JP2011211013A - Method for regenerating wafer with multilayer film/pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for highly precisely grinding a desired multilayer film/pattern without requiring much time and effort in execution by a conventional chemical etching method, without requiring quality of coating or damaging a silicon in execution by a sand blast method, or without seriously damaging the silicon in a laser method.SOLUTION: The regenerating method includes: a step for chucking a regeneratable wafer W with a multilayer film/pattern to a vacuum chuck 1: a step for rotating the wafer W by rotating a rotary shaft 3 for chuck; a step for rotating a honing stone 9 arranged on the upper surface by rotating a grindstone plate rotating shaft 11; and a step for grinding the wafer W by allowing the honing stone 9 to contact the wafer W due to the rotation of a ball screw 7 having a shock absorber 6 intervened.

Description

  The present invention relates to a method of reclaiming a silicon wafer from a recyclable multilayer film / patterned wafer. More specifically, the present invention relates to a test wafer, a rejected wafer, and a surplus semiconductor wafer that are conductive and insulated. Various film formation such as metal films, non-metal films, low-k films, organic films, other films and multilayer films for the purpose of properties, dielectric properties, resistance, etc., has been performed. The present invention relates to a method for reclaiming a silicon wafer from a possible multilayer film / patterned wafer.

Conventionally, this type of reclaimable multilayer film / patterned wafer has been reclaimed due to the rise of silicon crystals and the occurrence of defective products and surplus multilayer films / patterned wafers that occur at a certain rate in IC manufacturing processes. Already implemented to reuse the silicon part, for example, a process of removing a surface coating layer of a semiconductor wafer substrate by chemical etching, a process of removing a small amount of one surface of a wafer substrate by mechanical processing, mechanical processing Including a step of removing the altered layer caused by the chemical etching by chemical etching and a step of mirror polishing the other surface of the wafer substrate (see Patent Document 1), or a surface layer of a used silicon wafer that has been modified by the wafer process A step of removing heat, a step of heat-treating the silicon wafer from which the surface layer has been removed, and a silicon wafer subjected to the heat treatment And the step of measuring the conductivity type and resistivity (see Patent Document 2), and the thin film layer formed on the silicon wafer by CVD or PVD is removed by spraying an abrasive and then polished. Thing (refer patent document 3) etc. are disclosed.
JP 2002-57129 A JP 2001-223146 A JP 2001-237201 A

  However, it is relatively easy if the film is a single layer film when it is carried out by chemical etching in the reclaimable multilayer film / patterned wafer reclamation method and the apparatus for regeneration used in each of the above-discussed disclosures. However, in the case of a multilayer film, it must be replaced with an etching solution suitable for each film, which takes a lot of time and labor, and becomes expensive instead. Hard film such as non-metal film can be removed, but soft metal film and organic film can hardly be removed, and damage to silicon is caused. Laser processing also causes deep damage to silicon. Thus, they cannot be used as recycled wafers, and each has a problem.

  In view of the above-mentioned problems, the present invention solves these problems as a result of diligent research. A vacuum chuck that adsorbs the non-ground surface of a multilayer film / patterned wafer to the lower surface, and a vacuum chuck interposed with a universal joint. Connected chuck rotating shaft, rotating shaft drive source for rotating the chuck rotating shaft mechanically, a shock absorber device connected to the chuck rotating shaft via a bearing, and a shock absorber device A ball screw that moves the wheel back and forth, a geared motor that rotates the ball screw, a honing grindstone that faces the vacuum chuck, a grindstone plate that has the honing grindstone disposed on the top surface, and a grindstone plate rotation shaft that rotates the grindstone plate And a reclaimable vacuum chuck using a grinding device comprising Honing the chuck on the non-ground surface of the layer film / patterned wafer, rotating the chuck rotating shaft to rotate the multilayer film / patterned wafer, and rotating the grinding wheel plate rotating shaft. A step of rotating the grindstone, and a step of rotating the ball screw provided with a shock absorber to bring the honing grindstone into contact with the multilayer film / patterned wafer for grinding.

  The honing grindstone in the method for regenerating a multilayer film / patterned wafer according to the present invention configured as described above is a diamond fine particle or other grindstone in which a large number of strips are arranged in a donut shape at substantially equal intervals on the upper surface of the grindstone plate. Sandblasting that contains fine particles and grinds the multilayer film and pattern of a reproducible multilayer film and patterned wafer, and does not take much time and labor as in the case of the conventional chemical etching method. As with the method, the desired multi-layer film / pattern can be increased without questioning the coating, without damaging the silicon, and without damaging the silicon as with the laser method. This is an effective invention that is capable of grinding with high precision and is epoch-making and highly practical.

  The embodiment of the method for regenerating a multilayer film / patterned wafer according to the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a grinding apparatus used in the embodiment of the method for regenerating a multilayer film / patterned wafer according to the present invention. FIG. 2 is a schematic front view of a grinding apparatus used in the next embodiment of the multilayer film / patterned wafer recycling method of the present invention.

  The present invention relates to a regeneration method for regenerating a silicon wafer from a reproducible multilayer film / patterned wafer W, and more specifically, a test wafer, a rejected wafer, a surplus semiconductor wafer, a conductive material, Various types of film formation such as metal films, non-metal films, low-k films, organic films, patterns, other films and multilayer films for the purpose of insulation, dielectric properties, resistance, etc. have been performed. The present invention relates to a method for regenerating a silicon wafer W from a reproducible multilayer film / patterned wafer, a vacuum chuck 1 for adsorbing an unground surface of the multilayer film / patterned wafer W to the lower surface, and the vacuum chuck 1 is connected via a universal joint 2 and the chuck rotating shaft 3 is mechanically connected to the chuck rotating shaft 3 and rotated. A rotating shaft drive source 4 to be moved, a shock absorber device 6 connected to the chuck rotating shaft 3 via a bearing 5, a ball screw 7 for moving the shock absorber device 6 back and forth, and the ball screw 7 to rotate. A geared motor 8, a honing grindstone 9 disposed to face the vacuum chuck 1, a grindstone plate 10 having the honing grindstone 9 disposed on an upper surface, and a grindstone plate rotating shaft 11 for rotating the grindstone plate 10. And chucking the non-ground surface of the multilayer film / patterned wafer W which can be regenerated on the vacuum chuck 1 by rotating the chuck rotating shaft 3 to rotate the multilayer film / A step of rotating the patterned wafer W and the grindstone plate rotating shaft 11 are rotated and disposed on the upper surface. A step of rotating the honing grindstone 9 and a step of rotating the ball screw 7 interposed with the shock absorber 6 to bring the honing grindstone 9 into contact with the multilayer film / patterned wafer W for grinding. It is characterized by.

  That is, the method for regenerating a multilayer film / patterned wafer according to the present invention is to regenerate a silicon wafer from a recyclable multilayer film / patterned wafer W. A silicon wafer is regenerated from a test wafer that has been added and printed, a rejected wafer, and a surplus multilayer film / patterned wafer W.

  The vacuum chuck 1 is fixed to the lower end of a chuck rotating shaft 3 to be described later with a universal joint 2 interposed therebetween, and the non-ground surface of the multilayer film / patterned wafer W is connected to a vacuum source (not shown). The vacuum is sucked by the vacuum means and chucked on the upper surface with the porous plate 1a interposed.

  Next, the universal joint 2 is interposed between the vacuum chuck 1 and a chuck rotating shaft 3 to be described later, and a grinding surface of a multilayer film / patterned wafer W being ground with a honing grindstone 9 to be described later. It is intended to improve the parallelism and to align the center during rotary grinding.

  Next, the chuck rotating shaft 3 is rotated at 10 to 200 rpm by a motor of a rotating shaft drive source 4 described later, the lower portion is connected to the vacuum chuck 1 via the universal joint 2, and the upper portion is described later. It is connected to the bearing 5.

  Further, the rotation shaft drive source 4 is a motor that rotates the chuck rotation shaft 3. In the illustrated embodiment, the rotation shaft side wheel 3 a provided on the chuck rotation shaft 3 and the rotation shaft drive are provided. The motor side wheel 4a equipped on the drive shaft of the source 4 is connected by the endless belt 4b.

  Further, one of the bearings 5 is fixed to the chuck rotating shaft 3 and the other is connected to an air piston 6a of a shock absorber device 6 described later.

  In the embodiment shown in FIG. 1, the shock absorber device 6 is a pneumatic type composed of an air cylinder 6b and an air piston 6a, and applies a downward pressing force by an electropneumatic regulator 6c. By moving the chuck rotating shaft 3 up and down by the shock absorber device 6 of the air piston 6a and the air piston 6a, a constant grinding pressure is applied to the multilayer film / patterned wafer W vacuum-adsorbed to the vacuum chuck 1 and grinding is performed. It absorbs shock and inclination.

  Next, the ball screw 7 is screwed into a fixing bar 7a having a screw hole, the lower end is connected to the air cylinder 6b of the shock absorber device 6, and the upper end is mechanically connected to a geared motor 8 to be described later. By moving, the shock absorber device 6, the hair ring 5, the chuck rotating shaft 3, and the vacuum chuck 1 are moved up and down to position the vacuum-adsorbed multilayer film / patterned wafer W for grinding.

  Further, the geared motor 8 is for rotating the ball screw 7, and positioning of the multilayer film / patterned wafer W adsorbed to the vacuum chuck 1 by the rotation of the ball screw 7 by the honing grindstone 9 described later. Is.

  Further, the honing grindstone 9 is disposed so as to face the vacuum chuck 1, and in the embodiment, a large number of strips are disposed in a donut shape at substantially equal intervals on the upper surface of the grindstone plate 10 described later. It contains diamond fine particles.

  Furthermore, the grindstone plate 10 is rotatably fixed to the upper end of a grindstone plate rotating shaft 11 to be described later, and a honing grindstone 9 is disposed on the upper surface.

  Next, the grindstone plate rotating shaft 11 is rotated at 50 to 1000 rpm by a motor of a drive source (not shown), and the grindstone plate 10 is also rotated with the rotation.

  The dressing plate 12 is disposed so as to face the honing grindstone 9, and dresses the honing grindstone 9 by mounting the dressing ring 13 on the lower surface.

  Further, the dressing plate rotating shaft 14 is equipped with a dressing plate 12 at the lower end, and is rotated and raised and lowered by a driving source (not shown) so that the dressing ring 13 provided on the lower surface is brought into contact with the honing grindstone 9 by raising and lowering. In addition, the honing grindstone 9 is dressed by the dressing ring 13 by rotating.

  In the next embodiment shown in FIG. 2, the shock absorber device 6 includes a coil spring 6y interposed between a plate 6x provided on the ball screw 7 side and a plate 6z provided on the bearing 5 side. In addition to grinding, the shock is absorbed. Since other parts are the same as those in the embodiment, the detailed description is omitted.

  The grinding apparatus for carrying out the method for reclaiming a reproducible multilayer film / patterned wafer of the present invention is configured as described above.

  First, in the step of chucking the recyclable multilayer film / patterned wafer, the vacuum source 1 is driven to vacuum the vacuum chuck 1 to suck the non-ground surface of the disk-shaped recyclable multilayer film / patterned wafer W. It is something to be made.

  Next, in the step of rotating the multilayer film / patterned wafer, the multilayer film / patterned wafer W is rotated by rotating the chuck rotating shaft 3. The rotation speed is 10 to 200 rpm.

  Next, in the step of rotating the honing grindstone, the grindstone plate rotating shaft 11 is rotated to rotate the grindstone plate 10 disposed on the upper surface, and the grindstone plate 10 is rotated to rotate the honing grindstone 9. Yes, the rotation speed is 50 to 1000 rpm.

  Further, in the step of positioning at the grinding position, the geared motor 8 is driven to rotate the ball screw 7 and the vacuum chuck 1 is lowered to position the multilayer film / patterned wafer W at the grinding position. After that, the air cylinder 4 is used for grinding at a constant pressure.

  In the following embodiment, after positioning, grinding is performed at a constant pressure by a coil spring 6y interposed between a plate 6x provided on the ball screw 7 side of the shock absorber device 6 and a plate 6z provided on the bearing 5 side. is there.

  Further, in the step of grinding with the honing grindstone, the rotating shaft 3 for the chuck and the vacuum chuck 1 are moved down by rotating the ball screw 7 for positioning, and constant pressure is applied to the multilayer film / patterned wafer W at the grinding position. The honing grindstone 9 is used to grind the film such as a multilayer film / pattern which is an unnecessary portion laminated on the surface of the multilayer film / patterned wafer W with a predetermined grinding allowance.

  Then, the coating film such as the multilayer film / pattern, which is an unnecessary portion laminated on the surface of the multilayer film / patterned wafer W, is ground, and the dressing plate 12 with the dressing ring 13 attached to the lower end is attached to the dressing plate rotating shaft 14. It is lowered by driving, and the dressing ring 13 is brought into contact with the honing grindstone 9 and rotated to dress the honing grindstone 9 during and after grinding.

  That is, the method for reclaiming a multilayer film / patterned wafer according to the present invention chucks the non-ground surface of the reproducible multilayer film / patterned wafer W on the vacuum chuck 1 to form a multilayer film / pattern film formed by lamination. When the chuck rotating shaft 3 is rotated and lowered with a constant pressure by the air cylinder 4 and the chuck rotating shaft 3 is rotated, the vacuum chuck 1 is rotated, and when the vacuum chuck 1 is rotated, the chuck chucks the lower surface. The multilayer film / patterned wafer W also rotates, and is disposed on the upper surface of the grindstone plate 10 that rotates below, and the multiple film / pattern that is an unnecessary part of the multilayer film / patterned wafer W is ground by a number of honing grindstones 9. To do.

  The honing grindstone in the method for regenerating a multilayer film / patterned wafer of the present invention configured as described above includes diamond fine particles in which a large number of strips are arranged in a radial shape at substantially equal intervals in a donut shape on the upper surface of the grindstone plate. It is intended to grind multilayer film / pattern of multilayer film / patterned wafer that can be regenerated with a honing grindstone. For test wafer, rejected wafer, surplus semiconductor wafer, conductive, insulating, dielectric A wide variety of multilayer films and patterns such as metal films, non-metal films, low-k films, organic films, patterns, other films and multilayer films for the purpose of resistance, etc. have been formed, As with the conventional chemical etching method, it does not take a lot of time and labor, and the film is questioned as with the sandblasting method. Reproduction of multilayer film and patterned wafers that can grind the desired film with high precision without causing damage to silicon and without causing deep damage to silicon as in the laser method. A method is provided.

FIG. 1 is a schematic front view of a grinding apparatus used in an embodiment of a method for regenerating a multilayer film / patterned wafer according to the present invention. FIG. 2 is a schematic front view of a grinding apparatus used in the next embodiment of the method for regenerating a multilayer film / patterned wafer of the present invention.

W Multilayer film / patterned wafer 1 Vacuum chuck 1a Porous plate 2 Universal joint 3 Chuck rotating shaft 3a Rotating shaft side wheel 4 Rotating shaft drive source 4a Motor side wheel 4b Endless belt 5 Bearing 6 Shock absorber 6a Air piston 6b Air Cylinder 6c Electro-pneumatic regulator 6x Plate 6y Coil spring 6z Plate 7 Ball screw 7a Fixed bar 8 Geared motor 9 Honing wheel 10 Grinding wheel plate 11 Wheel plate rotating shaft 12 Dressing plate 13 Dressing ring 14 Dressing plate rotating shaft

Claims (1)

  A vacuum chuck that adsorbs the ground surface of the multilayer film / patterned wafer to the lower surface, a chuck rotating shaft to which the vacuum chuck is connected via a universal joint, and the chuck rotating shaft are mechanically connected. A rotating shaft drive source for rotating, a shock absorber device connected to the rotating shaft for chuck via a bearing, a ball screw for moving the shock absorber device back and forth, a geared motor for rotating the ball screw, and the vacuum The vacuum chuck using a grinding device comprising a honing grindstone disposed facing the chuck, a grindstone plate having the honing grindstone disposed on an upper surface thereof, and a grindstone plate rotation shaft for rotating the grindstone plate. Chuck the non-ground surface of the multilayer film / patterned wafer that can be recycled Rotating the chuck rotating shaft to rotate the multilayer film / patterned wafer, rotating the grindstone plate rotating shaft to rotate the honing grindstone disposed on the upper surface, A method of reclaiming a multilayer film / patterned wafer, comprising: rotating a ball screw interposed with a shock absorber to bring the honing grindstone into contact with the multilayer film / patterned wafer for grinding.

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