JP2008042220A - Substrate processing method and apparatus - Google Patents

Abstract

Provided is a substrate processing method and apparatus capable of effectively removing a surface roughness generated at a peripheral portion of a substrate in a semiconductor device manufacturing process or the like, or a film which becomes a contamination source attached to the peripheral portion of a substrate. To do.
After the CMP process, the bevel portion and the edge portion of the substrate are polished by the polishing film. In addition, to the place where the polishing head of the bevel portion of the substrate is not located, the unevenness of the bevel portion is measured by irradiating light of a predetermined shape and predetermined intensity from the normal direction of the device forming surface of the substrate, and measuring the scattered light, Based on this, the polishing end point is detected.
[Selection] Figure 2

Description

  The present invention relates to a substrate processing method and apparatus, and in particular, a substrate processing for removing a surface roughness generated on a peripheral portion (bevel portion and edge portion) of a substrate such as a semiconductor wafer or a film that adheres to the peripheral portion of the substrate and becomes a contamination source. It relates to a method and a device.

  In recent years, with the miniaturization of semiconductor elements and the increase in density of semiconductor devices, particle management has become increasingly important. One of the major problems in managing particles is dust generation due to surface roughness that occurs at the bevel and edge portions of the semiconductor wafer (substrate) during the manufacturing process of the semiconductor device. Here, the bevel portion means a portion having a curvature at the end portion of the semiconductor wafer, and the edge portion means a portion having a flat surface of about several mm from the bevel portion toward the inner peripheral side of the wafer. means.

For example, in the RIE (Reactive Ion Etching) process in which the trench (deep trench) of the trench capacitor is formed on the surface of the Si wafer, the surface roughness due to processing as described above occurs. In the RIE process, first, as shown in FIG. 18A, a hard mask composed of a laminated film of a SiN film 500 and a SiO ₂ film 510 is formed on the Si wafer 100, and the Si wafer 100 is formed using the hard mask as a mask. Is etched by the RIE method to form a deep trench 520 (see FIG. 18B).

  In this RIE process, a by-product generated during etching adheres to the bevel portion and the edge portion of the Si wafer 100, and this acts as an etching mask. As shown in FIG. Needle-like protrusions 530 may be formed on the bevel portion and the edge portion. In particular, when an attempt is made to form a deep trench 520 having an opening diameter of the order of submicron and an aspect ratio of several tens, which is very high, the above-described needle-like projections 530 may be beveled and edged depending on the process conditions. Will inevitably occur.

  The height of the needle-like protrusion 530 varies depending on the position, but it is as close as 10 μm at the maximum, which causes breakage during transport or process of the Si wafer 100 and generation of particles. Since such particles lead to a decrease in yield, it is necessary to remove the needle-like protrusions 530 formed on the bevel portion and the edge portion.

  Conventionally, a CDE (Chemical Dry Etching) method has been used to remove such needle-like protrusions 530. In this CDE method, first, as shown in FIG. 19A, a resist 540 is applied to the surface of the Si wafer 100 excluding the bevel portion and the edge portion of several millimeters. Then, the part of the Si wafer 100 not covered with the resist 540 is isotropically etched to remove the needle-like protrusions 530 at the bevel portion and the edge portion (see FIG. 19B). Thereafter, the resist 540 protecting the device surface is removed (see FIG. 19C).

  In such a CDE method, since it is necessary to protect the device surface with a resist 540, steps of resist coating and resist peeling are required. Further, the sharp needle-like portion can be removed by isotropic etching, but unevenness 550 is formed according to the variation in the height of the needle-like protrusion 530 (see FIG. 19C). This type of unevenness 550 is likely to cause a problem that dust tends to accumulate during processing such as CMP (Chemical Mechanical Polishing) performed in the subsequent steps, but depending on the conventional CDE method, It was difficult to completely remove the surface roughness of the bevel portion and the edge portion. Further, the processing time per sheet required for the CDE process is usually as long as 5 minutes or more, and the CDE process has a problem that the throughput is lowered and the raw material cost is high.

  In recent years, new materials such as Cu as a wiring material, Ru and Pt as capacitor electrode materials for next-generation DRAMs and FeRAMs, TaO and PZT as capacitor dielectric materials, etc. have been introduced one after another in the field of semiconductor devices. Has been. And when mass-producing semiconductor devices, it was time to seriously consider the problem of device contamination with these new materials. In particular, during the manufacturing process of the semiconductor device, the new material film adhering to the bevel portion, the edge, and the back surface of the wafer becomes a contamination source.

  For example, when forming a Ru film used as a capacitor electrode, it is important to remove the Ru film attached to the bevel portion, the edge portion, and the back surface. As a method for forming such a Ru film, a CVD (Chemical Vapor Deposition) method is generally used. However, in the CVD method, although there are differences depending on the apparatus configuration, a bevel portion, an edge portion, In addition, adhesion of the Ru film to the back surface cannot be avoided. Further, even when the Ru film is formed by using the edge cut ring in the sputtering method, it is difficult to completely eliminate the adhesion of the Ru film due to the sputter particles (Ru) entering the bevel portion and the edge portion. When the edge cut width is reduced in order to increase the yield of the outer peripheral chip, it is still difficult to completely eliminate the adhesion of the Ru film.

  In any film formation method, a Ru film is attached to the bevel portion, edge portion, or back surface of the wafer after Ru film formation. As described above, the Ru film adhering to this type of bevel portion or the like causes contamination of the apparatus in the next process and must be removed.

  The Ru film adhering to the bevel portion and the like has been conventionally removed by a wet etching method, and a common method is to drop a chemical solution onto a Si wafer that is rotating horizontally with the back surface of the Si wafer facing up. is there. The bevel portion and the edge portion are dealt with by adjusting the number of rotations and the like to adjust the amount of the chemical solution that wraps around the device forming surface.

  However, this method has a problem that since the removal rate of the Ru film is about 10 nm / min, the processing time per sheet is usually as long as 5 minutes or more, and the throughput is low. Furthermore, Ru diffused in the base cannot be removed, and in order to remove this, it is necessary to additionally perform wet etching with another chemical solution capable of etching the base, and the throughput is further lowered. There is also a problem that there is no appropriate chemical solution that does not damage the device.

  The present invention has been made in view of such problems of the prior art, and becomes a source of contamination by being attached to the surface roughness generated at the peripheral edge of the substrate or the peripheral edge of the substrate in the manufacturing process of the semiconductor device. It is an object of the present invention to provide a substrate processing method and apparatus capable of effectively removing a film.

In order to solve such a problem in the prior art, the first aspect of the substrate processing method of the present invention is characterized in that after the CMP step, the bevel portion and the edge portion of the substrate are polished with a polishing film. To do.
According to a second aspect of the substrate processing method of the present invention, light having a predetermined shape and a predetermined intensity is irradiated from the normal direction of the device forming surface of the substrate to a place where the polishing head of the bevel portion of the substrate is not located. By measuring, the unevenness of the bevel portion is measured, and based on this, the polishing end point is detected.
According to one aspect of the present invention, the light is a laser or an LED.
According to an aspect of the substrate processing apparatus of the present invention, light having a predetermined shape and a predetermined intensity is irradiated by optical means from the normal direction of the device forming surface of the substrate to a place where the polishing head of the bevel portion of the substrate is not located. It is characterized in that the unevenness of the bevel portion is measured by measuring and the polishing end point is detected based on this.
According to one aspect of the present invention, the light is a laser or an LED.
A preferred aspect of the present invention includes a polishing tape and a polishing head that presses the polishing tape at a predetermined position of the substrate, and the substrate is polished by sliding between the polishing tape and the substrate.

  If removal of the needle-like protrusions on the substrate bevel portion and edge portion is performed by polishing using such a polishing tape, it becomes unnecessary to protect the device formation surface by the resist, which is indispensable in the conventional CDE method. As a result, two steps of applying a resist for protection and removing the resist after removing the needle-like protrusions can be omitted, and the throughput is improved. In addition, since the surface after removing the needle-like protrusions from the bevel portion and the edge portion becomes a smooth surface, the above-described problems in the CDE method are solved.

  In addition, if the film that becomes a contamination source by adhering to the peripheral edge of the substrate or the like is removed by polishing using such a polishing tape, the removal process can be realized in a single process. Compared with the etching method, the film which becomes a contamination source can be removed in a short time, and the throughput is improved.

  Here, the polishing tape may be formed of a thin film polishing film. A polishing tape made of a highly flexible material can also be used. In this way, by using a thin film polishing film as the polishing tape, for example, the polishing tape is not bent at the surface of the substrate, particularly at the peripheral edge (bevel portion and edge portion). Therefore, since the polishing tape can be surely conformed to the curved surface shape of the peripheral portion of the substrate, the peripheral portion of the substrate can be evenly polished. As a result, it is possible to effectively remove the needle-like protrusions formed on the surface of the substrate and unnecessary films attached to the surface of the substrate by polishing. Here, “abrasive tape” means a tape-like polishing tool, and this abrasive tape includes both a polishing film in which abrasive grains are applied to a base film and a tape-like polishing cloth.

  In a preferred aspect of the present invention, a polishing tape, a polishing head provided with an elastic body that supports the polishing tape, and the polishing head is pressed with a predetermined pressing force to press the polishing tape against a predetermined portion of the substrate. A pressing mechanism, and the substrate is polished by sliding between the polishing tape and the substrate.

  In this way, the pressing mechanism presses the polishing head so that the pressing force applied to the polishing tape during polishing is a predetermined pressing force. Therefore, even if the elastic body deteriorates and extends, The pressing mechanism presses the polishing head by the extended amount. For this reason, the tension of the elastic body hardly changes and uniform polishing can be performed with the polishing rate by the polishing tape being always constant regardless of the deterioration of the elastic body.

  In a preferred aspect of the present invention, the pressing mechanism is configured such that the pressing force can be adjusted during polishing.

  By doing so, it is possible to change the pressing force applied to the polishing tape during polishing by appropriately changing the pressing force by the pressing mechanism and obtain a desired polishing profile at a predetermined location on the substrate.

  A preferred aspect of the present invention is an abrasive tape, a deformable fluid bag that supports the abrasive tape and is supplied with pressurized fluid, and a support portion that houses the fluid bag and supports the fluid bag. And a polishing head for pressing the polishing tape at a predetermined location on the substrate.

  With such a configuration, by supplying pressurized fluid to the fluid bag, the fluid bag that supports the polishing tape is deformed, and the polishing tape contacts the predetermined portion of the substrate evenly. Can be evenly polished.

  In this case, the polishing tape may be formed of a polishing film. Alternatively, the polishing tape may be formed of a polishing cloth, and the substrate may be polished while supplying an abrasive or an etchant to the surface of the substrate. In addition, the fluid bag can be constituted by an abrasive tape.

  Another preferable aspect of the present invention further includes a fluid supply source that supplies fluid of an arbitrary pressure to the fluid bag.

  As described above, if removal of the needle-like projections on the bevel portion and the edge portion of the substrate by polishing using a polishing tape, the protection of the device formation surface by the resist, which is indispensable in the conventional CDE method, is unnecessary. Become. As a result, two steps of applying a resist for protection and removing the resist after removing the needle-like protrusions can be omitted, and the throughput is improved. In addition, since the surface after removing the needle-like protrusions from the bevel portion and the edge portion becomes a smooth surface, the above-described problems in the CDE method are solved.

  Also, if the film that becomes a contamination source by adhering to the peripheral edge of the substrate or the like is removed by polishing using a polishing tape, the removal process can be realized in a single process, so that the conventional wet etching method is used. In comparison, the film that becomes a contamination source can be removed in a short time, and the throughput is improved.

  In addition, by using a thin film polishing film as the polishing tape, the polishing tape is not bent at the surface of the substrate, particularly at the peripheral portion (bevel portion and edge portion). Therefore, since the polishing tape can be surely conformed to the curved surface shape of the peripheral portion of the substrate, the peripheral portion of the substrate can be evenly polished. As a result, it is possible to uniformly and stably remove the needle-like protrusions formed on the surface of the substrate and the unnecessary Ru film attached to the surface of the substrate by polishing. In addition, the processing time can be shortened to improve the throughput.

  In addition, since the polishing head is pressed by the pressing mechanism so that the pressing force applied to the polishing tape during polishing is a predetermined pressing force, the tension of the elastic body hardly changes regardless of the deterioration of the elastic body. Uniform polishing can be performed with a constant polishing rate with the tape.

  Furthermore, by supplying pressurized fluid to the fluid bag, the fluid bag that supports the polishing tape is deformed, and the polishing tape comes into uniform contact with the surface of the substrate, so that the surface of the substrate is evenly polished. Is possible.

  Embodiments of a substrate processing apparatus according to the present invention will be described below in detail with reference to the drawings. A substrate processing apparatus according to the present invention performs processing of a bevel portion, an edge portion, and / or a back surface of a wafer by polishing the surface of a substrate such as a semiconductor wafer (Si wafer). A polishing unit is provided for polishing. In addition, the same code | symbol is attached | subjected to the component which is the same or it corresponds through drawing, and the overlapping description is abbreviate | omitted.

  First, the polishing unit of the substrate processing apparatus in the first embodiment of the present invention will be described. FIG. 1 is a schematic plan view showing a polishing unit according to the first embodiment of the present invention, and FIG. 2 is a front sectional view of the polishing unit shown in FIG. As shown in FIGS. 1 and 2, the polishing unit includes a plurality of rollers 1 that rotatably hold a semiconductor wafer 100, a polishing head 2 that polishes a bevel portion and an edge portion of the wafer 100, and a polishing head 2. An air cylinder (pressing mechanism) 3 that presses toward the wafer 100, a chemical solution supply nozzle 4 that supplies a chemical solution (or pure water) to the bevel portion and the edge portion of the wafer 100, and a device formation surface of the wafer 100 (ie, FIG. 2). , A notch sensor 6 for detecting a notch of the wafer 100, and a grindstone wheel 7 for polishing the notch of the wafer 100 are provided. The semiconductor wafer 100 is set so that the device formation surface is on the bottom to prevent particles falling from above.

  3 is a cross-sectional view showing a main part of the polishing head 2 of FIG. 1, and FIG. 4 is a cross-sectional view showing a state of the polishing head shown in FIG. 3 during polishing. As shown in FIGS. 1 to 4, the polishing head 2 is composed of a support portion 20 having two protrusions 20a and 20b and elastic rubber or the like stretched between the ends of the protrusions 20a and 20b. An elastic member 21, a polishing film 22 as a polishing tape supported by the elastic member 21, and a pressing plate 23 made of an elastic body are provided.

  The polishing head 2 can be moved in the radial direction of the semiconductor wafer 100 by a moving mechanism (not shown). An air cylinder 3 is connected to the base portion 20 c of the support portion 20 of the polishing head 2. When the support portion 20 is moved in the center direction of the wafer 100 by driving the air cylinder 3, the polishing film 22 is pressed against the bevel portion and the edge portion of the wafer 100 via the elastic member 21, as shown in FIG. The Details of driving of the air cylinder 3 will be described later. In addition, you may provide the mechanism in which the distance between protrusion part 20a, 20b of the grinding | polishing head 2 is variable.

  The polishing film 22 is accommodated in a polishing cassette (not shown), and is wound up with reels 24a and 24b (see FIG. 2) in the polishing cassette under a predetermined tension. The polishing film 22 worn by the polishing of the wafer 100 is wound before the polishing rate is lowered, and a new polishing film comes into contact with the wafer 100. The bevel portion and edge portion of the wafer 100 are pressed against the polishing film 22 with a predetermined pressing force, and the wafer 100 is rotated to bring the bevel portion and edge portion of the wafer 100 into contact with the polishing film 22 for polishing. Note that polishing may be performed by sliding the polishing film 22 against the wafer 100. Further, during polishing, the polishing film 22 is reciprocated or continuously fed at a predetermined speed by the reels 24a and 24b so that the polishing rate is increased by adding sliding at the relative speed in the thickness direction of the wafer in addition to the above-described rotational sliding. It may be.

  As the polishing film 22, for example, a polishing film in which diamond abrasive grains or SiC is bonded to one surface serving as a polishing surface can be used. The abrasive grains that adhere to the polishing film are selected according to the type of substrate and the required performance. For example, diamonds having a particle size of # 4000 to # 12000 or SiC having a particle size of # 4000 to # 10000 can be used.

  As shown in FIG. 4, a tension T is generated in the stretched elastic member 21 by pressing the elastic member 21 from the back side of the polishing film 22. Due to the tension T of the elastic member 21, the pressure P acts on the bevel portion of the wafer 100 from the polishing film 22. The magnitude of the pressure P is P = T / when the width of the polishing film 22 is W, the radius of curvature of the cross section of the bevel portion is ρ, and the thickness D of the polishing film 22 is sufficiently smaller than the radius of curvature ρ. (ΡW).

  The pressing plate 23 is disposed between the protruding portions 20 a and 20 b of the support portion 20 and can move in the radial direction of the wafer 100. By moving the pressing plate 23 toward the center of the wafer 100, the elastic member 21 and the polishing film 22 are pressed against the edge portion of the wafer 100.

  The chemical solution supply nozzle 4 is disposed in the vicinity of the polishing head 2, and the chemical solution or pure water is supplied from the chemical solution supply nozzle 4 to the bevel portion and the edge portion of the wafer 100. Further, the gas injection nozzles 5 are arranged radially with respect to the center of the wafer 100, and polishing dust generated during polishing contaminates the device formation surface by injecting gas onto the device formation surface of the wafer 100 during polishing. To prevent that. Note that if the gas injection nozzle 5 is installed not only on the device formation surface side but also on the back surface (that is, the upper surface in FIG. 2) side of the wafer 100, the wafer 100 can be more effectively cleaned. it can.

  5A is a front view showing the grinding wheel 7 shown in FIG. 1, and FIG. 5B is a plan view showing the grinding wheel 7 when the notch of the wafer 100 is being polished. As shown in FIGS. 5A and 5B, the grindstone wheel 7 includes a wheel 70 in which a groove 70 a having a shape corresponding to the notch shape and the bevel shape of the wafer 100 is formed, and a rotation that rotates the wheel 70. A shaft 71 is provided. For example, diamond abrasive grains having a particle size of about 10,000 are bonded to the groove 70a of the wheel 70.

  When the notch 72 of the wafer 100 is polished by the grinding wheel 7, the notch 72 of the wafer 100 is detected by the notch sensor 6, and the rotation of the wafer 100 is stopped so that the notch 72 comes to the position of the grinding wheel 7. Then, as shown in FIG. 5B, the wheel 70 is rotated about the rotation shaft 71 with the groove 70 a of the wheel 70 of the grinding wheel 7 aligned with the notch 72. At this time, the notch 72 of the wafer 100 is polished by moving the rotary shaft 71 in the vertical direction and the horizontal direction.

  Next, using the polishing unit having the above-described configuration, when the deep trench of the trench capacitor is formed on the surface of the semiconductor wafer (Si wafer) by the RIE method, the roughness generated on the surface of the bevel portion and the edge portion of the semiconductor wafer is removed. How to do will be described. This trench capacitor is used for a DRAM memory cell, for example.

First, a deep trench is formed on the surface of a semiconductor wafer by an RIE process (see FIGS. 18A and 18B). For example, the SiN film 500 has a thickness of 200 nm, the SiO ₂ film 510 has a thickness of 90 nm, the deep trench 520 has an opening diameter of 0.25 μm, and a depth of 7 μm. By this RIE process, needle-like protrusions 530 as shown in FIG. 18B are formed on the surface of the semiconductor wafer, and these needle-like protrusions 530 are removed using the above-described polishing unit.

  First, the semiconductor wafer 100 is nipped rotatably in the horizontal plane by the roller 1 with the device formation surface facing downward. Next, the polishing head 2 is moved toward the center of the wafer 100, and the polishing head 2 is pressed against the wafer 100 so that the bevel portion of the wafer 100 is sandwiched between the polishing films 22 of the polishing head 2. Further, the pressing plate 23 of the polishing head 2 is moved toward the center of the wafer 100, the horizontal surface of the pressing plate 23 is pressed from the vertical direction to the edge region, and the polishing film 22 is applied to the edge region with a pressure of about 98 kPa, for example. Make contact. By doing in this way, the area | region of several mm of the edge part of a device formation surface can be grind | polished. At this time, the chemical solution or pure water is supplied from the chemical solution supply nozzle 4 to the contact portion between the bevel portion and the edge portion of the wafer 100 and the polishing film 22. The wafer 100 is rotated by the rotation of the roller 1, and the bevel portion and the edge portion of the wafer 100 are brought into sliding contact with the polishing film 22 of the polishing head 2 to wet-polish the bevel portion and the edge portion of the wafer 100.

  Further, a gas such as air or nitrogen is jetted at a shallow angle with respect to the device formation surface at a flow rate of 5 m / s or more from the gas injection nozzle 5 arranged radially on the device formation surface side of the wafer 100. This prevents the device forming surface of the wafer 100 from being contaminated by polishing debris generated during polishing.

  Thereafter, as described above, the bevel portion and the entire edge portion of the notch 72 of the wafer 100 are polished using the notch sensor 6 and the grindstone wheel 7.

  In this way, the bevel portion and the edge portion of the wafer 100 are polished, but when the elastic member 21 deteriorates due to change over time, the elastic force is lost or the entire length is extended due to plastic deformation, The tension of the elastic member 21 at the time of polishing may decrease. When the tension of the elastic member 21 is reduced, the polishing load is reduced and the polishing rate is also reduced, so that the polishing efficiency is lowered. Further, when the tension of the elastic member 21 is lowered, the polishing rate is changed, so that a desired polishing profile cannot be obtained.

  The deterioration of the elastic member 21 here means an increase in natural length and a decrease in Young's modulus due to plastic deformation. When stress of tension is accumulated, the elastic member 21 is plastically deformed even if it is an elastic body, and the length (natural length) when no tension is applied is slightly increased. Further, it was found that when a stress of tension is accumulated, the Young's modulus of the elastic member 21 is slightly lowered.

  The deterioration of the elastic member 21 can be improved to some extent by selecting the elastic member 21 made of a material that does not easily deteriorate, or by increasing the thickness of the elastic member 21 to reduce the tension acting per unit area. it can. However, it is impossible to completely suppress the deterioration of the elastic member 21.

  Accordingly, when polishing is performed with a constant distance D (see FIG. 4) for pressing the polishing film 22 and the elastic member 21 against the wafer 100 (hereinafter, referred to as a fixed position method), the following problems occur. This fixed position method is a method in which a position where the elastic member 21 can press the polishing film 22 with a predetermined force is determined in advance, and polishing is performed by moving the polishing head 2 to this position during polishing. According to this fixed position method, initially, a predetermined tension acts on the elastic member 21, but due to the deterioration of the elastic member 21, the tension gradually decreases as time passes. Therefore, there arises a problem that the polishing rate gradually decreases with the passage of time.

When natural rubber having a Young's modulus of 0.6 MPa and a cross-sectional area of 13 mm ² was used as the elastic member 21, it was found that the tension acting on the elastic member 21 was reduced by 10% after 10 hours of cumulative use. For this reason, since the cumulative use time exceeds 10 hours, the needle-like projections formed on the bevel portion cannot be completely removed by rough polishing for 1 minute, and it is necessary to lengthen the processing time.

  From such a viewpoint, in this embodiment, the elastic member 21 always presses the polishing film 22 with a constant force F using the air cylinder 3 (constant force method). That is, the air cylinder 3 presses the support portion 20 and the elastic member 21 so that the pressing force applied to the polishing film 22 during polishing is constant. Thereby, even if the elastic member 21 extends due to deterioration, the air cylinder 3 presses the support portion 20 and the elastic member 21 as much as the elastic member 21 extends, so that the polishing film 22 moves to the bevel portion and the edge portion. The applied pressure is not changed. Therefore, the polishing rate by the polishing film 22 can always be kept constant regardless of the deterioration of the elastic member 21, the change in tension acting on the elastic member 21 can be almost ignored, and stable polishing can be realized. It becomes.

  The magnitude of the above-mentioned constant force F is determined so that the elastic member 21 is deformed with a predetermined tension T. That is, in FIG. 4, the pressing force F is adjusted so that the relationship of F = 2T cos θ is established. Here, θ is an angle formed by the surface of the wafer 100 and the elastic member 21.

Consider a case where the half length of the elastic member 21 when a certain force F is applied is L (see FIG. 4), and the elastic member 21 becomes longer by ΔL due to the above-described deterioration. If the elastic member 21 is lengthened by ΔL, the angle θ is decreased by Δθ, and the tension T is decreased by ΔT, the above-described relationship of F = 2T cos θ is established in the constant force method, and the force F is unchanged. (Constant), the relationship ΔT / T = Δθ tan θ is established. Further, since the relationship Δθ = (ΔL / L) tan θ is also established, eventually the relationship ΔT / T = (ΔL / L) tan ² θ is established. Here, if the angle θ is 15 degrees, considering that ΔL / L is less than the rate of tension decrease in the fixed position method, the rate of decrease in tension ΔT / T in the constant force method is It can be seen that it is only less than 7% of the rate of decrease in tension in the law and can be almost ignored. Actually, according to the constant force method, even when the cumulative usage time exceeds 100 hours, the tension acting on the elastic member 21 does not decrease, and the extension of the processing time becomes unnecessary.

  In order to achieve uniform polishing over the entire bevel portion, it is necessary to ensure that the polishing film 22 follows the curved shape of the bevel portion. In other words, the curvature of the cross section of the bevel portion varies depending on the type of semiconductor wafer, but in the case of an 8-inch wafer, on average, it is about 1 / (360 μm), but it is partially 1 / (120 μm). In some cases, the value may be large. In order for the polishing film 22 to follow the curved surface shape having such a large curvature, the polishing film 22 is not plastically deformed with respect to the curved surface having the (maximum) curvature of the cross section of the bevel portion, that is, is bent. It must be flexible enough not to bend.

  The flexibility of the polishing film is determined by the film material and thickness of the polishing film. When PET generally used as the material of the abrasive film is used, the abrasive film may be bent as shown in FIG. 6 even if an abrasive film having a thickness of 75 μm or more is caused to follow the curved surface of the bevel portion. . When the polishing film is bent as described above, a portion where the polishing film is difficult to contact is generated in the bevel portion, the polishing rate of this portion is lowered, and the bevel portion of the wafer 100 cannot be uniformly polished. When the polishing film is bent in this manner, for example, when rough polishing is performed for 1 minute, the needle-like protrusions formed on the bent portion of the polishing film 22 cannot be completely removed, and the bevel portion In order to completely remove the entire needle-like protrusions, it is necessary to lengthen the treatment time, for example, 2 minutes. This leads to a decrease in throughput.

  Therefore, in the present embodiment, the polishing film is thinned so as to be flexible enough not to bend with respect to the curved surface shape having the (maximum) curvature of the cross section of the bevel portion. When PET was used as the material of the polishing film, it was found that if the thickness of the polishing film was 50 μm or less, it could be bent along the curved shape of the (maximum) curvature of the bevel cross section without bending. In addition, when the material of the polishing film is not PET, the thickness of the film that can be bent along the curved shape of the (maximum) curvature of the bevel portion is naturally different from that described above.

  Thus, in this embodiment, since the thin film polishing film is used as the polishing film 22, the polishing film 22 is not bent at the bevel portion of the wafer 100. Therefore, since the polishing film 22 can be surely conformed to the curved surface shape of the bevel portion of the wafer 100, the bevel portion of the wafer 100 can be evenly polished. In the present embodiment, a thin film polishing film is used as the polishing film 22 so that the polishing film 22 conforms to the curved shape of the bevel portion of the wafer 100. However, a polishing film made of a highly flexible material is used. The same effect can be obtained.

  In the present embodiment, as described above, the polishing film 22 is pressed against the wafer 100 via the elastic member 21, but when the polishing film 22 is directly pressed against the wafer 100 without using such an elastic member 21. In this case, the polishing film 22 can contact only the central portion of the wafer 100 in the height direction, and the contact length becomes at most about 10 mm, so that the contact area cannot be increased. In addition, since it is not possible to absorb subtle fluctuations in the bevel portion accompanying the rotation of the wafer 100, it is difficult to apply pressure dynamically and stably to the bevel portion of the rotating wafer 100.

  In the method of pressing the polishing film 22 against the wafer 100 via the elastic member 21 as in the present embodiment, as described above, the pressure P applied from the polishing film 22 to the bevel portion of the wafer 100 is P = T / (ΡW), the pressure applied to the bevel portion can be made uniform when the cross section of the bevel portion is full round. Thus, if the polishing film 22 is pressed against the wafer 100 via the elastic member 21, the portion that contributes to polishing is expanded, the polishing rate is increased, and the pressure variation on the contact surface is reduced to reduce the polishing amount. Can be made uniform.

  Using the polishing unit having the above-described configuration, the needle-like protrusions formed on the bevel portion and the edge portion were removed under the following conditions. In this example, as shown in FIG. 7, a polishing unit provided with four rough polishing polishing heads 2a in the circumferential direction and four polishing polishing heads 2b in the circumferential direction, respectively.

As a polishing film for roughing, diamond particles having a particle size of # 4000 are bonded with a urethane type adhesive on a PET film having a thickness of 25 μm, and as a polishing film for finishing, diamond particles having a particle size of # 10000 have a thickness of 25 μm. What was couple | bonded with the urethane type adhesive agent on the PET film was used. The width of each polishing film was 30 mm. The tension T of the elastic member 21 was set to 9.8 N, and the angle θ was 15 degrees. Further, the rotation speed of the wafer 100 was set to 100 min ⁻¹ . At the time of polishing, pure water was supplied from each chemical solution supply nozzle 4 at 10 ml / min.

  First, the polishing film for roughing of the polishing head 2a was contacted at four locations along the circumference of the wafer and polished for 1 minute. By this rough grinding, the needle-like protrusions 530 of the wafer 100 were removed. Next, in order to remove polishing damage, the polishing head 2a for roughing and the polishing head 2b for finishing were exchanged, and polishing was performed for 1 minute with a polishing film for finishing. By this final polishing, the polishing scratches remaining on the surface were completely removed, and the bevel surface became a mirror surface having an average roughness Ra of several nm or less.

Next, the notch 72 of the wafer 100 was polished. The grindstone wheel 7 was rotated at a rotational speed of 1000 min ⁻¹ to polish the notch 72 of the wafer 100 for 30 seconds. Thereby, the acicular protrusion in the notch was completely removed.

  Thereafter, in another unit, cleaning was performed using pure water or an aqueous surfactant solution while the PVA sponge or the like was slidably contacted with the wafer 100 with the bevel portion and the edge portion as main components. And after rinsing, it was made to dry and the process was completed.

  As described above, by removing the beveled portion 530 at the bevel portion and the edge portion of the wafer 100 by polishing using the polishing film 22, it is unnecessary to protect the device formation surface by the resist, which is indispensable in the conventional CDE method. Become. As a result, two steps of applying a resist for protection and removing the resist after removing the needle-like protrusions can be omitted, and the throughput is improved.

  Further, since the surface after removing the needle-like protrusions 530 from the bevel portion and the edge portion of the wafer 100 becomes a smooth surface as shown in FIG. 8, the problem in the CDE method described above is solved. That is, in the conventional CDE method, as shown in FIG. 19C, after removing the needle-like protrusions, the unevenness 550 is formed according to the height variation of the needle-like protrusions 530, and CMP is performed in the subsequent steps. However, according to the present invention, this problem is solved.

  Further, when a cleaning unit for cleaning the wafer 100 is incorporated in the substrate processing apparatus described above, the processing time per wafer can be reduced to about 3 minutes. Compared with the conventional CDE method, which requires about 5 minutes, the processing time can be shortened, so that the throughput can be improved.

  Furthermore, since the above-described polishing unit and substrate processing apparatus have a simple apparatus configuration, the price of the apparatus alone can be reduced. Moreover, since the raw materials used are only pure water and a very small amount of chemical solution, the running cost can be greatly reduced. Thus, according to the present invention, there is a great advantage in terms of cost reduction.

  In the present embodiment, as the liquid supplied in the wet polishing, a chemical solution that wet-etches silicon, for example, KOH aqueous solution, alkali ion water, or the like can be used in addition to pure water. A surfactant aqueous solution can also be used. By using these chemicals, depending on the material and size of the abrasive grains of the polishing film 22, an effect of improving polishing characteristics such as polishing rate and surface flatness can be expected.

  Next, the substrate processing apparatus in the 2nd Embodiment of this invention is demonstrated. The substrate processing apparatus in the present embodiment removes the Ru film adhering to the bevel portion, the edge portion, and the back surface of the semiconductor wafer when the Ru film used as the capacitor electrode is formed on the device forming surface by the CVD method. .

  As shown in FIG. 9, when a Ru film 81 used as a lower capacitor electrode is deposited by 30 nm on a semiconductor wafer 100 on which a silicon nitride film 80 is deposited by batch-type CVD, the Ru film 81 is a device formation surface. In addition, the film is formed on the bevel portion, the edge portion, and the back surface of the wafer 100 by about 30 nm. A capacitor using this kind of Ru film 81 is, for example, a three-dimensional capacitor, and is used for DRAM or FeRAM. As described above, the Ru film 81 attached to the bevel portion, the edge portion, and the back surface causes contamination of the apparatus in the next process, and thus needs to be removed.

  Therefore, the Ru film adhering to the bevel portion, the edge portion, and the back surface of the semiconductor wafer is removed using the substrate processing apparatus in the present embodiment. The substrate processing apparatus in this embodiment includes a second polishing unit that removes the Ru film 81 attached to the back surface of the wafer 100 in addition to the (first) polishing unit in the first embodiment described above. . FIG. 10 is a schematic plan view showing a second polishing unit in the present embodiment, and FIG. 11 is a front sectional view of FIG.

  As shown in FIGS. 10 and 11, the second polishing unit includes a plurality of rollers 11 that rotatably hold the wafer 100, a polishing roll (polishing head) 12 in which a polishing film 12b is wound around an elastic body 12a, A chemical supply nozzle 13 (not shown in FIG. 11) having the form of a shower nozzle, a support roll 14 made of PVA sponge, and a cleaning liquid supply nozzle 15 (not shown in FIG. 10) for supplying a cleaning liquid to the wafer 100 are provided. I have. The wafer 100 is set so that the device formation surface is on the bottom.

  The polishing roll 12 is formed by adhering and winding a polishing film 12b around a cylindrical elastic body 12a made of elastic rubber, foamed urethane, etc. For example, for a 20.32 cm (8 inch) wafer, the diameter is about 30 mm. The length is about 210 mm. The chemical solution supply nozzle 13 is disposed in the vicinity of the polishing roll 12 disposed on the back surface (upper surface in FIG. 11) side of the wafer 100, and the chemical solution is dropped from the chemical solution supply nozzle 13 onto the back surface of the wafer 100. . The support roll 14 disposed below the wafer 100 comes into contact with the device forming surface of the wafer 100 while rotating, and the load of the polishing roll 12 is supported by the support roll 14.

  In the second polishing unit having such a configuration, the wafer 100 is rotatably held in the horizontal plane by the roller 11 with the device formation surface facing downward. Next, the polishing roll 12 is brought into contact with the back surface of the wafer 100 by a pressing mechanism (not shown) while rotating. At this time, the chemical solution is dropped from the chemical solution supply nozzle 13. Further, while rotating the support roll 14, the device is brought into contact with the device forming surface of the wafer 100 and the cleaning liquid is supplied from the cleaning liquid supply nozzle 15 to the front and back surfaces of the wafer 100. The wafer 100 is rotated by the rotation of the roller 11, and the back surface of the wafer 100 and the polishing roll 12 are brought into sliding contact with each other to wet-polish the back surface of the wafer 100. The surface of the substrate (device forming surface) may be polished with the polishing roll 12.

  Using the substrate processing apparatus in this embodiment, the Ru film 81 attached to the bevel portion and the edge portion was removed under the following conditions. In this example, a unit having eight polishing heads in the circumferential direction was used as the first polishing unit.

As the polishing film 22, a diamond particle having a particle size of # 10000 bonded to a PET film having a thickness of 25 μm with a urethane type adhesive was used. The width of the polishing film 22 was 30 mm. The tension of the elastic member 21 was set to 9.8 N, and the angle θ was set to 15 degrees. Further, the rotation speed of the wafer 100 was set to 100 min ⁻¹ . At the time of polishing, pure water was supplied from each chemical solution supply nozzle 4 at 10 ml / min.

First, polishing was performed for 1 minute by bringing the polishing film 22 of the polishing head 2 into contact with eight locations along the circumference of the wafer. By this polishing, the Ru film 81 adhering to the bevel portion and the edge portion could be completely removed. Next, the notch 72 of the wafer 100 was polished. The grindstone wheel 7 was rotated at a rotational speed of 1000 min ⁻¹ to polish the notch 72 of the wafer 100 for 30 seconds. As a result, the Ru film 81 adhering to the bevel portion and the edge portion of the notch 72 was completely removed.

  Next, using the above-described second polishing unit, the Ru film 81 attached to the back surface was removed under the following conditions.

As the polishing film 12b of the polishing roll 12, a diamond particle having a particle size # 10000 bonded to a PET film with a urethane type adhesive was used. The pressing force of the polishing roll 12 was 9.8 N, and the rotation speed was 100 min ⁻¹ . The rotation speed of the wafer 100 was set to 100 min ^−1, and pure water was supplied from the chemical solution supply nozzle 13 at 200 ml / min. Further, pure water was supplied from each cleaning liquid supply nozzle 15 at 1000 ml / min.

  First, the polishing roll 12 was brought into contact with the back surface of the wafer 100 for polishing for 2 minutes. By this polishing, as shown in FIG. 12, the Ru film on the back surface was also completely removed.

  Thereafter, in another unit, cleaning was performed using pure water or an aqueous surfactant solution while sliding the PVA sponge or the like over the entire wafer 100 including the bevel portion. And after rinsing, it was made to dry and the process was completed.

ICP analysis of the wafer 100 after removing the Ru film in this manner revealed that the Ru contamination was less than 10 ¹⁰ atoms / cm ² on the underlying silicon nitride film 80 exposed by removing the Ru film 81. It was confirmed that it was cleaned.

In the conventional wet etching method, for example, when using diammonium cerium nitrate aqueous solution of 20% as the chemical, Even for the Ru contamination to less than ¹⁰ 11 atmos / cm ² takes more than 5 ^minutes, less than 10 10 atoms / cm ² In order to achieve this, it is necessary to wet-etch the underlying silicon nitride film 80 with another chemical solution such as dilute hydrofluoric acid for about 2 minutes. Therefore, in the conventional method, it takes 7 minutes or more per sheet to remove the Ru film on the bevel portion, the edge portion, and the back surface.

  On the other hand, if the Ru film is removed by the substrate processing apparatus of the present invention, even if the bevel portion, the edge portion and the back surface are processed separately, the process can be completed in about 3.5 minutes. Note that the first polishing unit for bevel and edge processing and the second polishing unit for back surface processing may be integrated so as not to interfere with each other. When these are integrated, the removal of the Ru film on the bevel portion and the edge portion and the removal of the Ru film on the back surface can be performed simultaneously. As a result, the processing time is further shortened to about 2.5 minutes, which leads to a significant improvement in throughput.

  Furthermore, since the above-described polishing unit and substrate processing apparatus have a simple apparatus configuration, the price of the apparatus alone can be reduced. Moreover, since the raw materials used are only pure water and a very small amount of chemical solution, the running cost can be greatly reduced. Thus, according to the present invention, there is a great advantage in terms of cost reduction.

  In the present embodiment, a chemical liquid that wet-etches the Ru film, for example, an oxidizing agent such as a diammonium cerium nitrate aqueous solution or an ammonium persulfate aqueous solution, can be used as the wet polishing supply liquid in addition to pure water. The use of these chemicals can be expected to improve the polishing rate.

  In removing the contaminated film by polishing according to the present embodiment, a mechanical removal action of the abrasive grains is added. Therefore, the present invention can be applied to the removal of a chemically stable film, and the components of the chemically stable film diffused in the base are also removed by removing a part of the base. be able to. For this reason, the contamination film that can be removed by the substrate processing apparatus according to the present invention is not limited to the Ru film described above, but extends to Cu film, PZT film, BST film, etc. be able to.

  Next, the substrate processing apparatus in the 3rd Embodiment of this invention is demonstrated. FIG. 13 is a schematic view showing a polishing head in the substrate processing apparatus of this embodiment. As shown in FIG. 13, the polishing head 102 according to the present embodiment includes a support portion 120 having two projecting portions 120 a and 120 b and a fluid bag 122 to which fluid is supplied to the inside via a fluid path 121. Yes. The fluid bag 122 is made of a flexible material such as thin rubber or soft vinyl, and can be deformed according to the internal pressure. The fluid path 121 is connected to a fluid supply source 123, and fluid such as gas (air or the like) or liquid (water or the like) is supplied from the fluid supply source 123 to the fluid bag 122. The fluid supply source 123 can supply a fluid having an arbitrary pressure to the fluid bag 122, and the internal pressure of the fluid bag 122 is adjusted by the pressure of the supplied fluid.

  The fluid bag 122 is accommodated in a recess 120c formed between the projecting portions 120a and 120b of the support portion 120, and is supported by the recess 120c so that the fluid bag 122 does not jump out. The polishing film 22 is supported by the fluid bag 122.

  In the polishing unit of the first embodiment, the polishing head 2 is replaced with a polishing head having such a configuration, the polishing film 22 is pressed against the wafer 100 with a predetermined pressing force, and the wafer 100 is rotated to rotate the wafer 100. Polishing is performed by bringing the bevel portion and the polishing film 22 into sliding contact. Note that polishing may be performed by sliding the polishing film 22 against the wafer 100.

  In this embodiment, by supplying a pressurized fluid to the fluid bag 122, the fluid bag 122 that supports the polishing film 22 is deformed, and the polishing film 22 contacts the bevel portion of the wafer 100 evenly. It becomes possible to uniformly polish the peripheral portion of the wafer 100.

  As the polishing film 22, the same polishing film as in the first embodiment can be used, and a film-like polishing cloth (eg, SUBA-400 manufactured by Rodel) may be used as the polishing tape. In the case of using a polishing cloth, an abrasive or an etching solution is supplied to a surface to be polished from a supply nozzle (not shown). Further, the polishing film 22 may be directly attached to the fluid bag 122, or the fluid bag 122 may be configured by the polishing film 22.

Using the thus configured polishing head, the bevel and edge portions were polished. In this polishing, a thin film PET polishing film having a thickness of 25 μm bonded with diamond abrasive grains is used as the polishing film 22, and 196 kPa of air is supplied to the fluid bag 122 formed of fluororubber having a thickness of 0.1 mm to obtain the wafer 100. The bevel part and edge part of this were polished. The rotation speed of the wafer 100 was 500 min ⁻¹ . In this experiment, it was confirmed that the bevel portion of the wafer 100 was evenly polished.

  FIG. 14 is a plan view showing an example of the arrangement configuration of the substrate processing apparatus incorporating the above-described polishing unit. As shown in FIG. 14, the substrate processing apparatus includes a pair of load / unload stages 200 on which a wafer cassette 200a containing a plurality of semiconductor wafers (substrates) is placed, a first transfer robot 210 that handles dry substrates, , A second transfer robot 220 that handles wet substrates, a temporary placement table 230, the above-described polishing unit 240, and cleaning units 250 and 260 are provided. The first transport robot 210 transports the substrate between the cassette 200a on the load / unload stage 200, the temporary placement table 230, and the cleaning unit 260, and the second transport robot 220 includes the temporary placement table 230, the polishing unit 240, The substrate is transferred between the cleaning units 250 and 260.

  A wafer cassette 200 a containing a wafer that has undergone the CMP process or Cu film forming process is transferred to a substrate processing apparatus by a cassette transfer apparatus (not shown) and placed on a load / unload stage 200. The first transfer robot 210 takes out the semiconductor wafer from the wafer cassette 200 a on the load / unload stage 200 and places the wafer on the temporary placement table 230. The second transfer robot 220 receives the wafer placed on the temporary placement table 230 and transfers the wafer to the polishing unit 240. In the polishing unit 240, the bevel portion and the edge portion and / or the back surface described above are polished.

  In the polishing unit 240, during or after polishing, water or a chemical solution is supplied from one or more nozzles (not shown) disposed above the wafer to clean the upper surface and edge portion of the wafer. This cleaning liquid is performed for the purpose of controlling the surface material of the wafer in the polishing unit 240 (for example, forming a uniform oxide film while avoiding alteration such as non-uniform oxidation of the wafer surface due to a chemical solution or the like). . This cleaning in the polishing unit 240 is called primary cleaning.

  The cleaning units 250 and 260 perform secondary cleaning and tertiary cleaning, respectively. However, the first cleaned wafer in the polishing unit 240 is transferred to the cleaning unit 250 or 260 by the second transfer robot 220, and 2 in the cleaning unit 250. In the next cleaning, in some cases, the third cleaning is performed in the cleaning unit 260, or the second cleaning and the third cleaning are performed in both units 250 and 260.

  In the cleaning unit 250 or 260 where the final cleaning has been performed, the wafer is dried, and the first transfer robot 210 receives the dried wafer and returns it to the wafer cassette 200a on the load / unload stage 200.

  In the secondary cleaning and tertiary cleaning described above, contact-type cleaning (cleaning with a PVA sponge such as a pencil type or roll type) and non-contact type cleaning (cleaning with a cavitation jet or ultrasonically applied liquid). ) May be combined as appropriate.

  The polishing end point in the polishing unit 240 may be managed according to the polishing time, or light having a predetermined shape and intensity from the normal direction of the device forming surface of the wafer at a position where the polishing head of the bevel portion is not located. Irradiation (laser, LED, etc.) is performed by optical means (not shown), the unevenness of the bevel part is measured by measuring the scattered light, and the polishing end point may be detected based on this measurement.

  In the above-described embodiment, the rotation of the wafer is performed using the roller 1 or 11. However, the wafer 100 may be rotated in a state where the back surface of the wafer 100 is adsorbed by a vacuum chuck. In the above-described embodiment, an example in which gas is jetted onto the device forming surface of the wafer 100 in order to eliminate polishing dust has been described. However, a liquid such as pure water may flow on the device forming surface.

  Further, instead of the polishing unit shown in FIG. 2, a polishing unit as shown in FIG. 15 may be used. In this polishing unit, an endless polishing tape 322 is sandwiched by a pair of upper and lower elastic rollers 324a and 324b, and the elastic rollers 324a and 324b are rotated to feed the endless polishing tape 322. ing.

  Further, instead of the second polishing unit shown in FIG. 11, a polishing unit as shown in FIG. 16 may be used. The polishing head 312 of this polishing unit includes a polishing tape 316 that can be wound by reels 314a and 314b, and a roll 318 that presses the polishing tape 316 against the back surface of the wafer 100. The polishing film 316 is recovered by the reels 314a and 314b. Are reciprocated or continuously fed at a predetermined speed to polish the back surface of the wafer 100.

  Further, instead of the second polishing unit shown in FIG. 11, a polishing unit as shown in FIG. 17 may be used. In the polishing head 412 of this polishing unit, a polishing tape 416 is wound between rollers 414a and 414b, and the polishing tape 416 is fed by rotating the rollers 414a and 414b. At this time, the polishing tape 416 is pressed against the back surface of the wafer 100 by the lower roller 414a.

  Moreover, although embodiment mentioned above demonstrated the example which used the air cylinder as a press mechanism, not only an air cylinder but various press mechanisms can be used. Moreover, although embodiment mentioned above demonstrated the example which presses the grinding | polishing head 2 and the elastic member 21 with a press mechanism so that the pressing force given to the polishing film 22 may become fixed during grinding | polishing, it is not restricted to this, Pressing The pressing force applied by the mechanism can be appropriately adjusted to change the pressing force applied to the polishing film 22 during polishing, and a desired polishing profile can be obtained on the polished surface (bevel portion and edge portion or back surface) of the wafer 100. You may do it. In addition, in order to perform rough polishing to final polishing with only one type of polishing tape, the pressing force by the pressing mechanism is reduced stepwise or continuously from the rough polishing step to the final polishing step. You may make it adjust during grinding | polishing.

Various conditions in polishing can be changed as appropriate. The form of the polishing film and the abrasive grains on the polishing film are not limited to those described above. For example, a material having a mechanochemical action on silicon such as BaCO ₃ and CaCO ₃ can be used as the abrasive grains.

  Further, in the above-described embodiment, an example in which a Si wafer is used as a substrate has been described. However, an SOI wafer, another semiconductor wafer such as a SiGe wafer, a Si wafer having a device formation surface formed of SiGe, or the like is used. May be. Moreover, it is good also considering only the bevel part or back surface of a board | substrate as a grinding | polishing object.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is a schematic plan view which shows the grinding | polishing unit of the substrate processing apparatus in the 1st Embodiment of this invention. FIG. 2 is a front sectional view of the polishing unit shown in FIG. 1. It is sectional drawing which shows the principal part of the grinding | polishing head of the grinding | polishing unit of FIG. It is sectional drawing which shows the state at the time of grinding | polishing of the grinding | polishing head shown in FIG. 5A is a front view showing a grinding wheel of the polishing unit shown in FIG. 1, and FIG. 5B is a plan view showing the grinding wheel when a notch of a semiconductor wafer is being polished. It is a schematic sectional drawing which shows the state where the abrasive film was bent. It is a schematic plan view which shows the grinding | polishing unit used for grinding | polishing the bevel part and edge part of a semiconductor wafer. It is sectional drawing which shows the surface shape of the semiconductor wafer after grind | polishing using the grinding | polishing unit shown in FIG. It is sectional drawing which shows the semiconductor wafer (Si wafer) in which the Ru film | membrane was formed into a film. It is a schematic plan view which shows the 2nd grinding | polishing unit of the substrate processing apparatus in the 2nd Embodiment of this invention. FIG. 11 is a front sectional view of the second polishing unit shown in FIG. 10. It is sectional drawing which shows the surface shape of the semiconductor wafer after grind | polishing using the substrate processing apparatus in the 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the polishing head of the substrate processing apparatus in the 3rd Embodiment of this invention. It is a top view which shows an example of the arrangement configuration of the substrate processing apparatus which concerns on this invention. It is a front sectional view showing a modification of the polishing unit shown in FIG. FIG. 12 is a front sectional view showing a modification of the second polishing unit shown in FIG. 11. FIG. 12 is a front sectional view showing a modification of the second polishing unit shown in FIG. 11. FIG. 18A and FIG. 18B are cross-sectional views showing the formation process of the deep trench of the trench capacitor. FIG. 19A to FIG. 19C are cross-sectional views showing a process of removing the needle-like protrusions generated during the formation of the deep trench.

Explanation of symbols

1, 11 Rollers 2, 2a, 2b, 102 Polishing head 3 Air cylinder (pressing mechanism)
4,13 Chemical liquid supply nozzle 5 Gas injection nozzle 6 Notch sensor 7 Grinding wheel 12 Polishing roll 12b Polishing film 14 Support roll 15 Cleaning liquid supply nozzle 20 Support portion 21 Elastic member 22 Polishing film 23 Press plates 24a and 24b Reel 70 Wheel 71 Rotating shaft 72 Notch 80 Silicon nitride film 81 Ru film 100 Semiconductor wafer 120 Support part 120a, 120b Protrusion part 121 Fluid path 122 Fluid bag 123 Fluid supply source 200 Load / unload stage 210 First transport robot 220 Second transport robot 230 Temporary stand 500 SiN film 510 SiO ₂ film 520 Deep trench 530 Needle-like protrusion 540 Resist 550 Concavity and convexity

Claims (5)

  A substrate processing method comprising polishing a bevel portion and an edge portion of a substrate with a polishing film after the CMP step.   Irradiate light of a predetermined shape and intensity from the normal direction of the device forming surface of the substrate to a location where the polishing head of the substrate bevel portion is not located, and measure the unevenness of the bevel portion by measuring scattered light. And a polishing end point is detected on the basis of the substrate processing method.   The substrate processing method according to claim 2, wherein the light is a laser or an LED.   Irradiate light with a predetermined shape and a predetermined intensity from the normal direction of the device forming surface of the substrate to a location where the polishing head of the substrate bevel portion is not located, and measure the scattered light to make unevenness of the bevel portion. A substrate processing apparatus that measures and detects a polishing end point based on the measurement.   The substrate processing apparatus according to claim 4, wherein the light is a laser or an LED.

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