JP2011077480A - Reflection type mask, exposure apparatus, exposure method, and device manufacturing method - Google Patents

Abstract

A reflective mask capable of effectively suppressing the generation of contaminants is provided.
A first reflection part formed on a substrate and reflecting incident light in a first direction; and formed on the first reflection part and having a predetermined pattern shape; And a second reflecting portion 43 that reflects the incident light in a second direction different from the first direction.
[Selection] Figure 2

Description

  The present invention relates to a reflective mask, an exposure apparatus, an exposure method, and a device manufacturing method.

  In recent years, with the progress of miniaturization of semiconductor integrated circuit elements, EUVL (Extreme) having a shorter wavelength is used instead of ultraviolet light as exposure light in order to improve the resolving power of an optical system limited by the diffraction limit of light. UltraViolet (extreme ultraviolet) light is attracting attention. In this type of exposure apparatus, a reflection type optical integrator, a reflection type mask, and a reflection type projection optical system are used (for example, refer to Patent Document 1). In a reflective mask, a reflective layer (for example, a multilayer reflective layer) is formed on a mask substrate, and a light shielding portion (light absorber layer) having a shape corresponding to the pattern shape is formed on the reflective layer (for example, Patent Document 2).

Conventionally, in this type of exposure apparatus, if the contaminants adhere to the reflecting surface of the optical element, the reflectance is lowered, so that the exposure time becomes longer and the throughput is lowered. In particular, in a mask installed in an exposure apparatus, a large amount of secondary electrons are emitted by absorbing EUV light at a light shielding portion (non-reflective surface), and carbon-based molecules floating in the vicinity are fixed. Therefore, the amount of contaminants adhering to the light shielding part is large.
Therefore, conventionally, in order to suppress the generation of such contaminants, measures such as increasing the degree of vacuum in the exposure apparatus have been taken in order to reduce the carbon-based molecules that are the source of the contaminants.

US Pat. No. 6,452,661 JP-A-8-17716

However, the following problems exist in the conventional technology as described above.
The degree of vacuum is generally required to have a carbon-based molecular partial pressure of 10 ⁻⁸ Pa or less. However, even at such a high degree of vacuum, carbon-based molecules can be completely removed. It is difficult to develop a technique for effectively suppressing the generation and adhesion of pollutants.

  The present invention has been made in consideration of the above points, and an object thereof is to provide a reflective mask, an exposure apparatus, an exposure method, and a device manufacturing method that can effectively suppress the generation of contaminants.

In order to achieve the above object, the present invention employs the following configuration.
The reflective mask of the present invention is a reflective mask provided with a predetermined pattern, and is formed on the substrate, and reflects the incident light in a first direction, and the first reflection. And a second reflecting portion that has a shape of the predetermined pattern and reflects the incident light in a second direction different from the first direction. is there.

  Conventionally, incident light incident on the mask is separated by a reflective portion and a light shielding portion corresponding to the pattern shape. However, in the reflective mask of the present invention, the incident light is reflected in the first direction and the second direction. Since the first reflection part and the second reflection part can be separated from each other, there is no need to provide a light shielding part. Therefore, in the present invention, it is possible to suppress the secondary electrons generated by the incident light being absorbed in the light shielding portion, and to reduce the amount of contaminants attached to the reflective mask.

  Further, the exposure method of the present invention is an exposure method for forming a pattern of a reflective mask on a photosensitive substrate, using the reflective mask described above, irradiating the mask with exposure light, and the reflective mask. Exposing the photosensitive substrate with the exposure light reflected by the first reflective portion, and irradiating the exposure light reflected by the second reflective portion of the reflective mask at a position different from the photosensitive substrate. And the step of performing.

  Therefore, in the exposure method of the present invention, since the exposure light incident on the reflective mask is reflected by the second reflection part, the exposure light reflected by the first reflection part is sensitive while suppressing the generation of secondary electrons. The photosensitive substrate can be exposed.

  The exposure apparatus of the present invention is an exposure apparatus for forming a pattern of a reflective mask on a photosensitive substrate, the illumination optical system for irradiating the reflective mask with exposure light, and the first of the reflective mask. A projection optical system that guides the exposure light reflected in the first direction by one reflecting portion to the photosensitive substrate and projects the pattern onto the photosensitive substrate, and the first reflecting portion by the second reflecting portion of the reflective mask. A light receiving device that receives the exposure light reflected in a direction different from the direction at a position different from the photosensitive substrate is provided.

  Therefore, in the exposure apparatus of the present invention, since the exposure light incident on the reflective mask is reflected by the second reflection part, the exposure light reflected by the first reflection part is projected while suppressing the generation of secondary electrons. It can be exposed to a photosensitive substrate by an optical system.

  In the present invention, it is possible to effectively suppress the generation of contaminants.

It is sectional drawing which shows schematic structure of the exposure apparatus of an example of embodiment of this invention. It is a figure showing a sectional view of a reticle and a manufacturing procedure It is a principal part detail drawing in exposure apparatus. It is sectional drawing which shows another form of the reticle R. It is sectional drawing which shows another form of a light-receiving device. It is a flowchart which shows an example of the micro device manufacturing process of this invention. It is a figure which shows an example of the detailed process of step S13 of a microdevice manufacturing process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a reflective mask, an exposure apparatus, an exposure method, and a device manufacturing method according to the present invention will be described below with reference to FIGS.
FIG. 1 shows an exposure apparatus (EUV exposure) that uses EUV light (Extreme Ultraviolet Light) having a wavelength of 100 nm or less as the exposure light (illumination light) EL of this embodiment, for example, 11 nm or 13 nm within a range of about 3 to 50 nm. 1 is a cross-sectional view schematically showing an overall configuration of an apparatus 100.

  In FIG. 1, an exposure apparatus 100 includes a laser plasma light source 10 that generates exposure light EL, an illumination optical system ILS that illuminates a reticle (reflection mask) R with the exposure light EL, and a reticle that moves while holding the reticle R. A stage RST; and a projection optical system PO that projects an image of a pattern formed on the pattern surface (reticle surface) of the reticle R onto a wafer (photosensitive substrate) W coated with a resist (photosensitive material). Yes. Further, the exposure apparatus 100 includes a wafer stage WST that holds and moves the wafer W, a main control system 31 that includes a computer that controls the overall operation of the apparatus, and the like.

  In this embodiment, since EUV light is used as the exposure light EL, the illumination optical system ILS and the projection optical system PO are composed of a plurality of mirrors (reflection optical members) except for a specific filter (not shown). The reticle R is also a reflection type. A multilayer reflective film that reflects EUV light is formed on the reflective surface and reticle surface of these mirrors. Details of the reticle R will be described later.

In order to prevent the exposure light EL from being absorbed by the gas, the exposure apparatus 100 is accommodated in the box-like vacuum chamber 1 as a whole, and the space in the vacuum chamber 1 is evacuated through the exhaust pipes 32Aa, 32Ba and the like. Large vacuum pumps 32A, 32B and the like are provided. Further, a plurality of sub-chambers (not shown) are provided in order to further increase the degree of vacuum on the optical path of the exposure light EL in the vacuum chamber 1. As an example, the atmospheric pressure in the vacuum chamber 1 is about 10 ⁻⁵ Pa, and the atmospheric pressure in a sub-chamber (not shown) that houses the projection optical system PO in the vacuum chamber 1 is about 10 ⁻⁵ to 10 ⁻⁸ Pa.

  Hereinafter, in FIG. 1, the Z axis is taken in the normal direction of the surface (bottom surface of the vacuum chamber 1) on which wafer stage WST is placed, and X in the direction perpendicular to the paper surface of FIG. The axis will be described by taking the Y axis in a direction parallel to the paper surface of FIG. In the present embodiment, the illumination area 27R of the exposure light EL on the reticle surface has an arc shape elongated in the X direction, and the reticle R and the wafer W are in the Y direction (scanning direction) with respect to the projection optical system PO during exposure. Scanned synchronously.

  First, the laser plasma light source 10 includes a high-power laser light source (not shown), a condensing lens 12 that condenses laser light supplied from the laser light source through the window member 15 of the vacuum chamber 1, and xenon or The gas jet cluster type light source includes a nozzle 14 for ejecting a target gas such as krypton and a condensing mirror 13 having a spheroidal reflection surface. The exposure light EL emitted from the laser plasma light source 10 is condensed on the second focal point of the condenser mirror 13. The exposure light EL condensed at the second focal point becomes a substantially parallel light beam via the concave mirror 21, and an optical integrator comprising a pair of fly-eye optical systems 22 and 23 for uniformizing the illuminance distribution of the exposure light EL. Led to. More specific configurations and operations of the fly-eye optical systems 22 and 23 are disclosed in, for example, US Pat. No. 6,452,661.

  In FIG. 1, the surface in the vicinity of the reflecting surface of the fly-eye optical system 23 is the pupil surface of the illumination optical system ILS, and the aperture stop AS is disposed at this pupil surface or at a position near this pupil surface. The aperture stop AS typically represents a plurality of aperture stops having openings of various shapes. By changing the aperture stop AS under the control of the main control system 31, the illumination condition can be switched to normal illumination, annular illumination, dipole illumination, quadrupole illumination, or the like.

  The exposure light EL that has passed through the aperture stop AS is once condensed and then incident on the curved mirror 24. The exposure light EL reflected by the curved mirror 24 is reflected by the concave mirror 25, and then the arc shape of the blind plate 26A. After the edge in the -Y direction is shielded from light, the pattern surface of the reticle R is illuminated obliquely from below with an arcuate illumination region 27R having a uniform illuminance distribution. The curved mirror 24 and the concave mirror 25 constitute a condenser optical system. By the condenser optical system, light from a number of reflecting mirror elements constituting the second fly's eye optical system 23 illuminates the reticle surface in a superimposed manner, thereby forming an illumination region 27R on the reticle surface. In the example of FIG. 1, the curved mirror 24 is a convex mirror, but the curved mirror 24 may be formed of a concave mirror, and the curvature of the concave mirror 25 may be reduced by that amount. The illumination optical system ILS includes the concave mirror 21, the fly-eye optical systems 22 and 23, the aperture stop AS, the curved mirror 24, and the concave mirror 25. The configuration of the illumination optical system ILS is arbitrary. For example, a mirror may be disposed between the concave mirror 25 and the reticle R in order to further reduce the incident angle of the exposure light EL with respect to the reticle surface.

  The exposure light EL reflected by the illumination area 27R of the reticle R is incident on the projection optical system PO after the end in the + Y direction is shielded by the arc-shaped edge of the blind plate 26B. The exposure light EL that has passed through the projection optical system PO is projected onto an exposure region (region conjugate to the illumination region 27R) 27W on the wafer W. The blind plates 26A and 26B may be disposed in the vicinity of a conjugate plane with the reticle surface in the illumination optical system ILS, for example.

  Next, the reticle R is attracted and held on the bottom surface of the reticle stage RST via the electrostatic chuck RH. The reticle stage RST is, for example, a two-dimensional magnetic levitation type along a guide surface parallel to the XY plane of the outer surface of the vacuum chamber 1 based on a measurement value of a laser interferometer (not shown) and control information of the main control system 31. It is driven with a predetermined stroke in the Y direction by a drive system (not shown) composed of a linear actuator, and is also driven in a minute amount in the X direction and the θz direction (rotation direction around the Z axis). A partition 8 is provided so as to cover the reticle stage RST on the vacuum chamber 1 side, and the inside of the partition 8 is maintained at an atmospheric pressure between the atmospheric pressure and the atmospheric pressure in the vacuum chamber 1 by a vacuum pump (not shown).

Next, the reticle R will be described with reference to FIG.
FIG. 2A is a cross-sectional view of the reticle R. In FIG. 2A, the reticle shown in FIG. 1 is shown upside down.
A reticle R shown in this figure is formed on a first reflective layer (first reflective portion) 41 formed of a multilayer reflective film on a reticle substrate 40 made of, for example, quartz glass, and on the first reflective layer 41. A light shielding layer 42 having a surface 42a inclined at an angle θ with respect to the surface 41a of the first reflective layer 41, and a multilayer reflective film made of the same material as the first reflective layer 41, on the light shielding layer 42 along the surface 42a. And a second reflective layer (second reflective portion) 43 having a surface 43a formed and inclined at an angle θ with respect to the surface 41a of the first reflective layer 41.

The angle θ formed by the surface 41a of the first reflective layer 41 and the surface 42a of the light shielding layer 42 is set to be equal to or greater than the numerical aperture of the projection optical system PO described later. Specifically, the surface 41a of the first reflective layer 41 is formed in parallel with the holding surface by the electrostatic chuck RH, and the exposure light EL incident on the reticle R is a solid line as shown in the optical path diagram of FIG. As shown by, the light is reflected by the mirrors M1 to M6 and then reflected in the direction of irradiating the surface of the wafer W (first direction).
On the other hand, the second reflective layer 43 is incident on the light receiving device 45 disposed at a position different from the wafer W after the exposure light EL incident on the reticle R is reflected by the mirrors M1 to M6 as indicated by broken lines. It is inclined with respect to the surface 41 a of the first reflective layer 41 at an angle θ that reflects in the direction (second direction).

As the multilayer reflective film for forming the first reflective layer 41 and the second reflective layer 43, a structure in which two types of substances having different refractive indices with respect to vacuum, for example, molybdenum (Mo) and silicon (Si) are alternately laminated, A structure in which a substance such as ruthenium (Ru) or rhodium (Rh) and a substance such as Si, beryllium (Be), or carbon tetraboride (B ₄ C) are combined can be used. As the light shielding layer 42, nickel, silver, gold, copper, cadmium, cobalt, chromium, manganese, silicon, and alloys thereof can be used.

  Further, the reticle R is formed with a patterned opening 44 through the second reflective layer 43 and the light shielding layer 42 to expose the first reflective layer 41. The shape of the opening 44 defines the pattern shape of the reticle R, that is, the pattern shape transferred to the wafer W.

  On the pattern surface side of the reticle R, there is an optical reticle autofocus system (not shown) that measures the position in the Z direction (Z position) of the reticle surface by, for example, irradiating measurement light obliquely to the reticle surface. Has been placed. The main control system 31 sets the Z position of the reticle R within an allowable range using, for example, a Z drive mechanism (not shown) in the reticle stage RST based on the measurement value of the reticle autofocus system during scanning exposure.

  As an example, the projection optical system PO is configured by holding six mirrors M1 to M6 and a light receiving device 45 with a lens barrel (not shown), non-telecentric on the object (reticle R) side, and an image (wafer W). A telecentric reflection system on the side, and the projection magnification is a reduction magnification such as 1/4. The exposure light EL reflected by the illumination area 27R of the reticle R forms a reduced image of a part of the pattern of the reticle R on the exposure area 27W on the wafer W via the projection optical system PO.

  In the projection optical system PO, the exposure light EL from the reticle R is reflected upward (+ Z direction) by the mirror M1, subsequently reflected downward by the mirror M2, then reflected upward by the mirror M3, and reflected by the mirror M4. Reflected downward. Next, out of the exposure light EL reflected upward by the mirror M5, the exposure light EL reflected by the first reflective layer 41 of the reticle R is reflected downward by the mirror M6, and the pattern of the reticle R on the wafer W is reflected. The exposure light EL that forms a part of the image and is reflected by the second reflective layer 43 of the reticle R is reflected downward by the mirror M6 and enters the light receiving device 45 (see FIG. 3). As an example, the mirrors M1, M2, M3, M4, and M6 are concave mirrors, and the other mirror M5 is a convex mirror.

  As the light receiving device 45, a housing 46 having an opening 46a and having an inner surface coated with carbon is used here. The opening diameter of the opening 46a is larger than the condensing diameter of the condensing exposure light EL. Further, the depth inside the housing 46 (the length in the direction in which the exposure light EL is incident) is set to a sufficiently large length (for example, 10 times or more the opening diameter) with respect to the opening diameter of the opening 46.

  On the other hand, wafer W is attracted and held on wafer stage WST via an electrostatic chuck (not shown). Wafer stage WST is arranged on a guide surface arranged along the XY plane. Wafer stage WST is driven in the X direction and the Y direction by a drive system (not shown) composed of, for example, a magnetic levitation type two-dimensional linear actuator based on the measured value of a laser interferometer (not shown) and the control information of main control system 31. It is driven by a predetermined stroke, and is also driven in the θz direction or the like as necessary.

  In the vicinity of wafer W on wafer stage WST, for example, an aerial image measurement system 29 that detects an image of an alignment mark on reticle R is installed, and the detection result of aerial image measurement system 29 is supplied to main control system 31. . The main control system 31 can obtain optical characteristics (such as various aberrations or wavefront aberration) of the projection optical system PO from the detection result of the aerial image measurement system 29, and the optical characteristics are maintained within a predetermined allowable range as an example. As described above, the shape (surface shape) of the reflecting surface such as the mirror M1 is actively controlled using a driving device (not shown). The optical characteristics can also be obtained by a test print or the like. Further, since the deformation of the surface shape of the mirror M1 and the like due to the irradiation heat of the exposure light EL can be predicted, the surface shape of the mirror M1 and the like can be actively controlled so as to cancel the deformation of the surface shape during the exposure. .

At the time of exposure, the wafer W is disposed inside the partition 7 so that the gas generated from the resist on the wafer W does not adversely affect the mirrors M1 to M6 of the projection optical system PL. The partition 7 is formed with an opening through which the exposure light EL is passed, and the space in the partition 7 is evacuated by a vacuum pump (not shown).
When exposing one shot area (die) on the wafer W, the exposure light EL is irradiated onto the illumination area 27R of the reticle R by the illumination optical system ILS, and the reticle R and the wafer W are projected onto the projection optical system PO. It moves synchronously in the Y direction at a predetermined speed ratio according to the reduction magnification of the optical system PO (synchronous scanning). In this way, the reticle pattern is exposed to one shot area on the wafer W. Thereafter, after the wafer stage WST is driven to move the wafer W stepwise, the pattern of the reticle R is scanned and exposed to the next shot area on the wafer W. In this way, a pattern image of the reticle R is sequentially exposed to a plurality of shot areas on the wafer W by the step-and-scan method.

Next, a method for manufacturing the reticle R will be described with reference to FIG.
First, as shown in FIG. 2B, the first reflective layer 41 is entirely formed on the reticle substrate 40 by an ion beam sputtering method or the like, and the light shielding layer is formed on the first reflective layer 41 by a plating method or the like. 42 is formed over the entire surface.

  Next, the surface 42 a of the light shielding layer 42 is inclined at an angle θ with respect to the surface 41 a of the first reflective layer 41 by, for example, a surface flattening process called CMP (Chemical Mechanical Polishing). Then, as shown in FIG. 2D, the second reflective layer 43 is formed on the surface 42a of the light shielding layer 42 along the surface 42a by the above-described sputtering method or the like. Thereafter, a resist for patterning (not shown) is applied on the second reflective layer 43, and a pattern drawing process is performed according to the shape of the opening K with an electron beam. Then, the reflective reticle R shown in FIG. 2A can be obtained by removing the light shielding layer 42 and the second reflective film 43 at the position of the opening K by etching after resist development.

  In the exposure process using the reticle R, as shown in FIG. 3, out of the exposure light EL incident on the reticle R as an incident light at an incident angle α, the surface 41a of the first reflective layer 41 has an outgoing angle α. The reflected exposure light EL forms a pattern image defined by the shape of the opening K on the exposure area W of the wafer W after sequentially reflecting off the mirrors M1 to M6.

  On the other hand, of the exposure light EL incident on the reticle R, the exposure light EL reflected at the emission angle β (β = α−θ) on the surface 43a of the second reflective layer 43 is sequentially reflected by the mirrors M1 to M6 and then opened. The light enters the housing 46 of the light receiving device 45 through the portion 46a. Since the inner surface of the housing 46 is coated with carbon, the incident exposure light EL is absorbed and captured without emitting secondary electrons.

  As described above, in the present embodiment, since the exposure light EL that has entered the reticle R is reflected by both the first reflective layer 41 and the second reflective layer 43, the emission of secondary electrons generated particularly in the light shielding portion. It can be greatly suppressed. Therefore, in this embodiment, even in a situation where carbon-based molecules cannot be removed, it is possible to effectively suppress contaminants generated by the carbon-based molecules adhering to the reticle R. In particular, in this embodiment, since the surface layer 43a of the second reflective layer 43 is inclined with respect to the surface 41a of the first reflective layer 41, it is easy and low cost to generate contaminants. Can be effectively suppressed. In addition, in this embodiment, since the 1st reflective layer 41 and the 2nd reflective layer 43 are formed with the same material, the cost required for material procurement can also be reduced.

  In the present embodiment, since the exposure light EL that is not incident on the wafer W is captured by the light receiving device 45, the exposure light EL can be prevented from adversely affecting the pattern transfer on the wafer W as stray light. In particular, in the present embodiment, the exposure light EL can be effectively captured by applying a carbon coat to the inner surface of the housing 46 in the light receiving device 45.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the light-shielding layer 42 is formed on the first reflective layer 41, and the second reflective layer 43 as the second reflective portion is formed on the light-shielding layer 42. For example, as shown in FIG. 4, a light-shielding layer 42 made of a metal film in which a surface 42 a inclined at an angle θ with respect to the surface 41 a of the first reflective layer 41 is mirror-finished is used as the second reflective portion. Also good.
In this case, the reflectance may be inferior to that of the multilayer reflective film, but the exposure light EL that is originally reflected by the second reflective portion does not contribute to the pattern transfer onto the wafer W, and the light-shielding layer that is not subjected to the mirror surface treatment Compared with the above, by improving the reflectance with respect to the exposure light EL, the amount of secondary electrons emitted can be reduced, and the generation of contaminants can be suppressed.

  Moreover, in the said embodiment, it was set as the structure which uses the housing | casing 46 by which the carbon coat was given to the inner surface as the light-receiving device 45, but, as shown in FIG. 5, for example, the scattering member 47 which has the scattering surface 47a inside, for example. And a measuring device 48 that measures the irradiation dose of the scattered exposure light, and a configuration in which the exposure light EL is incident through the opening 49a. In this configuration, the incident exposure light EL is scattered by the scattering surface 47 a so as to be spatially integrated to make the entire inner wall uniform light, and the irradiation amount measured by the measuring device 48 is output to the main control device 31. In main controller 31, the correlation between the measurement result of measurement device 48 and the amount of exposure light EL irradiated to wafer W in advance, that is, the amount of exposure light EL reflected by the second reflecting portion of reticle R, and reticle R The amount of exposure light EL reflected on the first reflecting portion is obtained and stored, and the measurement result of the measuring device 48 is monitored to monitor the exposure amount of the exposure light EL on the wafer W. Can do. For this reason, when the irradiation amount of the exposure light EL on the wafer W changes due to a change over time, it is possible to quickly respond such as increasing the output of the light source 10 or stopping the exposure process to shift to the maintenance process. Become.

  The photosensitive substrate of each of the above embodiments is not only a semiconductor wafer for semiconductor device manufacturing, but also a glass substrate for display devices, a ceramic wafer for thin film magnetic heads, or an original mask or reticle used in an exposure apparatus ( Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus 100, in addition to a step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the reticle R by synchronously moving the reticle R and the wafer W, the reticle R, the wafer W, It can also be applied to a step-and-repeat projection exposure apparatus (stepper) in which the pattern of the reticle R is collectively exposed while the wafer is stationary and the wafer W is sequentially moved stepwise. The present invention can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on the wafer W.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two reticle patterns are synthesized on a substrate via a projection optical system, and one scanning exposure is performed on one substrate on the substrate. The present invention can also be applied to an exposure apparatus that performs double exposure of shot areas almost simultaneously.

  The type of the exposure apparatus 100 is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern onto the wafer W, but is an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). In addition, the present invention can be widely applied to an exposure apparatus for manufacturing a micromachine, MEMS, DNA chip, reticle, mask, or the like.

  Next, an embodiment of a manufacturing method of a micro device using the exposure apparatus and the exposure method according to the embodiment of the present invention in the lithography process will be described. FIG. 6 is a flowchart showing a manufacturing example of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micro machine, or the like).

  First, in step S10 (design step), function / performance design (for example, circuit design of a semiconductor device) of a micro device is performed, and pattern design for realizing the function is performed. Subsequently, in step S11 (mask manufacturing step), a mask (reticle) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S12 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

  Next, in step S13 (wafer processing step), using the mask and wafer prepared in steps S10 to S12, an actual circuit or the like is formed on the wafer by lithography or the like, as will be described later. Next, in step S14 (device assembly step), device assembly is performed using the wafer processed in step S13. This step S14 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S15 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S14 are performed. After these steps, the microdevice is completed and shipped.

FIG. 7 is a diagram illustrating an example of a detailed process of step S13 in the case of a semiconductor device.
In step S21 (oxidation step), the surface of the wafer is oxidized. In step S22 (CVD step), an insulating film is formed on the wafer surface. In step S23 (electrode formation step), an electrode is formed on the wafer by vapor deposition. In step S24 (ion implantation step), ions are implanted into the wafer. Each of the above steps S21 to S24 constitutes a pre-processing process at each stage of the wafer processing, and is selected and executed according to a necessary process at each stage.

  At each stage of the wafer process, when the above pre-process is completed, the post-process is executed as follows. In this post-processing process, first, in step S25 (resist formation step), a photosensitive agent is applied to the wafer. Subsequently, in step S26 (exposure step), the circuit pattern of the mask is transferred to the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, in step S27 (development step), the exposed wafer is developed, and in step S28 (etching step), exposed members other than the portion where the resist remains are removed by etching. In step S29 (resist removal step), the resist that has become unnecessary after the etching is removed. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the wafer.

  Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., from mother reticles to glass substrates and The present invention can also be applied to an exposure apparatus that transfers a circuit pattern to a silicon wafer or the like. Here, in an exposure apparatus using DUV (deep ultraviolet), VUV (vacuum ultraviolet) light, or the like, a transmission type reticle is generally used. As a reticle substrate, quartz glass, fluorine-doped quartz glass, fluorite, Magnesium fluoride or quartz is used. In proximity-type X-ray exposure apparatuses, electron beam exposure apparatuses, and the like, a transmissive mask (stencil mask, membrane mask) is used, and a silicon wafer or the like is used as a mask substrate. Such an exposure apparatus is disclosed in WO99 / 34255, WO99 / 50712, WO99 / 66370, JP-A-11-194479, JP-A2000-12453, JP-A-2000-29202, and the like. .

  DESCRIPTION OF SYMBOLS 40 ... Reticle substrate (board | substrate), 41 ... 1st reflection layer (1st reflection part), 42 ... Light-shielding layer, 43 ... 2nd reflection layer (2nd reflection part), 45 ... Light-receiving device, 47 ... Scattering member, 47a ... scattering surface, 100 ... exposure device, ILS ... illumination optical system, PO ... projection optical system, R ... reticle (reflection mask), W ... wafer (photosensitive substrate)

Claims (12)

A reflective mask provided with a predetermined pattern,
A first reflecting portion formed on the substrate and reflecting incident incident light in a first direction;
A second reflecting portion formed on the first reflecting portion and having a shape of the predetermined pattern and reflecting the incident light in a second direction different from the first direction; Reflective mask. The reflective mask according to claim 1, wherein
The reflective mask according to claim 1, wherein the surface of the second reflective part is formed to be inclined with respect to the surface of the first reflective part. The reflective mask according to claim 1 or 2,
The first reflective portion has a first reflective layer formed on the substrate,
The second reflective portion is formed on the first reflective layer and has a light shielding layer having a surface inclined with respect to the surface of the first reflective layer, and a second reflective layer formed on the light shielding layer; A reflective mask characterized by comprising: The reflective mask according to claim 3, wherein
The reflective mask, wherein the first reflective layer and the second reflective layer are formed of the same material. The reflective mask according to claim 1 or 2,
The first reflective portion has a first reflective layer formed on the substrate,
The second reflecting portion has a light-shielding layer formed on the first reflecting layer and having a mirror-treated surface capable of reflecting exposure light on a surface inclined with respect to the surface of the first reflecting layer. Reflective mask. In an exposure method for forming a reflective mask pattern on a photosensitive substrate,
Irradiating the mask with exposure light using the reflective mask according to any one of claims 1 to 5,
Exposing the photosensitive substrate with the exposure light reflected by the first reflective portion of the reflective mask;
Irradiating the exposure light reflected by the second reflective portion of the reflective mask to a position different from the photosensitive substrate;
An exposure method comprising: The exposure method according to claim 6.
An angle formed by the first direction and the second direction is equal to or greater than a numerical aperture of a projection optical system that projects an image of the pattern reflected by the first reflecting portion onto the photosensitive substrate. Method. In an exposure apparatus for forming a reflective mask pattern on a photosensitive substrate,
An illumination optical system for irradiating the reflective mask according to any one of claims 1 to 5 with exposure light;
A projection optical system that guides the exposure light reflected in the first direction by the first reflecting portion of the reflective mask to the photosensitive substrate, and projects the pattern on the photosensitive substrate;
An exposure apparatus comprising: a light receiving device that receives the exposure light reflected in a direction different from the first direction by the second reflecting portion of the reflective mask at a position different from the photosensitive substrate. The exposure apparatus according to claim 8, wherein
An exposure apparatus, wherein the light receiving device has a housing whose inner surface is carbon coated. The exposure apparatus according to claim 8, wherein
The light receiving device includes a scattering member formed with a scattering surface that scatters the incident exposure light, a measuring device that measures an irradiation amount of the scattered exposure light, and a housing that houses the scattering member and the measuring device. An exposure apparatus comprising: The exposure apparatus according to any one of claims 8 to 10,
An exposure apparatus, wherein the light receiving device is provided in the projection optical system. Exposing a photosensitive substrate using the exposure apparatus according to any one of claims 8 to 11;
And a step of processing the exposed photosensitive substrate.

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