JPS63111616A - Manufacture of semiconductor wafer - Google Patents

Abstract

PURPOSE:To automatically correct the inclining level of a semiconductor wafer at each wafer thereby to improve the quality and the productivity of the wafer by providing a drive motor controlled by a detection signal of wafer height detecting means in height regulating means provided at least three positions of a rotating mechanism with respect to a support and regulating the height positions of the support at peripheral edge parts. CONSTITUTION:A wafer 5 is placed on an attracting board 1 and attracted by vacuum. Then, the heights of both side positions A1, A2 in an X-direction and at both sides of a Y-direction on a wafer 5 are measured by an automatic focusing mechanism attached to the body of an exposure unit, not shown, by moving it in X-and Y- directions of an XY table. Then, the differences of the heights A1 and A2, and B1 and B2 are calculated from the height measuring results to produce the inclining level of the wafer 5 as an output signal, compared with a predetermined value stored in advance. If it is out of the predetermined value, an optimization for correcting the inclination of the wafer 5 is discovered from the calculated value of the inclination of the wafer 5, the number of pulses is calculated and output. A drive motor 13 of height regulating means 12 is driven by the detection signal, and the inclination of the wafer 5 is corrected by regulating the height positions of the peripheral edge parts of a support 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wafer manufacturing apparatus in which a semiconductor wafer suctioned and fixed on a suction cup is transferred by an exposure device, and in particular, it relates to a means for correcting the inclination of the semiconductor wafer surface. related to.

[Conventional technology]

A wafer mounting means section of a conventional semiconductor wafer (hereinafter referred to as "wafer") manufacturing apparatus is shown in FIGS. 6 and 7. In the figure, reference numeral 1 denotes a suction cup for the wafer 5, which is provided with a vacuum suction groove 1a, and is adapted to perform vacuuming through a plurality of vacuum holes (not shown).

Reference numeral 2 denotes a support base that supports the suction cup 1 so that it can be rotated by a small angle, and 3 is a rotation adjustment base that is fixed to XY table No. 1 and supports the support base 2 on the upper part. omitted)
The operation of the above-mentioned conventional apparatus, in which the IC suction cup 1 is rotated and the position of the wafer 50 in the circumferential direction is finely adjusted, is as follows.

First, the wafer 5 is placed on the suction cup 1 by a loader (not shown), and is vacuum-adsorbed. The circumferential position of the wafer 5 is detected, and in response to this signal, a drive motor (not shown) built in the rotation mechanism 3 corrects the wafer 5 to a predetermined rotation position via the suction cup 1.

Next, the perpendicularity of the top surface of the wafer 5 with respect to the optical axis of the exposure device is detected, and if there is any inclination, the adjustment is made using a height adjustment screw attached to the support stand 2 or by inserting shims or the like under the support stand 2. . After adjusting and fixing the - degree inclination in this manner, each wafer 5 was sequentially transferred in this state by an exposure device.

[Problem that the invention seeks to solve]

In the conventional wafer manufacturing equipment as described above, the wafer 5
All copies are initially transferred with the tilt adjusted. However, with the current state-of-the-art exposure equipment, the depth of focus is only 1
．． At around 0 to 1.2 μm, there was a problem that the difference in the tilt level between each wafer 5 affected the defocus amount.To address these issues, we manually adjusted the tilt for each wafer 5. Although it is possible to do this, it would take a lot of time and would be impractical, and the only option was to adjust the slope by averaging it first.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a wafer manufacturing apparatus that can automatically correct the tilt level of each wafer for each wafer, thereby improving quality and productivity. It is an object.

[Failure to solve the problem]

The wafer manufacturing apparatus according to the present invention includes a rotating mechanism provided with height adjustment means at at least three locations relative to the support base,
These height adjustment means each have a drive motor that is controlled by a detection signal from the wafer height detection means, and adjust the height position of each part of the periphery of the support base to correct the inclination of the wafer. It is something to do.

[Effect]

In this invention, the inclination of the wafer suctioned on the suction cup is detected by the height detection means, and the drive motor of each height adjustment means is driven by this detection signal, and the height of each peripheral portion of the support is adjusted. By adjusting the position, Ueno
Correct the slope of.

〔Example〕

1, 2, and 3 are a plan view, a partially cutaway front view, and a perspective view of a wafer mounting means showing an embodiment of the wafer manufacturing apparatus according to the present invention; ．． 2,4
．． 5 is the same as the conventional device described above. Reference numeral 11 denotes a rotation mechanism attached to XY table No. 1, which supports the support stand 2 on the upper part in a height-adjustable manner. I'm trying to fine-tune the rotation. Reference numeral 12 denotes four sets of height adjusting means arranged below the four corners of the support base 2 and supporting the support base 2 in an adjustable inclination manner. This height adjustment means 12 is constructed as follows. Reference numeral 13 denotes a drive motor attached to the rotating mechanism 11, which is driven by a pulse motor, for example, and rotates at a minute angle. Reference numeral 14 denotes a drive cam fixed to the shaft end of the drive motor 13, and the upper end thereof is formed into an inclined surface 14a having a slight angle. Reference numeral 15 designates four receiving portions fixed to the lower surface of the support base 2 at four corners, and eccentric protrusions 15a are eccentrically provided at the lower ends of the receiving portions 15, which are supported in contact with the inclined surfaces 14a of the corresponding drive cams 14. ing. Reference numeral 16 indicates four tension springs that keep the support base 2 attracted to the rotation adjustment base 11.

In the rotation adjustment means 12, the drive motor 13 is pulse-driven to rotate to a minute angle, and the drive cam 14 is also rotated in this direction, and the support base 2 is rotated through the corresponding receiving part 15. The side at that position is raised or lowered by a small amount. This rise or fall depends on the height or low side position of the inclined surface 14a of the drive cam 14 with respect to the protrusion 15a of the receiving part 15.

The operation of the apparatus of the above embodiment will be explained with reference to the flowchart shown in FIG. The steps in this operational flowchart are stored in a computer (not shown) and executed using this computer.

First, when a start command is given, the wafer 5 is placed on the suction cup 1.
Place it on top and vacuum adsorb it. Next, as shown in FIG. 5, an autofocus mechanism attached to the main body of an exposure device (not shown) (when the type is a stepper type)
The heights of the upper surface of the wafer 5 at positions Al and A2 on both sides in the X direction and on both sides in the Y direction are measured by moving the XY table in the X and Y directions.

Next, returning to Fig. 2, from the height measurement results, calculate the difference between A1 height and A2 height and the difference between B1 height and B2 height, calculate the tilt level of wafer 5, and convert this into an output signal, It is compared with a pre-stored specified value, and if it is within the range, a control signal is issued and the exposure device performs exposure processing.

Further, if it is outside the specified value, optimization for correcting the inclination of the wafer 5 is found from the calculated value of the inclination of the wafer 5, and the number of pulses is calculated.

For example, the number of pulses applied to each drive motor 13 at the A1 position and the A2 position is determined by (A1 height - A2 height)/2. Similarly, by (B1 height - B2 height)/2, B
The number of pulses applied to each electric motor 13 at the 1 position and the B2 position is determined. The direction of inclination of the inclined surface 14 & of each driving cam 14 at the A1 position and A2 position is reversed by 180 degrees, and similarly the inclined surface 1 of each driving cam 14 at the B1 position and B2 position is reversed by 180 degrees.
The direction of 4a is the opposite direction. As a result, A1 and A
It is sufficient to apply the same number of pulses to each drive motor 13 of 2.
The same number of pulses may be applied to each drive motor 13 of B1 and B2.

After the tilt of the wafer 5 is corrected in this way, the tilt level is again measured by the autofocus mechanism, and the process is performed according to the flowchart in the same manner as described above to correct the tilt to within the specified value.

The tilt level of the wafer 5 corrected in this way is 1
For a wafer with a diameter of 22.5 mm, it can be kept within 1 μm at maximum.

In the above embodiment, the exposure apparatus is of a stepper type that sequentially exposes each chip portion of the wafer 5, but a 1:1 graze exposure apparatus that exposes each chip of the wafer 5 at once is used. It can also be applied to aligner type cases. However, in this case, a laser for measuring the reference plane is used as a means for detecting the height position of the upper surface of the wafer 5, and the mask is still large and its inclination also becomes large, so the amount of correction of the inclination of the wafer 5 is correspondingly large. Therefore, it is necessary to make the inclination angle of the drive cam 14 larger than that in the above embodiment. Note that the inclination angle of the drive cam 14 in the above embodiment is 0.0.
This is OPP.

Further, in the above embodiment, as the movable support means 12, the drive cam 14 whose upper end is an inclined surface 14a is rotated by a small angle by the drive motor 13 to change the inclination of the support base 2. Rotate the screw shaft,
The rotation of the screw shaft may cause a screw sleeve fixed to the lower surface of the support base 2 to move up and down, thereby changing the inclination of the support base 2 and adjusting the inclination of the wafer 5.

Further, in the above embodiment, the movable support means 12 are provided at four locations, but they may be provided at three locations at equal intervals below the peripheral edge of the support base 2.

〔Effect of the invention〕

As described above, according to the present invention, the movable support means for supporting the support base in a finely adjustable height at at least three locations from below is disposed on the rotating mechanism, and the suction unit supported on the support base is The height position of each peripheral edge of the top surface of the wafer on the board is detected by the height detection means, and the inclination is calculated using this detection signal and compared with a specified value.The drive motor of the movable support means is slightly rotated using the control signal. Since the inclination of the wafer is adjusted through the support table, exposure can be performed automatically with good precision, the depth of focus is deep, and the wafer can be transferred with high pattern accuracy.

[Brief explanation of the drawing]

1 and 2 are a plan view and partially cutaway front view of a main part of a wafer mounting means showing a semiconductor wafer manufacturing apparatus according to the present invention, and FIG. 3 is a perspective view of the wafer mounting means shown in FIG. 1. 4 is a flowchart of wafer transfer using the wafer mounting means shown in FIG. 1, and FIG. 5 is an explanatory diagram of the procedure for measuring each height position of the wafer shown in FIG. 1 with an autofocus mechanism. 6 and 7 are a plan view and a front view of a main part of a wafer mounting means section showing a conventional wafer manufacturing apparatus. ],... Suction cup, 2... Support stand, 4... XY table, 5... Semiconductor wafer, 11... Rotating mechanism, 12... Movable support means, 13... Drive motor, 1
4... Drive cam, 14a... Inclined surface, 15... Receiving portion, 15a... Protrusion 0 Note that the same reference numerals in the drawings are the same -
Or go to ON indicating the corresponding part + brain yo CN"') Figure 4 Figure 5 Showa Year Month Day

Claims (5)

[Claims] (1) A semiconductor wafer is suctioned and held on a suction cup, the suction cup is rotatably supported on a support base, and the support base is fixed on a rotation mechanism mounted on an XY table. , in a manufacturing apparatus in which the wafer is transferred from above by an exposure device, at least one of the above-mentioned parts is disposed within the rotation mechanism, and the height position of the support base can be adjusted from below the periphery by small rotation of the drive motor; movable support means for supporting at three locations; height position detection means provided in the exposure apparatus for measuring the height positions of at least three locations on the periphery of the upper surface of the wafer so as to measure the inclination; The inclination of the wafer is calculated by the means, and compared with a preset specified value of inclination, and when the specified value is exceeded, a control signal is outputted and applied to the drive motor of each of the movable support means to cause a small rotation. A semiconductor wafer manufacturing apparatus comprising a control means for slightly raising and lowering a support stand to correct the inclination of the wafer. (2) The semiconductor wafer manufacturing apparatus according to claim 1, wherein the height position detection means comprises an autofocus mechanism provided in the exposure apparatus. (3) The semiconductor wafer manufacturing apparatus according to claim 1, wherein the height position detection means comprises a reference plane measuring laser provided in the exposure apparatus. (4) The movable support means includes a drive motor, a drive cam fixed to the shaft end extending upward from the motor, and whose upper end is formed into an inclined surface with a slight angle, and a support corresponding to the upper part of the drive cam. Semiconductor wafer manufacturing according to claims 1 to 3, comprising a receiving part fixed to the lower surface of the table and supported by abutting the inclined surface of the drive cam with a protrusion provided eccentrically at the lower part. Device. (5) The semiconductor wafer manufacturing apparatus according to claim 4, wherein the drive motor is a pulse motor.