JP5470081B2 - Compound semiconductor substrate planarization processing apparatus and planarization processing method - Google Patents

Description

  In the present invention, the surface of a compound semiconductor substrate used for a light emitting diode or a laser semiconductor chip is ground to reduce the thickness of the substrate, and the surface roughness Ra is several nanometers by lapping. The present invention relates to an apparatus for planarizing a compound semiconductor substrate used to obtain a precision-finished substrate of several tens of nanometers and a method for planarizing a surface of a compound semiconductor substrate using the apparatus.

Light emitting diode, which has to form single-crystal thin film having a thickness of 20 to 250 nano via a buffer layer on a sapphire or S _{i C} fragile compound semiconductor substrate surface, such as a (e.g. AlN), GaAs as a single crystal thin film InP, InAs, GaN, InGaN, etc. are used.

  In recent single crystal thin film formation technology, a single crystal thin film having a thickness of 5 to 60 nanometers can be obtained. Therefore, the sapphire substrate is also required to have a precision finish with a surface roughness Ra of several nanometers to several tens of nanometers. A precision finishing method for substrates is a lapping process in which abrasive grains are sandwiched between a substrate surface and a hard surface plate surface, and the abrasive grains roll when both surfaces rotate relative to each other (surface roughness 0.1 to 2 μm). Polishing process (surface roughness) in which abrasive grains are sandwiched between the substrate surface and the polishing pad surface, and when both surfaces rotate relative to each other, the abrasive grains are fixed to the polishing pad surface and the cutting edge performs micro-cutting 0.01 to 1 μm), MCP (Mechano-Chemical Polishing) processing using quartz glass or ABS resin surface plate (surface roughness 0.001 to 0.1 μm), CMP (Chemical Mechanical Polishing) using polyurethane foam or non-woven surface plate ) Processing (surface roughness 0.001 to 0.1 μm), EEM (Elastic Emission Machining) processing (surface roughness to 0.002 μm) using a polyurethane rubber fine particle driving tool has been proposed (for example, Non-Patent Document 1).

  Japanese Patent Laying-Open No. 2005-205542 (Patent Document 1) proposes a single-side polishing method using a polishing grindstone in which an α-type alumina having an average particle diameter of 0.6 μm is bonded with an epoxy resin binder.

  Japanese Patent Laying-Open No. 2001-18160 (Patent Document 2) discloses a lapping machine 4 having a polisher shown in FIGS. 3 and 4 that can be rotated in the horizontal direction, and a lapping machine polisher surface provided on the polisher of the lapping machine. A conditioner ring 10 for performing the conditioning of 3, a positioning mechanism 11 and a rotation drive mechanism 12 of the conditioner ring, and a pair of workpieces provided at positions symmetrical to the arrangement of the conditioner ring and the positioning mechanism and rotation drive mechanism of the conditioner ring (For example, LED glass substrate, semiconductor silicon wafer, ceramic substrate) processing station positioning mechanism 13, a pair of processing stations 14 for applying a load to a workpiece attached to a jig and holding the workpiece on a polisher surface, Work processing station position Determining mechanism 13 discloses a flat lapping machine 1 having a polishing agent supply mechanism 16 for supplying a driving mechanism 15 for reciprocating on polisher surface 3 (swings), and the abrasive on polisher pump 16a.

Japanese Patent Laid-Open No. 2008-211040 (Patent Document 3) discloses an arithmetic average surface roughness obtained by polishing a sapphire substrate attached to a ceramic fixture with a metal surface plate fixed at a rate of 5 to 30% by weight of alumina abrasive grains. It is disclosed that a sapphire substrate with Ra of 0.0002 to 0.001 μm was obtained.

Japanese Patent Laying-Open No. 2008-311404 (Patent Document 4) discloses a method of reducing the thickness by grinding the back surface of a sapphire substrate of an LED substrate whose surface is protected by sticking a protective tape with a grinding wheel.

Japanese Patent Laying-Open No. 2009-28814 (Patent Document 5) reports that a substrate having an Ra of about 0.2 nm was obtained by CMP processing of a sapphire substrate using an abrasive slurry.

The cutting means (rotating blade) of this flattening apparatus has many opportunities to cause chipping of the substrate during grinding, polishing and substrate transfer in the flattening apparatus of Patent Document 1, and the loss rate of the processed substrate is high. Therefore, the entire outer edge portion of the substrate is cut and removed by the rotating blade, and the chipping and cracking of the semiconductor substrate which are generated at the peripheral portion of the substrate are suppressed.

The various nano precision finishing methods described in Non-Patent Document 1 require a long processing time for reducing the thickness of the substrate. Therefore, actually, after the substrate is ground and thinned using a substrate grinding apparatus, The nano precision finishing process is applied.

US Pat. No. 7,238,087 (Patent Document 6) uses a substrate grinding apparatus 20 and a polishing apparatus 70 as shown in FIG. 5 by using an articulated arm transfer robot 40 and a rotary suction pad 17. An in-line planarizing apparatus 1 is disclosed. The substrate stored in the storage cassette K is ground on the backside of the semiconductor substrate by the substrate grinding device 20 and then subjected to CMP polishing by the polishing device 70 to reduce the thickness of the silicon substrate surface to a surface of about 0.1 μm. It is disclosed that a silicon substrate surface having a roughness Ra was obtained.

Furthermore, when a sapphire substrate fixed to a vacuum chuck was dry-polished using a surface grinding wheel in which ceria particles were dispersed, it was reported that a sapphire substrate having a mirror surface with a surface roughness of several hundred nanometers was obtained. I heard from a processing manufacturer.

Published by Nihonkaku Kogyo Shimbun, pages 106-110, February 28, 2006, published by the Ultraprecision Machining Committee. JP 2005-205542 A JP 2001-18160 A JP 2008-211040 A JP 2008-311404 A JP 2009-28814 A US Pat. No. 7,238,087

  As a nano-precision finishing method of a sapphire substrate, it is an invention to lap-polish while pressing the sapphire substrate against the polisher surface of the lap surface plate while supplying an abrasive liquid between the sapphire substrate and the polisher surface of the lap surface plate. We were able to confirm it by their additional tests. The fact that this confirmation is correct is supported by comparing the data described in Patent Document 3 with the data described in other Patent Documents.

  Therefore, the planar lapping apparatus disclosed in Japanese Patent Laid-Open No. 2001-18160 (Patent Document 2) is used for the grinding apparatus 20 disclosed in the above-mentioned US Pat. No. 7,238,087 (Patent Document 6). When an inlined substrate flattening apparatus was assembled using an articulated substrate transfer robot having a suction pad and a transfer arm having a reversing function instead of the substrate transfer robot 14, the sapphire substrate was flattened. The problem was found.

  1) Since a thin sapphire substrate that has been ground is easily warped, it is difficult to transfer (paste) the ground sapphire substrate to the chuck mechanism (template 14b) of the lapping apparatus. 2) In the lapping apparatus, two substrates are lapped at the same time, so one temporary table is insufficient. 3) It is difficult to reduce the number of impurities having a diameter of 0.1 μm or less to 10 or less by a cleaning device with grinding and lapping scraps adhering to the sapphire substrate that has been flattened.

  In the present invention, the chuck mechanism (template) 14b that can be pressed in the lap apparatus is replaced with a suction chuck mechanism that uses a porous template plate having excellent air permeability, and the suction chuck mechanism that can swing the pendulum is replaced by grinding. The above-mentioned problem 1) is solved by using an articulated substrate transfer robot provided with a suction pad and a transfer arm having a reversing function as the substrate transfer robot T that delivers the sapphire substrate. The problem 2) described above is solved by adding one temporary table. The grinding device installation position is further away from the substrate storage cassette K than the lapping device installation position, and the first cleaning device for the ground sapphire substrate, the second cleaning device for the lapped sapphire substrate, and the first chuck for the lapping device Solving the above-mentioned problem 3) by providing a first cleaning device for the mechanism, a second cleaning device for the second chuck mechanism of the lap device, and a vertical cleaning device for the suction pads of the articulated substrate transfer robot. An object of the present invention is to provide a flattening apparatus capable of performing the above.

According to the first aspect of the present invention, there is provided a loading / unloading stage chamber for Greek letter Γ-shaped substrates on the left side of the front portion where a plurality of substrate storage cassettes are installed outdoors. The right-side substrate lapping stage chamber and the back-side substrate grinding stage chamber can be divided into three chambers by partition walls, and the substrates leading to adjacent stage chambers can be taken in and out of the partition walls between the stage chambers. An apparatus for planarizing a compound semiconductor substrate, wherein an opening is provided, and a load port leading to a storage cassette for the plurality of substrates is provided in a front left side wall of the loading / unloading stage chamber,
The substrate loading / unloading stage chamber is provided with a second substrate cleaning machine and a second temporary placement table from the back of the load port toward the interior of the chamber, and has a polishing agent liquid supply mechanism, a suction pad, and a reversing function. It has an articulated substrate transfer robot with an arm, a vertical suction pad cleaner and a first temporary mounting table, and a first substrate cleaner and a rotary suction pad.
In the lap processing stage chamber of the substrate, there is provided a lap surface plate equipped with a conditioner ring for conditioning the lap surface plate polisher surface in the center, and a template having a suction mechanism in front of the lap surface plate and a pendulum swing and A second substrate suction chuck mechanism capable of moving up and down and a second substrate suction chuck cleaning mechanism for cleaning a template having the suction mechanism, and a template having a suction mechanism behind the lap surface plate and swinging the pendulum and moving up and down A first substrate suction chuck mechanism and a first substrate suction chuck cleaning mechanism for cleaning a template having the suction mechanism,
In the substrate grinding stage chamber, there is provided a substrate suction chuck surface plate in which three sets of substrate suction chuck tables are rotatably provided on the same circumference at an equal interval on one index type turntable. The numerical value control device stores the index of the substrate suction chuck table as the loading / unloading stage chuck (s ₁ ), substrate rough grinding stage chuck (s ₂ ), substrate finishing grinding chuck (s ₃ ) position, and A brush cleaning device and a chuck cleaning device are provided above the loading / unloading stage chuck (s ₁ ) so as to be laterally movable, vertically movable, and rotatable, and above the substrate rough grinding stage chuck (s ₂ ), a cup wheel type. A rough grinding wheel is provided so that it can be moved up and down and rotated and rotated. A cup wheel type finishing grinding wheel is provided above the cutting stage chuck (s ₃ ) so that it can be moved up and down and rotated and rotated.
The substrate stored in the storage cassette is sucked by the suction pad of the articulated substrate transfer robot provided in the center of the loading / unloading stage chamber, and transferred to the first driving table, the first temporary mounting table Transfer the upper substrate onto the loading / unloading stage chuck (s ₁ ) in the grinding stage chamber, suck the substrate on the first substrate cleaning machine, and transfer it to the first substrate suction chuck mechanism in the lapping stage chamber. , Picks up the substrate on the first substrate cleaning machine, transfers it to the second substrate suction chuck mechanism in the lapping stage chamber, transfers it, receives the substrate sucked on the first substrate suction chuck mechanism, and transfers it to the second substrate cleaning machine Receive the substrate adsorbed by the second substrate adsorption chuck mechanism, transport it to the second substrate cleaning machine, adsorb the substrate on the second substrate cleaning machine and place it temporarily Conveying upward, the task of conveying to the second provisional table the substrate on the adsorbed substrate storage cassettes performed,
The compound semiconductor substrate on the loading / unloading stage chuck (s ₁ ) is adsorbed by using a rotary suction pad in the loading / unloading stage chamber and rotated to place the compound semiconductor substrate on the first substrate cleaning machine. Transport,
An apparatus for planarizing a compound semiconductor substrate is provided.

According to a second aspect of the present invention, the compound semiconductor substrate is planarized using the compound semiconductor substrate planarization apparatus according to the first aspect of the present invention through the following steps. A method is provided.
(1) After the compound semiconductor substrate stored in the substrate storage cassette for loading is adsorbed on the suction pad of the articulated substrate transfer robot, it is transferred onto the first temporary placement table.
(2) After the substrate is centered on the first temporary placement table, the substrate on the first temporary placement table is transferred onto the loading / unloading stage chuck (s ₁ ) in the grinding stage chamber.
(3) The index type turntable in the grinding stage chamber is rotated 120 degrees counterclockwise to move the loading / unloading stage chuck (s ₁ ) to the substrate rough grinding stage chuck (s ₂ ) position. .
(4) At the substrate rough grinding stage chuck (s ₂ ) position, the back surface of the compound semiconductor substrate is roughly ground using a cup wheel type grindstone.
(5) The index type turntable is rotated 120 degrees counterclockwise to move the substrate rough grinding stage chuck (s ₂ ) to the substrate finishing grinding stage chuck (s ₃ ) position.
(6) The back surface of the compound semiconductor substrate that has been subjected to rough grinding using the cup wheel type grindstone at the substrate finish grinding stage chuck (s ₃ ) position is finish ground to thin the back surface of the compound semiconductor substrate.
(7) The index-type turntable is rotated 120 degrees counterclockwise or 240 degrees clockwise to place the substrate finish grinding stage chuck (s ₃ ) at the loading / unloading stage chuck (s ₁ ) position. Move to.
(8) Using a rotary suction pad in the loading / unloading stage chamber, the compound semiconductor substrate on the loading / unloading stage chuck (s ₁ ) is adsorbed and rotated to the first substrate cleaning machine. Transfer the substrate.
(9) Spin cleaning the compound semiconductor substrate on the first substrate cleaner.
(10) The compound semiconductor substrate on the first substrate cleaning machine is sucked by the suction pad of the articulated substrate transfer robot, and the suction pad is inverted, and then transferred to the second substrate suction chuck mechanism in the lapping stage. hand over.
(11) The newly cleaned compound semiconductor substrate on the first substrate cleaning machine is absorbed by the suction pad of the articulated substrate transfer robot, and the suction pad is inverted, and then the first substrate in the lapping stage chamber. It is transferred to the suction chuck mechanism and delivered.
(12) The lap platen is rotated and the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are swung to move above the polisher surface to which the abrasive liquid of the lap platen is supplied. After that, the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are moved down to press the compound semiconductor substrate being sucked against the polisher surface of the lap platen to apply a load, and lap polishing is started. The load on the substrate is continued by rotating the lapping plate and swinging and lowering the pendulum on the polisher surfaces of the first substrate suction chuck mechanism and the second substrate suction chuck mechanism to perform lapping of the compound semiconductor substrate.
(13) After completion of the lapping process of the compound semiconductor substrate, the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are swung to swing the first substrate suction chuck cleaning mechanism and the second substrate suction chuck cleaning mechanism. After being moved upward, it is lowered, and then the compound adsorbed on the first substrate adsorption chuck mechanism and adsorbed on the second substrate adsorption chuck mechanism by the first substrate adsorption chuck cleaning mechanism and the second substrate adsorption chuck cleaning mechanism Clean the lapping surface of the semiconductor substrate.
(14) The compound semiconductor substrate adsorbed by the second substrate adsorbing chuck mechanism is adsorbed by the adsorbing pad of the articulated substrate conveying robot, and then conveyed to the second substrate cleaning machine for delivery.
(15) The compound semiconductor substrate is cleaned with a second substrate cleaning machine.
(16) The compound semiconductor substrate on the second substrate cleaning machine is adsorbed by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary placement table, and then the core of the compound semiconductor substrate I will take out.
(17) The compound semiconductor substrate on the second temporary table is sucked by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred into the unloading substrate storage cassette.
(18) The compound semiconductor substrate adsorbed by the first substrate adsorbing chuck mechanism is adsorbed by the adsorbing pad of the articulated substrate conveying robot, and then conveyed to the second substrate cleaning machine for delivery.
(19) The compound semiconductor substrate is cleaned with a second substrate cleaning machine.
(20) The cleaned compound semiconductor substrate on the second substrate cleaning machine is sucked by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary placement table, and then the core of the compound semiconductor substrate I will take out.
(21) The compound semiconductor substrate on the second temporary table is sucked by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred into the substrate storage cassette for unloading.

  In addition, the delivery of the substrate to the suction chuck mechanism in steps (10) and (11) and the delivery of the substrate from the suction chuck mechanism in steps (14) and (18) to the second substrate cleaning machine are as follows: It may be modified so that the delivery of the compound semiconductor substrate by the first substrate suction chuck mechanism is given priority, and then the delivery of the compound semiconductor substrate by the second substrate suction chuck mechanism is performed.

  Further, after the step (21), (22) the suction pad of the articulated substrate transfer robot is rotated vertically, and then immersed in the cleaning liquid in the vertical suction pad cleaning machine, and the suction pad is ultrasonically cleaned and adhered. A process of returning the suction pad to the standby position is performed after washing away the scraps and abrasive grains remaining.

  Since the back surface of the substrate is ground before the lapping of the back surface of the compound semiconductor substrate is performed, it is possible to reduce the thickness of the back surface of the compound semiconductor substrate and the throughput time of nano precision surface processing.

The grinding device installation position is further away from the lap device installation position than the substrate storage cassette, and the ground sapphire substrate first cleaning device, the lapped sapphire substrate second cleaning device, and the lap device first chuck mechanism By attaching the first cleaning device, the second cleaning device of the second chuck mechanism of the lap device, and the vertical cleaning device of the suction pad of the articulated substrate transfer robot, it adheres to the flattened sapphire substrate. The number of foreign matters having a diameter of less than 1 μm could be extremely reduced to 2/100 mm ² or less.

FIG. 1 is a plan view of an apparatus for planarizing a compound semiconductor substrate. FIG. 2 is a left side view showing the main part of the planarizing apparatus for the compound semiconductor substrate. FIG. 3 is a plan view of the flat lapping apparatus. (Known) FIG. 4 is a side view in which a part of the flat lapping apparatus is cut away. (Known) FIG. 5 is a plan view of the substrate flattening apparatus. (Known)

Hereinafter, the present invention will be described in more detail with reference to FIGS.
1 is surrounded by a peripheral wall W and is largely divided into three rooms. A Greek Γ-shaped substrate loading / unloading stage chamber W1 is located on the left side of the front front portion, a substrate lapping stage chamber W3 is located on the right side of the front surface, and a substrate grinding stage chamber W3 is located on the back side. The partition wall between the stage chambers is provided with an opening through which the substrate leading to the adjacent stage chamber can be taken in and out, and the front left side wall of the loading / unloading stage chamber is provided on the partition wall between the stage chambers. A load port is provided that communicates with the loading substrate storage cassette K and the unloading substrate storage cassette K.

During the planarization of the substrate, the chamber pressure in the polishing stage chamber W2 is set higher than the chamber pressure in the grinding stage chamber W3.

When the suction pad diameter of the articulated substrate transfer robot is large enough to be taken in and out of the substrate storage cassette, the substrate storage cassette K may be used alone as a commercially available storage cassette. If the suction pad diameter is larger than the size that can be taken in and out of the substrate storage cassette, the substrate transport belt described in JP-A-61-230853 and the transport belt width adjusting mechanism are provided. using storage cassette K equipped with a belt apparatus k _1. In Figure 1, k ₂ is a locking plate, the left side of the substrate storage cassette K is a substrate storage cassettes for loading and the right of the substrate storage cassette K is a substrate storage cassette for unloading. In FIG. 2, the substrate storage cassette K is not shown, and the symbol B is a base.

  The substrate loading / unloading stage chamber W1 is provided with a second substrate cleaning machine 52 and a second temporary table 42 from the back of the load port provided on the wall toward the interior of the chamber. And an articulated substrate transport robot 40 having a liquid suction pad 40a and a transport arm 40b having a reversing function, a vertical suction pad cleaning machine 53 and a first temporary placement table 41, and a first substrate cleaning machine 51 A rotary suction pad 17 is also provided.

As shown in FIG. 1, the articulated substrate transfer robot 40 having the suction pad 40a and the transfer arm 40b having a reversing function is configured such that the suction pad is stored in the storage cassette as indicated by the solid line and the virtual line. The substrate stored in the substrate is adsorbed and transported onto the first driving table 41, and the substrate on the first temporary mounting table is transported onto the loading / unloading stage chuck t (s ₁ ) in the grinding stage. The substrate on the substrate cleaning machine 51 is sucked and transferred to the first substrate suction chuck mechanism 14a in the lapping stage, and the second substrate suction chuck in the lapping stage is picked up by sucking the substrate on the first substrate cleaner. Transported to mechanism 14b, delivered, received substrate sucked by first substrate chucking mechanism, transported to second substrate cleaning machine, second substrate suction The substrate adsorbed by the chuck mechanism is received and conveyed to the second substrate cleaning machine 61b, the substrate on the second substrate cleaning machine is adsorbed and conveyed onto the second temporary table 42, and the substrate on the second temporary table is adsorbed to the substrate. The operation of transporting to the storage cassette K is performed.

The substrate cleaning devices 51 and 52 are spin-type substrate cleaning devices that clean the processed surface of the compound semiconductor substrate. The cleaning liquid supplied from the cleaning liquid supply nozzle to the substrate surface includes distilled water, deep seawater, and deionized water. Such as pure water, surfactant-containing pure water, hydrogen peroxide water, ozone water, etc. are used.

  The first substrate suction chuck cleaning mechanism 61a and the second substrate suction chuck cleaning mechanism 61b perform high-pressure jet fountain spraying pure water toward the suction pad 40a and the substrate surface sucked by the suction pad, or the suction surface of the suction pad 40a. This is to wash away foreign substances adhering to the substrate processing surface.

  The vertical suction pad cleaning machine 53 is preferably a cleaning machine of a type in which cleaning water is vibrated by ultrasonic vibration to wash away foreign substances adhering to the suction pad 40a.

  In the lap polishing stage chamber W3 of the substrate, a wrap surface plate 4 on which a conditioner ring 10 for conditioning the surface of the lap disk polisher 3 is mounted is provided at the center, and a template having a suction mechanism in front of the lap surface plate 4 is provided. A second substrate suction chuck mechanism 14b that can swing and move up and down, a second substrate suction chuck cleaning mechanism 61b that cleans the template having the suction mechanism, and a template that has a suction mechanism behind the lap platen And a first substrate suction chuck mechanism 14a that can swing and move up and down, and a first substrate suction chuck cleaning mechanism 61a that cleans the template having the suction mechanism.

  The substrate suction templates of the first substrate suction chuck mechanism 14a and the second substrate suction chuck mechanism 14b are provided so as to be able to swing the pendulum about the rotation shaft 14c. The conditioner ring 10 is positioned on the polisher surface by the positioning mechanism 11 and is rotated on the polisher surface by the rotation drive mechanism 12.

  The material of the lap surface plate 4 includes nano-inorganic filling of kemet, cast iron, steel, tin, ceramic, engineering plastics (PEEK, nylon 6,10, polyacetal, aromatic epoxy resin, etc.), and the polisher surface 3 of the wrap surface plate 4 Examples include engineering plastics in which an agent (synthetic diamond, silica, ceria, α-type alumina, etc.) is dispersed and fixed in a proportion of 0.1 to 3% by weight. The sapphire substrate is preferably a chemet or α-type alumina implanted epoxy resin.

  The polishing liquid is supplied to the polisher surface 3 of the lapping surface plate 4 in contact with the substrate by the operation of the pump 16 a of the polishing liquid supply mechanism 16. The abrasive liquid is preferably pure water, but colloidal ceria or colloidal silica in which several nano to several tens of nanoparticles are dispersed may be used.

The rotation speed of the surface plate 4 is ^{1 to 5} min ⁻¹ , the lap load on the lap surface plate 4 of the substrate suction chuck mechanism 14 is 0.5 to 2 kgf, the rotation speed of the conditioner ring 10 is 5 to 20 min ⁻¹ , and the substrate suction The swinging width of the chuck mechanism 14 is preferably 5 to 20 mm, and the supply amount of the abrasive liquid is preferably 20 to 600 cc / min.

The substrate grinding stage chamber W2 is provided with a substrate suction chuck surface plate in which three sets of substrate suction chuck tables are provided on one index type turntable T so as to be rotatable at equal intervals on the same circumference, Three sets of substrate suction chuck tables t ₁ , t ₂ , and t ₃ are numerical values as loading / unloading stage chuck (s ₁ ), substrate rough grinding stage chuck (s ₂ ), and substrate finishing grinding chuck (s ₃ ) positions. The index is stored in the control device. A sliding plate 38f for fixing the brush cleaning device 38a and the chuck cleaning device 38b described in US Pat. No. 7,238,087 above the loading / unloading stage chuck (s ₁ ) is provided on the guide guide 38g. Are provided so as to be movable in the horizontal direction, and can be moved laterally by a distance to the position indicated by the phantom line. The brush of the brush cleaning device 38 a and the grindstone of the chuck cleaning device 38 b are rotatably provided by a motor and can be moved up and down by a cylinder 100.

Above the substrate rough grinding stage chuck (s ₂ ), a grinding wheel shaft 90b for supporting the cup wheel type rough grinding wheel 90a is driven, and a sliding plate 90c for fixing the grinding wheel shaft is driven by a ball screw by a motor 90d so that the surface of the guide guide 90e is lowered. The lifting / lowering movement and the grindstone shaft are rotatably provided by a built-in motor (not shown). 90t is a two-point gauge thickness measuring device, and 90s is a grinding fluid supply mechanism.

Above the substrate finishing grinding stage chuck (s ₃ ), a grinding wheel shaft 91b that supports the cup wheel type finishing grinding wheel 91a is driven, and a sliding plate 91c that fixes the grinding wheel shaft is driven by a ball screw by a motor 91d so that the surface of the guide guide 91e is lowered. The lifting / lowering movement and the grinding wheel shaft are rotatably provided by a built-in motor 91m. 91t is a two-point gauge thickness measuring device, and 91s is a grinding fluid supply mechanism.

91z shown in FIG. 2 is a mechanism for tilting the grindstone shaft in the front-rear direction, and 91x is a mechanism for tilting the grindstone shaft disclosed in Japanese Patent Publication No. 1-52148 in the front-rear direction. The operation of the motors 91m and 91m The grindstone shaft 91b can be inclined from 0 degree to 5 degrees with respect to a vertical plane perpendicular to the horizontal plane. By tilting the grindstone axis, the contact area between the grindstone cutting edge and the substrate can be reduced, so that the grindstone burn of the substrate can be prevented. Note that these grindstone shaft tilt mechanisms are also provided for the grindstone shaft 90b.

The rough grinding wheel 90a is preferably a diamond cup wheel type rough grinding wheel with a grinding number of 300 to 2,000, and the finish grinding wheel is preferably a diamond cup wheel type rough grinding wheel with a grinding number of 500 to 20,000.

The rotation speed of the substrate chuck t in the rough grinding stage (s ₂ ) is 8 to 300 rpm (min ⁻¹ ), the rotation speed of the cup wheel type rough grinding wheel 90 a is 1,000 to 4,000 min ⁻¹ , and the substrate surface The amount of grinding fluid supplied to is from 100 to 2,000 cc / min. The grinding speed of the finish grinding stage (s ₃ ) substrate chuck t is 5 to 80 min ⁻¹ , the rotational speed of the cup wheel type finishing grinding wheel 91 a is 400 to 3,000 min ⁻¹ , and the amount of grinding fluid supplied to the substrate surface Is 100 to 2,000 cc / min.

Examples of the grinding fluid supplied to the grinding point where the diamond cup wheel grinding wheels 90a and 91a contact the substrate include pure water, ceria particle aqueous dispersion, fumed silica aqueous dispersion, colloidal silica aqueous dispersion, or These grinding fluids containing tetramethylammonium, ethanolamine, caustic potash, imidazolium salt, etc. can be used.

The chuck cleaning device 38 includes a brush 38a, a rotary chuck cleaner grindstone 38b, and a pure water supply nozzle. While supplying pure water from the pure water supply nozzle to the surface of the rotating chucking / unloading stage (s ₁ ) of the rotating loading / unloading stage (s ₁ ), the rotating brush 38a is lowered and brought into contact with and rubbed with the surface of the chuck 30a. After removing the grinding residue and abrasive grains adhering to the surface, the brush is raised, and then the rotating rotary chuck cleaner grindstone 38b is lowered to abut and rub against the surface of the chuck t. The grinding residue stuck in the porous ceramic chuck t together with the pure water supplied from the supply nozzle is removed. Further, pressurized water is ejected from the back surface of the porous ceramic chuck t, and the grinding residue stuck into the porous ceramic chuck t is ejected from the porous ceramic chuck t to be completely removed.

On the base B beside the substrate rough grinding stage chuck t and the substrate finish grinding chuck t, two-point thickness indicators 91t and 91t for measuring the thickness of the substrate are provided. This thickness measuring instrument for measuring the thickness of a semiconductor substrate is a sensor head holder provided with a fluid passage capable of supplying gas to the outer periphery of a sensor head provided with a laser beam projector and a light receiver disclosed in JP 2009-88073 A A non-contact thickness measuring instrument including a control unit and data analysis means may be used.

As a thickness measuring device using the reflectance of such commercially available laser light, near infrared light (wavelength 1.3 μm) is irradiated to one side of a silicon substrate on a measurement stage with a laser beam spot diameter of 1.2 to 250 μmφ, As a silicon substrate thickness measuring device that detects the reflected light with a light receiver and calculates the thickness of the silicon substrate, the product name is LTM1001 from Presize Gauge Co., Ltd. and the product name is Thickness Measurement Device C8125 from Photogenic Co., Ltd. Available from FRONTIER SEMICONDUCTOR, USA under the trade name FSM413-300. In addition, as a non-contact optical thickness measuring instrument using reflectance spectroscopy using near infrared light having a wavelength of 650 nm to 1,700 nm with a beam spot diameter of 100 to 1,000 μmψ, non-contact optical from FILMETRICS, INC. It can be obtained from Otsuka Electronics Co., Ltd. under the trade name MCPD5000.

  The lapping process of the semiconductor substrate in the polishing stage chamber W3 takes about twice as long as the grinding process in the grinding stage 20. Therefore, the lapping polishing stage is configured so that lapping work of two compound semiconductor substrates can be performed simultaneously.

  Using the compound semiconductor substrate flattening apparatus 1 shown in FIG. 1, the operation of thinning and flattening the back surface of the substrate is performed through the following steps.

(1) The compound semiconductor substrate stored in the substrate storage cassette K for loading is unloaded from the cassette with the help of the belt transfer auxiliary means, and then the compound semiconductor substrate is sucked into the suction pad 40a of the articulated substrate transfer robot 40. And then transported onto the first temporary table.

(2) After the substrate is centered on the first temporary placement table 41, the substrate on the first temporary placement table is transported onto the loading / unloading stage chuck (s ₁ ) t in the grinding stage chamber.

(3) The index-type turntable T in the grinding stage chamber is rotated 120 degrees counterclockwise to move the loading / unloading stage chuck t (s ₁ ) to the substrate rough grinding stage chuck t position (s ₂ ). And move.

(4) At the substrate rough grinding stage chuck (s ₂ ) position, the back surface of the compound semiconductor substrate is roughly ground using the cup wheel type grindstone 90a.

(5) The index-type turntable T is rotated 120 degrees counterclockwise to move the substrate rough grinding stage chuck (s ₂ ) to the substrate finish grinding stage chuck t position (s ₃ ).

(6) The back surface of the compound semiconductor substrate that has been subjected to rough grinding using the cup wheel type grindstone at the position of the substrate finish grinding stage chuck t (s ₃ ) is finish-grinded to thin the back surface of the compound semiconductor substrate.

(7) The index-type turntable T is rotated 120 degrees counterclockwise or 240 degrees clockwise so that the substrate finish grinding stage chuck t (s ₃ ) is loaded / unloaded stage chuck position (s Move to ₁ ).

(8) Using the rotary suction pad 17 in the loading / unloading stage chamber, the compound semiconductor substrate on the loading / unloading stage chuck (s ₁ ) is sucked by the suction pad 17a, and the arm of the pad 17a is rotated. Then, the compound semiconductor substrate is transferred onto the first substrate cleaning machine 51.

(9) Spin cleaning the compound semiconductor substrate on the first substrate cleaner 51.

(10) After the compound semiconductor substrate on the first substrate cleaning machine 51 is sucked by the suction pad 40a of the articulated substrate transport robot 40 and the suction pad 40a is reversed, the second substrate suction chuck mechanism in the lapping stage chamber 14b to deliver the substrate.

(11) The newly cleaned another compound semiconductor substrate on the first substrate cleaning machine 51 is adsorbed by the adsorption pad 40a of the articulated substrate transfer robot, and after the adsorption pad is inverted, the first in the lap processing stage chamber It is conveyed and delivered to the single substrate suction chuck mechanism 14a.

(12) The lapping surface plate 4 is rotated, and the first substrate suction chuck mechanism 14a and the second substrate suction chuck mechanism 14b are swung by a motor to supply the polishing liquid of the lap surface plate 4. The first semiconductor substrate chucking mechanism 14a and the second semiconductor substrate chucking mechanism 14b are moved down to move the adsorbed compound semiconductor substrate to the polishing surface 4 of the lapping surface plate by about 1 kgf. Press with load and start lapping. The lap polishing of the compound semiconductor substrate is performed by continuing the rotation of the lap platen, the swinging of the pendulum on the polisher surface 4 of the first substrate suction chuck mechanism and the second substrate suction chuck mechanism 14b, and the load load on the substrate. .

(13) After completing the lapping of the compound semiconductor substrate, the first substrate suction chuck mechanism 14a and the second substrate suction chuck mechanism 14b are swung to swing the first substrate suction chuck cleaning mechanism 61a and the second substrate suction chuck. The first substrate suction chuck cleaning mechanism 61a and the second substrate suction chuck cleaning mechanism 61b perform suction and second substrate suction chuck on the first substrate suction chuck cleaning mechanism 61b. The substrate is cleaned by spraying a high pressure jet fountain of 1.2 to 4 kgf / cm ² onto the lapped surface of the compound semiconductor substrate adsorbed by the mechanism 14b.

(14) The compound semiconductor substrate adsorbed by the second substrate adsorption chuck mechanism 14b is adsorbed by the adsorption pad 40a of the articulated substrate conveyance robot, and then conveyed to the second substrate cleaning machine 61b for delivery.

(15) The compound semiconductor substrate is spin cleaned by the second substrate cleaning machine 52. On the second substrate suction chuck cleaning mechanism 61b, the template of the second substrate suction chuck mechanism 14b is jet cleaned.

(16) The cleaned compound semiconductor substrate on the second substrate cleaning machine 52 is sucked by the suction pad 40a of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary table 42, and then the compound semiconductor Center the board.

(17) adsorbing the compound semiconductor substrate on the second temporary table 52 by the suction pads 40a articulated substrate transfer robot, also the auxiliary k ₁ of a compound semiconductor substrate of the belt conveyor in the substrate storage cassette K for unloading And transfer to.

(18) The compound semiconductor substrate adsorbed by the first substrate adsorption chuck mechanism 14a is adsorbed by the adsorption pad 40a of the articulated substrate conveyance robot, and then conveyed to the second substrate cleaning machine 52 and delivered.

(19) The compound semiconductor substrate is spin cleaned by the second substrate cleaning machine 52. On the first substrate suction chuck cleaning mechanism 61a, the template of the first substrate suction chuck mechanism 14a is jet cleaned.

(20) The cleaned compound semiconductor substrate on the second substrate cleaning machine is sucked by the suction pad 40a of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary table 42, and then the compound semiconductor substrate Perform centering.

(21) The compound semiconductor substrate on the second temporary table 42 is sucked by the suction pad 40a of the articulated substrate transport robot, and the compound semiconductor substrate is transported in a belt in the substrate storage cassette K for unloading. to transfer under the auxiliary _{k 1.}

  (22) The arm 40b is rotated so that the surface of the suction pad 40a of the articulated substrate transfer robot is vertical, then immersed in the cleaning liquid in the vertical suction pad cleaning machine 53, and the suction pad is ultrasonically cleaned and adhered. After washing away the polishing scraps and abrasive grains remaining, the suction pad 40a position is returned to the standby position.

Thereafter, the steps (1) to (22) are repeated, and the back surface planarization of the two compound semiconductor substrates is continued.

  In addition, the delivery of the substrate to the suction chuck mechanism in steps (10) and (11) and the delivery of the substrate from the suction chuck mechanism in steps (14) and (18) to the second substrate cleaning machine are as follows: It may be modified so that the delivery of the compound semiconductor substrate by the first substrate suction chuck mechanism is given priority, and then the delivery of the compound semiconductor substrate by the second substrate suction chuck mechanism is performed.

  The planarization processing apparatus for a compound semiconductor substrate of the present invention can perform grinding and lapping of the back surface of the substrate with high throughput. In addition, it is possible to manufacture an ultrathin compound semiconductor substrate with a small number of adhered foreign substances.

DESCRIPTION OF SYMBOLS 1 Substrate flattening apparatus B Base K Storage cassette T Index type turntable W1 Loading / unloading stage chamber W2 Substrate lapping stage W3 Substrate grinding stage s ₁ Substrate loading / unloading stage s ₂ Substrate rough grinding stage s ₃ Substrate finish grinding stage 3 Lap surface plate 4 Polisher surface 14 Suction chuck mechanism 16 Abrasive liquid supply mechanism 17 Rotary suction pad 40 Articulated substrate transfer robot 40a Suction pads 41 and 42 Temporary table 51 Substrate cleaner 61 Adsorbent pad vertical cleaner 90a Coarse grinding wheel 91a Finish grinding wheel

Claims (2)

A room for installing the flattening processing equipment outdoors. A loading / unloading stage chamber for Greek letter Γ-shaped substrates is placed on the left side of the front part where a plurality of substrate storage cassettes are installed. The processing stage chamber and the back substrate grinding processing stage chamber are divided into three chambers by a partition wall, and the partition wall between the stage chambers is provided with an opening through which a substrate leading to an adjacent stage chamber can be taken in and out, A compound semiconductor substrate planarization apparatus provided with a load port communicating with a storage cassette of the plurality of substrates on a front left side wall of a loading / unloading stage chamber,
The substrate loading / unloading stage chamber is provided with a second substrate cleaning machine and a second temporary placement table from the back of the load port toward the interior of the chamber, and has a polishing agent liquid supply mechanism, a suction pad, and a reversing function. It has an articulated substrate transfer robot with an arm, a vertical suction pad cleaner and a first temporary mounting table, and a first substrate cleaner and a rotary suction pad.
In the lap processing stage chamber of the substrate, there is provided a lap surface plate equipped with a conditioner ring for conditioning the lap surface plate polisher surface in the center, and a template having a suction mechanism in front of the lap surface plate and a pendulum swing and A second substrate suction chuck mechanism capable of moving up and down and a second substrate suction chuck cleaning mechanism for cleaning a template having the suction mechanism, and a template having a suction mechanism behind the lap surface plate and swinging the pendulum and moving up and down A first substrate suction chuck mechanism and a first substrate suction chuck cleaning mechanism for cleaning a template having the suction mechanism,
In the substrate grinding stage chamber, there is provided a substrate suction chuck surface plate in which three sets of substrate suction chuck tables are rotatably provided on the same circumference at an equal interval on one index type turntable. The numerical value control device stores the index of the substrate suction chuck table as the loading / unloading stage chuck (s ₁ ), substrate rough grinding stage chuck (s ₂ ), substrate finishing grinding chuck (s ₃ ) position, and A brush cleaning device and a chuck cleaning device are provided above the loading / unloading stage chuck (s ₁ ) so as to be laterally movable, vertically movable, and rotatable, and above the substrate rough grinding stage chuck (s ₂ ), a cup wheel type. A rough grinding wheel is provided so that it can be moved up and down and rotated and rotated. A cup wheel type finishing grinding wheel is provided above the cutting stage chuck (s ₃ ) so that it can be moved up and down and rotated and rotated.
The substrate stored in the storage cassette is sucked by the suction pad of the articulated substrate transfer robot provided in the center of the loading / unloading stage chamber, and transferred to the first driving table, the first temporary mounting table Transfer the upper substrate onto the loading / unloading stage chuck (s ₁ ) in the grinding stage chamber, suck the substrate on the first substrate cleaning machine, and transfer it to the first substrate suction chuck mechanism in the lapping stage chamber. , Picks up the substrate on the first substrate cleaning machine, transfers it to the second substrate suction chuck mechanism in the lapping stage chamber, transfers it, receives the substrate sucked on the first substrate suction chuck mechanism, and transfers it to the second substrate cleaning machine Receive the substrate adsorbed by the second substrate adsorption chuck mechanism, transport it to the second substrate cleaning machine, adsorb the substrate on the second substrate cleaning machine and place it temporarily Conveying upward, the task of conveying to the second provisional table the substrate on the adsorbed substrate storage cassettes performed,
The compound semiconductor substrate on the loading / unloading stage chuck (s ₁ ) is adsorbed by using a rotary suction pad in the loading / unloading stage chamber and rotated to place the compound semiconductor substrate on the first substrate cleaning machine. Transport,
An apparatus for planarizing a compound semiconductor substrate, comprising: A planarization method for a compound semiconductor substrate, comprising: planarizing a compound semiconductor substrate through the following steps using the planarization apparatus for a compound semiconductor substrate according to claim 1.
(1) After the compound semiconductor substrate stored in the substrate storage cassette for loading is adsorbed on the suction pad of the articulated substrate transfer robot, it is transferred onto the first temporary placement table.
(2) After the substrate is centered on the first temporary placement table, the substrate on the first temporary placement table is transferred onto the loading / unloading stage chuck (s ₁ ) in the grinding stage chamber.
(3) The index type turntable in the grinding stage chamber is rotated 120 degrees counterclockwise to move the loading / unloading stage chuck (s ₁ ) to the substrate rough grinding stage chuck (s ₂ ) position. .
(4) At the substrate rough grinding stage chuck (s ₂ ) position, the back surface of the compound semiconductor substrate is roughly ground using a cup wheel type grindstone.
(5) The index type turntable is rotated 120 degrees counterclockwise to move the substrate rough grinding stage chuck (s ₂ ) to the substrate finishing grinding stage chuck (s ₃ ) position.
(6) The back surface of the compound semiconductor substrate that has been subjected to rough grinding using the cup wheel type grindstone at the substrate finish grinding stage chuck (s ₃ ) position is finish ground to thin the back surface of the compound semiconductor substrate.
(7) The index-type turntable is rotated 120 degrees counterclockwise or 240 degrees clockwise to place the substrate finish grinding stage chuck (s ₃ ) at the loading / unloading stage chuck (s ₁ ) position. Move to.
(8) Using a rotary suction pad in the loading / unloading stage chamber, the compound semiconductor substrate on the loading / unloading stage chuck (s ₁ ) is adsorbed and rotated to the first substrate cleaning machine. Transfer the substrate.
(9) Spin cleaning the compound semiconductor substrate on the first substrate cleaner.
(10) The compound semiconductor substrate on the first substrate cleaning machine is sucked by the suction pad of the articulated substrate transfer robot, and the suction pad is inverted, and then transferred to the second substrate suction chuck mechanism in the lapping stage. hand over.
(11) The newly cleaned compound semiconductor substrate on the first substrate cleaning machine is absorbed by the suction pad of the articulated substrate transfer robot, and the suction pad is inverted, and then the first substrate in the lapping stage chamber. It is transferred to the suction chuck mechanism and delivered.
(12) The lap platen is rotated and the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are swung to move above the polisher surface to which the abrasive liquid of the lap platen is supplied. After that, the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are moved down to press the compound semiconductor substrate being sucked against the polisher surface of the lap platen to apply a load, and lap polishing is started. The load on the substrate is continued by rotating the lapping plate and swinging and lowering the pendulum on the polisher surfaces of the first substrate suction chuck mechanism and the second substrate suction chuck mechanism to perform lapping of the compound semiconductor substrate.
(13) After completion of the lapping process of the compound semiconductor substrate, the first substrate suction chuck mechanism and the second substrate suction chuck mechanism are swung to swing the first substrate suction chuck cleaning mechanism and the second substrate suction chuck cleaning mechanism. After being moved upward, it is lowered, and then the compound adsorbed on the first substrate adsorption chuck mechanism and adsorbed on the second substrate adsorption chuck mechanism by the first substrate adsorption chuck cleaning mechanism and the second substrate adsorption chuck cleaning mechanism Clean the lapping surface of the semiconductor substrate.
(14) The compound semiconductor substrate adsorbed by the second substrate adsorbing chuck mechanism is adsorbed by the adsorbing pad of the articulated substrate conveying robot, and then conveyed to the second substrate cleaning machine for delivery.
(15) The compound semiconductor substrate is cleaned with a second substrate cleaning machine.
(16) The compound semiconductor substrate on the second substrate cleaning machine is adsorbed by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary placement table, and then the core of the compound semiconductor substrate I will take out.
(17) The compound semiconductor substrate on the second temporary table is sucked by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred into the unloading substrate storage cassette.
(18) The compound semiconductor substrate adsorbed by the first substrate adsorbing chuck mechanism is adsorbed by the adsorbing pad of the articulated substrate conveying robot, and then conveyed to the second substrate cleaning machine for delivery.
(19) The compound semiconductor substrate is cleaned with a second substrate cleaning machine.
(20) The cleaned compound semiconductor substrate on the second substrate cleaning machine is sucked by the suction pad of the articulated substrate transfer robot, and the compound semiconductor substrate is transferred onto the second temporary placement table, and then the core of the compound semiconductor substrate I will take out.

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