JP6032643B2 - Backing material and substrate carrier head structure using the same - Google Patents

Description

  The present invention relates to a backing material used for a carrier head structure (substrate holder) of a polishing apparatus and a carrier head structure of a substrate using the backing material. In particular, a flexible substrate in which the semiconductor substrate of Japanese Patent Application Laid-Open No. 2001-105305 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2012-91240 (Patent Document 2) previously filed by the present applicant is provided at the lower center of the carrier head. A semiconductor substrate is received and held in a substrate storage pocket formed by the lower surface of the elastic elastic rubber backing film and the inner wall of an annular holding ring provided at the lower outer periphery of the carrier head, and the carrier head for holding the semiconductor substrate is The semiconductor substrate is polished while blowing the compressed air from the back surface of the flexible elastic rubber backing film by lowering while rotating and bringing the semiconductor substrate into contact with and rubbing against the polishing cloth of the polishing platen (platen). After the polishing process, the carrier head is raised, and then the polished substrate is held in the next polishing process stage or unloading stage. Further, the invention is an improvement of the invention relating to the carrier head structure of the semiconductor substrate used for moving the carrier head, and the previous invention holds the substrate on the lower surface of the flexible elastic rubber backing film of the carrier head by water bonding. The present invention relates to a carrier head structure in which a process is not required and a substrate can be held on a carrier head by utilizing the adhesion of a surface layer of a backing material.

  As a carrier head structure for holding a substrate on the lower surface of a flexible elastic rubber backing film of the carrier head by applying water, JP-A-2001-105305 (Patent Document 1) is a fixed bearing supported by a rotating drive shaft. A substrate carrier head structure of a polishing apparatus for polishing a surface of a substrate by pressing the substrate held by a carrier from above the polishing cloth and rubbing the substrate and the polishing cloth against the surface of the polishing cloth affixed to the board. The carrier head structure includes a bowl-shaped main body supported by a hollow spindle shaft, a diaphragm made of a flexible material horizontally fixed to a lower end portion of the bowl-shaped main body, and a central portion fixed to the diaphragm. A rigid support plate having a gas passage in the vertical direction and having a recess formed through the gas passage portion on the lower surface, means for supplying and discharging gas in the gas passage, bowl-shaped main Means for supplying gas to a pressurizing chamber formed by the inside of the section and the upper surface side of the diaphragm, a flexible film on the lower surface of the rigid support plate, and a gap between the rigid support plate and the flexible film A substrate carrier portion to which a flexible film is attached so that a highly confidential space of 0.1 to 0.3 mm is formed, and protrudes from the lower surface of the flexible film to the lower outer periphery of the rigid support plate And a substrate storage pocket portion formed by a side wall of the annular retaining ring and a lower surface of the flexible film, and a substrate carrier head in a polishing apparatus. Propose structure.

Patent 5,072,161 (Patent Document 3) is a wafer carrier head,
The outer housing comprising a retaining ring, the retaining ring projecting from the outer housing;
An inner housing with an inner ring disposed inside the outer housing and secured to the outer housing and positioned in a region surrounded by the retaining ring;
The inner ring is movable with respect to the inner housing and has a soft membrane (flexible membrane) that seals the edge of the wafer and moves the wafer surface during wafer transfer. Holding and sized and positioned to pressurize the surface of the wafer as it falls onto the polishing surface;
The retaining ring can move relative to the outer housing independently of the inner ring;
The inner ring and the inner housing are configured to limit a vertical distance that the inner ring can extend or contract;
A wafer carrier head is proposed.

Furthermore, the above-mentioned JP2012-91240A (Patent Document 2)
A bowl-shaped main body portion (104) supported by a hollow spindle shaft (105), and a middle cylindrical hollow portion (106) at the center on the outer peripheral edge of the lower surface of the bowl-shaped main body portion, the cylindrical hollow portion (106) three punched-in portions (107,
107, 107) having a concave cross-section intermediate plate (108),
A hollow shaft (with a built-in tip of a gas supply / exhaust supply pipe (16) provided in the hollow spindle shaft (105) on the inner wall of the cylindrical hollow portion (106) of the concave intermediate plate (108). 2) is fixed vertically, the lower end of this hollow shaft (2) is supported by a spherical bearing (3), and the lower end of the gas supply / exhaust pipe (16) is fluidized vertically in the center. A passage (8a) is provided, and is fixed to the inner wall of the gas passage (8a) of the concave rigid support plate (8) having a narrow space (8b) formed through the gas passage (8a).
A height adjusting bolt (11b) is inserted into the three punched-through portions (107, 107, 107) of the concave intermediate plate (108) through the bottom surface from the top surface of the bowl-shaped main portion (104). The fixing disk (11a) provided at the lower part of the head of the position adjusting device (11) and the hook-like engagement flange (9b) that engages with the fixing disk (11a) are present, The lower part of the flange-like engagement flange (9b) is fixedly provided on the upper surface of the concave rigid support plate (8), and the fixing disk (11a) in the three punch-through parts (107, 107, 107) is provided. ) And the space excluding the space occupied by the hook-shaped engagement flange (9b) is used as a compressed air flow passage (18a),
A flexible film (19) is formed on the lower surface of the concave rigid support plate (8), and a narrow space (8b) on the lower surface of the concave rigid support plate and the flexible film (19) have a gap of 0.1. A substrate carrier part (4) provided with a flexible membrane (19) is provided so as to form a highly confidential space (21) of ~ 0.3 mm, and is provided outside the lower part of the concave rigid support plate (8). An annular holding ring (22) is attached to the lower surface of the flexible membrane (19) existing at the peripheral position, and a space formed by the inside of the side wall of the annular holding ring (22) and the lower surface of the flexible membrane (19). To form the substrate storage pocket (4a),
and,
An annular bellows (110) that is vertically expandable and contractible from the outer peripheral edge of the lower surface of the concave cross-section intermediate plate (108), and a fixed plate in which the annular bellows lower annular end surface is provided on the upper surface of the cross-section concave rigid support plate (8) (8a) and back pressure is applied by compressed air to the upper concave portion of the concave rigid support plate (8) by the inner wall of the annular bellows (110) and the concave portion of the concave rigid support plate (8). Formed a space (18) that can
A carrier head structure (1) for a substrate having a structure is proposed.

In the carrier head structures described in Patent Documents 1 to 3, a water film is formed on a flexible film as a backing material, and the substrate is held on the flexible film of the carrier head structure by water. . The holding ring (22) rotates the rotating shaft of the carrier head structure to bring the substrate into contact with the polishing pad, and when the surface of the substrate is polished by rubbing, the substrate jumps out of the carrier head due to rotational centrifugal force. It has the function to prevent. However, the disadvantage that the thickness of the water film is not uniform compensates for the normality of the surface of the polishing pad on the lower surface of the substrate due to the fluctuation of the air pressure of the pressurized air supplied to the back surface of the flexible film of the carrier head structure. Semiconductor device manufacturers that require a substrate polishing surface roughness of 0.2 μm or less are abbreviations of TTV (total thickness variation for substrate polishing surface roughness. The difference between the maximum value and the minimum value of the entire surface of the wafer measured in the thickness direction with reference to the reference plane is desired to be further improved.

In the description of paragraph 0038 of Japanese Patent Application Laid-Open No. 2011-670 (Patent Document 4), the present applicant of the present patent application forms a substrate adhesion layer as a surface layer via an adhesive layer on the surface of a rigid base supported by a rotating shaft. A substrate holder (carrier head structure) in which a provided base film is laminated, wherein the substrate adhesion layer is peeled off from the substrate surface on which the substrate adhesion layer is adhered to the substrate adhesion layer (JIS K-6).
854) is 10 mN / 12.7 mm width or less, and is formed of a polyorganosiloxane-based silicone resin layer having a shearing force of 1.0 N / cm ² or more for shifting the substrate in parallel from the substrate adhesion layer surface. We proposed a substrate holder featuring the characteristics of

  The substrate holder (carrier head structure) does not require a water film for holding the substrate, and a polished substrate having a surface TTV of 0.83 μm is obtained, but a polished substrate close to the inside of the holding ring. It has been found that the edges tend to bend like processed substrates that have been polished using conventional polishing head carrier structures.

JP 2001-105305 A JP 2012-91240 A Patent No. 5,072,161 JP 2011-670 A

  A carrier head in which an annular holding ring is bonded to the outer peripheral edge of the substrate holder described in Patent Document 4, and a substrate pasting area is formed in an area surrounded by the lower surface of the polyorganosiloxane-based silicone resin layer and the inner edge of the annular holding ring. The structure allows easy removal of the substrate from the carrier head structure, and the effect of improving the TTV of the polished substrate can be seen, but the improvement of the anti-sagging effect at the edge of the polished substrate is accompanied by the value desired by the semiconductor device manufacturer. There are no drawbacks.

  The inventors of the present application have an elastic resin foam sheet intermediate layer on the back surface of the polyorganosiloxane-based silicone resin adhesion layer, and a flexible rubber film base disclosed in Patent Document 2 on the back surface of the elastic resin foam sheet intermediate layer. A disk-shaped flexible laminate having a material layer bonded thereto is used, and a circular region that holds the substrate of the polyorganosiloxane-based silicone resin adhesion layer of the disk-shaped flexible laminate and an annular holding ring is bonded. By providing the polyorganosiloxane silicone resin adhesion layer and the elastic resin foam sheet intermediate layer with a groove having a groove width of 0.5 to 2 mm which is divided into two parts in the organosiloxane silicone resin adhesion layer region, the circular shape is obtained when the substrate is polished. The stress applied to the flexible laminate region reduces the stress that pulls the annular flexible laminate region that adheres and holds the annular retaining ring. Part of the mountain was inspired to help anyone overcome, it led to the present invention.

The invention of claim 1
The elastic resin foam sheet intermediate layer (192) is adhered to the back surface of the polyorganosiloxane-based silicone resin adhesion layer (191), and the flexible rubber film substrate layer (193) is adhered to the back surface of the elastic resin foam sheet intermediate layer. The disc-shaped flexible laminate (19) is used, and the circular region (191a) for holding the substrate of the polyorganosiloxane-based silicone resin adhesion layer (191) of the disc-shaped flexible laminate and the annular retaining ring ( 22) An annular groove (191c) having a groove width of 0.5 to 2 mm divided into two in an annular polyorganosiloxane silicone resin adhesion layer region (191b) to which 22) is bonded is formed into a polyorganosiloxane silicone resin adhesion layer (191) and elasticity. The annular polyorganosiloxane-based silicone resin adhesion layer of the disc-shaped flexible laminate (19) provided on the resin foam sheet intermediate layer (192) A backing material having an annular retaining ring (22) bonded to a region (191b), wherein the substrate carrier region portion (4) is formed by the polyorganosiloxane-based silicone resin circular adhesion layer (191a), and the annular retaining ring A backing material in which a substrate storage pocket portion (4a) is formed in a space formed by the inner side wall of (22) and the lower surface of the polyorganosiloxane-based silicone resin circular adhesion layer (191a);
The substrate surface and the polyorganosiloxane on which the polyorganosiloxane-based silicone resin adhesion layer (191a, 191b) of the disc-shaped flexible laminate (19) is bonded to the polyorganosiloxane-based silicone resin circular adhesion layer (191a) The peeling force (based on JIS K-6854) with the silicone-based silicone resin adhesion layer is 10 mN / 12.7 mm width or less, and the shearing force that shifts the substrate in parallel from the surface of the polyorganosiloxane silicone resin circular adhesion layer (191a) is It is a polyorganosiloxane-based silicone resin adhesion layer (191) that is 1.0 N / cm ² or more.
A backing material (BM) for a carrier head structure of a polishing apparatus characterized by the above.

The invention of claim 2
A bowl-shaped main body portion (104) supported by a hollow spindle shaft (105), and a cylindrical hollow portion (106) in the center on the outer peripheral edge of the lower surface of the bowl-shaped main body portion, the cylindrical hollow portion ( 106) three punched portions (107, 1) at three equally spaced positions on the same circumference centered on the center point
07, 107) with a concave cross-section intermediate plate (108),
A hollow shaft (with a built-in tip of a gas supply / exhaust supply pipe (16) provided in the hollow spindle shaft (105) on the inner wall of the cylindrical hollow portion (106) of the concave intermediate plate (108). 2) is fixed vertically, the lower end of this hollow shaft (2) is supported by a spherical bearing (3), and the lower end of the gas supply / exhaust pipe (16) is fluidized vertically in the center. A passage (8a) is provided, and is fixed to the inner wall of the gas passage (8a) of the concave rigid support plate (8) having a narrow space (8b) formed through the gas passage (8a).
A height adjustment bolt (11b) is inserted into the three punched-through portions (107, 107, 107) of the concave intermediate plate (108) through the lower surface from the upper surface of the bowl-shaped main portion (104). The fixing disk (11a) provided at the lower part of the head of the position adjusting device (11) and the hook-like engagement flange (9b) that engages with the fixing disk (11a) are present, The lower part of the flange-like engagement flange (9b) is fixedly provided on the upper surface of the concave rigid support plate (8), and the fixing disk (11a) in the three punch-through parts (107, 107, 107) is provided. ) And the space excluding the space occupied by the hook-shaped engagement flange (9b) is used as a compressed air flow passage (18a),
The flexible rubber film base of the backing material (BM) for carrier head structure according to claim 1, wherein the bottom surface of the concave rigid support plate (8) and the lower surface of the annular circumferential portion of the bowl-shaped main body (104). The material layer (193) is bonded to the back surface so that the polyorganosiloxane-based silicone resin circular adhesion layer (191a) and the polyorganosiloxane-based silicone resin annular adhesion layer (191b) face downward, and the support plate made of a rigid body having a concave cross section. (8) A highly confidential space (21) having a gap of 0.1 to 0.3 mm is formed between the narrow space (8b) on the lower surface and the back surface of the disk-shaped flexible laminate (19), and the polyorgano A siloxane-based silicone resin circular adhesion layer (191a) is formed as a substrate carrier part (4),
An annular bellows (110) that is vertically expandable and contractable from the outer peripheral edge of the lower surface of the concave intermediate plate (108) is suspended, and the annular bellows lower annular end surface is fixed to the upper surface of the concave rigid support plate (8). Fixed to the plate (8a), the back surface pressure is applied to the upper concave portion of the concave rigid support plate (8) by the compressed air by the inner wall of the annular bellows (110) and the concave portion of the concave rigid support plate (8). The carrier head structure (1) of the substrate adopts a structure in which a space (18) that can be formed is formed.

A polyorganosiloxane-based silicone resin that holds the substrate tightly by providing an annular groove (191c) in the adhesion layer (191) of the disk-shaped flexible laminate (19) and the elastic resin foam sheet (192) as a backing material Since the circular adhesion layer (191a) region portion and the polyorganosiloxane-based silicone resin annular adhesion layer (191b) region portion for adhering the holding ring (22) are used separately, the degree of edge crests of the polished substrate is reduced. Resolved to a lower value. Further, since it is not necessary to attach water to the surface of the disk-shaped flexible laminate (19), it is easy to remove the polished semiconductor substrate from the carrier head structure (1). Further, the work for removing the worn annular holding ring (22) from the disk-like flexible laminate (19) and the replacement work for bringing the new annular holding ring (22) into close contact with the disk-like flexible laminate (19). Becomes easy. In addition, by adopting the elastic resin foam sheet intermediate layer (192), the followability of the surface irregularity shape of the polishing cloth on the surface of the semiconductor substrate is improved, and the TTV of the obtained polished substrate is improved.

FIG. 1 is a front sectional view of the backing material. FIG. 2 is a sectional view of the carrier head structure of the substrate. FIG. 3 is a plan view of the concave intermediate plate viewed from the AA direction of the carrier head structure of the substrate shown in FIG. FIG. 4 is a distribution diagram showing the surface roughness of the polished 150 mm diameter semiconductor substrate at intervals of 5 mm in the diameter direction.

  The backing material shown in FIG. 1 has an elastic resin foam sheet intermediate layer 192 on the back surface of the polyorganosiloxane-based silicone resin adhesion layer 191 and a flexible rubber film base material layer 193 on the back surface of the elastic resin foam sheet intermediate layer. Is used, and a circular region 191a for holding the substrate of the polyorganosiloxane-based silicone resin adhesion layer 191 of the disk-like flexible laminate and an annular holding ring are bonded to each other. A disk-like shape in which a polyorganosiloxane silicone resin adhesion layer 191 and an annular groove 191c having a groove width of 0.5 to 2 mm are provided in the polyorganosiloxane silicone resin adhesion layer region 191b in the polyorganosiloxane silicone resin adhesion layer 191 and the elastic resin foam sheet intermediate layer 192. In the flexible laminate 19, the annular polyorganosiloxane silicone resin adhesion layer region 191 b has an annular holding ring. A substrate carrier region 4 formed of the polyorganosiloxane silicone resin circular adhesion layer 191a, and the inner side wall of the annular retaining ring 22 and the polyorganosiloxane silicone resin circle. A backing material BM for a carrier head structure of a polishing apparatus in which a substrate storage pocket portion 4a is formed in a space formed by the lower surface of the adhesion layer 191a is shown.

  The annular groove 191c preferably has a groove width of 0.5 to 2 mm, a groove depth of 2 to 3 mm, and a groove bottom reaching the surface of the flexible rubber film substrate layer 193.

  The semiconductor substrate w adhered to the lower surface of the polyorganosiloxane-based silicone resin circular adhesion layer 191a in the substrate storage pocket portion 4a is a polishing cloth on a polishing surface plate by pressurized air supplied to the back surface of the disk-shaped flexible laminate 19. Will follow the uneven shape.

  Examples of the material of the flexible rubber film base layer 193 include a rubber substance described in Patent Document 1, a mixture of a rubber substance and a thermoplastic elastomer or an adhesive thermoplastic resin.

Rubber materials include butyl rubber, chloroprene rubber, silicone rubber, ethylene / propylene / ethylidene norbornene copolymer rubber, ethylene / propylene / butadiene copolymer rubber, ethylene / propylene copolymer rubber, brominated styrene / butadiene / styrene block. Copolymer rubber, Chlorinated styrene / butadiene / styrene block copolymer rubber, Hydrogenated bromostyrene / butadiene / styrene block copolymer rubber, Hydrogenated butadiene / acrylonitrile copolymer rubber, Chlorinated styrene -Hydrogenated butadiene / styrene block copolymer rubber, brominated styrene / isoprene / styrene block copolymer rubber, chlorinated styrene / isoprene / styrene block copolymer rubber, brominated styrene / isopre · Styrene block copolymer hydrogenated product of the rubber, chlorinated styrene-isoprene-styrene block copolymer hydrogenation product of rubber, vinylidene fluoride-ethylene copolymer rubber. These may be cross-linked.

  Examples of thermoplastic elastomers or adhesive thermoplastic resins include ethylene / vinyl acetate copolymer, soft polyvinyl chloride, chlorinated polyethylene, chloro / sulfonated polyethylene, ethylene / acrylic acid copolymer, and ethylene / methyl acrylate. Examples include copolymers, ethylene / ethyl acrylate copolymers, ethylene / methyl acrylate / 2-ethylhexyl acrylate copolymers, and the like.

  In the case of a mixture, the rubber substance is used in a proportion of 30 to 97% by weight, and the thermoplastic elastomer or adhesive thermoplastic resin is used in a proportion of 70 to 3% by weight. The rubber material is used for the purpose of spreading the flexible rubber film and returning to the elongation, and the thermoplastic elastomer or the thermoplastic resin is used for the purpose of improving the strength, hardness and heat resistance of the flexible rubber film.

As a physical property of the flexible rubber film base material layer 193, hardness (JIS K-6301) is 10 to 1.
00, preferably 35-85, tensile strength (JIS K-6301) is 30-200 kgf
/ Cm ² , preferably 50 to 150 kgf / cm ² , tensile elongation (JIS K-6301) is 50 to 1000%, 200 to 800%, thickness is 0.03 to 2 mm, preferably 0.05 to 1. 5 mm.

  As the elastic resin foam sheet intermediate layer 192 material, a foam sheet-like material having a high compression elastic modulus such as polyurethane foam, polyethylene foam, polypropylene foam, polystyrene foam or the like is used. The thickness is preferably 2 to 3.5 mm. Such an elastic resin foam sheet includes, for example, a backing material “R301” (trade name) from Nitta Haas Co., Ltd., “Miramat” (trade name), “Capron” (trade name) and Miraboard (trade name) from Nippon Styrene Paper Co., Ltd. ).

The adhesion layer 191 that is in direct contact with the semiconductor substrate is a polyorganosiloxane-based silicone resin adhesion layer, and the peeling force (conforming to JIS K-6854) between the adhesion layer 191a and the semiconductor substrate is 10 mN / 12.7 mm or less. The shearing force for shifting the semiconductor substrate from the polyorganosiloxane-based silicone resin adhesion layer 191a in the horizontal direction is 1.0 N / cm ² or more. The thickness of the polyorganosiloxane-based silicone resin adhesion layer 191 is 5 to 100 μm, preferably 5 to 30 μm.

  When the adhesion between the polyorganosiloxane-based silicone resin adhesion layer 191 and the elastic resin foam sheet 192 is lower than 50 gf / 25 mm width or less, the adhesive, pressure-sensitive adhesive, or primer 0.5 to 10 μm layer is elastic. After being provided on the resin foam sheet 192, a polyorganosiloxane-based silicone resin adhesion layer-forming liquid coating agent is applied and dried to form the adhesion layer 191.

The adhesive layer 191 is a double-sided fixed sheet made of release paper / adhesive layer / base film / adhesive layer 19b / release paper laminate sold in the market, for example, FIXFILM (trade name) series STD1 from Fujikopian Corporation. , STD2, HG1, HG2 (adhesion layer single side) grade name, HGW1, HGW2 (adhesion layer both sides), or “Q-Chuck” series (trade name) release paper / polyorgano sold by Maruishi Sangyo Co., Ltd. Siloxane silicone resin adhesive layer, synthetic rubber adhesive layer or acrylic adhesive layer / base film / adhesion layer 19b / release paper laminate or release paper / polyorganosiloxane silicone resin adhesive layer, synthetic rubber adhesive Purchase the adhesive layer or acrylic adhesive layer / adhesion layer 19b / release paper laminate and peel the release paper It may be used after that.

The polyorganosiloxane-based silicone resin material for the adhesion layer (191) includes a silicone composed of a linear polyorganosiloxane having vinyl groups only at both ends, and a linear polyorgano having vinyl groups at both ends and side chains. At least one silicone selected from a silicone comprising a siloxane, a silicone comprising a branched polyorganosiloxane having a vinyl group only at the terminal, and a silicone comprising a branched polyorganosiloxane having a vinyl group at the terminal and side chain. Polyorganosiloxane silicone resins obtained by copolymerization and crosslinking can be used.

  As the cross-linking agent, organohydropolyene polysiloxane is preferred.

  As the crosslinking accelerator, 3-methyl-1-buten-3-ol is preferable.

  Examples of platinum-based catalysts used for the crosslinking reaction include chloroplatinic acid such as chloroplatinic acid and chloroplatinic acid, alcohol compounds of chloroplatinic acid, aldehyde compounds, and chain salts of chloroplatinic acid and various olefins. It is done. The polyorganosiloxane-based silicone resin obtained by the cross-linking reaction has flexibility such as a silicone gel, and this flexibility facilitates the close contact with the semiconductor substrate w that is the adherend.

The polyorganosiloxane-based silicone resin adhesion layer 191 has an Asker FP hardness of 25 or more and an Asker CSC2 hardness of 80 or less. The peeling force (conforming to JIS K-6854) between the surface of the semiconductor substrate adhered to the polyorganosiloxane silicone resin circular adhesion layer 191a and the polyorganosiloxane silicone resin adhesion layer 191a is 10 mN /
The shear force for shifting the substrate in parallel from the surface of the polyorganosiloxane-based silicone resin circular adhesion layer 191a is 1N mm or less and 1.0 N / cm ² or more.

  As the material for the annular retaining ring 22, glass fiber reinforced epoxy resin, poly (tetrafluoroethylene), poly (difluorochloroethylene), polyacetal, PEEK resin, or a laminate of two or more of these is used. Although the thickness of the annular holding ring 22 depends on the thickness of the semiconductor substrate w, it is usually 0.08 to 2 mm. The dynamic friction coefficient between the polishing cloth (polishing pad) of the polishing surface plate and the annular holding ring 22 is preferably 0.30 or more.

  Divided into a circular region 191a for holding the substrate of the polyorganosiloxane silicone resin adhesion layer 191 of the disc-shaped flexible laminate and an annular polyorganosiloxane silicone resin adhesion layer region 191b for closely adhering the annular holding ring 22 The annular groove provided in the polyorganosiloxane-based silicone resin adhesion layer 191 and the elastic resin foam sheet intermediate layer 192 is formed by a cutting operation.

  In the substrate carrier head structure 1 of the present invention shown in FIG. 2, 4 is a substrate carrier head in a polishing apparatus, 105 is a hollow spindle shaft, 104 is a bowl-shaped main body, 105a is a coupler, and the bowl-shaped main body is a hollow spindle shaft 105. Bearing on the bottom of the. A cylindrical hollow portion 106 is provided in the center on the outer peripheral edge of the lower surface of the bowl-shaped main portion, and three at three equally spaced positions on the same circumference centered on the center point O of the cylindrical hollow portion 106. A concave intermediate plate 108 having a cut-through portion 107, 107, 107 is provided.

  The hollow shaft 2 containing the tip of a gas supply / exhaust pipe (polyurethane coil tube) 16 provided in the hollow spindle shaft 105 is vertically arranged on the inner wall of the cylindrical hollow portion 106 of the concave intermediate plate 108. The lower end portion of the hollow shaft 2 is pivot-supported by the spherical bearing 3. The spherical bearing 3 is provided in the upper recessed space 8c of the rigid support plate 8 having a concave cross section.

The lower end of the gas supply / exhaust pipe 16 is provided with a fluid passage 8a in the vertical direction in the central portion communicating with the upper concave space 8c provided in the central portion of the rigid support plate 8 having a concave cross section. A quick seal joint 16a is fixed to the inner wall of the gas passage 8a of the rigid support plate 8 having a concave cross section in which a narrow space 8b is formed through the space 8a.

The three through-holes 107, 107, 107 of the concave intermediate plate 108 penetrate through the lower surface from the upper surface of the bowl-shaped main body 104 using a flange 11 c fixed to the upper surface of the bowl-shaped main body 104. The height adjusting bolt 11b is provided at the head of the height position adjusting device 11, and a fixing disc 11a provided at the lower portion thereof and a hook-like engagement flange 9b that engages with the fixing disc 11a are provided. A flange ring 9 is present. The carrier substrate 4 is lowered by the clockwise rotation of the height adjusting bolt 11b, and the carrier portion 4 is raised by the counterclockwise rotation of the height adjusting bolt 11b, so that the semiconductor substrate with respect to the polishing cloth surface of the polishing surface plate You can fine-tune the height position. Each axial center (O ₁ , O ₂ , O ₃ ) of the height adjusting bolt 11 b provided in the _three punched-through portions 107, 107, 107 is a circle having a center point O of the cylindrical punched-out portion 106. They are at equally spaced positions (vertices of equilateral triangles) on the same circumference. (See Figure 3)

  The lower part of the flange-like engagement flange 9b is fixed to the upper surface of the support plate 8 made of a rigid body having a concave cross section, and the fixing disk 11a and the hook-like engagement flange 9b in the three through-holes 107, 107, 107 are provided. The space excluding the space occupied by is used as the compressed air flow passage 18a. Aluminum or stainless steel can be used as the material of the rigid support plate 8.

  The back surface of the flexible rubber film base material layer 193 of the backing material BM for the carrier head structure is bonded to the lower surface of the support plate 8 made of concave rigid body and the lower surface of the annular circumferential portion of the bowl-shaped main body 104 with an adhesive S. The polyorganosiloxane-based silicone resin circular adhesion layer 191a and the polyorganosiloxane-based silicone resin annular adhesion layer 191b face downward, and the narrow space 8b on the lower surface of the concave rigid support plate 8 and the disk-shaped flexible A highly confidential space 21 having a clearance of 0.1 to 0.3 mm is formed between the back surface of the conductive laminate 19 and the polyorganosiloxane-based silicone resin circular adhesion layer 191 a is formed as the substrate carrier portion 4. A space formed by the inner side wall of the annular retaining ring 22 and the lower surface of the polyorganosiloxane-based silicone resin circular adhesion layer 191a is defined as a substrate storage pocket portion 4a.

  Returning to FIG. 2, an annular bellows 110 that is vertically expandable and contractible from the outer peripheral edge of the lower surface of the concave intermediate plate 108 is suspended, and a lower annular end surface of the annular bellows 110 is provided on the upper surface of the concave rigid support plate 8. It fixes to the fixed plate 8a. A space 18 is formed by the inner wall of the annular bellows 110 and the recess of the concave rigid support plate 8 so that a back pressure can be applied to the upper concave portion of the concave rigid support plate 8 by compressed air. The compressed air is introduced into the inner space of the hollow spindle 105.

  The annular bellows 110 is optimally made of stainless steel having a thickness of 0.18 to 0.25 mm and sufficient rigidity to prevent twisting of the rotating support plate 8 having a concave concave section. The annular bellows 110 receives the rotational driving force of the bowl-shaped main body 104 that receives the rotational driving force of the hollow spindle shaft 105, transmits the rotational driving force to the support plate 8 made of a rigid body having a concave cross section, and the pocket of the substrate carrier head 1. The semiconductor substrate accommodated in the part functions to rotate in the horizontal direction.

  The process of polishing the back surface of the semiconductor substrate using the substrate carrier structure 1 is performed as follows.

The carrier portion 4 of the substrate carrier head structure 1 is moved above the semiconductor substrate that has been transported to the temporary mounting base in advance, the substrate carrier head portion is lowered and brought into contact with the semiconductor substrate, and then the pressurizing chamber 18 is pressurized. When the carrier part 4 is pressed by supplying gas, the air in the circular adhesion layer 191a of the disc-shaped flexible laminate 19 and the pocket part 4b between the semiconductor substrates is discharged, the pocket part is depressurized, and the substrate contacts the carrier part 4. The substrate is fixedly held by the adhesion of the circular adhesion layer 191a. At the time of holding the substrate, the substrate is fixed and held in contact with the polyorganosiloxane silicone resin adhesion layer 191a with a shearing force of 1.0 N / cm ² or more that shifts the substrate in parallel from the surface of the polyorganosiloxane silicone resin adhesion layer 191a. .

  Next, after the carrier head structure 1 holding the substrate is moved above the polishing cloth (polishing pad) of the polishing surface plate, the hollow spindle 105 of the carrier head structure 1 is lowered while rotating to polish the substrate on the polishing surface plate. While contacting the cloth, pressurized air is introduced into the tube 16 to expand the disc-shaped flexible laminate 19, and the pressurized gas supplied to the pressurizing chamber 18 and the expanded circular flexible laminate film 19 on the back surface are expanded. The carrier portion 4 presses the substrate onto the polishing cloth of the polishing surface plate by the compressed air, and starts a polishing process for rotating and rubbing the substrate on the polishing cloth.

At this time, the polishing process is performed while the abrasive slurry is supplied to the surface of the polishing cloth and the compressed air is supplied to the hollow spindle 105. The rotation speed of the polishing surface plate is 10 to 150 rpm, the rotation speed of the substrate carrier part 4 is 10 to 150 rpm, and the substrate held by the circular flexible adhesive layer 191a of the disk-like flexible laminate 19 of the carrier part 4 is The pressure applied to the polishing cloth is 0.05 to 0.3 kg / cm ² , preferably the gas pressure supplied to the pressurizing chamber 18 is 100 to 300 g / cm ² .
The gas pressure applied to the back surface of the disc-like flexible laminate 19 from cm ² and the tube 16 is 100 to 200.
g / cm ² is preferred.

  As the abrasive slurry, an abrasive slurry in which abrasive grains such as colloidal silica, cerium oxide, alumina, boehmite, and manganese dioxide are dispersed in pure water, an abrasive liquid such as SC-1, SC-2, and ozone water is used. If necessary, a surfactant, a chelating agent, a pH adjuster, an oxidizing agent, a reducing agent, and a preservative are blended in the abrasive slurry and polishing liquid. The abrasive slurry or polishing liquid is supplied to the polishing cloth surface at a rate of 50 to 1,500 cc / min.

  During polishing of the substrate, the substrate receives a pressure change due to irregular undulations on the surface of the polishing cloth, but the back surface of the substrate, the circular flexible rubber base layer 193 of the disc-shaped flexible laminate 19 and the rigid support plate The pressure applied to each part of the back surface of the substrate by the pressurized gas existing in the space 21 between the eight becomes a uniform pressure according to Pascal's principle, so that the substrate easily follows the undulations (fine irregularities) of the surface shape of the polishing cloth. it can.

After the polishing of the substrate is completed, the supply of the pressurized gas to the pressurizing chamber 18 is stopped, and the hollow spindle shaft 105 of the carrier head structure 1 is slightly raised from the polishing cloth surface to be supplied into the tube 16. The disk-shaped flexible laminate 19 is expanded by the pressurized air, and the peeling force for pulling the substrate downward from the circular polyorganosiloxane-based silicone resin adhesion layer 191a to peel it off (according to JIS K-6854) ) Is 10 mN / 12.7 mm width or less, the polished substrate is easily peeled off from the circular polyorganosiloxane silicone resin adhesion layer 191a of the carrier.

Example 1
As the substrate carrier head structure 1, the carrier head structure shown in FIG. 2 was used, and a semiconductor substrate having a diameter of 150 mm and a TTV of 59.448 μm was processed by CMP. As the disc-like flexible laminate 19, a polyorganosiloxane-based silicone resin adhesive layer 191/20 μm thick, an elastic polyurethane resin foam substrate sheet layer “R301” (trade name of Nita Haas Co., Ltd.) 192 / A laminate of an adhesive / vinylidene chloride / ethylene copolymer rubber base material layer having a thickness of 1.5 mm was used. An annular groove 191c having a width of 1 mm and a depth of 2.52 mm was provided on the laminated body, and an annular holding ring made of glass fiber reinforced epoxy resin was adhered to the surface of the annular adhesion layer (191b). The peel force (conforming to JIS K-6854) between the surface of the semiconductor substrate adhered to the polyorganosiloxane silicone resin adhesion layer 191a and the polyorganosiloxane silicone resin adhesion layer 191a is 8 mN / 12.7 mm width. The shear force for shifting the substrate in parallel from the surface of the polyorganosiloxane-based silicone resin adhesion layer 191 is 1.8 N / cm ² . In addition, the abrasive | polishing agent "GLANZOX-1302" (brand name) by Fujimi Incorporated was used as CMP polishing liquid.

  The TTV of the polished substrate was 0.535 μm, and the K-value was 3.45%. FIG. 4 shows a roughness distribution diagram at intervals of 5 mm in the diameter direction of the polished substrate.

Comparative Example 1
As the substrate carrier head structure 1, a semiconductor substrate having a diameter of 150 mm was subjected to CMP processing in the same manner as in Example 1 except that the carrier head structure (1) shown in FIG. That is, the backing material before providing the annular cutting groove 191c in the backing material BM used in Example 1 was used as the disc-shaped flexible laminate sheet 19.

  The TTV of the polished substrate was 0.832 μm, and the K-value was 6.46%. FIG. 4 shows a roughness distribution diagram at intervals of 5 mm in the diameter direction of the polished substrate.

  The substrate carrier head structure 1 of the present invention is superior to the substrate carrier head structure described in Patent Document 2 in conformity with the uneven shape of the substrate to the polishing pad, and the polished substrate in which the degree of ridges at the substrate edge is reduced. give. Further, it is easy to replace the worn retaining ring 22 with a new retaining ring 22.

BM Carrier head structure backing material 1 Substrate carrier head structure 2 Hollow shaft 3 Spherical bearing 4 Substrate carrier portion 4a Substrate storage pocket portion 8 Recessed rigid support plate 9 Hook engagement flange 11 Height position adjustment device 16 Gas supply / Exhaust tubes 18 and 21 Space 18a Pressure air flow passage 19 Disc-shaped flexible laminate 191 Polyorganosiloxane-based silicone resin adhesion layer 191a Circular flexible adhesion layer 191b Toroidal flexible adhesion layer 192 Elastic resin foam Sheet intermediate layer 193 Flexible rubber film base layer 22 Annular retaining ring 104 Bowl-shaped main part 105 Hollow spindle shaft 106 Cylindrical hollow part 107 Boring through part 108 Recessed intermediate plate 110 Annular bellows

Claims (2)

The elastic resin foam sheet intermediate layer (192) is adhered to the back surface of the polyorganosiloxane-based silicone resin adhesion layer (191), and the flexible rubber film substrate layer (193) is adhered to the back surface of the elastic resin foam sheet intermediate layer. The disc-shaped flexible laminate (19) is used, and a circular region (191a) for holding the substrate of the polyorganosiloxane-based silicone resin adhesion layer (191) of the disc-shaped flexible laminate and an annular retaining ring are provided. An annular groove (191c) having a groove width of 0.5 to 2 mm divided into two to be bonded to the annular polyorganosiloxane silicone resin adhesion layer region (191b) is formed into a polyorganosiloxane silicone resin adhesion layer (191) and an elastic resin foam. The annular polyorganosiloxane-based silicone resin adhesion layer region (1) of the disc-shaped flexible laminate (19) provided in the sheet intermediate layer (192). 1b) is a backing material in which an annular retaining ring (22) is bonded, and a substrate carrier region portion (4) is formed by the polyorganosiloxane-based silicone resin circular adhesion layer (191a), and the annular retaining ring (22) ) And the polyorganosiloxane-based silicone resin circular adhesion layer (191a) underside, a backing material in which a substrate storage pocket portion (4a) is formed in a space formed by:
The substrate surface and the polyorganosiloxane on which the polyorganosiloxane-based silicone resin adhesion layer (191a, 191b) of the disc-shaped flexible laminate (19) is bonded to the polyorganosiloxane-based silicone resin circular adhesion layer (191a) The peeling force (based on JIS K-6854) with the silicone-based silicone resin adhesion layer is 10 mN / 12.7 mm width or less, and the shearing force that shifts the substrate in parallel from the surface of the polyorganosiloxane silicone resin circular adhesion layer (191a) is It is a polyorganosiloxane-based silicone resin adhesion layer (191) that is 1.0 N / cm ² or more.
A backing material (BM) for a carrier head structure of a polishing apparatus. A bowl-shaped main body portion (104) supported by a hollow spindle shaft (105), and a cylindrical hollow portion (106) in the center on the outer peripheral edge of the lower surface of the bowl-shaped main body portion, the cylindrical hollow portion ( 106) three punched portions (107, 1) at three equally spaced positions on the same circumference centered on the center point
07, 107) with a concave cross-section intermediate plate (108),
A hollow shaft (with a built-in tip of a gas supply / exhaust supply pipe (16) provided in the hollow spindle shaft (105) on the inner wall of the cylindrical hollow portion (106) of the concave intermediate plate (108). 2) is fixed vertically, the lower end of this hollow shaft (2) is supported by a spherical bearing (3), and the lower end of the gas supply / exhaust pipe (16) is fluidized vertically in the center. A passage (8a) is provided, and is fixed to the inner wall of the gas passage (8a) of the concave rigid support plate (8) having a narrow space (8b) formed through the gas passage (8a).
A height adjustment bolt (11b) is inserted into the three punched-through portions (107, 107, 107) of the concave intermediate plate (108) through the lower surface from the upper surface of the bowl-shaped main portion (104). The fixing disk (11a) provided at the lower part of the head of the position adjusting device (11) and the hook-like engagement flange (9b) that engages with the fixing disk (11a) are present, The lower part of the flange-like engagement flange (9b) is fixedly provided on the upper surface of the concave rigid support plate (8), and the fixing disk (11a) in the three punch-through parts (107, 107, 107) is provided. ) And the space excluding the space occupied by the hook-shaped engagement flange (9b) is used as a compressed air flow passage (18a),
The flexible rubber film base of the backing material (BM) for carrier head structure according to claim 1, wherein the bottom surface of the concave rigid support plate (8) and the lower surface of the annular circumferential portion of the bowl-shaped main body (104). The material layer (193) is bonded to the back surface so that the polyorganosiloxane-based silicone resin circular adhesion layer (191a) and the polyorganosiloxane-based silicone resin annular adhesion layer (191b) face downward, and the support plate made of a rigid body having a concave cross section. (8) A highly confidential space (21) having a gap of 0.1 to 0.3 mm is formed between the narrow space (8b) on the lower surface and the back surface of the disk-shaped flexible laminate (19), and the polyorgano A siloxane-based silicone resin circular adhesion layer (191a) is formed as a substrate carrier part (4),
An annular bellows (110) that is vertically expandable and contractable from the outer peripheral edge of the lower surface of the concave intermediate plate (108) is suspended, and the annular bellows lower annular end surface is fixed to the upper surface of the concave rigid support plate (8). Fixed to the plate (8a), the back surface pressure is applied to the upper concave portion of the concave rigid support plate (8) by the compressed air by the inner wall of the annular bellows (110) and the concave portion of the concave rigid support plate (8). A substrate carrier head structure (1) adopting a structure in which a space (18) that can be formed is formed.

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