JP2007190593A - Substrate holding device and substrate working device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate holding device, which inhibits a holder from generating dust when working a substrate with an ion beam, and to provide a substrate working device, which enhances yield by inhibiting the holder from generating the dust. <P>SOLUTION: The substrate holding device has a stage 14, on which a substrate 100 is placed, and a holder 16 having a pawl part 15, which comes into contact with the peripheral part of the substrate 100 placed on the stage 14 and holds the substrate 100 between the stage 14 and the pawl part 15. A rigid body part 21 consisting of a material that is harder to work with an ion beam than the base material of the pawl part 15 is provided at least on the front end part of the pawl part 15 of the holder 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate holding device for holding a substrate surface such as a silicon wafer, and a substrate processing device for processing the substrate surface by irradiating an ion beam, such as an ion milling device. About.

  In the manufacture of semiconductors, a substrate processing apparatus such as an ion milling apparatus is used for processing a substrate surface using a physical action caused by ion collision, or processing a wiring or an element provided on the substrate. It has been. Such a substrate processing apparatus using an ion beam is widely used in the manufacture of semiconductor devices and the like because of its anisotropy in processing and easy control.

  For example, in an ion milling apparatus, a substrate, for example, a semiconductor wafer is placed on a stage, and for example, the semiconductor wafer on the stage is irradiated with an ion beam generated by an ion source while rotating the stage. Process the surface. That is, ions (for example, Ar ions) generated by an ion source are accelerated by a high voltage and collide with the surface of a semiconductor wafer as a target. By making the ions collide with the semiconductor wafer in this way, the surface of the semiconductor wafer other than the resist film is scraped off, and the surface of the semiconductor wafer is processed into a desired shape.

  Here, in such a substrate processing apparatus such as an ion milling apparatus, the surface is processed in a state where the semiconductor wafer is held by a predetermined substrate holding apparatus. As a substrate holding device, for example, there is one in which a semiconductor wafer placed on a stage (platen) is fixed by pressing a peripheral portion of the substrate onto the stage by a claw portion (clamp) of a holder. (For example, refer to Patent Document 1).

  Thus, when the semiconductor wafer is fixed by the claw portion of the holder and the semiconductor wafer is irradiated with the ion beam, the surface of the claw portion is also irradiated with the ion beam. For this reason, a part of the surface of the claw portion is removed (milled) to become dust and adhere to the processed surface of the semiconductor wafer. Further, the contact surface of the claw portion with the semiconductor wafer is in physical contact with the surface of the semiconductor wafer, and therefore becomes rough as the number of uses increases. When the semiconductor wafer is pressed with the contact surface of the claw portion being rough, the surface of the semiconductor wafer is scraped by the claw portion and becomes dust and adheres to the processed surface of the semiconductor wafer. Then, when dust adheres to the processed surface of the semiconductor wafer in this way, there arises a problem that processing defects occur and the yield decreases.

Japanese Patent Laid-Open No. 9-181153

  In view of such circumstances, the present invention provides a substrate holding device that can prevent dust generation from a holder during substrate processing by an ion beam, and a substrate processing device that prevents dust generation from the holder and improves yield. The issue is to provide.

The first aspect of the present invention that solves the above problem is that a substrate is placed on the stage, and the substrate is placed between the stage and the peripheral edge of the substrate placed on the stage. A holder having a claw portion provided in a possible manner, and at least a tip portion of the claw portion of the holder is provided with a rigid body portion made of a material that is harder to be processed by an ion beam than a base material of the claw portion. The substrate holding device is characterized in that:
In the first aspect, when the substrate is processed by the ion beam, dust generation due to processing of the claw portion together with the substrate is prevented. The tip part of the claw part is particularly easy to process, and at least the tip part of the claw part has a rigid part, so that such dust generation is greatly reduced. Accordingly, it is possible to prevent the occurrence of processing defects due to dust adhering to the substrate surface, and to greatly improve the yield.

According to a second aspect of the present invention, in the substrate holding device according to the first aspect, the abutment surface of the claw portion that abuts on the substrate is constituted by the rigid body portion.
In the second aspect, since the rigid portion made of a material that is difficult to be processed by the ion beam has a relatively high hardness, deformation (roughness) of the joint surface of the claw portion with the substrate can be prevented. Therefore, it is possible to further prevent dust generation due to the claw portion coming into contact with the substrate and scraping the substrate surface. Moreover, a nail | claw part can be used over a long term, and reduction of cost can be aimed at.

According to a third aspect of the present invention, in the substrate holding apparatus according to the first or second aspect, the exposed surface of the claw portion is constituted by the rigid body portion.
In the third aspect, when the substrate is processed by the ion beam, dust generation due to the processing of the claw portion together with the substrate is more reliably prevented.

According to a fourth aspect of the present invention, in the substrate holding apparatus according to any one of the first to third aspects, the base material of the claw portion is a material having a larger heat capacity than the rigid body portion.
In such a fourth aspect, even when the surface temperature of the substrate rises during processing, since the base material of the claw portion is a material having a large heat capacity, the temperature rise of the claw portion is slow and the surface temperature can be kept relatively low. For example, even when the resist provided on the substrate is pressed by the nail portion of the holder, the thermal history during processing given to the resist is not changed by the temperature rise of the nail portion, and the resist can be prevented from being deteriorated. The substrate can be processed satisfactorily.

According to a fifth aspect of the present invention, in the substrate holding device according to any one of the first to fourth aspects, the base material of the claw portion is a material having a higher thermal conductivity than the rigid body portion. .
In the fifth aspect, even when the surface temperature of the substrate rises during processing, the nail portion is made of a material having high thermal conductivity, so that the nail portion easily escapes heat and its surface temperature is kept relatively low. It is done. Therefore, for example, it is possible to satisfactorily process the substrate while preventing resist deterioration and the like.

According to a sixth aspect of the present invention, in the substrate holding apparatus according to any one of the first to fifth aspects, the rigid body portion is made of titanium (Ti) or a titanium compound.
In the sixth aspect, by forming the rigid body portion with a predetermined material, it is possible to more reliably prevent dust generation due to irradiation of the ion beam to the claw portion.

According to a seventh aspect of the present invention, in the substrate holding device according to the sixth aspect, the base material of the claw portion is stainless steel (SUS).
In the seventh aspect, it is possible to more reliably prevent adverse effects on the substrate or the resist on the substrate due to the temperature rise of the nail portion while preventing dust generation from the nail portion.

According to an eighth aspect of the present invention, there is provided a substrate processing apparatus comprising: an ion source; and substrate holding means for holding the substrate, wherein the substrate surface is processed by an ion beam generated by the ion source. The holding means has a stage on which the substrate is placed, and a claw portion that is in contact with a peripheral portion of the substrate placed on the stage so as to be able to sandwich the substrate between the stage. A substrate processing apparatus comprising: a holder, and a rigid body portion made of a material that is harder to be processed by the ion beam than a base material of the claw portion at least at a tip portion of the claw portion of the holder. .
In the eighth aspect, when the substrate is processed by the ion beam, dust generation due to processing of the claw portion together with the substrate is prevented. The tip part of the claw part is particularly easy to process, and at least the tip part of the claw part has a rigid part, so that such dust generation is greatly reduced. Accordingly, it is possible to prevent the occurrence of processing defects due to dust adhering to the substrate surface, and to greatly improve the yield.

According to a ninth aspect of the present invention, in the substrate processing apparatus according to the eighth aspect, the processing of the substrate by the ion beam is ion milling.
In the ninth aspect, the surface of the substrate can be satisfactorily processed into a desired shape.

According to a tenth aspect of the present invention, in the substrate processing apparatus according to the eighth aspect, the processing of the substrate by the ion beam is ion implantation.
In the tenth aspect, a predetermined amount of ions can be favorably implanted into a desired region on the surface of the substrate.

  Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 is a schematic configuration diagram of an ion milling apparatus which is a substrate processing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view and a cross-sectional view of a substrate holding means according to the present embodiment. 3 is an enlarged cross-sectional view of a holder constituting the substrate holding means.

  As shown in FIG. 1, an ion source chamber 3 is connected to a vacuum processing chamber 2 constituting an ion milling apparatus 1 according to the present embodiment. The ion source chamber 3 is connected to an introduction tube 4 into which an inert gas such as argon (Ar) is introduced. For example, a filament 5 that emits thermoelectrons is provided on the surface opposite to the vacuum processing chamber 2. A power source 6 is connected to the filament 5. The ion source chamber 3 is provided with an acceleration electrode 7 and a deceleration electrode 8 on the boundary side with the vacuum processing chamber 2.

  On the other hand, in the vacuum processing chamber 2, a plurality of substrate holding means 9 are fixed, and a rotation stage 11 is rotatably supported by a support shaft 10. The substrate holding means 9 will be described in detail later. A plurality of wafers (substrates) 100 as members to be processed are placed and held. For example, in the present embodiment, four substrate holding means 9 are fixed on the rotary stage 11 at a predetermined interval on the same circumference around the support shaft 10. In this embodiment, the rotary stage 11 is arranged in a state inclined at a predetermined angle with respect to the irradiation direction of the ion beam extracted from the ion source chamber 3 when the wafer 100 is processed. . A shutter 12 is disposed between the rotary stage 11 and the deceleration electrode 8 provided in the ion source chamber 3 so that the ion beam drawn from the ion source chamber 3 can be blocked as necessary. ing.

  The vacuum processing chamber 2 or the ion source chamber 3 is connected to an exhaust system (a rotary pump and a turbo molecular pump or a claion pump) 13. The exhaust system 13 allows the vacuum processing chamber 2 and the ion source chamber 3 to be connected to each other. The inside is held at a predetermined pressure under reduced pressure. In the present embodiment, the exhaust system 13 is connected to the vacuum processing chamber 2.

  In such an ion milling apparatus 1, first, the vacuum processing chamber 2 and the ion source chamber 3 are decompressed to a predetermined pressure by the exhaust system 13, and an inert gas, For example, argon gas is introduced through the introduction tube 4. When power is supplied from the power source 6 to the filament 5 in a state where the ion source chamber 3 is filled with argon gas, the argon gas in the ion source chamber 3 is ionized. By applying a voltage to the accelerating electrode 7 and the decelerating electrode 8 with a power source (not shown), the ionized argon gas (argon ions) is accelerated and extracted into the vacuum processing chamber 2 as an ion beam. Then, by opening the shutter 12 arranged in the vacuum processing chamber 2, each wafer 100 held by the substrate holding means 9 is irradiated with an ion beam. When irradiating each wafer 100 with the ion beam in this way, the rotary stage 11 to which the substrate holding means 9 is fixed is continuously rotated at a predetermined speed, and thus, on the rotary stage 11. A plurality of wafers 100 held by the substrate holding means 9 are processed uniformly.

  Here, the configuration of the substrate holding means 9 according to the present embodiment will be described. As shown in FIG. 2, the substrate holding unit 9, which is a substrate holding apparatus according to the present embodiment, is provided on the wafer stage 14 on which the wafer 100 is placed and on the peripheral portion of the wafer 100 placed on the wafer stage 14. And a holder 16 having a claw 15 provided so as to be able to contact and hold the wafer 100 between the wafer stage 14.

  The wafer stage 14 has a substantially circular outer shape, and a groove portion 17 is formed in the vicinity of the periphery of the wafer stage 14 along the outer shape of the wafer stage 14. An O-ring 18 is fitted in the groove portion 17. Yes. The wafer 100 is placed on the wafer stage 14 via the O-ring 18. The O-ring 18 plays a role as a slip stopper for the wafer 100 placed on the wafer stage 14, a role as a so-called shock absorber, and the like.

  On the other hand, the holder 16 is for pressing and holding the peripheral portion of the wafer 100 on the wafer stage 14 toward the wafer stage 14, and in this embodiment, it is formed in a ring shape corresponding to the peripheral portion of the wafer 100. Has been. Further, the vicinity of the end portion on the inner peripheral side of the holder 16 is a claw portion 15 provided so as to protrude to the wafer stage 14 side from the end portion on the outer peripheral side. For example, in the present embodiment, the claw portion 15 is formed so that the thickness gradually decreases toward the tip end side. The holder 16 is arranged so that the tip surface of the claw portion 15 can come into contact with the surface of the wafer 100 placed on the wafer stage 14. That is, the holder 16 is disposed so that the tip surface (contact surface) 15a of the claw portion 15 faces the peripheral edge of the wafer 100 placed on the wafer stage 14, and for example, the holder 16 according to the present embodiment. Is held in a state in which a pair of guide members 19 provided in the vicinity of the outer peripheral end portion are inserted into guide holes 20 formed in the wafer stage 14.

  In the substrate holding unit 9 according to the present embodiment, the claw portion 15 of the holder 16 is moved by moving the holder 16 to the wafer stage 14 side with the wafer 100 placed at a predetermined position on the wafer stage 14. The wafer 100 is pressed by the contact surface 15 a, that is, the wafer 100 is sandwiched between the claw portion 15 and the wafer stage 14. Thereby, the wafer 100 is favorably held on the wafer stage 14.

  In the present invention, at least the tip of the claw 15 of the holder 16 constituting the substrate holding means 9 is made of a material that is harder to be processed by the ion beam than the base material of the claw 15 (holder 16). A rigid body portion 21 is provided. For example, in the present embodiment, the front end surface of the claw portion 15, that is, the entire surface of the contact surface 15 a with the wafer 100 is configured by the rigid portion 21. The thickness of the rigid body portion 21 is not particularly limited. However, as shown in FIG. 3, the thickness L1 from the tip portion of the claw portion 15 is at least about 1 mm, preferably about 2 mm. It is desirable.

  Since the substrate processing apparatus according to the present embodiment is an ion milling apparatus as described above, the rigid body portion 21 is formed of a material that is less likely to be ion milled than the base material of the claw portion 15. The material for forming such a rigid portion 21 may be determined as appropriate according to the base material of the claw portion 15, and is not particularly limited. For example, in the present embodiment, stainless steel (SUS) is used as the base material of the claw portion 15, whereas the material forming the rigid body portion 21 is a material that is less likely to be ion milled than stainless steel (SUS). Titanium (Ti) or a titanium compound is used. The milling rate of titanium (Ti) is about 19 (nm / min), while that of stainless steel (SUS) is about twice that. That is, the rigid body portion 21 according to the present embodiment is formed of a material that is less likely to be ion milled about twice as much as the base material of the claw portion 15.

  Moreover, the formation method of this rigid body part 21 is not specifically limited, For example, you may make it join plate | board materials, such as titanium (Ti), to the base material of the nail | claw part 15, and of course, on the surface of the nail | claw part 15. A material such as titanium (Ti) may be coated.

  By providing such a rigid body portion 21 on the claw portion 15 of the holder 16, it is possible to prevent foreign matters such as dust from adhering to the surface of the wafer 100 during the processing of the wafer 100. That is, by providing the rigid body portion 21, when the surface of the wafer 100 is processed (ion milling) by the ion beam, a part of the surface of the claw portion 15 is milled to become dust and adhere to the wafer 100. can do. The tip portion of the claw portion 15 is particularly easily milled, but if the rigid body portion 21 is formed in a range of about 1 mm to 2 mm from the tip, it effectively suppresses dust generation due to the claw portion 15 being milled. Can do. Therefore, it is possible to prevent processing defects due to the adhesion of dust to the wafer 100 and to significantly improve the yield.

  Moreover, the material which is hard to be ion-milled constituting the rigid portion 21 has a relatively high rigidity. For this reason, the contact surface 15a of the claw portion 15 with the wafer 100 is configured by the rigid portion 21 as in the present embodiment, so that the contact surface 15a comes into contact with the wafer 100 physically. The deformation (roughness) of the surface 15a can be prevented. Thereby, dust generation due to the surface of the wafer 100 being scraped by the claw portion 15 can be prevented. Therefore, the yield can be improved more reliably, the claw portion 15 (holder 16) can be used over a long period of time, and the cost can be reduced.

  The base material of the claw portion 15 of the holder 16 is preferably a material having a larger heat capacity than the rigid body portion 21. Further, the base material of the claw portion 15 of the holder 16 is preferably made of a material having a higher thermal conductivity than the rigid body portion 21. When the wafer 100 is milled, the temperature of the wafer 100 may rise. At this time, if heat is accumulated in the claw portion 15, the accumulated heat causes the wafer 100 or on the wafer 100. There is a risk of adversely affecting the resist and the like formed on the substrate. For example, the resist may be altered by heat. However, by using such a material as the base material of the claw part 15 of the holder 16, even when the temperature of the wafer 100 rises, the temperature of the claw part 15 can be kept relatively low. Therefore, the wafer 100 can always be processed satisfactorily.

As described above, in this embodiment, stainless steel (SUS) is used as a base material of the claw portion 15, whereas titanium (Ti) is used as a material for forming the rigid portion 21. The heat capacity of titanium (Ti) is 2.4 × 10 ⁶ (J / m ³ K), whereas the heat capacity of stainless steel (SUS) is 4.0 × 10 ⁶ (J / m ³ K). Yes, the heat capacity of stainless steel (SUS) is much larger than that of titanium (Ti). Moreover, the thermal conductivity of titanium and the thermal conductivity of stainless steel (SUS) are substantially equal. Therefore, stainless steel (SUS) is preferably used as the base material of the claw portion 15, and particularly preferably used when titanium (Ti) is used as the material of the rigid body portion 21.

  As described above, a material having a relatively large heat capacity and a relatively high thermal conductivity, such as stainless steel (SUS), is used as a material for the claw portion 15 and is difficult to be ion milled as a material for the rigid body portion 21. By using a material such as titanium (Ti) or the like, it is possible to prevent the dust from the holder 16 and prevent the yield as described above, and to increase the temperature of the holder 16 (claw portion 15). The effect that the wafer 100 can always be satisfactorily processed while being suppressed can also be obtained.

  In the present embodiment, the contact surface 15a of the claw portion 15 of the holder 16 with the wafer 100 is configured by the rigid body portion 21. However, the present invention is not limited to this, and for example, as shown in FIG. In addition, the surface of the claw portion 15 exposed when the wafer 100 is pressed, that is, the portion irradiated with the ion beam at the time of ion milling may be configured by the rigid body portion 21. In addition, the rigid body part 21 should just be provided at the front-end | tip part of the nail | claw part 15 as shown in FIG. Even with such a configuration, the generation of dust due to milling of the claw portions 15 can be suppressed to an extremely low level, so that the wafer 100 can always be processed satisfactorily.

  As mentioned above, although one Embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this Embodiment. For example, in the above-described embodiment, an ion milling apparatus that processes a plurality of wafers (substrates) at the same time has been exemplified. However, the present invention is not limited to this, and of course, a so-called single-sheet processing method that processes one substrate at a time. It goes without saying that the present invention can also be adopted in an apparatus. Further, for example, in the above-described embodiment, the present invention has been described by exemplifying an ion milling apparatus. However, the substrate holding apparatus according to the present invention is, for example, an ion implantation apparatus or the like that processes a substrate by an ion beam It can be employed in a substrate processing apparatus.

It is a schematic block diagram of the ion milling apparatus which concerns on one Embodiment. It is the top view and sectional view of a substrate holding means concerning one embodiment. It is an expanded sectional view showing a holder concerning one embodiment. It is an expanded sectional view showing a modification of a holder. It is an expanded sectional view showing a modification of a holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ion milling apparatus, 2 Vacuum processing chamber, 3 Ion source chamber, 4 Introducing tube, 5 Filament, 6 Power supply, 7 Acceleration electrode, 8 Deceleration electrode, 9 Substrate holding means, 10 Support shaft, 11 Rotating stage, 12 Shutter, 13 Exhaust system, 14 wafer stage, 15 claw part, 16 holder, 17 groove part, 18 O-ring, 19 guide member, 20 guide hole, 21 rigid body part, 100 substrate

Claims (10)

A stage on which the substrate is placed, and a holder having a claw portion that is in contact with a peripheral portion of the substrate placed on the stage so as to be sandwiched between the stage and the stage The substrate holding apparatus is characterized in that a rigid body portion made of a material that is harder to be processed by an ion beam than a base material of the claw portion is provided at least at a tip portion of the claw portion of the holder. The substrate holding device according to claim 1, wherein a contact surface of the claw portion that contacts the substrate is configured by the rigid portion. The substrate holding apparatus according to claim 1, wherein the exposed surface of the claw portion is configured by the rigid body portion. The substrate holding apparatus according to claim 1, wherein the base material of the claw part is a material having a larger heat capacity than the rigid body part. The substrate holding apparatus according to claim 1, wherein a base material of the claw portion is a material having higher thermal conductivity than the rigid body portion. The substrate holding apparatus according to claim 1, wherein the rigid portion is made of titanium (Ti) or a titanium compound. The substrate holding apparatus according to claim 6, wherein a base material of the claw portion is stainless steel (SUS). A substrate processing apparatus comprising an ion source and a substrate holding means for holding a substrate, and processing the substrate surface with an ion beam generated by the ion source,
The substrate holding means is a stage on which the substrate is placed, and a claw portion that comes into contact with the peripheral portion of the substrate placed on the stage so that the substrate can be sandwiched between the stage. A substrate processing apparatus, characterized in that at least the tip of the claw part of the holder has a rigid part made of a material that is harder to be processed by the ion beam than the base material of the claw part. . The substrate processing apparatus according to claim 8, wherein the processing of the substrate by the ion beam is ion milling. The substrate processing apparatus according to claim 8, wherein the processing of the substrate by the ion beam is ion implantation.

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