JPH11123655A - Manufacturing device and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically adjust a spindle to a required inclination with high accuracy by suspending the spindle by a plurality of screws, and automatically adjusting the inclination of the spindle by controlling rotation of the screws. SOLUTION: A spindle 3 is suspended, for example, by four ball screws 5, and an exclusive jig having four displacement sensors 1 is arranged on a chuck table 6 to place a semiconductor substrate under a mount disk 7. After adjusting this inclination, an exclusive member of the displacement sensors 1 containing a disk member is removed from above the chuck table 6, and the semiconductor substrate is horizontally vacuum-sucked to the chuck table 6 for grinding. In adjusting inclination, signals from the displacement sensors 1 are sent to a control circuit 2, and a difference from a display of the inclination is automatically calculated by the control circuit 2, and a correction signal is sent to stepping motors 4 (M1 to M4). Then, rotation of stepping motors 4 is transmitted to the ball screws 5, and is automatically adjusted to an inclination of an inclination preset value 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for manufacturing a semiconductor device, and more particularly to an apparatus and a method for grinding a semiconductor substrate.

[0002]

2. Description of the Related Art First, a general technique of a method for polishing a semiconductor substrate will be briefly described with reference to FIG. The mount disk 7 is coupled to the spindle 17, and the grinding wheel 16 is fixed to the lower surface of the mount disk 7. By rotating the spindle 17 in a tilted state as shown by an arrow 18, the mount disk 7 and the grinding wheel 16 are also rotated in a tilted state, and the semiconductor substrate (not shown) vacuum-adsorbed on the upper surface of a chuck table (not shown). (Semiconductor wafer) 15 IN
From the side to the OUT side in the horizontal direction 19 together with the chuck table. Thus, the main surface of the semiconductor substrate 15 is ground by the grinding wheel 16. Then, a grinding wheel having a roughness and a hardness necessary for grinding a desired semiconductor substrate is attached.

For example, a three-axis grinding apparatus is provided with three types of grinding mechanisms as shown in FIG. 4, that is, three axes, each of which has a grinding wheel suitable for the grinding. The reason why a plurality of axes (a plurality of grinding mechanisms) are used in this way is that if only one axis is ground to a desired thickness, the load applied to the grindstone and the semiconductor substrate becomes large, which may cause breakage (crack). For this purpose, rough cutting is performed stepwise on the first axis,
Medium grinding is performed on the shaft, and finish grinding is performed on the third shaft, and the roughness Rmax of the roughness and the amount of grinding is reduced to 1.0 μm or less.

In the grinding of such a semiconductor substrate, since the semiconductor substrate is ground at the peripheral tip of the grinding wheel, the adjustment of the inclination of the spindle is an important item that cannot be suppressed.

Next, a conventional method of adjusting the inclination of the spindle and its procedure will be described with reference to FIGS.

FIG. 5 is a configuration diagram of a conventional grinding apparatus, FIG. 6 is a diagram showing a method of measuring the inclination of the spindle, FIG. 7 is a diagram showing a value obtained by standardizing the inclination of the spindle, and FIG. FIG.

First, the flow of tilt adjustment will be described with reference to FIG. In the step of the flow 20, the semiconductor substrate is ground. In the step of flow 30, it is checked whether the roughness and the amount of grinding are within the standard Rmax. If it is within the standard, no tilt adjustment is required. If it is out of the standard in the step of the flow 40, the inclination is adjusted so as to satisfy the standard.

Next, a specific adjusting method will be described with reference to FIGS.

In FIG. 5, the shim 11 is connected to the device base 10.
And the fixing guide 12, and tightened with the fixing bolt 13.
As a result, the spindle 3 and the mount disk 7 coupled thereto are tilted. The tilt is, for example, as shown in FIG.
Adjust so that the point C is about 0 μm and the point C is about −20 μm. Since the dial gauge 9 shown in FIG. 6 is fixed to the lower surface 7A on the side of the mount desk 7 and is based on the point O,
If the height from the chuck table 6 where the semiconductor substrate is set is higher than the point, the absolute value of-(minus) is displayed larger.

In particular, at point A and point C, the difference in the thickness of the outer peripheral portion of the semiconductor substrate becomes large, so that it is necessary to adjust it with high accuracy. For example, if the spindle is tilted to the point C side when viewed from the IN side, the grinding amount of the semiconductor substrate at the point C side is large, the grinding amount at the point A side is small, Since the grinding amount is different on the point C side, a great difference occurs in the thickness of the semiconductor substrate between the two.

When the point B is changed to a small inclination such as −40 μm → −10 μm, the angle of contact with the semiconductor substrate becomes small, so that the degree of roughness becomes small. What should originally be able to be ground once (one direction) requires two times grinding (reciprocation direction). Conversely, if the point B is changed from −40 μm to −60 μm, the angle in contact with the semiconductor substrate increases, so that a single grinding enables a thick grinding, but the degree of roughness increases, and a grinding wheel or a semiconductor substrate May be damaged.

For this reason, in order to satisfy the specifications of roughness and thickness and to prevent the above-mentioned problem from occurring, the flow 2 shown in FIG.
From 0, the operation of the flow 40 must be adjusted many times. Therefore, these series of operations required skilled skills. In particular, in the above-described three-axis system, since adjustment work is required for three grinding mechanisms, many man-hours are required.

[0013]

In such a conventional technique, the work of adjusting the inclination takes a long time.

The reason for this is that skill is required to adjust the inclination of the spindle, and manual adjustment in units of 1 μm requires repeated adjustment work.

Accordingly, an object of the present invention is to make it possible to highly accurately and automatically adjust a value required for the inclination of a spindle, and to set an arbitrary inclination as determined by the grinding thickness and surface roughness of a semiconductor substrate. An object of the present invention is to provide an apparatus and a method for manufacturing a semiconductor device of a variable setting system that can be adjusted.

[0016]

SUMMARY OF THE INVENTION A feature of the present invention is a manufacturing apparatus for grinding a semiconductor substrate which moves while facing a rotating grinding wheel, comprising: a spindle; a plurality of screws suspending the spindle; A control unit for controlling the rotation of each screw; and a semiconductor device manufacturing apparatus capable of automatically adjusting the inclination of the spindle by each rotation of the screw. here,
Providing a displacement sensor for detecting the inclination of the spindle,
Preferably, there is provided means for sending a signal regarding the inclination from the displacement sensor to the control unit. Further, it is preferable that the screw is a ball screw that performs a predetermined rotation by a stepping motor driven by a correction signal from the control unit. Further, the displacement sensor is an eddy current sensor, and the distance between the surface on which the grinding wheel is mounted and the mount disk on which the semiconductor substrate is mounted can be measured at a plurality of locations. Also,
The surface on which the grinding wheel is mounted may be a lower surface of a mount disk connected to the spindle.

Another feature of the present invention is a method of manufacturing a semiconductor device in which the spindle is set at a predetermined inclination and the main surface of the semiconductor substrate is ground using any of the above-described semiconductor device manufacturing apparatuses.

As described above, according to the present invention, for example, the inclination of the spindle is detected by the displacement sensor, the current inclination is displayed by the control circuit, and the difference between the surface on which the grinding wheel is mounted and the upper surface of the mount disk on which the semiconductor substrate is mounted is provided. It is possible to instantaneously calculate and display the amount of deviation of the interval between four peripheral points (four points). The deviation from the inclination setting is transmitted from the control circuit as an adjustment signal (correction signal) for the stepping motor 4 as an adjustment mechanism, and the ball screw is driven to adjust the inclination of the spindle.

According to the present invention, the inclination of the spindle is detected by the displacement sensor.
The following highly accurate tilt detection is possible. Also, the means for inputting the signal of the displacement sensor and the inclination set value to the control circuit makes it possible to immediately grasp the current inclination state and the deviation amount. Further, the means for adjusting the inclination having the stepping motor and the ball screw enables a fine adjustment of the inclination of 1 μm or less, which is impossible with the conventional method.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIGS. 1 to 3 are views showing an embodiment of the present invention. FIG. 1 is a configuration diagram of a grinding device, FIG. 2 is a side view showing a method of detecting a height H, and FIG. FIG.

In FIG. 1, the height is 930 mm and the width is 380
A fixed guide 10A fixed to a side surface of the device base 10 having a depth of 390 mm and a depth of 390 mm projects laterally. At the center of the fixed guide 10A, a large opening is formed for the spindle 3 so that the spindle 3 can move freely, and four ball screws 5 are connected therearound to extend downward. I have. Each ball screw 5 is rotated by a stepping motor 4 (M1, M2, M3, M4) via a gear (not shown) having an ultra-low speed ratio.

The lower surface 7A of the mount disk 7 connected to the lower portion of the spindle 3 is a surface on which a grinding wheel is mounted. Then, the main surface of the semiconductor substrate (semiconductor wafer) is ground.

The spindle 3 is connected to the positions corresponding to the four ball screws 5 by two upper and lower female screw portions. Thereby, the spindle 3 is suspended by the four ball screws 5.

A dedicated jig provided with four displacement sensors 1 is provided on the chuck table 6 on which the semiconductor substrate under the mount disk 7 is placed.

That is, the dedicated jigs have the same area as the semiconductor substrate to be ground, for example, the displacement sensors 1 are equally spaced from each other at four places around the surface of the disk member 1A having a diameter of 200 mm.
The disk member 1A is horizontally attracted to the chuck table 6 by vacuum suction. After the adjustment of the inclination, the dedicated member of the displacement sensor including the disk member is removed from the chuck table 6, and the semiconductor substrate is horizontally vacuum-sucked to the chuck table 6, and as shown in FIG. Grinding is performed.

In this tilt adjustment, a signal from each displacement sensor 1 is sent to the control circuit 2, and a correction signal from the control circuit 2 is sent to each stepping motor 4 (M1, M2, M3, M4). It has become.

As described above, in the grinding apparatus of FIG. 1, the displacement sensor 1 for detecting the inclination of the spindle 3, the control circuit 2 for automatically calculating the amount of deviation from the display of the inclination, and the spindle 3
Stepping motor 4 which is a mechanism to adjust the inclination of
And a ball screw 5 respectively.

Next, a method of setting the inclination of the grinding apparatus shown in FIG. 1 will be described. In order to make the spindle 3 have an appropriate inclination, it is input to the control circuit 2 as an inclination set value 8. A dedicated jig with a displacement sensor is set on the chuck table 6, the spindle 3 is lowered to a detectable height H of 1 μm, and a height H4 point with the lower surface 7A of the mount disk 7 is measured.
The present inclination of the spindle 3 is displayed, and at the same time, the deviation amount up to the inclination set value 8 is also displayed. This allows the operator to simultaneously check the current inclination and the amount of deviation.
Further, a correction signal for the deviation amount is sent to a stepping motor 4 which is an adjusting mechanism, and its rotation is transmitted to a ball screw 5 of the same, and is automatically adjusted to the inclination of the inclination set value 8.

Next, the displacement sensor 1 of the embodiment shown in FIG. 2 will be described. This displacement sensor is, for example, an EX series displacement sensor manufactured by Keyence Corporation, and the detection method is an overcurrent type. The principle is that a high-frequency current flows through a coil inside the sensor head to generate a high-frequency magnetic field 14 indicated by a dotted line. If there is an object to be measured (the lower surface 7A) in the high-frequency magnetic field, the passage of the magnetic flux and the overcurrent in the vertical direction flow on the surface of the object due to the electromagnetic induction, and the impedance of the sensor coil changes. The distance is measured by the oscillation state due to this phenomenon.

The operation of the embodiment of the present invention will be described.

In the control circuit 2, first, the reference point O is set to 0 μm, the point A is set to −20 μm, and the point B is set to −4.
Input 0 μm and -20 μm at point C. The value of H detected by the displacement sensor 1 is also input to the control circuit 2 at the same time, and is compared with the inclination setting value 8. Each stepping motor automatically operates so as to fall within a range of ± 2 μm of the inclination setting value 8.

That is, the measured values H from the four displacement sensors 1 are automatically sent to the control circuit 2, respectively, and the deviation from the inclination set value 8 is automatically calculated. Motor 4 (M1, M2, M3,
M4), and the inclination is automatically corrected by automatically rotating the respective stepping motors 4.

Since the inclination adjustment of the spindle, that is, the adjustment value Δ from a predetermined inclination is about 50 μm at most, the μm is adjusted by a mechanism using a ball screw and a gear having an ultra low speed ratio as shown in FIG. Is optimal.

In the above-described embodiment, the method of measuring the distance H by the displacement sensor and adjusting the inclination using the grinding device of FIG. 1 has been described. However, it is also possible to omit the measurement of the distance H and adjust the inclination using only past data. That is, this method has a function of storing the past data in the control circuit 2 and automatically selecting the optimum inclination by inputting the type of the grinding wheel, the grinding thickness, the thickness of the semiconductor substrate after grinding, and the like. It is.

[0036]

The first effect is that the finishing accuracy of the ground surface of the wafer is greatly improved.

The reason for this is that there is no variation in inclination due to adjustment, and the required inclination can always be maintained in accordance with the state of grinding.

The second effect is that a fine adjustment of the inclination of 1 μm or less, which was impossible with the conventional method, becomes possible, and no skill is required. Therefore, anyone can work easily, faster and more accurately.

The reason is that the provision of a stepping motor and a ball screw around the spindle makes it possible to perform fine adjustment with high accuracy.

A third effect is that productivity can be improved. As a result, the stagnation time of the product is shortened, and it is possible to increase production.

The reason is that the maintenance time can be reduced to about 1/10 or less of the conventional one for the above-mentioned reason, so that the operation time can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a polishing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view showing a method for detecting a height H in the embodiment of the present invention.

FIG. 3 is a plan view showing a displacement sensor according to the embodiment of the present invention.

FIG. 4 is a diagram showing grinding of a semiconductor substrate.

FIG. 5 is a diagram showing a configuration of a conventional polishing apparatus.

FIG. 6 is a side view showing a height detection method in the related art.

FIG. 7 is a diagram showing an inclination setting value serving as a guide of a spindle in the related art.

FIG. 8 is a diagram showing a flow of tilt adjustment in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Displacement sensor 1A Disk member of jig for exclusive use of displacement sensor 2 Control circuit 3 Spindle 4 Stepping motor 5 Ball screw 6 Chuck table 7 Mount disk 8 Tilt setting 9 Dial gauge (Exclusive jig with dial gauge) 10 Device base 10A Fixed guide 11 Shim 12 Fixing guide 13 Fixing bolt 14 High-frequency magnetic field 15 Semiconductor substrate 16 Grinding wheel 17 Spindle 18 Rotation direction 19 Horizontal movement direction of semiconductor substrate 20 Grinding flow 30 Grinding amount / roughness judgment flow 40 Tilt adjustment flow

Claims (6)

[Claims] 1. A manufacturing apparatus for grinding a semiconductor substrate moving while facing a rotating grinding wheel, comprising: a spindle;
A semiconductor, comprising: a plurality of screws for suspending the spindle; and a control unit for controlling the rotation of each of the screws, and the inclination of the spindle can be automatically adjusted by the rotation of each of the screws. Equipment manufacturing equipment. 2. The apparatus for manufacturing a semiconductor device according to claim 1, further comprising a displacement sensor for detecting a tilt of the spindle, and a unit for sending a signal relating to the tilt from the displacement sensor to the control unit. 3. The semiconductor device manufacturing apparatus according to claim 1, wherein said screw is a ball screw which performs a predetermined rotation by a stepping motor driven by a correction signal from said control unit. 4. The displacement sensor according to claim 2, wherein the displacement sensor is an eddy current sensor, and measures a distance between a surface on which a grinding wheel is mounted and a mount disk on which a semiconductor substrate is mounted at a plurality of locations. Equipment for manufacturing semiconductor devices. 5. The apparatus according to claim 4, wherein the surface on which the grinding wheel is mounted is a lower surface of a mount disk coupled to the spindle. 6. The semiconductor device manufacturing apparatus according to claim 1, wherein the main surface of the semiconductor substrate is ground after setting the spindle at a predetermined inclination. Device manufacturing method.