JP4617196B2 - Sample wafer and method for producing sample wafer - Google Patents

Description

  The present invention relates to a sample wafer having a plurality of polishing regions polished by a plurality of polishing tools and a method for manufacturing the sample wafer.

  As is well known to those skilled in the art, in a semiconductor device manufacturing process, a semiconductor wafer on which a plurality of circuits such as ICs and LSIs are formed is polished by a polishing apparatus before being divided into individual chips. It is formed in the thickness. As a polishing tool attached to the polishing apparatus, for example, a rough polishing tool, a medium polishing tool, a finish polishing tool, and a mirror polishing tool are prepared, and are appropriately selected and used according to the purpose of polishing.

  In addition, the wafer is polished by each polishing tool so that the polishing state polished by the polishing tool can be visually confirmed, and a sample wafer is manufactured for each polishing tool.

However, manufacturing a sample wafer for each polishing tool requires manufacturing a plurality of sample wafers corresponding to the type of polishing tool, which is uneconomical and complicated to manage the sample wafer.
In addition, when comparing a plurality of sample wafers and comparing the polished state, it is difficult to make the reflection angles of the sample wafers the same, and there is a problem that the reflection conditions are different and cannot be compared accurately.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is to provide a sample wafer having a plurality of polishing regions polished on a single wafer by a plurality of polishing tools, and a method for manufacturing the sample wafer. It is in.

In order to solve the main technical problem, according to the present invention, a plurality of annular polishing regions that are respectively polished by a plurality of polishing tools from the central region to the outer periphery are formed on the surface to be polished of the wafer.
A sample wafer is provided.

Further, according to the present invention, a polishing apparatus including a chuck table for holding a wafer and a polishing unit including a mounter for detachably mounting a polishing tool for polishing the wafer held by the chuck table is used. A plurality of polishing tools are sequentially mounted on the mounter, and the wafer is polished by pressing the polishing tool against the surface of the wafer held by the chuck table while rotating the chuck table and the polishing tool. There is a sample wafer manufacturing method for forming a plurality of polishing regions on a surface,
A first polishing tool is mounted on the mounter, the outer peripheral edge of the first polishing tool is positioned near the center of rotation of the chuck table, and the surface to be polished of the wafer is polished from the central region to the outer periphery. A first polishing step for forming a polishing region;
A second polishing tool is mounted on the mounter, the outer peripheral edge of the second polishing tool is positioned at a predetermined position of the first polishing region polished by the first polishing step, and the first polishing region A second polishing step in which a second polishing region is formed by polishing over the outer periphery while leaving a part of the center side of
A method for producing a sample wafer is provided.

  In the first polishing step, it is desirable that the outer peripheral edge of the first polishing tool is positioned on the outer peripheral side by a predetermined amount from the center of rotation of the chuck table, and the unpolished region remains in the central region of the surface to be polished of the wafer. .

In the sample wafer according to the present invention, since a plurality of annular polishing regions are formed on a single wafer by a plurality of polishing tools, respectively, it is economical and management of the sample wafer is facilitated. In addition, since the sample wafer has a plurality of annular polishing regions formed on one wafer, the reflection angle of the plurality of polishing regions can be made the same when comparing the polishing state. The polishing area can be accurately compared and examined.

  Preferred embodiments of a sample wafer and a sample wafer manufacturing method configured according to the present invention will be described below in more detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a polishing apparatus for carrying out a method for manufacturing a sample wafer according to the present invention.
The illustrated polishing apparatus is provided with an apparatus housing generally indicated by numeral 2. This device housing 2 has a rectangular parallelepiped main portion 21 that extends long and an upright wall 22 that is provided at the rear end portion (upper right end in FIG. 1) of the main portion 21 and extends substantially vertically upward. ing. A pair of guide rails 221 and 221 extending in the vertical direction are provided on the front surface of the upright wall 22. The pair of guide rails 221 and 221 is mounted with a polishing unit 3 as a polishing means so as to be movable in the vertical direction.

  The polishing unit 3 includes a moving base 31 and a spindle unit 32 attached to the moving base 31. The movable base 31 is provided with a pair of legs 311 and 311 extending in the vertical direction on both sides of the rear surface. The pair of legs 311 and 311 is slidably engaged with the pair of guide rails 221 and 221. Guided grooves 312 and 312 are formed. As described above, a support portion 313 protruding forward is provided on the front surface of the movable base 31 slidably mounted on the pair of guide rails 221 and 221 provided on the upright wall 22. The spindle unit 32 is attached to the support portion 313.

  The spindle unit 32 includes a spindle housing 321 mounted on the support portion 313, a rotating spindle 322 rotatably disposed on the spindle housing 321, and a servo motor as a driving unit for rotationally driving the rotating spindle 322. 323. A lower end portion of the rotary spindle 322 protrudes downward beyond the lower end of the spindle housing 321, and a disc-shaped mounter 324 is provided at the lower end. The mounter 324 is formed with a plurality of bolt insertion holes (not shown) at intervals in the circumferential direction. The polishing tool 4 is detachably attached to the lower surface of the mounter 324.

Here, the polishing tool 4 detachably attached to the mounter 324 will be described with reference to FIGS.
The polishing tool shown in FIG. 2 is a rough polishing tool 4a, and includes an annular support member 41a and a plurality of electroformed grinding wheels 42a mounted on the same circumference on the lower surface of the annular support member 41a. The annular support member 41a is formed with a plurality of screw holes 411a extending downward from the upper surface at intervals in the circumferential direction. As shown in FIG. 1, the rough polishing tool 4 a configured as described above is formed on the annular support member 41 a through the through hole formed in the mounter 324 with the annular support member 41 a positioned on the lower surface of the mounter 324. The fastening bolt 325 is screwed into the screw hole 411a, and is mounted on the mounter 324.

  The polishing tool shown in FIG. 3 is a medium polishing tool 4b, and includes an annular support member 41b and a plurality of resin bond grindstones 42b mounted on the lower surface of the annular support member 41b on the same circumference. Similarly to the rough polishing tool 4a, the intermediate polishing tool 4b has an annular support member 41b positioned on the lower surface of the mounter 324 as shown in FIG. 1, and the annular support member 41b passes through a through hole formed in the mounter 324. The mounting bolts 325 are screwed into the screw holes 411b formed in the mounting holes 411b to be mounted on the mounter 324.

  The polishing tool shown in FIG. 4 is a finish polishing tool 4c, and includes an annular support member 41c and a plurality of porous vitrified grindstones 42c mounted on the lower surface of the annular support member 41c on the same circumference. Similarly to the rough polishing tool 4a and the intermediate polishing tool 4b, the finish polishing tool 4c is also provided with an annular support member 41c positioned on the lower surface of the mounter 324 as shown in FIG. 1 and through a through hole formed in the mounter 324. The mounting bolt 325 is screwed into a screw hole 411c formed in the annular support member 41c, so that the mounter 324 is mounted.

  The polishing wheel shown in FIG. 5 is a mirror polishing tool 4d, and includes a disk-shaped support member 41d and a circular buffing wheel 42d mounted on the lower surface of the disk-shaped support member 41d. The disk-like support member 41d is formed with a plurality of screw holes 411d extending downward from the upper surface at intervals in the circumferential direction. As shown in FIG. 1, the mirror polishing tool 4d thus configured has a disk-like support member 41d positioned on the lower surface of the mounter 324, and is formed on the disk-like support member 41d through a through-hole formed in the mounter 324. The fastening bolt 325 is screwed into the screw hole 411d, and is mounted on the mounter 324.

  Referring back to FIG. 1, the polishing apparatus in the illustrated embodiment moves the polishing unit 3 up and down along the pair of guide rails 221 and 221 (perpendicular to a holding surface of a chuck table described later). The polishing unit feed mechanism 5 is provided to be moved in the direction). The polishing unit feed mechanism 5 includes a male screw rod 51 disposed on the front side of the upright wall 22 and extending substantially vertically. The male screw rod 51 is rotatably supported by bearing members 52 and 53 whose upper end and lower end are attached to the upright wall 22. The upper bearing member 52 is provided with a pulse motor 54 as a drive source for rotationally driving the male screw rod 51, and an output shaft of the pulse motor 54 is transmission-coupled to the male screw rod 51. A connecting portion (not shown) that protrudes rearward from the center portion in the width direction is also formed on the rear surface of the movable base 31, and a through female screw hole (not shown) that extends in the vertical direction is formed in this connecting portion. The male screw rod 51 is screwed into the female screw hole. Accordingly, when the pulse motor 54 rotates in the forward direction, the moving base 31, that is, the polishing unit 3 is lowered or moved forward, and when the pulse motor 54 rotates in the reverse direction, the moving base 31, that is, the polishing unit 3 is raised or moved backward.

  Continuing the description with reference to FIG. 1, the chuck table mechanism 6 is disposed in the main portion 21 of the housing 2. The chuck table mechanism 6 includes a chuck table 61, a cover member 62 that covers the periphery of the chuck table, and bellows means 63 and 64 disposed before and after the cover member 62. The chuck table 61 is configured to be rotated by a rotation driving unit (not shown), and is configured to suck and hold a wafer as a workpiece on its upper surface by operating a suction unit (not shown). Further, the chuck table 61 is moved between a workpiece placing area 24 shown in FIG. 1 and a polishing area 25 facing the polishing tool 4 constituting the spindle unit 32 by a chuck table moving means (not shown). The bellows means 63 and 64 can be formed from any suitable material such as campus cloth. The front end of the bellows means 63 is fixed to the front wall of the main portion 21, and the rear end is fixed to the front end surface of the cover member 62. The front end of the bellows means 64 is fixed to the rear end surface of the cover member 62, and the rear end is fixed to the front surface of the upright wall 22 of the apparatus housing 2. When the chuck table 61 is moved in the direction indicated by the arrow 23a, the bellows means 63 is expanded and the bellows means 64 is contracted. When the chuck table 61 is moved in the direction indicated by the arrow 23b, the bellows means 63 is The bellows means 64 is expanded by contraction.

A method for manufacturing a sample wafer using the polishing apparatus configured as described above will be described.
FIG. 6 shows a perspective view of a disk-shaped wafer 10 made of silicon for forming a sample wafer. In order to form the wafer 10 on the sample wafer, the rough polishing tool 4a shown in FIG. 2 is first mounted on the mounter 324 of the spindle unit 32 as a first polishing tool.
Then, the wafer 10 is placed on the chuck table 61 positioned in the workpiece placement area 24 of the polishing apparatus shown in FIG. At this time, the wafer 10 is placed so that the center of rotation of the chuck table 61 and the center of the wafer 10 coincide. The wafer 10 placed on the chuck table 61 in this way is sucked and held on the chuck table 61 by suction means (not shown). When the wafer 10 is sucked and held on the chuck table 61, the chuck table moving means (not shown) is operated to move the chuck table 61 in the direction indicated by the arrow 23a and position it in the polishing zone 25. As shown in FIG. 7, the outer peripheral edges of the plurality of electroformed grinding wheels 42 a of the rough polishing tool 4 a are positioned at the rotation center P of the chuck table 61, that is, near the center of the wafer 10. In the embodiment shown in FIG. 7, the outer peripheral edge of the electroformed grindstone 42a of the rough polishing tool 4a is positioned with a predetermined distance S1 from the rotation center P of the chuck table 61.

  When the wafer 10 held on the rough polishing tool 4a and the chuck table 61 is set in the positional relationship shown in FIG. 7, the chuck table 61 is moved in the direction shown by the arrow 610 in FIG. While rotating, the rough polishing tool 4a is rotated in the direction indicated by the arrow 40 at a rotation speed of, for example, 6000 rpm. Then, the rough polishing tool 4 a is lowered to press the plurality of electroformed grinding wheels 42 a against the surface to be polished which is the upper surface of the wafer 10 with a predetermined pressure. As a result, the surface to be polished of the wafer 10 is roughly polished from the central region to the outer periphery to form a rough polishing region 101 as a first polishing region (first polishing step). In the embodiment shown in FIG. 7, the outer peripheral edge of the electroformed grindstone 42a of the rough polishing tool 4a is positioned at a predetermined distance S from the rotation center P of the chuck table 61, so that the surface 10a to be polished of the wafer 10 is polished. The unpolished region 100 is left in the central region.

  When the first polishing step is performed, the rough polishing tool 4a mounted on the mounter 324 of the spindle unit 32 is removed, and the medium polishing tool 4b shown in FIG. 3 is mounted on the mounter 324 as the second polishing tool. As shown in FIG. 8, the outer peripheral edges of the plurality of resin bond grindstones 42b of the intermediate polishing tool 4b are positioned at predetermined positions in the rough polishing region 10 formed on the surface to be polished of the wafer 10 by the first polishing step. . In the embodiment shown in FIG. 8, the outer peripheral edge of the resin bond grindstone 42b of the intermediate polishing tool 4b is positioned with a predetermined distance S2 from the inner peripheral edge of the rough polishing region 101. When the wafer 10 held on the intermediate polishing tool 4b and the chuck table 61 is set in the positional relationship shown in FIG. 8, the chuck table 61 is moved in the direction indicated by the arrow 610 in FIG. While rotating, the middle polishing tool 4b is rotated in the direction indicated by the arrow 40 at a rotation speed of, for example, 6000 rpm. Then, the intermediate polishing tool 4 b is lowered to press the plurality of resin bond grindstones 42 b against the surface to be polished of the wafer 10 with a predetermined pressure. As a result, the surface to be polished 10a of the wafer 10 is subjected to intermediate polishing over the outer periphery leaving the annular rough polishing region 101 having the width of the interval S2, thereby forming the intermediate polishing region 102 as the second polishing region ( Second polishing step).

  When the second polishing step is performed, the middle polishing tool 4b mounted on the mounter 324 of the spindle unit 32 is removed, and the finish polishing tool 4c shown in FIG. 4 is mounted on the mounter 324 as the third polishing tool. Then, as shown in FIG. 9, a predetermined position in the intermediate polishing region 102 where the outer peripheral edges of the plurality of porous vitrified grindstones 4c of the finish polishing tool 4c are formed on the polished surface 10a of the wafer 10 by the second polishing step. Position. In the embodiment shown in FIG. 9, the outer peripheral edge of the porous vitrified grindstone 4c of the finish polishing tool 4c is positioned with a predetermined distance S2 from the inner peripheral edge of the intermediate polishing region 102. If the wafer 10 held on the finish polishing tool 4c and the chuck table 61 is set in the positional relationship shown in FIG. 9, the chuck table 61 is moved in the direction indicated by the arrow 610 in FIG. While rotating, the finish polishing tool 4c is rotated in the direction indicated by the arrow 40 at a rotation speed of, for example, 6000 rpm. Then, the finish polishing tool 4c is lowered and a plurality of porous vitrified grindstones 4c are pressed against the surface to be polished of the wafer 10 with a predetermined pressure. As a result, the polished surface 10a of the wafer 10 is finish-polished over the outer periphery leaving the annular medium-polishing region 102 having the width of the interval S2, thereby forming a finish-polished region 103 as a third polishing region ( Third polishing step).

When the third polishing step is performed, the finish polishing tool 4c mounted on the mounter 324 of the spindle unit 32 is removed, and the mirror polishing tool 4d shown in FIG. 5 is mounted on the mounter 324 as the fourth polishing tool. Then, as shown in FIG. 10, the outer peripheral edge of the circular buffing wheel 4d of the mirror polishing tool 4d is placed at a predetermined position in the final polishing region 103 formed on the surface to be polished 10a of the wafer 10 by the third polishing step. Position. In the embodiment shown in FIG. 10, the outer peripheral edge of the circular buffing stone 4d of the mirror polishing tool 4d is positioned with a predetermined distance S2 from the inner peripheral edge of the finish polishing region 103. When the wafer 10 held on the mirror polishing tool 4d and the chuck table 61 is set in the positional relationship shown in FIG. 10, the chuck table 61 is moved in the direction indicated by the arrow 610 in FIG. While rotating, the mirror polishing tool 4d is rotated in the direction indicated by the arrow 40 at a rotation speed of, for example, 6000 rpm. Then, the mirror polishing tool 4d is lowered to press the circular buffing stone 4d against the surface to be polished of the wafer 10 with a predetermined pressure. As a result, the polished surface 10a of the wafer 10 is mirror-polished over the outer periphery leaving the annular finish polishing region 103 having the width of the interval S2, and an annular mirror-polished region 104 is formed as a fourth polishing region. (Fourth polishing step).
In each polishing step described above, a polishing liquid is appropriately supplied to a polishing portion using a polishing tool.

  As described above, by performing the first polishing process to the fourth polishing process, an unpolished region 100 remains in the center of the surface to be polished of the wafer 10 as shown in FIG. An annular rough polishing region 101 is formed on the outer peripheral side of the polishing region 100, an annular medium polishing region 102 is formed on the outer peripheral side of the rough polishing region 101, and an annular final polishing region is formed on the outer peripheral side of the intermediate polishing region 102. 103 is formed, and a sample wafer 110 in which an annular specular polishing region 104 is formed on the outer peripheral side of the finish polishing region 103 is formed. Thus, since the sample wafer 110 is formed with a plurality of annular polishing regions on a single wafer by a plurality of polishing tools, it is economical and management of the sample wafer is facilitated. In addition, since the sample wafer 110 is formed with a plurality of annular polishing regions on a single wafer by a plurality of polishing tools, the reflection angles of the plurality of polishing regions are the same when comparing the polishing state. It is possible to accurately compare and examine a plurality of polishing regions.

The perspective view of the polish device for enforcing the polish method by the present invention. FIG. 2 is a perspective view of a rough polishing tool that is detachably mounted on a mounter that constitutes a polishing unit equipped in the polishing apparatus shown in FIG. 1. FIG. 2 is a perspective view of a middle polishing tool that is detachably mounted on a mounter that constitutes a polishing unit equipped in the polishing apparatus shown in FIG. 1. FIG. 2 is a perspective view of a finish polishing tool that is detachably mounted on a mounter that constitutes a polishing unit equipped in the polishing apparatus shown in FIG. 1. The perspective view of the mirror polishing tool with which the mounter which comprises the grinding | polishing unit with which the grinding | polishing apparatus shown in FIG. 1 is a perspective view of a wafer for forming a sample wafer according to the present invention. Explanatory drawing which shows the 1st grinding | polishing process in the manufacturing method of the sample wafer by this invention. Explanatory drawing which shows the 2nd grinding | polishing process in the manufacturing method of the sample wafer by this invention. Explanatory drawing which shows the 3rd grinding | polishing process in the manufacturing method of the sample wafer by this invention. Explanatory drawing which shows the 4th grinding | polishing process in the manufacturing method of the sample wafer by this invention. The perspective view of the sample wafer manufactured by the manufacturing method of the sample wafer by this invention.

Explanation of symbols

2: Device housing 3: Polishing unit 31: Moving base 32: Spindle unit 321: Spindle housing 322: Rotary spindle 323: Servo motor 324: Tool mounting member 325: Polishing tool 326: Support member 327: Polishing grindstone 4: Polishing tool 4a: Coarse polishing tool 42a: Electroformed grinding wheel 4b: Medium polishing tool 42b: Resin bond grinding wheel 4: c Finish polishing tool 42c: Porous vitrified grinding wheel 4d: Mirror polishing tool 42d: Buffing wheel 5: Polishing unit feed mechanism 54: Pulse motor 6: Chuck table mechanism 61: Chuck table 10: Wafer 110: Sample wafer

Claims (3)

A plurality of annular polishing regions that are respectively polished by a plurality of polishing tools from the center region to the outer periphery are formed on the surface to be polished of the wafer.
A sample wafer characterized by that. A polishing apparatus comprising: a chuck table for holding a wafer; and a polishing means having a mounter for detachably mounting a polishing tool for polishing the wafer held by the chuck table. A plurality of polishing tools are mounted on the mounter. By sequentially mounting and rotating the chuck table and the polishing tool, the polishing tool is pressed against the surface to be polished of the wafer held by the chuck table, thereby forming a plurality of polishing regions on the surface to be polished of the wafer. A sample wafer manufacturing method
A first polishing tool is mounted on the mounter, the outer peripheral edge of the first polishing tool is positioned near the center of rotation of the chuck table, and the surface to be polished of the wafer is polished from the central region to the outer periphery. A first polishing step for forming a polishing region;
A second polishing tool is mounted on the mounter, the outer peripheral edge of the second polishing tool is positioned at a predetermined position of the first polishing region polished by the first polishing step, and the first polishing region A second polishing step in which a second polishing region is formed by polishing over the outer periphery while leaving a part of the center side of
A method for producing a sample wafer.   In the first polishing step, the outer peripheral edge of the first polishing tool is positioned on the outer peripheral side by a predetermined amount from the rotation center of the chuck table, and an unpolished region remains in the central region of the surface to be polished of the wafer. 2. A method for producing a sample wafer according to 2.

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