JPH09216152A - End face grinding device and end face grinding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly grind a circumference end part of a semiconductor wafer with high precision. SOLUTION: A spindle 18 is arranged along the Y-axis direction. When an end face of the outer circumference part in a wafer 2 is ground, a spindle 16 is moved in the Y-axis direction and in the Z-axis direction while a table 14 is rotated, so that a diamond wheel 18 is brought into contact with the wafer 2. When an end face of an orientation flat part in the wafer 2 is ground, the spindle 16 is moved in the Y-axis direction and in the Z-axis direction while the rotation of the table 14 is stopped, and at the same time, the table 14 is moved in the X-axis direction, so that the diamond wheel 18 is brought into contact with the wafer 2. In this process, the outer circumferential face of the diamond wheel 18 touches the wafer 2 linearly, so that a load working on the diamond wheel 18 and on the wafer 2 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end face grinding apparatus and an end face grinding method for grinding a peripheral edge portion of a semiconductor wafer, particularly an SOI (Silicon On Insulator) crystal.

[0002]

2. Description of the Related Art A semiconductor wafer, especially an SOI crystal produced by bonding two silicon wafers together,
BACKGROUND ART In order to prevent chipping, cracking and dimples on a supporting substrate, the peripheral end portion thereof is ground into a substantially L shape. Conventionally, in the end surface grinding of such a semiconductor wafer, a vertical axis type surface grinding apparatus has been used. In this surface grinding device, a cup wheel is used as a grinding tool, and a spindle to which the cup wheel is attached is arranged along the vertical direction (Z-axis direction). When the peripheral edge portion of a semiconductor wafer is ground into a substantially L shape by using this vertical axis type surface grinder, first, the semiconductor wafer 102 is placed on the table 11 as shown in FIG.
Fixed at 2, the table 112 is rotated about an axis parallel to the Z axis. Then, the spindle is rotated to impart rotation to the cup wheel 114, and then the spindle is moved in the Z-axis direction to bring the working surface of the cup wheel 114 into contact with the semiconductor wafer 102 and
Grind the peripheral edge of.

[0003]

By the way, in such a vertical axis type surface grinding apparatus, as shown in FIG. 17B, the working surface of the cup wheel 114 comes into surface contact with the semiconductor wafer 102. Therefore, an excessive load is applied to the cup wheel 114 and the semiconductor wafer 102 during the grinding work. Further, since the cup wheel 114 contacts the semiconductor wafer 102 on only one side, the cup wheel 114 slightly tilts during the grinding work, and the working surface of the cup wheel 114 and the semiconductor wafer 10 are slightly tilted.
The parallelism with the upper surface of 2 cannot be maintained with high accuracy. Therefore, in the conventional vertical axis type surface grinding apparatus, there is a problem that the peripheral edge portion of the semiconductor wafer 102 has a large variation and the peripheral edge portion cannot be ground with high accuracy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an end surface grinding apparatus and an end surface grinding method which can grind the peripheral end portion of a semiconductor wafer with high precision and evenness. It is a thing.

[0005]

In order to achieve the above object, an end surface grinding apparatus according to the invention of claim 1 is capable of reciprocating movement and rotation, and a mounting table for fixing a semiconductor wafer, Arranged along a direction perpendicular to the moving direction of the mounting table and the rotation axis direction of the mounting table, a spindle that is movable in the rotation axis direction of the mounting table and movable in the perpendicular direction, and Attached to the tip of the main shaft and given rotation by rotating the main shaft, a disk-shaped grinding tool provided with abrasive grains on the outer peripheral part, and by controlling the movement of the mounting table and the main shaft And a control means for causing at least the outer peripheral surface of the grinding tool to linearly contact the semiconductor wafer to grind the peripheral end portion of the semiconductor wafer into a substantially L shape.

An end surface grinding apparatus according to a second aspect of the present invention is the end surface grinding apparatus according to the first aspect of the invention, wherein the semiconductor wafer is made by bonding two silicon wafers together.
It is characterized by being an OI crystal. In order to achieve the above-mentioned object, an end surface grinding method according to a third aspect of the present invention is such that a disk-shaped grinding tool having abrasive grains on its outer peripheral portion is rotated, and at least the outer peripheral surface of the grinding tool is a semiconductor wafer. Linearly contacting the semiconductor wafer with the peripheral edge portion of the semiconductor wafer at a substantially L
It is characterized by grinding in a letter shape.

An end surface grinding method according to a fourth aspect of the present invention is the end surface grinding method according to the third aspect, wherein the semiconductor wafer is manufactured by bonding two silicon wafers together.
It is characterized by being an OI crystal.

[0008]

According to the invention described in claim 1, the main shaft is arranged along the direction perpendicular to the moving direction of the mounting table and the rotation axis direction of the mounting table by the above-mentioned structure, so-called horizontal axis type structure,
By grinding the peripheral edge portion of the semiconductor wafer, the outer peripheral surface of the grinding tool does not tilt during the grinding operation, and the outer peripheral surface of the grinding tool can be brought into linear contact with the semiconductor wafer. Therefore, compared with the conventional device, it is possible to reduce the load applied to the grinding tool and the semiconductor wafer during the grinding work.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 is a schematic block diagram of an end surface grinding apparatus according to an embodiment of the present invention, FIG. 2 is a schematic plan view of the end surface grinding apparatus, FIG. 3 is a schematic front view of the end surface grinding apparatus, and FIG. 4 is an end surface grinding apparatus thereof. Of FIG. 5, FIG. 5 is a schematic view of a grinding portion of the end surface grinding device, FIG. 6 is a view for explaining a vertical feed mechanism of a spindle of the end surface grinding device, and FIG. 7 is an SOI (Silicon On Insulator) crystal. FIG. 8 is a diagram for explaining, FIG. 8 is a diagram showing an example of grinding accuracy required when grinding a peripheral edge portion of the SOI crystal, FIG. 9 is a diagram for explaining a grinding tool, and FIG. It is a figure which shows a mode when grinding a peripheral edge part.

In this embodiment, a case where a peripheral edge portion of a semiconductor wafer (hereinafter also simply referred to as a wafer) is ground into an approximately L shape by using an end surface grinding device will be considered. here,
In particular, an SOI crystal will be used as a semiconductor wafer. As shown in FIG. 7, such an SOI crystal is obtained by stacking a silicon wafer (active substrate) having no oxide film formed on its surface on a silicon wafer having an oxide film formed on its surface (support substrate). It is manufactured by a bonding method in which an oxide film is formed on the surface and two silicon wafers are bonded at the same time. The end face grinding of this SOI crystal is
Similar to the usual chamfering process, it is performed for the purpose of chipping, cracking, and prevention of dimples on the supporting substrate. The SOI crystal whose peripheral edge has been ground is ground to a predetermined thickness in the factory of each user by sequentially grinding the oxide film part and the silicon part of the pattern processing part (the part other than the part where the end face is ground). After that, pattern processing or the like is performed and the dicing process is started.

When the end face of the SOI crystal is ground, for example, the grinding accuracy shown in FIG. 8 is required. That is, as shown in FIG. 8A, the grinding width of the outer peripheral portion (hereinafter also simply referred to as the outer peripheral portion) excluding the orientation flat (orientation flat) portion is α mm, and the grinding width of the orientation flat portion is β mm. The parallelism of the orientation flat portion shown in FIG. 8B is θ ° or less. Further, as shown in FIG. 8C, the remaining thickness of the ground portion of the active substrate (hereinafter referred to as the terrace portion) is t μm, and the variation in the remaining thickness of the terrace portion is r μm or less. In general, the dimensional value of grinding required when grinding the end face of the SOI crystal is slightly different for each user.

As shown in FIGS. 1 and 2, the end surface grinding apparatus of this embodiment includes a grinding section 10, an NC control section 20, a transfer mechanism section 30, a transfer control section 40, an alignment apparatus 50, and Cleaning unit 60, input panel 70, and display device 8
0 and. Here, in particular, as the end surface grinding device, as shown in FIGS. 2 to 4, an improved dicing machine ADM-6F manufactured by our company is used.
The improvement is that the alignment device 50 is provided separately from the alignment device originally installed in the dicing machine ADM-6F, and a diamond wheel described below is used as a grinding tool instead of the cutting tool. That is the point.

As shown in FIGS. 2 and 5, the grinding section 10 has a feed table 12, a chuck table 14, a spindle 16 and a diamond wheel 18. The feed table 12 can be moved in the X-axis direction (the direction perpendicular to the paper surface in FIG. 5) by the roller 12a. In FIG. 10, the chuck table 14
Is a table on which the wafer 2 is placed and fixed by vacuum suction. . The chuck table 14 is the feed table 12
It is mounted on and is driven to rotate. Here, the rotation axis direction of the chuck table 14 is the Z axis direction. A direct drive method using an AC servo motor is adopted for the rotation drive of the chuck table 14.

The spindle 16 is a main shaft that rotates by attaching a grinding tool to its tip. In the present embodiment, the spindle 16 is moved in the direction (Y) perpendicular to the X-axis direction and the Z-axis direction.
The so-called horizontal axis type structure is arranged along the (axial direction). A high frequency motor is used to drive the spindle 16 to rotate. Further, the spindle 16 can move in the Y-axis direction as well as in the Z-axis direction. As a vertical feed mechanism for the spindle 16 in the Z-axis direction, as shown in FIG. 6, a high-rigidity support system is employed in which the spindle 16 is installed at the center of the center of rotation and the vertical feed drive unit.

For feeding the feed table 12 in the X-axis direction, the spindle 16 in the Y-axis direction, and the spindle 16 in the Z-axis direction, a ball screw drive using a rolling slide on the sliding surface is used. Is adopted to perform semi-closed loop control with an AC digital servo motor and encoder. With such a feeding mechanism, highly accurate positioning can be performed.

The diamond wheel 18 is a disk-shaped grinding tool having diamond abrasive grains adhered to the outer periphery thereof. The diamond wheel 18 is provided with rotation by rotating the spindle 16, whereby the wafer 2
Grind the peripheral edge of. Here, as the diamond wheel 18, as shown in FIG. 9, the model is 1A1, the wheel outer diameter is Dmm, the wheel length is Tmm, the thickness of the grindstone layer is Xmm, and the hole diameter is Hmm. I am using.

The NC controller 20 controls the operations of the feed table 12, chuck table 14 and spindle 16. In this embodiment, the work of grinding the peripheral edge of the wafer is divided into grinding of the outer peripheral portion excluding the orientation flat portion and grinding of the orientation flat portion. When grinding the outer peripheral portion, the NC control unit 20 moves the spindle 16 in the Y-axis direction and the Z-axis direction while rotating the chuck table 14 as shown in FIG.
The contact position between the wafer and the diamond wheel 18 is adjusted, and the outer peripheral portion of the wafer is ground into a substantially L shape on the outer peripheral surface of the diamond wheel 18. On the other hand, when the orientation flat portion is ground, the spindle 16 is moved in the Y-axis direction and the Z-axis direction while the rotation of the chuck table 14 is stopped, and the feed table 12 is moved in the X-axis direction. Adjust the contact position between the wafer and the diamond wheel 18 to adjust the orientation flat to the diamond wheel 1.
The outer peripheral surface of 8 is ground into a substantially L shape. The peripheral edge of the wafer may be ground by the side surface of the diamond wheel 18.

The end surface grinding apparatus of this embodiment has a so-called horizontal axis type structure in which the spindle 16 is arranged along the Y-axis direction (horizontal direction). Therefore, as shown in FIG. The outer peripheral surface of 18 comes into linear contact with the wafer. Therefore, as compared with the conventional vertical axis type surface grinding apparatus, there is an advantage that it is possible to prevent an excessive load from being applied to the diamond wheel 18 and the wafer when grinding the peripheral edge portion of the wafer.

As shown in FIGS. 2 and 4, the transfer mechanism section 30 has a wafer cassette 32, a lifter 34, and a shifter 36. The wafer cassette 32 stores the wafer. The wafer cassette 32 is stored inside by opening the door 90 on the front surface of the end surface grinding apparatus shown in FIG. 3, and then raised to a predetermined position by the elevator mechanism. The lifter 34 transfers the wafer between the wafer cassette 32 and the shifter 36. Lifter 34
Can move up and down in FIG. A vacuum pad is attached to the tip of the lifter 34, and holds the wafer from below by vacuum suction.
Further, the shifter 36 conveys the wafer to the grinding unit 10, the alignment device 50, the cleaning unit 60 and the like. The shifter 36 can move in the left-right direction in FIG. 2 and can move in a direction perpendicular to the plane of the drawing. Similar to the lifter 34, a vacuum pad is attached to the tip of the shifter 36, and holds the wafer from above by vacuum suction. Where lifter 3
When the wafer is transferred between the No. 4 and the shifter 36, a pad-to-pad handing method is adopted, whereby the wafer can be reliably transferred and the cleanliness of the wafer is maintained. be able to. Further, the transfer control unit 40 controls the operations of the wafer cassette 32, the lifter 34, and the shifter 36 based on an instruction from the NC control unit 20.

The alignment device 50 aligns the wafer, and specifically, aligns the center position of the wafer with the center position of the chuck table 14, and
Align the orientation flat with the specified direction. As the alignment device 50, a device that employs a non-contact detection method using a transmissive sensor is used. The cleaning unit 60 is shown in FIG.
As shown in FIG. 3, it has a chuck cleaning device 62, a wafer cleaning device 64, a cleaner device 66, and a blow device (not shown). Before the wafer is placed on the chuck table 14, the chuck cleaning device 62 is configured to
Is to be washed. The wafer cleaning device 64 grinds the peripheral edge of the wafer and then chucks the wafer on the chuck table 1.
The upper surface of the wafer is cleaned and air blown while it is placed on the wafer 4. Further, the cleaner device 66 is to apply pure water to clean the wafer after grinding while rotating it, and blow air on the upper surface of the wafer. The blower device is to clean the wafer after the cleaning by the cleaner device 66 is completed. With the wafer held by the shifter 36, the back surface of the wafer is blown with air.

The input panel 70 is for inputting predetermined parameters for wafer end surface grinding. As shown in FIG. 13, the parameters relating to the end face grinding of the orientation flat portion are the wafer diameter, the orientation flat position which is the distance between the wafer center and the orientation flat, the grinding width of the orientation flat, and the length of the orientation flat extending from one end in the orientation flat direction. Overrun length, wafer thickness, residual thickness of wafer, grinding depth per grinding, which is the depth to which the diamond wheel 18 grinds in one descent, moving speed of the feed table 12 in the X-axis direction, There are the amount of retract, the number of spark outs, etc. In addition, as parameters for the end surface grinding of the outer peripheral portion,
As shown in FIG. 15, the wafer diameter, the grinding width of the outer peripheral portion,
Wafer thickness, rotation speed and rotation direction of the chuck table 14, remaining grinding thickness of the wafer, grinding depth per time which is the depth to which the diamond wheel 18 grinds in one descent,
There is a spark-out timer. Display device 8 shown in FIG.
0 is for displaying a parameter setting screen when a parameter is input from the input panel 70.

Next, the operation of the end surface grinding apparatus of this embodiment will be described with reference to FIG. FIG. 11 is a flowchart of the entire operation of the end surface grinding device. First, the chuck cleaning device 62 is used in advance for the chuck table 14
Wash (step 12). Next, the wafer cassette 32
Of the wafers stored in, the position of the wafer to be subjected to the end face grinding this time is indexed (step 14), and the lifter 34 vacuum sucks the wafer from the lower side and pulls it out of the wafer cassette 32 (step 16). The shifter 36 moves to the position of the lifter 34, and after vacuum suctioning the wafer from above, the air suction of the lifter 34 is stopped, and the wafer is transferred from the lifter 34 to the shifter 36 (step 18). Next, the shifter 36 is moved to the alignment device 50, and the wafer is placed on the table of the alignment device 50 (step 2
2). In the alignment device 50, the center position of the wafer is adjusted to the center position of the chuck table 14, and the orientation flat position is adjusted to a predetermined direction (step 24). Thereafter, the shifter 36 adsorbs and detaches the wafer placed on the alignment device 50 (step 26), moves the wafer to the chuck table 14, and then moves the wafer onto the chuck table 14.
When placed on the chuck table 14, the chuck table 14 vacuum-adsorbs and fixes the wafer (step 28).

Next, in the grinding section 10, end face grinding of the orientation flat portion and end face grinding of the outer peripheral portion are performed (step 32). First, a method of grinding the end face of the orientation flat portion will be described. 12
FIG. 13 is a flowchart of the operation of grinding the peripheral edge of the orientation flat portion, and FIG. 13 is a diagram for explaining the operation of grinding the peripheral edge of the orientation flat portion. First, the operator operates the display device 80.
While looking at the screen, the respective parameters as shown in FIG. 13 are input from the input panel 70. After each axis is returned to the origin (step62), it is moved to a predetermined machining position (step6).
Four). That is, the feed table 12 is moved to a predetermined start point in the X-axis direction, and the spindle 16 is moved to a predetermined start point in the Y-axis direction. Here, the start point of the feed table 12 is determined based on the overrun length, and the start point of the spindle 16 is determined based on the orientation flat position and the orientation flat grinding width. Further, the spindle 16 is rapidly moved in the Z-axis direction to move to the descending point.
The descending point is defined as a position higher than the surface of the chuck table 14 by a distance obtained by adding a few mm to the wafer thickness.
Next, the spindle 16 is lowered from the origin in the Z-axis direction by the grinding depth per time, and unidirectional grinding is performed (step6
6). After that, the spindle 16 is retracted in the Z-axis direction, and the feed table 12 is quickly returned to the start point (step 68). Next, the NC control unit 20 determines whether or not the total grinding depth in the Z-axis direction has reached a reference value obtained by subtracting the remaining grinding thickness of the wafer from the wafer thickness (step 72). When it is determined that the total grinding depth has not reached the reference value, one-way grinding is performed again. On the other hand, if it is determined that the total grinding depth has reached the reference value, after sparking out (st
ep74), the spindle 16 is moved upward to the descending point. After that, the spindle 16 is returned to the origin in the Z-axis direction, the feed table 12 is returned to the origin in the X-axis direction, and the spindle 16 is returned to the origin in the Y-axis direction (step 76). Thus, the end face grinding work of the orientation flat portion is completed.

Next, a method for grinding the end face of the outer peripheral portion will be described. FIG. 14 is a flowchart of the operation of grinding the peripheral edge of the outer peripheral portion, and FIG. 15 is a diagram for explaining the operation of grinding the peripheral edge of the outer peripheral portion. First, the operator operates the display device 8
While looking at the screen of 0, each parameter as shown in FIG. 15 is input from the input panel 70. First, each axis is returned to the origin (step 82) and then moved to a predetermined machining position (step 84). That is, the feed table 12 is moved to a predetermined start point in the X axis direction, and the spindle 16 is moved to the Y axis.
Move to a given start point in the axial direction. here,
The starting point of the spindle 16 is determined based on the wafer diameter and the grinding width of the outer peripheral portion. Further, the rotation axis (B axis) of the chuck table 14 is stopped (orientation stop) at a predetermined angular position, and the spindle 16 is fast-forwarded in the Z-axis direction to move to the descending point. The descending point is several meters from the surface of the chuck table 14 to the wafer thickness.
It is defined as a position that is higher by a distance of m. After that, the chuck table 14 is rotated around its rotation axis at a predetermined rotation speed in a predetermined direction (step 86). Next, the spindle 16 is lowered from the origin in the Z-axis direction by the grinding depth per time to grind the peripheral end portion of the outer peripheral portion (step 88). Next, the NC control unit 20 determines whether or not the total grinding depth in the Z-axis direction has reached a reference value obtained by subtracting the remaining grinding thickness of the wafer from the wafer thickness (step 92). When it is determined that the total grinding depth has not reached the reference value, the peripheral edge portion grinding of the outer peripheral portion is continued. On the other hand, if it is determined that the total grinding depth has reached the reference value, after sparking out (st
ep94), the spindle 16 is moved upward to the descending point, and the rotation axis of the chuck table 12 is orientation stopped (step 96). Then, the spindle 16 is returned to the origin in the Z-axis direction, the feed table 12 is returned to the origin in the X-axis direction, and the spindle 16 is returned to the origin in the Y-axis direction (step 98). In this way, the end surface grinding work of the outer peripheral portion is completed.

Next, the work cleaning device 64 cleans the upper surface of the wafer with the wafer placed on the chuck table 14 and blows air (step 34). At this time, the wafer is indexed in the direction in which the wafer is stored in the wafer cassette 32 (step 36). Then, the shifter 36 takes out the wafer placed on the chuck table 14 and then moves it to the cleaner device 66 to place the wafer on the cleaner table of the cleaner device 66 (step 38). In the cleaner device 66, while the wafer is rotated, pure water is applied to clean the wafer, and the upper surface of the wafer is blown with air (step 42). Next, the shifter 36 sucks the wafer placed on the cleaner device 66 (step 44), and while the shifter 36 holds the wafer, the blower blows air on the back surface of the wafer (step 46). Thereafter, the lifter 34 receives the wafer from the shifter 36 (step 48) and stores the wafer at a predetermined position of the wafer cassette 32 (step 52).

In the end surface grinding apparatus of this embodiment, the spindle is arranged along the Y-axis direction (horizontal direction), so-called horizontal axis type structure is used, and the peripheral edge portion of the semiconductor wafer is ground to perform the grinding work. The outer peripheral surface of the diamond wheel is not inclined inside, and the outer peripheral surface of the diamond wheel can be linearly contacted with the semiconductor wafer. Therefore, compared with the conventional vertical type surface grinder, the load applied to the diamond wheel and the semiconductor wafer during the grinding operation can be reduced, so that the peripheral edge portion of the semiconductor wafer can be made highly accurate and uniform. It can be ground.

Further, the inventors of the present invention actually carried out end face grinding of an SOI crystal by using the end face grinding device of this embodiment,
The effect was verified. FIG. 16 is a diagram showing the measurement results of the residual thickness of the terrace portion and variations in the residual thickness when the peripheral edge of the SOI crystal is ground. When the conventional vertical axis type surface grinder is used, the terrace remaining thickness is about 170 at maximum.
It can only be made to be μm, and the variation in the remaining thickness is considerably large at ± 20 μm. On the other hand, when the end surface grinding apparatus of this embodiment is used, the remaining thickness of the terrace portion can be set to about 30 μm, and the remaining thickness variation can be suppressed to a small value of about ± 3 μm. Therefore, the end surface grinding apparatus of the present embodiment is required to grind the peripheral edge portion with high accuracy as in the case of grinding the peripheral edge portion of the SOI crystal produced by bonding two silicon wafers together. It is suitable for use when By the way, when a peripheral edge portion of a semiconductor wafer is ground by using a conventional vertical axis type surface grinder, many minute dents called dimples are formed on the ground surface. The present inventors have found that when the peripheral edge portion of a semiconductor wafer is ground by using the end surface grinding apparatus of this embodiment, the number of dimples is one digit compared to the case where a conventional vertical axis type surface grinding apparatus is used. Therefore, it was confirmed that the number of dimples was significantly reduced by two digits.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist thereof. For example, in the above-described embodiment, when grinding the peripheral edge of the wafer, first, the case where the end face grinding of the orientation flat portion is performed and then the end surface grinding of the outer peripheral portion is performed has been described. After performing the end surface grinding, the end surface grinding of the orientation flat portion may be performed. Also,
In the end surface grinding apparatus of the above embodiment, it is possible to perform only the end surface grinding of the orientation flat portion or only the end surface grinding of the outer peripheral portion, if necessary.

[0029]

As described above, according to the first aspect of the invention, the main shaft is arranged along the direction perpendicular to the moving direction of the mounting table and the rotating axis direction of the mounting table, that is, a so-called horizontal shaft type. With the structure, by grinding the peripheral edge of the semiconductor wafer, the outer peripheral surface of the grinding tool is prevented from tilting during the grinding work, and the outer peripheral surface of the grinding tool is brought into linear contact with the semiconductor wafer. Since it is possible to reduce the load applied to the grinding tool and the semiconductor wafer during the grinding work as compared with the conventional device, the peripheral edge portion of the semiconductor wafer can be highly accurately moved to the chipping, cracking and supporting substrate. It is possible to provide an end surface grinding device capable of preventing dimples and grinding.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an end surface grinding apparatus that is an embodiment of the present invention.

FIG. 2 is a schematic plan view of the end surface grinding device.

FIG. 3 is a schematic front view of the end surface grinding device.

FIG. 4 is a schematic side view of the end surface grinding device.

FIG. 5 is a schematic view of a grinding portion of the end surface grinding device.

FIG. 6 is a view for explaining a vertical feed mechanism of a spindle of the end surface grinding device.

FIG. 7 is a diagram for explaining an SOI crystal.

FIG. 8 is a diagram showing an example of grinding accuracy required when grinding the peripheral edge portion of the SOI crystal.

FIG. 9 is a diagram for explaining a grinding tool.

FIG. 10 is a diagram showing a state when a peripheral edge portion of a semiconductor wafer is ground by the end surface grinding apparatus of the present embodiment.

FIG. 11 is a flowchart of the entire operation of the end surface grinding device.

FIG. 12 is a flowchart of an operation of grinding the peripheral edge portion of the orientation flat portion.

FIG. 13 is a diagram for explaining the operation of grinding the peripheral edge portion of the orientation flat portion.

FIG. 14 is a flowchart of an operation of grinding the peripheral end portion of the outer peripheral portion.

FIG. 15 is a diagram for explaining an operation of grinding the peripheral end portion of the outer peripheral portion.

FIG. 16 is a diagram showing the measurement results of the residual thickness of the terrace portion and variations in the residual thickness when the peripheral edge of the SOI crystal is ground.

FIG. 17 is a diagram for explaining an operation of grinding a peripheral edge portion of a semiconductor wafer in a conventional vertical axis type surface grinding apparatus.

[Explanation of symbols]

 2 semiconductor wafer 10 grinding unit 12 feed table 14 chuck table 16 spindle 18 diamond wheel 20 NC control unit 30 transfer mechanism unit 32 wafer cassette 34 lifter 36 shifter 40 transfer control unit 50 alignment device 60 cleaning unit 62 chuck cleaning device 64 wafer cleaning device 66 Cleaner device 70 Input panel 80 Display device 90 Door

Claims (4)

[Claims] 1. A mounting table capable of reciprocating movement and rotation, fixed to a semiconductor wafer, and arranged along a direction perpendicular to a moving direction of the mounting table and a rotation axis direction of the mounting table, A spindle that is movable in a direction at right angles and movable in the rotation axis direction of the mounting table, and is attached to the tip of the spindle, and is given rotation by rotating the spindle. By controlling the movement of the disk-shaped grinding tool provided with and the mounting table and the spindle,
An end surface grinding apparatus comprising: a control unit configured to bring at least an outer peripheral surface of the grinding tool into linear contact with the semiconductor wafer to grind a peripheral end portion of the semiconductor wafer into a substantially L shape. 2. The end surface grinding apparatus according to claim 1, wherein the semiconductor wafer is an SOI crystal produced by bonding two silicon wafers together. 3. A disk-shaped grinding tool having abrasive grains provided on the outer periphery thereof is rotated to linearly abut at least the outer peripheral surface of the grinding tool to the semiconductor wafer so that the peripheral edge portion of the semiconductor wafer is fixed. An end surface grinding method characterized by grinding in a substantially L shape. 4. The end surface grinding method according to claim 3, wherein the semiconductor wafer is an SOI crystal produced by bonding two silicon wafers together.