JP2011155095A - Apparatus for flattening semiconductor substrate, and temporary displacement surface plate used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flattening apparatus that grinds and polishes the backside of a semiconductor substrate at high throughput to thin and flatten the substrate and manufactures the semiconductor substrate with less contamination sticking thereto, and to provide a temporary placement surface plate used for the flattening apparatus. <P>SOLUTION: The flattening apparatus 1 includes a loading/unloading stage chamber 11a for the semiconductor device, a backside polishing stage chamber 11c, and a backside grinding stage chamber 11b, each stage chamber housing each mechanical element. The flattening apparatus 1 is so designed that a backside polishing stage 70 capable of polishing two substrates at the same time achieves a throughput time twice as high as a throughput time of a backside polishing stage 20 polishing one substrate at a time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the pretreatment process of the IC substrate, the present invention grinds the back surface of a semiconductor substrate such as a next generation DRAM, SOI (Silicon On Insulator wafer, 3D-TSV wafer (Through Silicon Vias Wafer, sapphire substrate), etc. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planarization processing apparatus and a semiconductor substrate planarization method used for thinning and planarizing a substrate by polishing, and in particular, in thinning planarization processing to a thickness of a silicon base layer of DRAM up to a thickness of 15 to 70 μm. Alternatively, a semiconductor substrate flattening apparatus and flattening that can process a semiconductor substrate without cracking or chipping when thinning and flattening a substrate at an upper position of a laminated substrate such as a TSV wafer or an SOI wafer The present invention also relates to a processing method, and also relates to a temporary table base plate used as a part of constituent members of the flattening apparatus.

  Planarization processing apparatus comprising a substrate loading / unloading stage, a substrate grinding stage, a substrate polishing stage, and a substrate cleaning stage as a planarization processing apparatus that thins and mirrors a substrate by grinding and polishing a semiconductor substrate Has been proposed and put to practical use. A flattening processing apparatus is proposed in which a substrate storage cassette for a substrate load port is provided outdoors. These flattening apparatuses have the ability to perform a flattening process for thinning a thickness of about 750 μm on a 300 mm diameter semiconductor substrate at a throughput of 7 to 20 sheets / hour.

  For example, Japanese Patent Laid-Open No. 2001-252853 (Patent Document 1) is formed with a grinding means for grinding a wafer, a polishing means for polishing a wafer ground by the grinding means, and a diameter smaller than the diameter of the wafer. A wafer holding member, a chamfering means having a chamfering grindstone for chamfering the periphery of the wafer held by the wafer holding member, and a conveying means or a polishing means for conveying the wafer after chamfering by the chamfering means to the grinding means. And a planarization apparatus provided with a transfer means for transferring the wafer after polishing by the wafer holding member of the chamfering means, and after mounting the ground and polished wafer on the stage of the chamfering means, Chamfering the sharp edge of the polished wafer with a chamfering grindstone, and then storing this flattened wafer in a cassette There has been proposed.

  Japanese Patent Laid-Open No. 2005-98773 (Patent Document 2) has four sets of substrate holder tables (vacuum chucks) installed on the same index-type rotary table, and one of the substrate holder tables is loaded / unloaded. A rotating spindle equipped with a rough grinding cup wheel type diamond wheel, a rotating spindle equipped with a finish grinding cup wheel type diamond grinding wheel, and a rotating spindle equipped with a dry polished flat grinding wheel were arranged above the remaining three substrate holder tables. A flattening device is proposed.

U.S. Pat. No. 7,238,087 (Patent Document 3) discloses a substrate planarization apparatus 10 shown in FIG. The flattening apparatus 10 includes a plurality of substrate storage stages (load ports) 13 outside the room, and an indoor articulated transfer robot 14, a temporary positioning table 15, a movable transfer pad 16, and a substrate on the base 11. The substrate holders 30a, 30b, and 30c constituting the three stages of the loading / unloading stage S ₁ , the rough grinding stage S ₂ , and the finish grinding stage S ₃ are arranged concentrically on the first index type rotary table 2. The substrate holder table 70 a constituting the grinding stage 20, the substrate loading / unloading / finish polishing stage ps _1, and the substrate holder table 70 b constituting the rough polishing stage ps ₂ are concentrically arranged on the second index type rotary table 71. Substrate flattening provided with a polishing stage 70 arranged It is an engineering equipment.

Japanese Patent No. 4,260,251 (Patent Document 4) includes a base comprising a plurality of (n groups; n is an integer of 2 to 4) polishing disks arranged on the same circumference. An index type head formed by rotatably supporting a plurality (n + 1 sets) of chuck mechanisms on the rotating shaft above the base, a wafer before polishing transferred from the cassette, and after polishing transferred by the chuck mechanism A plurality of sets of chuck mechanisms in a wafer polishing apparatus for holding a wafer from a back surface with a chuck mechanism and polishing the wafer surface by pressing the surface against a polishing disk. The circumference connecting the center line of the rotation axis is on the circumference, and the pedestal is a wafer receiving plate and a rotating brush for cleaning the chuck mechanism that are integrally arranged on a straight line. Receiving plate and rotating brush arranged side by side The cradle is provided so as to be movable back and forth in a linear direction so that a vertical vertical surface in which the cradle advances and retreats is below the index head and intersects the circumference. A wafer polishing apparatus has been proposed.

Further, Japanese Patent Laid-Open No. 2002-219646 (Patent Document 5) is also attached to four sets of spindles provided at equal intervals on the same circumference around the rotating shaft on an index head supported on the rotating shaft at the top. A substrate chuck mechanism, a rotation mechanism for rotating the rotation axis of the index head in the clockwise direction by 90 degrees, 90 degrees, 90 degrees, 90 degrees, or 90 degrees, 90 degrees, 90 degrees, -270 degrees, An elevating mechanism for elevating and lowering the spindle of the substrate chuck mechanism, a mechanism for rotating the spindle in the horizontal direction, and a center where the axis of the rotation axis of the index head is the same so as to face each other below the four sets of substrate chuck mechanisms Substrate loading / substrate unloading / chuck cleaning stage, first polishing stage, first polishing stage, equidistantly arranged on the same circumference from the point An index table in which a polishing stage and a third polishing stage, a first substrate loading / unloading stage on the upper surface, a cleaning stage for a substrate chuck mechanism and a second substrate loading / unloading stage are provided at equal intervals on the same circumference (however, These three stays are moved by the rotation of the index table to constitute the substrate loading / substrate unloading / chuck cleaning stage.), 120 degrees, 120 degrees, 120 increments in the clockwise direction, or A rotation mechanism that rotates 120 degrees, 120 degrees, and -240 degrees; a substrate supply mechanism that includes a substrate loading cassette and a substrate loading transport robot; Ring cassette and the substrate discharging mechanism consisting of a substrate unloading conveyor robot proposes polishing apparatus of the substrate including the capital.

Japanese Patent Application Laid-Open No. 2007-165802 (Patent Document 6) is a substrate flattening apparatus for holding and grinding and polishing on four sets of suction tables provided on an index type turntable with the back side of the substrate facing up. There,
A rotating blade (cutting means) that performs a process of cutting the outer edge portion from the back surface to the outer edge portion (edge portion) of the substrate before the grinding process adsorbed on the adsorption table;
A grinding wheel provided with a grinding wheel arranged to face the suction table, and grinding the substrate by pressing the grinding wheel while rotating the grinding wheel against the back surface of the substrate while holding the substrate, the outer edge of which has been cut. Two sets of grinding wheels (grinding means)
A polishing puff (polishing means) disposed opposite to the suction table is provided, and the ground puffed substrate is held on the suction table and pressed against the back surface of the substrate while rotating the polishing puff. A polishing means for polishing,
These flattening devices are installed indoors, and a plurality of load ports (substrate storage cassettes) are provided outside the room.
The present invention proposes a substrate flattening apparatus including a two-barrel type substrate transfer robot, an alignment temporary table, and a cleaning device in a room behind the load port.

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.

Further, Japanese Patent Laid-Open No. 4-14849 (Patent Document 7) discloses that a substrate on a porous material temporary mounting table (chuck mechanism) having a recessed portion is floated by a water flow and adsorbed to a conveyance suction pad, and then in the recessed portion. A method is disclosed in which after the water is discharged from the bottom of the recessed portion, the suction pad that sucks the substrate is raised and then transferred to the next grinding stage. The method of floating the substrate on the temporary mounting table with a water flow and adsorbing it to the adsorption pad is effective in bridging the ultrathin semiconductor substrate having a silicon substrate thickness of 15 to 70 μm without damaging it.

JP 2001-252853 A JP 2005-98773 A US Pat. No. 7,238,087 Patent No. 4,260,251 JP 2002-219646 A JP 2007-165802 A JP-A-4-14849

  Semiconductor substrate processing manufacturers who want to reduce the thickness of the silicon substrate layer of the next generation 300mm diameter and the next generation 450mm diameter semiconductor substrate thickness of around 770μm to 15-50μm are as substrate planarization processing equipment The flattening apparatus is compact (small footprint), the throughput of 300 mm diameter semiconductor substrate is 20-25 sheets / hour, and the throughput of 450 mm diameter semiconductor substrate is 7-12 sheets / hour. Wants the appearance of. In addition, there is a demand for the emergence of a flattening apparatus capable of throughput of 10-15 wafers / hour of ground / polished TSV wafers whose 300mm diameter TSV wafer has an electrode head protrusion height of 0.5-20 μm. Yes.

  There was no problem when obtaining a semiconductor substrate with a silicon substrate thickness of 80 μm or more, but when a semiconductor substrate with a silicon substrate thickness of 15 to 50 μm was extremely thin, chipping or cracking occurred in the semiconductor substrate. Therefore, it is pointed out by a semiconductor substrate processing manufacturer that it is necessary to provide an edge grinding stage of a semiconductor substrate as described in Patent Document 1 and Patent Document 6. Also, the conventional method of pressing the lower part of the polishing head against the substrate on the temporary table and adhering the substrate to the polishing head or sticking it to the backing material of the polishing head is Since the substrate processing manufacturer is concerned, it is preferable to attach or adsorb the substrate to the polishing head by the water flow method described in Patent Document 7.

  In the flattening apparatus described in Patent Document 1 and Patent Document 6, since the edge (end face) grinding process and the back surface polishing process of the semiconductor substrate are performed on the same index type rotary table, the polishing stage portion is generated on the grinding stage. There is a defect that it is easy to get dirty with the grinding scraps. In particular, when the polishing stage of the flattening apparatus is used for projecting a head of a TSV wafer (through electrode wafer) (1 to 20 μm high), the presence of these grinding scraps becomes a fatal defect.

Furthermore, it is difficult to chamfer the edge portion (including the bevel portion) of the laminated bonding portion of wafers such as TSV wafers and SOI wafers with the edge cutting rotary blade of Patent Document 6 and the polishing tape edge chamfering device used in the market. It is. Further, the protective tape protecting the printed wiring surface of the semiconductor substrate is peeled off at the silicon substrate edge portion, and grinding scraps and polishing scraps are likely to adhere to the outer periphery of the silicon substrate edge.

  Furthermore, in the production of next-generation 450 mm diameter semiconductor substrates, the area to be planarized is 2.25 times larger than that of 300 mm diameter semiconductor substrates. Therefore, even if the semiconductor substrate planarization apparatus described in the prior art patent document group is simply enlarged, high throughput cannot be achieved, and a clean semiconductor substrate cannot be obtained.

  Further, the method of floating the substrate on the temporary placement table disclosed in the Patent Document 7 with a water flow and adsorbing it to the suction pad is adopted as the method of causing the substrate on the temporary placement table to float with water flow and sucking or sticking to the polishing head. However, in order to bridge the semiconductor substrate adsorbed or adhered to the polishing head onto the temporary placement table in the reverse direction, the temporary placement table structure described in Patent Document 7 positions the substrate (centering) on the temporary placement table. There is a drawback that can not be.

  A first object of the present invention is to replace the polishing stage of the flattening apparatus for a semiconductor substrate described in Patent Document 3 with four sets of index-type turn heads in place of the two-chuck polishing head described in Patent Document 4 and Patent Document 5. By improving the polishing time (throughput) of the semiconductor substrate on the polishing stage, and by changing the rotating blade of the edge cutting means described in Patent Document 6 to a grinding wheel, it is possible to chamfer the edge of the laminated wafer. An object of the present invention is to provide an apparatus for planarizing a semiconductor substrate.

  A second object of the present invention is to provide a temporary placement table that can be centered and is suitable for delivering a substrate between a polishing head capable of holding the substrate and the temporary table.

According to the first aspect of the present invention, the chamber for installing the planarizing apparatus is loaded from the front portion into an L-shaped semiconductor substrate loading / unloading stage chamber, the intermediate semiconductor substrate polishing stage chamber, and the back semiconductor substrate grinding. The processing stage chamber is divided into three chambers by partition walls, and the partition walls between the stage chambers are provided with openings through which the substrates leading to the adjacent stage chambers can be taken in and out, and the front wall of the loading / unloading stage chamber A semiconductor substrate flattening apparatus provided with a plurality of load port substrate storage cassettes outside the room,
A first articulated substrate transfer robot is provided in the chamber behind the load port in the loading / unloading stage chamber of the semiconductor substrate, the substrate cleaning device on the left side, and the first positioning above the substrate cleaning device. A temporary placement table is provided, and a second transfer-type articulated substrate transfer robot is provided at the rear back of the first positioning temporary placement table,
The polishing stage chamber has a cylindrical recess having a size capable of mounting two or four substrates, and water supply means for supplying water from the bottom of the porous ceramic recess into the recess. A temporary mounting table surface plate provided with two or four sets of temporary mounting tables provided on the same circumference, and three sets of first, second and third polishing surface plates having a planar circular shape for polishing two substrates simultaneously. The center point of the four sets of surface plates is composed of the polishing means installed on the same circumference and rotatably at equal intervals, and the polishing surface plate is located beside each of the three sets of polishing surface plates. Three sets of dressers for dressing the polishing cloth are provided, and one index type head is provided above the four sets of surface plates, and the surface of the substrate to be polished is placed below the index type head. One of the substrate polishing heads that attracts or sticks toward A substrate chuck means that can fix eight substrates on a concentric circle provided with four sets of substrate chuck mechanisms that are supported on a main shaft so as to be capable of rotating independently and independently is sucked or stuck to each substrate polishing head. A polishing stage that enables each of the substrates to face each of the four sets of the surface plates is provided,
In the semiconductor substrate grinding stage, a second temporary positioning table is provided on the back side of the second transfer type articulated substrate transfer robot, and a hand arm is placed on the right side of the second temporary positioning table. A front and back rotating third articulated transfer robot is provided, and a substrate front / back surface cleaning device is provided on the right side of the third articulated transfer robot. On the back side of the back surface cleaning device, there are provided a substrate chuck surface plate in which four sets of substrate chuck tables are provided on one index type turntable so as to be rotatable on the same circumference at equal intervals. Loading / unloading stage chuck, substrate rough grinding stage chuck, substrate edge grinding stage chuck, and substrate finish grinding chuck position are indexed to the numerical controller. And an edge grinding device that enables an edge grinding wheel to move back and forth and move up and down alongside the substrate edge grinding stage chuck, and a cup wheel type rough grinding above the substrate rough grinding stage chuck. A grindstone is provided so as to be movable up and down and rotatable, and a cup wheel type finish grinding grindstone is provided above and above the substrate finishing grinding stage chuck so as to be movable up and down and rotatable, and the third articulated transfer robot is provided with the above-mentioned The semiconductor substrate on the second positioning temporary table is transferred onto the loading / unloading stage chuck, the semiconductor substrate on the loading / unloading stage chuck is transferred onto the substrate front / back surface cleaning device, and the substrate front / back surface cleaning device. The upper semiconductor substrate is placed in front of the polishing stage chamber. Providing a grinding stage chamber to perform the task of transferring to the provisional table platen,
A flattening apparatus for a semiconductor substrate is provided.

The invention of claim 2 is a temporary table base plate provided with a substrate temporary table having a recessed portion in the center on a temporary table fixed base supported by a rotating shaft,
The substrate temporary mounting table includes a ring-shaped bottom made of a porous material, a cylindrical outer peripheral wall made of a non-water-permeable material having a recessed portion protruding from the outer periphery of the bottom, and an inner side of the cylindrical outer peripheral wall made of the non-water-permeable material. A plurality of positioning rods that can be moved up and down in a plurality of vertical through-holes provided at intervals, and the cylindrical outer peripheral wall made of the non-water-permeable material can be moved up and down by an external stress on the temporary table fixing base. Water is supplied from the ring-shaped bottom of the porous material to store water in the central recess of the temporary substrate mounting base, and a fixing mechanism attached thereto, an elevating mechanism for moving an annular fixing plate for fixing the bottoms of the plurality of positioning rods in the vertical direction, and a ring-shaped bottom made of porous material. And a water supply means for providing a temporary table surface plate.

  By providing an edge grinding process that reduces the edge thickness of the semiconductor substrate with an edge grinding wheel while the rough grinding process and the finish grinding process on the back surface of the semiconductor substrate are performed, the finishing grinding process after the edge grinding process, the polishing process, In the cleaning process and the substrate transport process, the chances of cracks in the semiconductor substrate and chipping at the edges are extremely rare. In addition, since the thickness of the edge portion and the bevel portion of the semiconductor substrate is reduced by the rough grinding, the grinding allowance in the edge grinding process is reduced, and a grinding wheel having a diameter of 25 to 50 mm can be used. Therefore, the footprint (installation area) of the edge grinding apparatus can be designed to be small.

  In addition, the room for installing the planarization processing apparatus includes a loading / unloading stage chamber for an inverted L-shaped semiconductor substrate in the front portion, a polishing stage chamber for the semiconductor substrate in the middle portion, and a grinding processing chamber for the semiconductor substrate in the rear portion. A semiconductor substrate that has been flattened by partitioning into three chambers by partition walls, and installing a substrate cleaning device in the loading / unloading stage chamber and a substrate front / back surface cleaning device in the semiconductor substrate grinding stage chamber The number of foreign matters having a particle diameter of less than 0.1 μm adhering to the surface can be made as clean as 100 or less.

  Since the semiconductor substrate held by the polishing head is rubbed against the polishing cloth of the polishing surface plate having a diameter larger than the diameter of the semiconductor substrate for polishing, the polishing processing speed can be increased and the entire surface of the semiconductor substrate can be increased. Since the pressure distribution over which the polishing surface pressure of the polishing surface plate is applied is substantially constant, a flattened semiconductor substrate having a uniform film thickness distribution can be obtained. When the semiconductor substrate is a copper electrode penetrating silicon substrate, obtain a TSV wafer having a copper electrode head protruding 1 to 20 μm high from the silicon substrate surface according to the polishing allowance (abrasion removal amount of the silicon substrate). Can do.

  Since the semiconductor substrate polishing process is a rate-limiting process that requires approximately twice the time required for the grinding process, a CMP polishing apparatus equipped with a pair of substrate suction chucks that can simultaneously polish two substrates can be obtained by grinding. The two ground substrates thus obtained were held on a polishing head and rubbed against the polishing surface plate to adjust the throughput so that two semiconductor substrates could be polished simultaneously.

  The temporary table surface plate enables the transfer of the semiconductor substrate between the temporary table and the polishing head to be carried out using floating by water flow. When transferring the semiconductor substrate on the temporary mounting table to the polishing head, a water flow is supplied from the water supply means into the recessed portion of the temporary mounting table to float the semiconductor substrate, and is fed into the substrate holding pocket of the polishing head, and is adsorbed to the polishing head. Affixed to the backing member under the polishing head. Conversely, when placing the semiconductor substrate held by the polishing head on the temporary mounting table, after raising the positioning pin, water is supplied into the recessed portion of the temporary mounting table, and then the polishing head pocket for holding the semiconductor substrate is placed. The bottom part of the outer peripheral annular part to be configured is brought into contact with the upper surface of the cylindrical outer peripheral wall made of a non-water-permeable material of the temporary table, so that the semiconductor substrate is immersed in the water stored in the recessed part, and if necessary, the back surface or backing of the suction plate in the pocket part configuration A compressed air is blown from the back of the material, and then the semiconductor substrate centered and held on the top of the positioning pin is placed on the ring-shaped bottom made of the porous material of the temporary table by discharging the water stored in the recessed portion to the outside while lowering the positioning pin. be able to. In addition, the centering of the semiconductor substrate mounted on the temporary table on the temporary table with respect to the polishing head is performed by the rotation of a rotating shaft that supports the temporary table fixed base.

FIG. 1 is a plan view of an apparatus for planarizing a semiconductor substrate. FIG. 2 is a flowchart showing an edge grinding process of a semiconductor substrate. FIG. 3 is a cross-sectional view showing a state in which two semiconductor substrates are held and polished by a third polishing surface plate. FIG. 4 is a plan view of a semiconductor substrate flattening apparatus. (Known) FIG. 5 is a partial cross-sectional view of the temporary table base. FIG. 6 is a plan view of the temporary table.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
1 includes a loading / unloading stage chamber 11a for the L-shaped semiconductor substrate from the front, a polishing stage chamber 11c for the semiconductor substrate in the middle, and a back portion. The semiconductor substrate is divided into three chambers, namely, a grinding stage chamber 11b by partition walls. The partition wall between the stage chambers is provided with an opening through which a substrate leading to an adjacent stage chamber (11a, 11c or 11c, 11b) can be taken in and out, and is provided outside the front wall chamber of the loading / unloading stage chamber 11a. A plurality of substrate storage cassettes 13, 13, 13 are installed, and a load port portion having an opening is provided also in a portion of the front wall of the chamber that is in contact with the back of the substrate storage cassette. There is a door that can be opened and closed. In order to see the status of the appliances in each chamber 11a, 11b, 11c, each chamber is provided with a semi-rotating transparent window 11d, 11d, 11d, 11d, 11d, 11d, 11d. In FIG. 1, the rotation trajectory is indicated by a virtual arc. The substrate storage cassettes 13, 13, 13 are provided with a non-contact three-dimensional roughness meter (Aspector) manufactured by AFM that can confirm the presence of a semiconductor substrate.

During planarization of the semiconductor substrate, the chamber pressure in the polishing stage chamber 11c is set higher than the chamber pressure in the grinding stage chamber 11b.

  In the semiconductor substrate loading / unloading stage chamber 11a, a first transfer type articulated substrate transfer robot 14 is provided on a base 12 in a chamber behind the load port, and a substrate cleaning device 3 is provided on the left side thereof. A first positioning temporary table 15 is provided above the substrate cleaning device, and a second transfer multi-joint type substrate transport robot 16 is provided at the rear rear of the first positioning temporary table (centering device). As shown in FIG. 1, the second transfer type articulated substrate transfer robot 16 includes a transfer type articulated substrate transfer robot 16 indicated by a solid line and a second transfer type articulated substrate transfer robot 16 indicated by a virtual line. It can be moved back and forth by driving the ball screw 16a.

  The first transfer type articulated substrate transfer robot 14 is movable in the left-right direction (X-axis direction) along the guide rail 14a, and holds the semiconductor substrate in the substrate storage cassette 13 by the robot hand 14b. The semiconductor substrate on the substrate cleaning device 3 is gripped by the robot hand 14b and transferred to and stored in the substrate storage cassette 13 (unloading). The second transfer type articulated substrate transfer robot 16 can be transferred in the front-rear direction (Y-axis direction) by a ball screw drive 16a. The first transfer type articulated substrate transfer robot 14 may be an articulated substrate transfer robot 14 in which the extension / contraction length of the arm hand extends a sufficient distance for transferring the semiconductor substrate.

  The first temporary positioning table 4 is a positioning device that performs centering (centering position adjustment) of the semiconductor substrate.

  The substrate cleaning device 3 is a spin-type substrate cleaning device for cleaning a polished silicon substrate surface of a semiconductor substrate. Pure water is supplied from one cleaning liquid supply nozzle 3a, and chemical cleaning liquid is supplied from the other cleaning liquid supply nozzle 3b. Is supplied onto the silicon substrate surface. The cleaning liquid supply nozzles 3a and 3b can swing.

  As pure water, distilled water, deep seawater, deionized water, surfactant-containing pure water, or the like is used. Examples of the chemical cleaning liquid include hydrogen peroxide water, ozone water, hydrofluoric acid aqueous solution, SC1 liquid, SC1 liquid and ozone water mixed liquid, hydrogen fluoride liquid, hydrogen peroxide water and water-soluble amine compound liquid, etc. Alternatively, those in which any of water-soluble anionic or nonionic, cationic, or betaine type amphoteric surfactants are blended with these are used.

  As the substrate cleaning device 3, a chemical cleaning device described in Japanese Patent Application No. 2008-183398 may be used. The chemical cleaning device 3 includes a spin chuck in a cleaning tank, and the spin chuck places a semiconductor substrate and rotates it in the horizontal direction. The spin chuck is supported by a hollow rotary shaft, a pure water supply pipe is provided in the hollow rotary shaft, and pure water is used to clean the surface of the protective tape. A decompression fluid passage is provided between the inside of the hollow rotary shaft and the outside of the pure water supply pipe. Above the spin chuck, an alkali cleaning liquid supply nozzle 3b is provided on a support rod that is erected by a rotary drive mechanism so as to rotate by a pendulum on a track passing through the spin chuck center point by an arm, and the acid cleaning liquid supply nozzle 3b. Is provided on a support rod that stands up from a rotary drive mechanism so that the pendulum rotates on an orbit passing through the center point of the spin chuck by the arm. Further, the rinse liquid supply nozzle is provided at an angle at which the rinse liquid reaches the spin chuck center point from above the base.

As the alkaline cleaning liquid, ammonia water (SC1), trimethylammonium water, or the like is used, and is used to remove foreign substances adhering to the silicon substrate surface. As the acid cleaning solution, ozone-dissolved water, hydrogen peroxide water, hydrofluoric acid aqueous solution, hydrofluoric acid / hydrogen peroxide / isopropanol mixed aqueous solution, hydrogen peroxide / hydrochloric acid / pure water mixed solution (SC2), etc. are used. It serves to return the oxidized silicon substrate surface (S _i O ₂ ) to silicon (S _i ).

  As the rinsing liquid, pure water such as deionized exchange water, distilled water, and deep seawater is used. The rinsing liquid serves to wash off alkali and acid so that they do not remain on the semiconductor substrate surface. The silicon substrate surface of the semiconductor substrate is cleaned first by alkali cleaning, second by acid cleaning, and third by rinsing cleaning. If necessary, a rinse wash may be added between the first alkaline wash and the second acid wash.

Using the planarization lowering device 1, the thickness of the silicon substrate surface of the semiconductor substrate (DRAM) having a single silicon substrate is reduced by 720 to 770 μm, and the thickness of the silicon substrate surface is 10 to 80 μm. When performing, protect the printed wiring surface of the semiconductor substrate with an ultraviolet curable acrylic resin adhesive tape, or use a template such as a glass disk, polycarbonate disk, polymethyl methacrylate disk, or polyether ester ketone (PEEK) disk. The printed wiring surface of the semiconductor substrate is pasted using wax or a heat decomposable foaming adhesive and stored in the storage cassette 13. Since TSV wafers and SOI wafers have sufficient thickness and high rigidity, it is not necessary to use the protective tape or the protective disk.

The second transfer type articulated substrate transfer robot 16 holds the semiconductor substrate centered on the first positioning temporary table 4 with an arm 16b and is installed in the grinding stage chamber 11b. The semiconductor substrate is transferred onto the temporary positioning table 5. Further, the semiconductor substrate on the substrate front / back surface cleaning device 6 in the grinding stage chamber 11b is held by the arm 16b, and onto the temporary table 70a1 in front of the circular temporary table base 70a in the polishing stage chamber 11c. Transport. A virtual circle 16c indicates the maximum area in which the arm 16b of the second transfer type articulated substrate transfer robot can move.

The grinding work of the semiconductor substrate in the grinding stage 20 is longer than the loading / unloading work time of the semiconductor substrate. In the semiconductor substrate grinding stage 11b of the semiconductor substrate, the second temporary positioning table 5 is provided on the back side of the second transfer type articulated substrate transfer robot 16, and the second temporary positioning substrate 5 is provided. A third articulated transfer robot 17 that rotates the front and back of the hand arm is provided on the right side of the table, and the substrate front and back surface cleaning device 6 is provided on the right side of the third articulated transfer robot. . Four sets of substrate chuck tables 30a, 30b, 30c, and 30d on the back side of the third articulated transfer robot 16 and the substrate front and back surface cleaning device 6 are arranged on the same circumference on one index type turntable 2 and the like. A substrate chuck surface plate provided rotatably at intervals is provided, and the four sets of substrate chuck tables are loaded in the counterclockwise direction from the front side to the loading / unloading stage chuck 30a, the substrate rough grinding stage chuck 30b, and the substrate edge grinding stage chuck. The positions of 30c and substrate finishing grinding chuck 30d are stored as index positions in a machining program stored in a memory (not shown) of a numerical controller. The third articulated transfer robot 17 transfers the semiconductor substrate on the second positioning temporary table 5 onto the loading / unloading stage chuck 30a, and transfers the semiconductor substrate on the loading / unloading stage chuck 30a. It has a function of transferring to the substrate front / back surface cleaning device 6 and transferring the semiconductor substrate on the substrate front / back surface cleaning device 6 onto the temporary table base plates PS1f and PS1b in the polishing stage chamber 11c.

The index-type turntable 2 is supported by a rotating shaft, and the rotating shaft is rotated 90 degrees in a counterclockwise direction by a rotation driving device (not shown), or a service pipe such as an electric wire, a coolant, or air is twisted. In order to prevent breakage, it is rotated 270 degrees in the clockwise direction once every four rotations. By the rotation of the index type turntable 2, the four pairs of substrate chuck tables 30a, 30b, 30c, 30d are numerically controlled recording units (not shown) as the positions of the other names of the substrate chuck tables 30b, 30c, 30d, 30a. The changed chuck name is recorded in.

A chuck cleaning device 38 disclosed in US Pat. No. 7,238,087 (Patent Document 3) is provided above the loading / unloading stage chuck 30a. 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 loading / unloading stage chuck 30a, the rotating brush 38a is lowered and brought into contact with and rubbed to adhere to the surface of the chuck 30a. After removing grinding residues and abrasive grains, the brush is raised, and then the rotating rotary chuck cleaner grindstone 38b is lowered and brought into contact with and rubbed against the surface of the chuck 30a, and supplied from a pure water supply nozzle. The grinding residue stuck in the porous ceramic chuck 30a is removed together with pure water. Further, pressurized water is ejected from the back surface of the porous ceramic chuck 30a, and the grinding residue stuck into the porous ceramic chuck 30a is ejected from the porous ceramic chuck 30a to be completely removed.

Above the substrate rough grinding stage chuck 30b, a stationary plate 90c having a grinding wheel shaft 90b for bearing a diamond cup wheel type rough grinding wheel 90a having a grinding number of 300 to 2,000 is fixed on the front surface of the column. The rough grinding means 90 which can be moved up and down on the guide rail 90f by driving is provided. Rotation driving devices such as a motor, a pulley, and a transmission belt, which are rotation driving devices for the grindstone shaft 90b, are not shown in the figure because they are provided in the column. Rotational speed of the substrate chuck 8~300rpm ^{(min -1),} the rotational speed of the cup wheel type grinding wheel 1,000~4,000min ^-1, grinding fluid supply to the silicon base surface is 100～2,000Cc / Minutes.

A grinding fluid is supplied from a grinding fluid supply nozzle (not shown) to a grinding point where the diamond cup wheel type rough grinding wheel 90a contacts the semiconductor substrate. As such a grinding liquid, pure water, ceria particle aqueous dispersion, fumed silica aqueous dispersion, colloidal silica aqueous dispersion, or tetramethylammonium, ethanolamine, caustic potash, imidazolium salt, etc. are blended in these grinding liquids. Can be used.

The edge grinding wheel 9a is moved on the base 12 beside the substrate edge grinding stage chuck 30c, the slider 9d is moved back and forth by driving the motor 9e on the guide rail 9c, and the grinding wheel shaft that supports the edge grinding wheel 9a is fixed. An edge grinding device 9 is provided that allows the plate to move up and down on the guide plate 9f rail by driving a motor 9g.

In order to edge-grind the outer periphery of the silicon substrate of the semiconductor substrate w that has been roughly ground using the edge grinding apparatus 9, as shown in FIG. 2, the semiconductor substrate on the rotating substrate edge grinding stage chuck 30c The diamond cup wheel type edge grinding wheel 9a rotating above the outer periphery of the silicon base of w is moved forward (FIG. 2a), and then the diamond cup wheel type edge grinding wheel 9a is moved down to move out of the silicon base. When the circumferential surface of the edge grinding wheel 9a is brought into contact with and rubbed within a peripheral edge of 0.5 to 3 mm, infeed grinding is performed (FIG. 2b), and the desired thickness is reduced, the diamond cup wheel type edge grinding wheel This is done by raising the wheel 9a and moving it away from the edge grinding surface of the semiconductor substrate w.

The grinding fluid supplied to the grinding point where the edge grinding wheel 9a and the outer periphery of the silicon substrate of the semiconductor substrate abut is pure water, ceria particle water dispersion, fumed silica water dispersion, colloidal silica water dispersion. Alternatively, those in which tetramethylammonium, ethanolamine, caustic potash, imidazolium salt or the like is blended with these grinding fluids can be used.

Above the substrate finishing grinding stage chuck 30d is a sliding plate 91d having a fixed plate 91c fixed to a front surface of the column with a grinding wheel shaft 91b fixed to a diamond cup wheel type finishing grinding wheel 91a having a grinding number of 2,500 to 30,000. A finish grinding means 91 is provided which can be moved up and down on the guide rail 91f by driving the motor 91e. Rotation drive devices such as a motor, a pulley, and a transmission belt, which are rotation drive devices for the grindstone shaft 91b, are not shown in the figure because they are provided in the column. Rotational speed of the substrate chuck 5~80rpm ^{(min -1),} the rotational speed of the cup wheel type grinding wheel 400~3,000min ^-1, grinding fluid supply to the silicon base surface in 100～2,000Cc / min is there.

  The grinding allowance (730 to 750 μm thickness) of the silicon base surface having a thickness of about 750 to 770 μm at the grinding stage 20 is removed by the rough grinding stage of the semiconductor substrate, and the thickness of 10 to 40 μm is removed by the finish grinding stage.

Two-point thickness indicators 89 and 89 for measuring the thickness of the semiconductor substrate are provided on the base 12 beside the substrate rough grinding stage chuck 30b and the substrate finishing grinding chuck 30d. 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. White light (420 to 720 nm wavelength) is used as the spectral wavelength for measuring the thickness of the printed wiring board surface of the semiconductor substrate, and 650 nm or 1.3 μm wavelength is used as the spectral wavelength for measuring the thickness of the silicon substrate. .

The hand arm front / back rotation type third articulated transfer robot 7 grips the semiconductor substrate on the loading / unloading stage chuck 30a with the hand arm 7a and transfers it onto the substrate front / back surface cleaning device 6.

The substrate front and back surface cleaning device 6 includes, for example, a pair of brushes 6a and 6a for cleaning the outer peripheral edges of the semiconductor substrate front and back surfaces, and cleaning liquid supply nozzles 6b and 6c for supplying a cleaning liquid to the semiconductor substrate front and back surfaces. The cleaning of the front and back surfaces of the semiconductor substrate is performed by transferring the semiconductor substrate onto the disk-shaped porous ceramic suction chuck 6d of the substrate front and back surface cleaning device 6, and then supplying a cleaning liquid to the front and back surfaces of the mounted semiconductor substrate. Brush scrub cleaning while spinning the porous ceramic suction chuck 6d, and then holding the outer peripheral edge of the semiconductor substrate with six pairs of fixed claws, and raising the ring that supports the six pairs of fixed claws at equal intervals. The semiconductor substrate is moved away from the upper surface of the disk-shaped porous ceramic suction chuck 6d, and the cleaning liquid is supplied to the front and back surfaces of the semiconductor substrate from the cleaning liquid supply nozzles 6b and 6c. Further, the substrate front and back surface cleaning device 6 disclosed in the back of JP-A-2009-277740, specifically, a cleaning liquid water storage tank is provided in the central portion of the cleaning device, and is provided upright in the central portion of the water storage tank. A support flange is provided around the rotary spindle, and a planetary rotation axis is provided upright from the support flange in parallel with the rotary spindle, and a substrate surface wiping tool having a diameter ranging from the outer peripheral edge of the semiconductor substrate to the center point is provided as a planet. A substrate front and back surface cleaning device 6 that is provided above the rotation shaft and planetarily rotates the substrate surface wiping tool by rotating the rotation spindle so that the surface from the outer peripheral edge of the semiconductor substrate w to the center point is rotated on the planet. There may be.

  As the rough grinding liquid, finish grinding liquid, and cleaning liquid, pure water is generally used, but since the semiconductor substrate is subjected to a polishing process or a cleaning process in a later process, the pure water contains an alkali or a water-soluble amine compound. You may do it.

  The semiconductor substrate whose front and back surfaces on the substrate front and back surface cleaning device 6 have been cleaned is held by the arm 17a of the third transfer type articulated substrate transfer robot 17 and is a circular temporary table in the polishing stage chamber 11c. The surface plate PS1 is transferred onto the temporary placement tables PS1f and PS1b.

  The polishing work of the semiconductor substrate in the polishing stage chamber 11c takes about twice as long as the grinding work in the grinding stage 20. Therefore, the polishing stage 70 is configured so that the polishing work of two semiconductor substrates can be performed simultaneously.

In the polishing stage chamber 11c, a temporary table base plate PS1 in which four sets of circular temporary tables on which four substrates can be placed are provided on the same circumference and at equal intervals, and two substrates are mounted. The center points of the four sets of surface plates PS1, PS2, PS3, and PS4 are the same for the first, second and third polishing surface plates of the planar circular polishing surface plate that are simultaneously polished. Polishing means disposed on the circumference and rotatably arranged at equal intervals, and three dressers 76 for dressing the polishing cloth of the polishing surface plate beside each of the three sets of polishing surface plates PS2, PS3, PS4 , 76, 76 are provided. Dresser cleaning nozzles 76a, 76a, and 76a are provided beside the support column of the dresser. Above these four sets of surface plates PS1, PS2, PS3 and PS4, one index type head 71 is provided, and below this index type head, the semiconductor substrate is placed with the surface to be polished facing downward. Four sets of polishing head mechanisms for holding a substrate are provided on concentric circles, wherein a pair of polishing heads 70a and 70b having a substrate storage pocket portion 71p to be adsorbed or attached are simultaneously and independently supported by a main shaft so as to freely rotate. The polishing stage 70 is provided with a polishing head capable of fixing a single substrate.

As shown in FIG. 3, the pair of polishing heads (substrate chucks) 70a, 70b is rotated by 90 degrees of the rotation shaft 71s of the index type head 71. , PS2, PS3, PS4 can be faced in correspondence.

Further, the spindle shafts 70s and 70s of the pair of polishing heads 70a and 70b can be independently rotated by driving motors 70m and 70m, respectively, and support plates for supporting the fixing plates of both polishing heads 70a and 70b. 70e is suspended by a shaft 78, and a fixed screw moving table with a ball screw screwed to the back surface of a sliding plate 78a for fixing the shaft 78 is provided. Can be slid. By this vertical movement, the pair of polishing heads 70a and 70b can be moved up and down.

The rotating shafts (spindles) 79 of the four sets of surface plates PS1, PS2, PS3, PS4 are rotated by a servo motor 79m.

  As shown in FIGS. 5 and 6, the temporary table base plate PS <b> 1 is provided with temporary substrate table PS <b> 1 f and PS <b> 1 b having a recessed portion 100 in the center on the temporary table fixed base supported by the hollow rotating shaft 79. The substrate temporary mounting table PS1f includes a ring-shaped bottom 101 made of a porous material (porous ceramic, porous polyacetal, porous polytetrafluoroethylene, porous poly-2-fluorinated 2-chloroethylene, porous urea resin, etc.) A non-water-permeable material bottom portion 102 that protrudes from the outer periphery of the bottom portion and has a recessed portion in the center, a cylindrical outer peripheral wall 103 that is vertically movable upright on the outer periphery of the bottom portion of the non-water-permeable material, and this non-water-permeable material tube 6 positioning rods 105 movably provided in the upper and lower through holes 104 provided at equal intervals on the inner side of the outer peripheral wall, and the non-water-permeable material cylinder The outer peripheral wall 103 is fixed on the temporary mounting base fixing base PS1R by a spring 107a that expands and contracts due to external stress, and the cylindrical outer peripheral wall 103 is attached so as to be movable up and down, and the bottoms of the six positioning rods 105 are fixed. And an elevating mechanism (air cylinder) 108 for moving the annular fixing plate 105b up and down, and water supply means 109 for supplying water from the ring-shaped bottom portion 101 made of the porous material and storing the water in the central recessed portion 100 of the temporary substrate mounting table, A cleaning water supply mechanism 110 is provided at the center of the substrate temporary placement tables PS1f and PS1b. The tip of the outlet of the water supply nozzle 110a of the cleaning water supply mechanism 110 is directed so that pure water is jetted and supplied toward the central portion of the substrate temporary placement table PS1R.

  The temporary table base PS1 can carry out the transfer of the semiconductor substrate w between the temporary substrate tables PS1f and PS1b and the polishing head 70a by using floating by water flow. When the semiconductor substrate w on the temporary substrate mounting table is transferred to the polishing head 70a, a water flow is supplied from the water supply nozzle 110a of the cleaning water supply mechanism 110 into the recessed portion 100 of the temporary mounting table to float the semiconductor substrate. The substrate is fed into the substrate holding pocket 70p and is adsorbed on the polishing head adsorption plate or attached to the backing member 70BC below the polishing head. Reference numeral 70R denotes an annular retainer.

  On the contrary, when the semiconductor substrate w held by the polishing head 70a is placed in the central recess 100 of the temporary substrate table, the positioning pin 105 is lifted by the air cylinder 108 and then the concave portion 100 of the temporary table. Then, the bottom of the outer peripheral annular portion (annular retainer) 70R constituting the pocket portion 70p of the polishing head holding the semiconductor substrate is brought into contact with the upper surface of the cylindrical outer peripheral wall 103 made of the non-water-permeable material of the temporary table. The substrate is immersed in the water storage in the recessed portion 100, and if necessary, compressed air is blown from the back surface of the suction plate or the backing material of the pocket portion configuration of the polishing head, and then the semiconductor substrate centered and held on the positioning pin top portion 105a is positioned. The ring-shaped bottom 10 made of a porous material of the temporary table PS1R is provided by discharging the water stored in the recessed portion to the outside while lowering 105. It can be put to. Further, the centering of the semiconductor substrate mounted on the temporary mounting table PS1 on the temporary mounting table with respect to the polishing head 70a is performed by a servo motor (not shown) on the hollow rotary shaft 79 that supports the temporary mounting table fixed base PS1R. This is done by rotating the drive.

  The rotary shaft 79 rotates on the silicon substrate surfaces of the two (first and second) semiconductor substrates w and w adsorbed or attached to the pair of polishing heads 70a and 70b on which the spindle shafts 70s and 70s are rotated. A polishing process is performed in which the surface of the polishing surface plate is in contact with and rubbed against the surface of the polishing pad PS. A breathable backing material sheet such as a polyurethane foam sheet or suede may be attached to the bottom of the polishing head.

When polishing the semiconductor substrate, a water-based abrasive is supplied from supply nozzles 72 and 72 to a processing point where the semiconductor substrate w and w held by the polishing head and the polishing surface plate polishing cloth PS rub. . Examples of such aqueous abrasives include pure water, ceria particle aqueous dispersion, fumed silica aqueous dispersion, colloidal silica aqueous dispersion, or these grinding liquids such as tetramethylammonium hydroxide, ethanolamine, caustic potash, imidazolium salt, etc. And a base, a surfactant, a chelating agent, a pH adjuster, an oxidizing agent and a preservative can be used. The water-based abrasive is supplied to the polishing cloth (polishing pad) surface at a rate of 50 to 2,500 cc / min.

A foamed polyurethane laminate sheet as a polishing cloth for polishing surface plates PS2, PS3, PS4, and a non-woven fabric coated with a coating agent composed of a urethane prepolymer and a curing agent compound having an active hydrogen group, impregnated, and heated and foamed. Those are preferred. For the polishing cloth, purchase a polyurethane laminated sheet pad from Nitta Haas Co., Ltd. and Toyobo Co., Ltd., purchase a polyester fiber non-woven pad from Toray Cortex Co., Ltd. and Mitsui Chemicals Co., Ltd., and purchase a ceria-containing polyurethane pad from Toyobo Co., Ltd. it can. As the polishing cloth for cueing the electrode of the TSV wafer, a soft polyurethane foam pad having a JIS-A hardness of 60 to 85 is preferable.

Although not disclosed in FIG. 1, the non-contact type thickness measuring instrument disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2009-88073 is used as a thickness measuring instrument for measuring the thickness of a polished semiconductor substrate. preferable.

The rotation speed of the pair of polishing heads 70a and 70b on which the spindle shafts 70s and 70s are rotated is 5 to 100 min ⁻¹ on the polishing surface plates PS2 and PS3 and 2 to 55 min on the polishing surface plate PS4. ^-1 . Rotational speed of the polishing platen PS2, PS3 is, 5~100min ^-1, rotational speed of the polishing platen PS4 is, 2~55min ^-1 are preferred. The pressure applied to the semiconductor substrate by the polishing platen is 50 to 300 g / cm ² , preferably 80 to 250 g / cm ² . The polishing conditions for rough polishing and intermediate finish polishing, and the type of aqueous abrasive may be the same or different.

  85 to 95% of the polishing allowance (5 to 20 μm thickness) of the semiconductor substrate at the polishing stage 70 is removed by the rough polishing stage and the intermediate finish polishing stage of the semiconductor substrate, and 0.1 to 2 μm by the final polishing process. Remove the thickness. By using an abrasive slurry containing ceria particles or silica particles as an aqueous abrasive, the silicon substrate surface is polished in preference to the metal electrode, so that the electrode head with a height of 1 to 20 μm protrudes from the silicon substrate surface. A TSV substrate is obtained.

When a polishing cloth with uniform surface properties is used, the electrode head protrusion height of the TSV wafer obtained is a protrusion height of 90 to 95% of the amount of polishing removal at the location where the electrode is present in isolation, Where the electrodes are densely present, the protrusion height is 55 to 60% of the polishing allowance. Therefore, if the JIS-A hardness of the polishing cloth that polishes the places where the electrodes are densely present is made lower than the JIS-A hardness of the polishing cloth that polishes the places where the electrodes exist in isolation, both patterns It is expected that a TSV wafer with a more approximate electrode protrusion height will be obtained.

  Using the substrate planarization processing apparatus 1 shown in FIG. 1, the operation of thinning and planarizing the silicon substrate surface on the back surface of the semiconductor substrate or the through electrode silicon substrate surface on the back surface of the TSV substrate is performed through the following steps. The work time in parentheses indicates the work time for processing a 300 mm diameter and 450 mm diameter semiconductor substrate, although it depends on the diameter of the semiconductor substrate and the silicon substrate removal allowance (thickness) to be thinned.

  1) The semiconductor substrate w stored in the substrate storage cassette 13 is transferred and moved into the loading / unloading stage chamber 11a by using the first articulated substrate transfer robot 14, and further transferred to the positioning temporary table 4 The semiconductor substrate is centered on the temporary positioning table. (3-8 seconds)

2) The semiconductor substrate on the first positioning temporary table 5 is transferred onto the second positioning temporary table 5 in the grinding stage chamber 11b by using the second transfer type articulated substrate transfer robot 16. The semiconductor substrate is centered by the second positioning temporary table. (3-8 seconds)

3) After placing the semiconductor substrate on the second positioning temporary placement table 5 on the loading / unloading stage chuck 30a mounted on the index type turntable 2 using the third articulated transfer robot 17, the chuck is then mounted. The pressure of 30a is reduced and the semiconductor substrate is fixed on the suction chuck 30a with the back surface (silicon substrate surface) of the semiconductor substrate facing upward. (3-8 seconds)

4) The index type turntable 2 is rotated 90 degrees counterclockwise, and the semiconductor substrate on the loading / unloading stage chuck 30a is moved to the substrate rough grinding stage chuck 30b position. (0.5-2 seconds)

5) The substrate rough grinding stage chuck 30b is rotated at a rotational speed of 8～300Min ^-1, then it is lowered while rotating the cup wheel type rough grinding 90a at a rotational speed of 1,000～4,000Min ^-1 Infeed rough grinding is performed while abutting and rubbing against the silicon substrate surface of the semiconductor substrate. The thickness to be reduced is, for example, 730 μm. During the in-feed rough grinding, the grinding liquid is supplied at a rate of 100 to 2,000 cc / min to the work point where the cup wheel type rough grinding wheel 90a and the semiconductor substrate w come into contact. When the thickness of the semiconductor substrate measured by the thickness measuring device 89 reaches a desired threshold value, the cup wheel type rough grinding wheel 90a is raised and moved away from the silicon substrate surface of the semiconductor substrate. (2.5-5 minutes)

6) The index type turntable 2 is rotated 90 degrees counterclockwise to move the roughly ground semiconductor substrate on the substrate rough grinding stage chuck 30b to the substrate edge grinding stage chuck 30c position. (0.5-2 seconds)

7) The semiconductor substrate while rotating the substrate edge grinding stage chuck 30c at a rotational speed of 50 to 300 min ⁻¹ and rotating the edge grinding wheel 9a of the edge grinding apparatus at a rotational speed of 1,000 to 8,000 min ^−1. Next, the rotating edge grinding wheel 9a is lowered, and a desired thickness (20 to 100 μm) of the outer periphery of the silicon substrate on the back surface of the semiconductor substrate on the substrate edge grinding stage chuck 30c is lowered. Reduce infeed edge grinding. Grinding fluid is supplied to the working point where the edge grinding wheel 9a contacts the semiconductor substrate w. When the thickness of the outer peripheral edge of the semiconductor substrate measured by a thickness measuring device (not shown) reaches a desired thickness threshold, the edge grinding wheel 9a is raised to move away from the outer peripheral edge surface of the semiconductor substrate. . Next, the edge grinding wheel 9a is retracted and returned to the edge grinding start position. (0.5 to 1 minute)

8) The index-type turntable 2 is rotated 90 degrees counterclockwise, and the edge-ground semiconductor substrate on the substrate edge grinding stage chuck 30c is moved to the substrate finishing grinding stage chuck 30d position. (0.5-2 seconds)

9) The substrate finish grinding stage chuck 30d is rotated at a rotational speed of 8 to 300 min ⁻¹ , and then the cup wheel type finish grinding wheel 91a is lowered while rotating at a rotational speed of 400 to 3,000 min ⁻¹ to perform rough grinding. Infeed finish grinding is performed while contacting the silicon substrate surface of the semiconductor substrate. The thickness to be reduced is 1 to 20 μm, preferably 2 to 10 μm. During the in-feed finish grinding, a grinding liquid is supplied to a work point where the cup wheel type finish grinding wheel and the semiconductor substrate are in contact with each other. When the thickness of the semiconductor substrate measured by the thickness measuring device 89 reaches a desired threshold value, the cup wheel type finish grinding wheel 91a is raised and moved away from the silicon substrate surface of the semiconductor substrate. (2-4 minutes)

10) The index type turntable 2 is rotated 270 degrees clockwise or 90 degrees counterclockwise to move the semiconductor substrate on the substrate finishing grinding stage chuck 30d to the loading / unloading stage chuck 30a position. . (0.5-2 seconds)

11) A substrate front and back surface cleaning apparatus using a third articulated transfer robot 17 for a semiconductor substrate subjected to rough grinding, edge grinding and finish grinding fixed on the loading / unloading stage chuck 30a. 6 and the front surface and the back surface of the semiconductor substrate are cleaned at that location. (5-15 seconds)

12) The semiconductor substrate w on the substrate front and back surface cleaning device 6 is transferred onto the temporary table base plate PS1 in the polishing stage chamber 11c by using the third articulated transfer robot 17, and the silicon of the semiconductor substrate is transferred. The substrate surface is reversed so that the base surface faces downward, and then placed on the temporary table PS1f of the temporary table. (1-2 seconds)

13) Return the transfer arm of the third articulated transfer robot to the standby position. (0.5 to 1 second)

14) During the above steps 1) to 13), the newly transferred second semiconductor substrate is subjected to rough grinding, edge grinding, finish grinding, and double-sided cleaning. The semiconductor substrate w on the front and back surface cleaning device 6 is transferred onto the temporary table PS1 in the polishing stage chamber 11c by using the third articulated transfer robot 17, and the silicon substrate surface of the semiconductor substrate is The front and back are reversed so as to face downward, and then placed on the temporary table base PS1b. (2-4 seconds)

15) The rotary shaft 79 of the temporary table base plate PS1 on which the two semiconductor substrates w and w are placed is rotated 180 degrees to center the semiconductor substrates w and w with respect to the polishing head. Next, a pair of substrate holding polishing heads 70 a and 70 b provided below the index-type head 71 is lowered from above the temporary table base plate PS 1, and the bottom of the annular retainer of the polishing head is brought into contact with the upper surface of the cylindrical outer peripheral wall 103. Let After that, a water flow is supplied from the water supply nozzle 110a of the cleaning water supply mechanism 110 into the recessed portion 100 of the temporary table PS1f to float the semiconductor substrate, and is sent into the substrate holding pocket 70p of the polishing head, and is applied to the suction plate at the bottom of the polishing head. Adhere to the backing member under the suction or polishing head. Further, after draining the water stored in the recessed portion 100, the pair of polishing heads 70a and 70b holding the semiconductor substrate is raised. (2-4 seconds)

16) The main shaft of the index type head is rotated 90 degrees clockwise, and the pair of polishing heads (substrate suction chucks) holding the two semiconductor substrates on the lower surface is moved to a position facing the first polishing surface plate PS2. Moving. (1 to 2.5 seconds)

17) while rotating the first polishing platen PS2 at a rotational speed of 5~100min ^-1, 1 pair 70a of the polishing head is lowered while rotating the 70b at a rotation speed of 5～100Min ^-1, the 2 Rough polishing is performed by rubbing the silicon substrate surface of the semiconductor substrates w and w against the polishing cloth of the first polishing surface plate PS2. During this rough polishing process, a polishing liquid is supplied from polishing liquid supply nozzles 72 and 72 to a polishing work point where the silicon substrate surface of the semiconductor substrate and the polishing cloth of the first polishing surface plate rub. After roughly polishing the silicon substrate surface of the semiconductor substrate to a desired thickness reduction (for example, 10 μm), the pair of polishing heads is raised, and the rotation of the pair of polishing heads 70a and 70b is stopped. (5-10 minutes)

18) The pair of polishing heads 70a and 70b for holding the two roughly polished semiconductor substrates w and w on the lower surface are rotated by rotating the main shaft 71s of the index type head 90 degrees clockwise, and the second polishing surface plate PS3. Move to a position opposite to. (1 to 2.5 seconds)

19) while rotating in the rotational speed of the second polishing platen PS3 5~100min ^-1, polishing head pair 70a for holding the substrate is lowered while rotating the 70b at a rotation speed of 5～100Min ^-1, The silicon substrate surfaces of the two semiconductor substrates w and w are rubbed against the polishing cloth of the second polishing surface plate PS3 to perform intermediate finishing polishing. During this intermediate finish polishing, the polishing liquid is supplied from the polishing liquid supply nozzles 72 and 72 to the polishing work point where the silicon substrate surface of the semiconductor substrate and the polishing cloth of the second polishing surface plate rub against each other. After the silicon substrate surface of the semiconductor substrate is subjected to intermediate finish polishing to a desired thickness reduction (for example, 5 μm), the polishing head pair is raised, and then the rotation of the polishing head pair is stopped. (5-10 minutes)

20) A pair of polishing heads 70a and 70b holding the two semi-finished semiconductor substrates w and w on the lower surface by rotating the spindle 71s of the index type head clockwise by 90 degrees, and a third polishing surface plate Move to a position facing PS4. (1 to 2.5 seconds)

21) while rotating at a rotational speed of the third polishing platen PS4 2~55min ^-1, the polishing head pair 70a, 70b and is lowered while rotating at a rotational speed of 2~55min ^-1, the two The silicon substrate surface of the semiconductor substrate is rubbed against the polishing cloth of the third polishing surface plate PS4 to perform precision finish polishing. During this precision finish polishing, the polishing liquid is supplied from the polishing liquid supply nozzles 72 and 72 to the polishing work point where the silicon substrate surface of the semiconductor substrate and the polishing cloth of the third polishing surface plate rub against each other. After the silicon substrate surface of the semiconductor substrate is precisely finished and polished to a desired thickness reduction (for example, 1 to 2 μm), the rotation of the pair of polishing heads 70a and 70b is stopped, and the rotation of the third polishing surface plate PS4 Also stop. (2-8 minutes)

22) A pair of polishing heads 70a and 70b for holding the two final polished semiconductor substrates w and w on the lower surface by rotating the main shaft 71s of the index type head 90 degrees clockwise or counterclockwise 270 degrees. Is moved to an upper position facing the temporary table base plate PS1.

23) After the positioning pins 105 of the temporary substrate table are raised by the air cylinder 108, water is supplied into the recessed portion 100 of the temporary table, and then the polishing head pockets for holding the semiconductor substrate by lowering the polishing heads 70a and 70b. The bottom part of the annular retainer 70R constituting the part 70p is brought into contact with the upper surface of the cylindrical outer peripheral wall 103 made of a non-water-permeable material of the temporary mounting table so that the semiconductor substrates w and w are immersed in the water storage in the recessed part 100, and if necessary, the polishing head By blowing compressed air from the back surface of the suction plate or the backing material of the pocket portion for 0.5 to 1 second, the fixing of the semiconductor substrate from the polishing head is released, and the semiconductor substrate is moved to the inside of the positioning pin top portion 105a. Next, after the supply of pressurized air is stopped, the pair of polishing heads 70a and 70b is raised, and the positioning pin 105a is lowered while discharging the water stored in the recessed portion 100 to the outside, and the temporary table base plate After centering and placing the two precision-finished and polished semiconductor substrates on the porous material ring-shaped bottom 101 of the PS1 temporary table PS1f and PS1b, the temporary table base PS1 is rotated 180 degrees. Let (3-5 seconds)

24) A pair of polishing heads 70a and 70b for holding the two final polished semiconductor substrates w and w on the lower surface by rotating the main shaft 71s of the index type head by 90 degrees clockwise or counterclockwise by 270 degrees. Is moved to an upper position facing the temporary table base plate PS1.

25) The precision placed on the temporary table PS1 in the polishing stage chamber 11c using the second transfer-type transfer articulated substrate transfer robot 16 in the loading / unloading stage chamber 11a. A semiconductor substrate that has been subjected to finish polishing and grips the first semiconductor substrate w located on the front side PS1f of the second transfer-type transfer articulated substrate transfer robot 16 and then this precision finish polishing processing was performed. The first semiconductor substrate is transferred onto the substrate cleaning device 3 where the semiconductor substrate that has been subjected to precision finish polishing is spin-cleaned. (0.5-2 minutes)

26) The cleaned first semiconductor substrate w on the substrate cleaning device 5 is gripped by using the first transfer type articulated substrate transfer robot 14, transferred to the storage cassette 13 at the load port position, and stored. To do. During this period, the second precision finish polishing semiconductor substrate w on the temporary table base plate PS1b is held by the second transfer type transfer articulated substrate transfer robot 16, and then this precision finish polishing process is performed. The second semiconductor substrate w is transferred onto the substrate cleaning device 5 where the semiconductor substrate that has been subjected to precision finish polishing is spin-cleaned. (0.5-2 minutes)

27) The second semiconductor substrate w cleaned on the substrate cleaning device 5 is gripped by using the first transfer-type transfer-type transfer articulated substrate transfer robot 14 and placed in the storage cassette 13 at the load port position. Transport and store. (1-3 seconds)

  While steps 1) to 27) are being performed, the mechanical elements in each substrate loading / substrate unloading stage chamber 11a, grinding stage chamber 11b, and polishing stage chamber are the same as those described above. Loading stage work, grinding stage work and polishing stage work.

  Therefore, the throughput of the planar planarization processing of two semiconductor substrates with a reduced thickness of 740 μm and a reduced polishing process of 10 μm on the backside of the semiconductor substrate on which the wiring is printed on the surface of the silicon substrate with a diameter of 300 mm and a thickness of 770 μm. Since the maximum time is about 5 minutes, up to about 24 planarized semiconductor substrates can be obtained in one hour. In addition, the maximum throughput of planar planarization of a pair of semiconductor substrates with a reduced thickness of 730 μm and a reduced polishing process of 10 μm on the backside of the semiconductor substrate with a printed wiring on the surface of a silicon substrate with a diameter of 450 mm and a thickness of 770 μm Since the time is about 11 minutes, about 12 planarized semiconductor substrates can be obtained in one hour.

  Furthermore, the planarization processing time of a pair of TSV wafers with 300 mm diameter and 775 μm thick through-electrode wafers stacked on one side of a copper electrode head protrusion is about 10 minutes, so 12 copper electrode head protrusion TSV wafers per hour are obtained. Obtainable.

Example 1
Using the substrate flattening apparatus shown in FIG. 1, a through silicon via copper electrode (TSV wafer, thickness 1,550 μm) of a TSV wafer in which two through electrode wafers having a diameter of 300 mm and a thickness of 775 μm are stacked under the following processing conditions. The copper electrode head protrusion was flattened. Table 1 shows the copper electrode head protrusion height distribution (unit: μm) in the isolated electrode portion and the dense electrode portion of the obtained TSV wafer. No chipping or cracking of the TSV wafer was observed during the copper electrode head protrusion flattening of the 26 TSV wafers.

Processing conditions:
Rough grinding machining allowance: 700μm thickness
Edge grinding allowance: 2mm width from the outer periphery to the center inside, thickness 50μm
Finish grinding machining allowance: thickness 33μm
Rough polishing and intermediate finish polishing machining allowance: 10 μm thickness
Final polishing machining allowance: thickness 12μm
Processing-limited stage and its throughput:
Rough polishing stage and intermediate finish polishing stage 5 minutes 50 seconds each Grinding fluid: Ion exchange water (pure water)
Abrasive liquid used for rough polishing, intermediate finish polishing, and finish polishing:
Colloidal silica abrasive slurry “Glanzox-1302 (trade name)” by Fujimi Incorporated
Substrate front and back surface cleaning liquid: ion exchange water Cleaning liquid used in the first cleaning equipment: SC for the first time, SC2 for the first time, ion exchange water for the last time Diamond cup wheel type rough grinding wheel grinding number: No. 500 Rotational speed: 2,400 min ^-1
Diamond vitrified bond grinding wheel grinding number: No. 500 rough grinding stage rotation speed of chucking chuck: 200 min ⁻¹
Number of diamond cup wheel type finishing grinding wheel: 8,000 Number of finishing grinding wheel shaft rotation: 1,700 min ⁻¹
Rotation speed of finish grinding stage suction chuck: 200 min ⁻¹
Polishing cloth for each polishing platen: SUBA1400 (trade name) manufactured by Nitta Haas
Rotation speed of polishing head during rough polishing and intermediate finish polishing: 41 min ⁻¹
Number of rotations of second and third polishing surface plates during rough polishing and intermediate finish polishing: 40 min ⁻¹
Rotation speed of polishing head during finish polishing: 21 min ⁻¹

Examples 2-3
In Example 1, the copper electrode head protrusion flattening process of the copper electrode penetrating silicon substrate (TSV wafer) was performed in the same manner except that the machining allowance of the TSV silicon substrate surface was performed under the processing conditions shown in Table 1. The copper electrode head protrusion height (μm) distribution of the obtained TSV wafer is shown in Table 1.

Table 1

Example 4
1. Using the substrate planarization apparatus shown in FIG. 1, the planarization processing of the backside silicon substrate of the DRAM substrate in which an adhesive protective sheet is pasted on the printed wiring surface of the semiconductor substrate having a diameter of 300 mm and a thickness of 775 μm under the following processing conditions Went. The obtained DRAM having a 25 μm thick silicon substrate had a surface average roughness Ra of 0.5 nm or less.

  In addition, the average roughness of the ground silicon substrate surface when the grinding process was completed and moved to the polishing stage was 4 nm for Ra, 0.022 μm for Ry, and 0.014 μm for Rz.

No chipping or cracking of the DRAM was observed during the back surface planarization of the 26 DRAMs. The throughput time per DRAM was 4 minutes 43 seconds.

Processing conditions:
Rough grinding machining allowance: Thickness 540 μm
Edge grinding allowance: 2mm width, 210μm thickness from the outer periphery to the center inside
Finish grinding machining allowance: Thickness 200μm
Rough polishing and intermediate finish polishing machining allowance: 8μm thickness
Final polishing machining allowance: Thickness 2μm
Processing-limited stage and its throughput:
Rough polishing stage and intermediate finish polishing stage 4 minutes 42 seconds each Grinding fluid: Ion exchange water (pure water)
Abrasive liquid used for rough polishing, intermediate finish polishing, and finish polishing:
Colloidal silica abrasive slurry “Glanzox-1302 (trade name)” by Fujimi Incorporated
Substrate front and back surface cleaning liquid: ion exchange water Cleaning liquid used in the first cleaning equipment: SC for the first time, SC2 for the first time, ion exchange water for the last time Diamond cup wheel type rough grinding wheel grinding number: No. 500 Rotational speed: 2,400 min ^-1
Number of rotations of rough grinding stage suction chuck: 200 min ⁻¹
Grinding number of diamond vitrified bond grinding wheel: No. 500 Diamond cup wheel type finishing grinding wheel grinding number: 8,000 No. of finishing grinding wheel shaft rotation speed: 1,700 min ⁻¹
Rotation speed of finish grinding stage suction chuck: 200 min ⁻¹
Polishing cloth for each polishing platen: SUBA1400 (trade name) manufactured by Nitta Haas
Rotation speed of polishing head during rough polishing and intermediate finish polishing: 41 min ⁻¹
Number of rotations of second and third polishing surface plates during rough polishing and intermediate finish polishing: 40 min ⁻¹
Rotation speed of polishing head during finish polishing: 21 min ⁻¹

  The planarization processing apparatus for a semiconductor substrate according to the present invention can perform grinding and polishing of the silicon base surface on the back surface of the semiconductor substrate with high throughput. In addition, it is possible to manufacture an extremely thin semiconductor substrate with a small number of foreign substances attached.

DESCRIPTION OF SYMBOLS 1 Substrate flattening processing device 2 Index type turntable 3 Substrate cleaning equipment 4 First positioning temporary placement table 5 Second positioning temporary placement table 6 Substrate front and back surface cleaning device 9 Edge grinding device 11 Partial chamber 11a Substrate loading / unloading stage Chamber 11b Substrate grinding stage chamber 11c Substrate polishing stage chamber 12 Base 13 Storage cassette 14 First articulated substrate transfer robot 15 First positioning temporary table 15
16 Second transfer type articulated substrate transfer robot 17 Third articulated type transfer robot 20 Grinding stage 30a, 30b, 30c, 30d Substrate chuck table 38 Chuck washer 70 Polishing stage 70a, 70b Polishing for holding substrate Head 71 Index type head 79 Hollow rotating shaft PS1 Temporary table surface plate PS2, PS3, PS4 Polishing surface plate 90 Coarse grinding stage 91 Finish grinding stage PS1f, PS1b Substrate temporary table 100 Recessed portion 101 Porous material ring-shaped bottom portion 102 Non Bottom portion 103 made of water-permeable material Cylindrical outer peripheral wall 104 movable up and down slightly Vertical through-hole 105 Positioning rod 107 movable up and down Cylindrical outer peripheral wall fixture 109 Water supply means 110 Washing water supply mechanism

Claims (2)

The room for installing the flattening processing apparatus is divided into three chambers: an L-shaped semiconductor substrate loading / unloading stage chamber from the front, an intermediate semiconductor substrate polishing stage chamber, and a back semiconductor substrate grinding stage chamber. The partition wall is partitioned by a partition wall, and the partition wall between the stage chambers is provided with an opening through which a substrate leading to the adjacent stage chamber can be taken in and out, and a plurality of loads are provided outside the front wall chamber of the loading / unloading stage chamber. A flattening apparatus for a semiconductor substrate provided with a port substrate cassette,
A first articulated substrate transfer robot is provided in the chamber behind the load port in the loading / unloading stage chamber of the semiconductor substrate, the substrate cleaning device on the left side, and the first positioning above the substrate cleaning device. A temporary placement table is provided, and a second transfer-type articulated substrate transfer robot is provided at the rear back of the first positioning temporary placement table,
The polishing stage chamber has a cylindrical recess having a size capable of mounting two or four substrates, and water supply means for supplying water from the bottom of the porous ceramic recess into the recess. A temporary mounting table surface plate provided with two or four sets of temporary mounting tables provided on the same circumference, and three sets of first, second and third polishing surface plates having a planar circular shape for polishing two substrates simultaneously. The center point of the four sets of surface plates is composed of the polishing means installed on the same circumference and rotatably at equal intervals, and the polishing surface plate is located beside each of the three sets of polishing surface plates. Three sets of dressers for dressing the polishing cloth are provided, and one index type head is provided above the four sets of surface plates, and the surface of the substrate to be polished is placed below the index type head. One of the substrate polishing heads that attracts or sticks toward A substrate chuck means that can fix eight substrates on a concentric circle provided with four sets of substrate chuck mechanisms that are supported on a main shaft so as to be capable of rotating independently and independently is sucked or stuck to each substrate polishing head. A polishing stage that enables each of the substrates to face each of the four sets of the surface plates is provided,
In the semiconductor substrate grinding stage, a second temporary positioning table is provided on the back side of the second transfer type articulated substrate transfer robot, and a hand arm is placed on the right side of the second temporary positioning table. A front and back rotating third articulated transfer robot is provided, and a substrate front / back surface cleaning device is provided on the right side of the third articulated transfer robot. On the back side of the back surface cleaning device, there are provided a substrate chuck surface plate in which four sets of substrate chuck tables are provided on one index type turntable so as to be rotatable on the same circumference at equal intervals. Loading / unloading stage chuck, substrate rough grinding stage chuck, substrate edge grinding stage chuck, and substrate finish grinding chuck position are indexed to the numerical controller. And an edge grinding device that enables an edge grinding wheel to move back and forth and move up and down alongside the substrate edge grinding stage chuck, and a cup wheel type rough grinding above the substrate rough grinding stage chuck. A grindstone is provided so as to be movable up and down and rotatable, and a cup wheel type finish grinding grindstone is provided above and above the substrate finishing grinding stage chuck so as to be movable up and down and rotatable, and the third articulated transfer robot is provided with the above-mentioned The semiconductor substrate on the second positioning temporary table is transferred onto the loading / unloading stage chuck, the semiconductor substrate on the loading / unloading stage chuck is transferred onto the substrate front / back surface cleaning device, and the substrate front / back surface cleaning device. The upper semiconductor substrate is placed in front of the polishing stage chamber. Providing a grinding stage chamber to perform the task of transferring to the provisional table platen,
An apparatus for planarizing a semiconductor substrate, comprising: A temporary table base plate provided with a substrate temporary table having a recess in the center on a temporary table fixed base supported by a rotating shaft,
The substrate temporary mounting table includes a ring-shaped bottom made of a porous material, a cylindrical outer peripheral wall made of a non-water-permeable material having a recessed portion protruding from the outer periphery of the bottom, and an inner side of the cylindrical outer peripheral wall made of the non-water-permeable material. A plurality of positioning rods that can be moved up and down in a plurality of vertical through-holes provided at intervals, and the cylindrical outer peripheral wall made of the non-water-permeable material can be moved up and down by an external stress on the temporary table fixing base. Water is supplied from the ring-shaped bottom of the porous material to store water in the central recess of the temporary substrate mounting base, and a fixing mechanism attached thereto, an elevating mechanism for moving an annular fixing plate for fixing the bottoms of the plurality of positioning rods in the vertical direction, and a ring-shaped bottom made of porous material. And a water supply means.

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