Thereafter, the program is terminated. The program pattern 1 is the same, and the refractive index and the attenuation coefficient considering the wavelength dispersion can also be used. The detailed function has been described above, and will not be described here. (4) Program pattern 4 - program pattern 4, is The method of improving the program type 1 is used according to 39 201007116 The matching is more surely converged. In other words, the initial value is very important in order to fit the film thickness of each layer of the test layer of the '*' spear 2 layer. Therefore, the program pattern 4 first The initial values of the film thicknesses of the respective layers are determined by an optimization method, and then the film thicknesses of the first layer and the second layer are determined by using the initial values and the fits. FIG. 17 is a view showing an implementation according to an embodiment of the present invention. The control structure block diagram of the film thickness calculation program related to the program pattern 4. In the block diagram of the second drawing, the CPU 2 reads the program previously stored in the hard disk portion 2, etc. to the memory portion. Part 212, and then executed. The control structure related to the program type 4 shown in Fig. 17 is in addition to the optimization of the calculation part 75 and the program type shown in the figure η: The same is true. The optimization calculation section 75 uses the MEM or other optimization method to analyze the reflectance of the buffer portion 71 (4), the ai 瞀 瞀, and the two-day component 'to calculate the film thickness of the first layer, respectively. · And the second floor of the membrane house η dry arms and film thick heart. In particular, hanging # ❿ ^ ^Part 751 analyzes the frequency of the measured reflectance spectrum, and uses it to take two or more peaks from the (four) pieces, and then the thicker corresponding to these materials, to calculate the film thickness d of the first layer, respectively. 16 The film thickness d2 of the order (1) and the second layer. The film thickness of the layer 1 of the layer a and the film thickness of the layer 2 of the second layer are used for the initial value of the fit. Therefore, no strict precision calculation is required. The specific frequency analysis method of the department 51: The best calculation part 74i is the same, and will not be described here. The optimization of the part 721 and the fitting part of the fascia are as calculated by receiving the injury 751. The thickness of the shoulder layer of the i-th layer and the thickness of the second layer are determined by the 40 201007116 as the initial value 'the thickness of the second layer of the original layer of the original amine Ηβ. The modeled portion 721 and the fit have been described above and will not be described here. In the program of the kiss, Fig. 18 is a flow chart showing the method of calculating the film thickness associated with the Zengshan program type 4 according to the embodiment of the present invention. In the flowchart of the 18th m ^ m solid state, the procedures of steps S111A and S111B are used, and M is replaced by ^ ^ 汴 第 图 = graph: step SU°. Regarding other programs, the same symbols are used to distinguish them from the first program. Referring to Figure 18, after the execution of step (10), the steps are as follows: In the step, the user enters the refractive index ηι of the i-th layer of the object to be tested and the decay coefficient ^, and the refractive index Π2 and the attenuation coefficient k2 of the first layer of the object to be tested, according to the input screen displayed. , ^ Search range and the search range of the second layer of film. In the next step; = su1B, the CPU (10) uses the optimization method to analyze the buffer: the frequency component of the reflectance spectrum stored in the 12th, for calculating the film thickness dl of the first film layer and the film thickness of the second layer &amp; . The film thickness d and the film thickness 第' of the second layer calculated in the step SHU are used as initial values. Next, after the step S111B, the same procedure as the step SU2 of the Fig. 12 is performed. Further, in the case of the above-described program pattern 1, the refractive index and the attenuation coefficient in consideration of the dispersion can be used. The detailed function has been explained above and will not be described here. (5) Program type 5 41 201007116 The layer thickness of the layer is only analyzed by another

In the block diagram shown, the CPU 200 program mold 5 is a method suitable for the case where the film thickness is known. In the description of the following, the block diagram of the control structure to be tested. The program stored in advance on the hard disk portion 21, etc. is read out to the memory portion 212 in Fig. 19, and then executed. The control structure related to the program type 5 shown in Fig. 19 is configured with the program type 1 phase modeling portion 721A shown in Fig. 11 for use in the control structure of Fig. 11 Instead of the modeled part 721. The refractive index ηι of the first layer and the attenuation factor modeling portion 721A receive the first ^, and the refractive index m of the second layer and the attenuation coefficient kz, while receiving the film thickness &amp; initial value of the first layer and the second layer The film thickness ch is known (known value). Furthermore, the parameters may be input by the user, or the parameters of the standard material may be stored in advance as files, and then read if necessary. Further, if necessary, the refractive index η« of the atmosphere and the attenuation coefficient ko may be input. Furthermore, the modeled portion 721A is used to sequentially update the film thickness of the second layer according to the parameter update instruction of the matching portion 722, and then display the theoretical reflectance according to the updated film thickness dl' of the first layer. The function is updated. Further, the modeled portion 721A calculates the theoretical reflectance (spectrum) of each wavelength based on the updated function. According to this aspect, the film thickness i of the first layer is determined by an appropriate method. _ Regarding other architectures, as described above, it will not be described here. 42 201007116 Section 20 shows a flowchart of a method for calculating a film thickness according to the program type 5 of the embodiment of the present invention. In the flowchart shown in Fig. 2G, the procedures of steps S110A, S118A & sl1〇A are set in place of the steps sn, phantom 18 and si2 流程图 of the flowchart shown in Fig. 12. The procedures for the other procedures are denoted by the same reference numerals and are not described herein. The following is a description of the differences from the program in Figure 12. Referring to FIG. 20', in step S110A, 'the user inputs the refractive index (1) of the second layer of the object to be tested according to the displayed φ input screen, etc., and the refractive index φ of the second layer of the object to be tested and the refractive index nz of the second layer of the object to be tested. The decay coefficient is 匕, and at the same time, the initial value of the film thickness d] of the first layer and the known value of the film thickness d2 of the second layer are input. In step sim, the CPU 200 changes the present value of the film thickness d of the i-th layer. In other words, in the program pattern 5, only the film thickness 第 of the i-th layer is suitable for the object. In step S120A, when the calculated residual is below the predetermined threshold value, the cpu 200 uses the current value of the dielectric thickness di of the i-th layer as the film thickness (analytical value) of each layer of the object φ to be output. Further, similarly to the above-described program type, it is also possible to use a refractive index and a decay coefficient which take into consideration the dispersion of the wavelength. The detailed function has been explained above and will not be described here. (6) Program pattern 6 The program pattern 6' is a modified example in which the film thickness of one layer is known and only the film thickness of the other layer is analyzed. In the following description, the film thickness of the second layer of the test object is known, and the film thickness of the first layer is determined by the fitting method or Fourier transform. 43 201007116 Fig. 21 is a block diagram showing the control structure of the film thickness calculation program relating to the program type 6 according to the embodiment of the present invention. In the block diagram shown in the figure, the CPU 200 reads out the program previously stored in the hard disk portion 21, etc., to the memory portion 212, and then executes it. The structure associated with the program type 4 shown in FIG. 21 is a configuration portion 722A for replacing the fitting portion 722 with the control structure related to the program pattern 4 shown in FIG. At the same time, the wave changing portion 731, the buffer portion 732, and the rich search portion 734 are further added. The Fourier transform part and the peak are matched with ==. In this program type, the film of the first layer of the object to be tested is determined by the method, but when the fit is not within the specified number of times, the Fourier is used. The conversion determines the film thickness d′ of the layer! The matching portion 722A reads the buffer portion 7 value, and then transmits the reflected reflectance spectrum to measure the parameter update instruction to the modeled part of the measured value and The residual between the modeled part 721 is below the established threshold. The theoretical value of the input=radiation spectrum==================================================================================================== Regarding the wave number conversion portion 731, the leaf conversion portion 733, and the buffer portion 732 and the program type II of the Fourier, the μ傈2 shown in the thirteenth circle has been described above, and will not be described herein. Figure 22 is a flow chart showing the method of implementing the film thickness calculation program in accordance with the present invention. In the 22nd circle = type '%6 related figure, the flowchart is not shown, 44 201007116 • The step S117 of the flowchart shown in Fig. 20 is added, and the steps S134 to S140 of the flowchart shown in Fig. 14 are added. For the other procedures, the same steps are denoted by the same symbols, and are not described herein. The following description differs from the program of Fig. 20 and Fig. 20. • Referring to Fig. 22, in step S117, cpu 2〇〇 determines whether the adaptation procedure has been repeated a predetermined number of times or more. The fitting procedure is not repeated for the specified number of times (in the case of N0 in step SU7), after the execution of the step sm spring material, the program returns to step SU2. On the other hand, if the matching program has been repeated for more than the number of times (in the case of YES in step SU7), the program proceeds to step S134. In steps S134 to S140, the film thickness d of the first layer is determined by Fourier transform. The procedure for these steps has been described above, and is described in detail. "Measurement Example" Fig. 23 shows the use of the embodiment of the present invention. The film thickness measuring device measures the measurement result of the 'thickness of the substrate'. In the 23rd figure, after the frequency conversion (m conversion) of the reflectance spectrum is performed, the obtained power map shows the first layer of Si. The film thickness of the layer is 22._, and the measurement result of the SOI substrate having a thickness of 3·0 (10) in the layer of the second layer of Sl2 is used. In the figure 23(a), the mo(10) in the reflectance spectrum measured by the system is used. The components are used to perform the frequency clock „ conversion. As a result, a maximum peak is generated at a position corresponding to 21. 8613μηι. Figure 23(b) shows a thousand flutes ^ a. The film thickness of the first Si layer is 32. 〇um, and the measurement result of the SOI substrate of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of the layer of In Fig. 23(b), the frequency conversion is performed using a composition of 1500 nm to 1 600 nm in the measured reflectance spectrum. As a result, a maximum peak is generated at a position corresponding to 3〇.6269μηη. Figure 23(c) shows the first! The film thickness of the Si layer is i6 〇um, and the film thickness of the second layer S10z layer is 1.3 μm. In Fig. 23(c), the frequency conversion is performed using a component of 14 〇〇 nffi 〜 16 〇〇 nm in the measured reflectance spectrum. As a result, the maximum peak is generated at the position corresponding to the l5.9〇69|Jin. @ This shows that the above test results are generally good. <<Presence of Masking Material As described above, the film thickness measuring apparatus 1 of the present embodiment mainly measures the film thickness of the object to be tested 〇Bj based on the reflectance spectrum of the infrared light field, and therefore, from the light source 10 for measurement ( Fig. 1) The path to the object to be tested 0BJ can be measured even if a masking material such as a polymer resin exists. In other words, although the light in the visible light region cannot penetrate the material of the polymer resin, the light in the infrared light region can penetrate. Fig. 24 is a view showing the measurement of the object to be tested 〇BJ on which the opaque pad is placed by using the film thickness measuring device 1 实施 of the embodiment of the present invention. Referring to Fig. 24, the planar object to be tested 〇BJ is placed on the stage 50 via a spacer, and the planar opaque pad 52 is placed on the object to be tested OBJ (measurement side of the light) . The opaque pad 52' is an abrasive body used for the grinding process, and is mainly made of a polymer resin shape 46 201007116 into an n (four) pad 52' which has a small amount of penetration but is capable of allowing an infrared light field (for example, '900~ 1600 nm) light penetration. Fig. 25 and Fig. 26 are views showing measurement results of an Ig plate on which an opaque pad 52 is placed by using the film thickness measuring apparatus 100 of the embodiment of the present invention. Fig. 25 shows the result of using a magnifying lens having a magnification of 1 来 as the objective lens 40 (Figs. 1 and 24), and Fig. 26 showing the use of a magnifying lens having a magnification of 2.83 times as the objective lens 40. (Results of Figures 1 and 24). In addition, in Fig. 25 and Fig. 26, for comparison, the results in the state in which the opaque pad 52 is not disposed are also shown. Furthermore, it should be noted that the range (absolute value) of the respective reflectance spectra is not the same. Fig. 27 is a view showing the power spectrum obtained by transmitting the reflectance spectrum of the pad 52 shown in Fig. 25 and Fig. 26 without being disposed. Fig. 28 is a view showing the power spectrum obtained by transmitting the reflectance spectrum in the state in which the pads 52 shown in Figs. 25 and 26 are arranged. Referring to Fig. 25, in the case where the magnifying lens having a magnification of 1 〇 is used as the objective lens 40, as a result of the presence of the opaque pad 52, the noise component is increased as compared with the case where the opaque pad 52 is not present. On the other hand, in the case of using the magnifying lens having a magnification of 2.83 times as the objective lens 40, the result of the opaque pad 52 is substantially the same as that when the opaque pad 52 is not present. The periodicity is fully determined. As shown in Figs. 27 and 28, in the case of using the magnifying lens having a magnification of 2.83 times as the objective lens 40, the same power spectrum is obtained substantially regardless of whether or not the opaque solder 47 201007116. In the case where the magnifying lens having a magnification of 10 is used as the objective lens 40, it is understood that a power spectrum having sufficient accuracy cannot be obtained. This is because, as the objective lens 40 changes the magnification, the number of openings also changes, and in the case of using the magnifying lens 5 having a magnification of 10, the diffused light is increased and the noise component is increased. As described above, the film thickness of the object to be tested 0BJ in which the opaque pad 52 is disposed can be measured by the mold thickness measuring device 1 of the present embodiment. Among them, for an optical system that illuminates the measuring light and an optical system that receives the reflected light, it is necessary to have a design that can eliminate the influence of the diffused light. <<Modifications>> Y-type optical fiber can also be used as a pre-learning system for measuring the measurement of the light 及BJ and receiving the reflected light. Fig. 29 is a view showing the structure of the optical system of the film thickness measuring apparatus 100# according to another embodiment of the present invention. Referring to Fig. 29, the film thickness measuring device 100# is an optical system in which the measuring light guide of the measuring light source 1 (Fig. 1) is directed to the object to be tested 0BJ, and the reflected light of the test object OBJ is guided to the detecting portion. 64 (Fig. 1), and has a light-receiving optical fiber 56. The light-receiving optical fiber 56 is a Y-type optical fiber, which combines two light rays into a single light, and simultaneously separates a single light into two light rays. More specifically, in one embodiment, the optical fiber 56 is formed of a germanium (Ge) doped single-line gamma fiber. The measurement light generated by the light source 10 for measurement (Fig. 1) is incident on the object to be tested 〇BJ through the first branch 48 201007116 of the optical fiber 56a, and the reflected light generated by the object 〇BJ is reflected by the second branch. The optical fiber 56b is guided to the detecting portion 64. A pinhole optical system 54 as an aperture is disposed between the light-receiving optical fiber 56 and the object to be tested OBJ. According to the film thickness measuring apparatus 1# shown in Fig. 29, even if the object OBJ is placed in a solution such as a polishing liquid, the film thickness can be measured. Fig. 30 is a view showing the measurement of the thickness of the analyte 〇BJ in the solution without using the film thickness measuring device 100# of another embodiment of the present invention. Referring to Fig. 30, the table 57 is placed in a container, and then the object to be tested OBJ' is placed on the table 57 via a spacer, which is filled with the solution of the slurry or the like, and then the optical fiber 56 is received. One of the light-receiving side of the light-receiving side is immersed in the liquid 58. With this structure, the film thickness of the analyte OBJ in the solution can be determined. Furthermore, when (four) 58 uses water as a solvent, the above-mentioned infrared light field (10) 〇 ~! In __, when measuring the thickness of the crucible, it is preferable to prepare the optical domain of the absorption wavelength of the removed water. Specifically, the water absorbs the wavelength field of about ^^2, and it is preferable to use the reflected light spectrum of the range of _~1320 nm for the film thickness measurement of the BJ to be edited. <<Other Embodiments>> The program of this month is provided as a computer operating system (10) to the program module, and the necessary modules can be called in a predetermined arrangement and then executed. In this case, the above modules are not included, but the related programs are executed in cooperation with the operating system. 49 49071071 A program containing such a module may also be included in the program of the present invention. Further, the program of the present invention can also be programmed into one of the other programs. In this case, the above-mentioned modules containing the 匕転 type are not included in the process.

In the formula itself, but in conjunction with its eve, i__L, 匕 program to perform related procedures. The program incorporated in this other program can also be included in the program of the present invention. The program products provided are executed by the women's program storage unit such as a hard disk. Furthermore, the program Q, and ^, port 0 are the memory of the program itself and the memory program.

Progressive part or all of the work performed in accordance with the program of the present invention may also be constructed of dedicated hardware. According to the embodiment of the present invention, the reflectance spectrum (or the transmittance spectrum) obtained by irradiating the measurement light to the object to be tested is used to independently calculate the film thickness of each layer of the structure to be tested, (1) FFT, etc. Discrete Fourier transform, the method of optimizing the surface of the heart, etc., to calculate the main wavenumber component, and the method of determining the film thickness by the illusion' (7) Using the fit of the model to determine the film thickness

The method ' can be selectively performed. In this way, even if the number of the objects to be tested is large or the film thickness of each layer is large, the film thickness of each layer can be measured more accurately. In addition, according to the embodiment of the present invention, in the object to be measured which is the object to be measured, the film thickness of each layer constituting the object to be tested can be appropriately grasped by the wavelength range of the measurement light (or the wavelength detection range). And the wavelength resolution of the detection portion, so that the film thickness of each layer can be more accurately measured. The present invention has been described in detail above, but the above description is only an example, and the present invention is not limited thereto, and the scope of the present invention is defined by the scope of the appended claims 50 201007116. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing the structure according to the present invention. The outline of the film thickness measuring device of Fig. 2 is a cross-sectional view of the object to be tested which is the object of the present invention. Film thickness % 疋 device measurement 3 (a) to 3 (c) sin thickness measurement device A 固竹 shows a schematic diagram of the measurement results after the SGI substrate is not measured by the membrane device of the embodiment of the present invention. The thickness is shown in Fig. 4 to Fig. 4(b) to show another measurement result after the coffee substrate is measured by the film crucible device of the embodiment of the present invention. Figs. 5(a) to 5(b) are views showing another measurement result after measurement of a substrate by using the film thickness measuring device of the embodiment of the present invention. 6(a) to 6(c) are schematic views for explaining the film thickness measurement range and the detection wavelength range of the detection portion according to the embodiment of the present invention, and the relationship between φ and the number of detection points. Figs. 7(a) to 7(b) are diagrams showing simulation results of measurement results using a film thickness measuring device having a wavelength resolution close to a theoretical value. Fig. 8(a) to Fig. 8(b) are diagrams showing the results of simulation of the measurement results using a film thickness measuring device having a wavelength resolution and an accuracy higher than twice the theoretical value. Figure 9 is a schematic diagram showing the measurement results of the reflectance spectrum associated with the s〇 I substrate. 51 201007116 The figure shows a slightly hardware diagram of the data processing part according to an embodiment of the present invention. Fig. 11 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 1 according to the embodiment of the present invention. The =2 diagram shows a flow chart of a method for programming a program according to an embodiment of the present invention. Figure 13 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program pattern 2 according to an embodiment of the present invention. The m-cavity system shows a flow chart of a method for calculating a film thickness according to the program type 2 of the embodiment of the present invention. Fig. 15 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 3 according to the embodiment of the present invention. The ^16 diagram shows a flow chart of a method for calculating the film thickness associated with the program type 3 according to the embodiment of the present invention. Fig. 17 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 4 according to the embodiment of the present invention. The gland factory = 18 diagram shows a flow chart of the method for calculating the thickness of the program type 4 in accordance with an embodiment of the present invention. Fig. 19 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 5 according to the embodiment of the present invention. Fig. 20 is a flow chart showing the method of calculating the film thickness associated with the program type 5 according to the embodiment of the present invention. Fig. 21 is a block diagram showing the control structure for executing the film thickness calculation program relating to the program type 6 according to the embodiment of the present invention. 52 201007116 • Fig. 22 is a flow chart showing a method of implementing a film thickness calculation program in accordance with the present invention. The pattern of Fig. 23(a) to Fig. 23(c) shows the measurement results of the thickness of the SOI substrate measured by the film thickness measuring device. Fig. 24 is a view showing the measurement of the object to be tested on which the opaque pad is placed by using the film thickness measuring device of the embodiment of the present invention. Fig. 25 is a view showing the measurement results of the s?I substrate on which the opaque pad is placed by the film thickness measuring apparatus according to the embodiment of the present invention. The 26th lap shows a measurement result of the s?I substrate on which the opaque pad is placed by the film thickness measuring apparatus of the embodiment of the present invention. Figure 27 shows the power frequency obtained by transmitting the reflectance spectrum in the state where the soldering iron shown in Fig. 25 and Fig. 26 is not arranged. Fig. 28 shows the 25th and 26th views. The power spectrum obtained by transmitting the reflectance spectrum in the state of n(4). Figure 29 is a diagram showing the structure of the optical system of Jyatt. Film Thickness Measuring Apparatus of the Example Fig. 30 is a view showing the measurement of the film thickness of the test object in the solution by the film thickness measuring apparatus of another embodiment of the present invention. [Description of main component symbols] 1 0 0~ film thickness measuring device; 10 ~ measuring light source; 12~ focusing lens; 14, 66~ filter; 53 201007116 16, 36~ imaging lens; 18~ aperture; 20, 30 ~ Beam splitter; 22 ~ observation light source; 24, 56, 56a, 56b ~ fiber; 26 ~ shot part; 26a ~ mask part; 32 ~ pinhole mirror; 3 2 a ~ pinhole; 34~ axis Conversion mirror; 38~ observation camera; 39~ display part; 40~ objective lens; 5 0 ~ stage; 51~ movable mechanism; 60~ spectrometry part; 52~ pad; 54~ pinhole optics System; 57~ table; 5 8 solution; 62~ diffraction grating; 64~ detection part; 68~shutter; 70~ data processing part; 201007116 206~ interface part; 204~ display part; 200~CPU; 208~ input part; 216~floppy disk drive; 216a~floppy disk; 214~disc drive device; 214 a~disc; 210~hard disk part; 212~memory part; 731~wavenumber conversion part; 71, 732~ buffer part; 733~ Fourier transform part; 734~ peak search part; 721, 721A, 735, 742~ Modeling part; 722, 722A, 736, 749, 751 ~ fitting part; 74 optimization optimization part; AX1, AX2, AX3, AX4~ optical axis; OBJ~ object to be tested. 55

Claims (1)

201007116 VII. Patent application scope: 1. A film thickness measuring device, comprising: a light source, the measuring light having a predetermined wavelength range is irradiated to form at least one layer of the object to be tested on the substrate; The light reflected by the object or the light penetrating the object to be tested is used to obtain the wavelength distribution characteristic of the reflectance or the transmittance. The spectrometry portion can detect the lower limit wavelength included in the predetermined wavelength range by using the wavelength resolution Μ The wavelength distribution characteristic between Ληίη and the upper limit wavelength, and the "determination unit, the large wave number component of the amplitude value included in the wave number distribution characteristic" is used to determine the film thickness of each layer constituting the object to be tested, and is characterized in that The wavelength resolution Δ of the spectrometry portion and the maximum thickness of the film which can be measured by the film thickness measuring device and the target layer refractive index wmax of the upper limit wavelength hiax satisfy the following relationship: ^ ^max A(^max + 2 · nmaK · Jmax ) ❹ 2. The film thickness measuring device according to the invention, wherein the lower limit wavelength /imin of the spectrometry portion The film thickness minimum value dmjn which may be measured by the film thickness measuring device satisfies the following relationship: ^min - ^min * ^max /^(^max * Wmin ~ ^min * ^max ) where '%iin is the lower limit wavelength> ; ^nin target layer refractive index. 3. If the film thickness measurement described in item 或 or item 2 of the patent application is set to 'where' the use factor α (0&lt; 〇: $ 1), the wavelength resolution △ is again 56 201007116, as in the following relationship The film thickness measuring device according to the third aspect of the invention is characterized in that the coefficient α is less than 1/2. 57