JPH01268122A - Electron beam exposure device - Google Patents

Abstract

PURPOSE:To handle wafers of various sizes by using a same sample base and to acquire small-sized electron beam exposure device having a simple structure, by irradiating electron beam which is focus-adjusted by being irradiated to a mark on a wafer, to a beam adjustment pattern and by controlling an actuator to position a pattern surface at a focus position of electron beam based on a detected signal from a detection means. CONSTITUTION:A controlling means 40 irradiates electron beam EB which is focus-adjusted to an upper surface of a wafer mounted on a sample base 10 to a beam adjustment pattern and controls an actuator 22 to permit a pattern surface to be positioned at a focus position of the electron beam EB based on a detected signal from a detection means 28. It becomes possible thereby to mount wafers 3 on the sample base even if they differ in thickness; therefore wafers 3 of various sizes can be handled using the same sample base 10. A holder of the wafers 3 to the sample base 10 and a holder of the sample base 10 can be simplified in this way.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Prior art (Figure 7) Problems to be solved by the invention Means for solving the problems (Figure 1) Working examples One example ( Figures 2 to 6) Effects and Summary of the Invention] The purpose of this invention is to simplify the configuration and reduce the size of an electron beam exposure device by making it possible to handle various sizes of wafers using the same sample stage. A sample stage on which a wafer is placed; a beam adjustment jig having a beam adjustment pattern formed on one side; an acticoator that is slightly driven in a direction perpendicular to the wafer mounting surface of the sample stage; a detection means that outputs a signal according to the spot shape of the electron beam irradiated onto the beam adjustment pattern; The beam adjustment pattern is irradiated with an electron beam whose focus has been adjusted by irradiating it onto a mark on the wafer, and the beam adjustment pattern is adjusted so that the pattern surface is at the focus position of the electron beam based on the signal from the detection means. and a control means for controlling the acticoator.

[Industrial application field] The present invention relates to an electronic heater 1 and an exposure device.

[Prior Art] A conventional electronic P11 exposure apparatus has an opening 1.1 as shown in FIG. The upper edge of the wafer 3 is pressed against the lower surface of the holder 2 on which the boulder 2 is formed, using a pressing leaf spring of 4.4 degrees, the edge of this boulder 2 is inserted into the sample stage 5, and the fixing pin is held at 6.6 degrees. The holder 2 was fixed to the sample stage 5 by.

This boulder 2 is equipped with a beam adjustment jig (not shown), whose two surfaces are flush with the top surface of the wafer 3.
It is located so that it is located at The thickness of wafer 3 is
Even if the diameter is the same, there are variations from wafer to wafer, and it may not be constant, but due to this arrangement, the top surface position of the wafer 3 always coincides with the top surface of the beam adjustment jig.

[Problems to be Solved by the Invention] However, since an opening n I corresponding to the diameter of the wafer 3 is required, it is necessary to prepare various holders 2 according to the diameter of the wafer 3 and use them selectively. .

Furthermore, since the sample stage 5 holds the holder 2 from the outside, the apparatus becomes large.

Furthermore, after pushing down the tip of the pressing leaf spring and inserting the wafer 3 between the lower surface of the holder 2 and the pressing leaf spring 4.4°, the pressing leaf spring 4.4' is pressed against the wafer 3. In addition, a mechanism is required to adjust the widthwise spacing of the sample stage 5 and push the fixing pin 6.6° downward.1. After the holder 2 is lowered and inserted into the sample stage 5, a mechanism is required to bias the pressing leaf spring 6,6' upward, and the drive mechanism is complicated.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an electron beam exposure apparatus that can handle wafers of various sizes using the same sample stage, has a simple configuration, and can be miniaturized. be.

[Means to solve the problem] FIG. 1 is a diagram showing the principle of the present invention.

In the figure, 10 is a sample stage, on which wafers of various sizes are placed.

24 (JP1, J19) adjustment tools, and a beam adjustment pattern is formed on one side.

Reference numeral 22 denotes an aczicoator, which is composed of, for example, a piezoelectric element, is fixed to the sample stage 1, and minutely drives one side of the beam adjustment jig 24 in the direction perpendicular to the wafer mounting surface of the sample stage 10. .

A detection means 28 outputs a signal corresponding to the spot shape of the electron beam EB irradiated with the beam adjustment pattern.

Reference numeral 40 denotes a control means, which irradiates the beam adjustment pattern with an electron beam B whose focus is adjusted on the upper surface of the wafer placed on the sample stage 10, and controls the pattern based on the detection signal from the detection means 28. The actuator 22 is controlled so that the surface is at the focus position of the electron beam EB.

[Function] Even if the wafers 3 have different thicknesses, the wafers 3 can be placed on the sample stage, so the same sample stage 10 can be used to handle wafers 3 of various sizes.

Therefore, the mechanism for holding the wafer 3 on the sample stage 10 and the mechanism for holding the sample stage 10 can be simplified.

[Example] (1)-Example An embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of one embodiment, showing an electron beam exposure apparatus. FIG. 3 is a sectional view taken along the line l-lTl in FIG. 2.

One surface of the sample stage 10 is flat, and wafers 3 of various sizes are placed on it. This sample stage IO has
An arm insertion groove 14 is formed on the mounting surface of the wafer 3, and a wafer transfer arm 16 that electrostatically attracts and transfers the wafer 3 is inserted into the arm insertion groove 14. Four parts (not shown) are formed on the sample stage 10-1 on both sides of the arm insertion groove I4, and electrostatic adsorption plates 18 and 18' for adsorbing and fixing the wafer 3 are attached to these recesses. The upper surface of the plate coincides with the upper surface of the sample stage 10.

A rectangular attachment hole 20 is cut in the corner of the sample stage 10, and the base end surface of the actuator 22A is fixed to the bottom surface of this attachment hole 20. This actuator 22A has a structure in which a piezoelectric element is sandwiched between electrode plates (not shown), and when a voltage is applied to the electrode plates, the upper end surface of the piezoelectric element 22A moves slightly in a direction perpendicular to the sample stage 10. The maximum width of this movement is, for example, 100 μm.

The lower surface of the beam adjustment jig 24 is fixed to the upper end surface of the piezoelectric element 22A. The upper surface of the beam adjustment jig 24 is parallel to the sample stage 10, and a beam adjustment pattern (not shown), such as a pattern on a base, is formed on this upper surface.

Next, a height adjusting device for the beam adjusting jig 24 will be explained based on FIG. 4.

Here, when the electron beam EB is deflected in a direction that crosses the mark 26, which is a part of the pattern formed on the upper surface of the beam adjustment jig 24, the detection A waveform signal as shown in FIG. 5(A) is obtained from the devices 28A and 28B. That is, the spot of the electron beam EB is on the side surface 26a of the mark 26.
When moving from the top surface 26b side, the detection signal rises,
When the upper surface 2-7=6bl, the detection signal becomes approximately constant, and when it moves from the second surface 26b to the opposite side surface 26c, the detection signal falls. The slope of this rise or fall becomes steeper as the focal position of the electron beam EB approaches the second surface of the beam adjustment jig 24.

The output signals of the detectors 28A and 28B are supplied to the amplifier 32, amplified, and differentiated by the differentiating circuit 34, as shown in FIG. 5(B).
A pulse signal P as shown in is output. This pulse P
The peak value of . Read by OA. The control circuit 40A is composed of, for example, a microcomputer, and outputs control data to the D/A converter 42 in response to changes in the read value, and supplies a control voltage to the actuator 22Δ via the driver 44.

Next, this control circuit 4. The OA processing procedure will be explained based on FIG.

(50) S ma+t is set to 0 and E is set to 0.

Here, S mnx is the maximum value of the peak value S of the pulse P, and E is the operating voltage output to the D/A converter 42 .

(52) Next, wait for a beam deflection completion signal for one scan to be supplied from the electron beam control circuit (not shown), and (54) read the peak value S from the A/D converter 38.

(56)S,! : Compare the value with S mgx, S>
If S, , , then (58) Make S m, , equal to the value of S, and increase the operating voltage E by ΔE, (60) Apply this operating voltage E to the D/A converter 42. Outputs a voltage proportional to the operating voltage E to the actuator 22A.
Apply to. This applied voltage is latched.

Next, the process returns to step 52 and the above process is repeated.

Further, if it is determined in step 56 that s = s, . . . ax, the process ends.

If it is determined in step 56 that s < s max, (62) the value of the operating voltage E is decreased by ΔE, and (64)
The actuator 2 is outputted to the D/A converter 42 so that the peak value S substantially matches Smax.
Finely adjust 2Δ.

Next, the overall operation of this embodiment, which is configured as a "double" system, will be explained.

In FIG. 2, the wafer transfer arm 16 on which the wafer 3 is electrostatically attracted is moved to the sample stage 10 side, and after the wafer transfer arm 16 is inserted into the arm insertion groove 14, the electrostatic adsorption plate 18.18° is moved. A voltage is applied to electrostatically adsorb the wafer 3 onto the sample stage 10 , the electrostatic adsorption by the wafer transfer arm 16 is released, and the wafer transfer arm I6 is pulled out from within the arm insertion groove 14 .

Next, the alignment mark formed at the center of the upper surface of the wafer 3 is irradiated with the electron beam E B, and the electron beam E
Adjust the focus.

Next, the sample stage 10 is moved to irradiate the beam adjustment jig 24 with the electron beam EB, and the height of the beam adjustment jig 24 is adjusted so that the top surface of the beam adjustment jig 24 is at the focus position of the electron beam EB. Make adjustments.

It is sufficient that the matching precision between the two surfaces of the wafer 3 and the -1 surface of the beam adjustment jig 24 is 2 to 3 μm or less, but the actuator 22Δ using a piezoelectric element performs expansion and contraction adjustment with an accuracy of about 0.02 μm. There is no problem because it can be done.

"Effects of the Invention" As described in the following, according to the present invention, an electron beam whose focus has been adjusted by irradiating a mark on a wafer placed on a sample stage is irradiated onto a beam adjustment pattern, Based on the signal from the detection means that outputs a signal corresponding to the spot shape of the electron beam irradiated onto the beam adjustment pattern, the wafer mounting surface of the sample stage is placed so that the pattern surface becomes the focus position of the electron beam. The beam adjustment jig is minutely driven by an actuator in orthogonal directions, and even if the wafer thickness differs from wafer to wafer, the wafers can be placed on the sample stage, so the same sample stage can be used. This has the excellent effect of being able to handle wafers of various sizes.

Moreover, the wafer can be placed on the sample stage,
In addition, since wafers of various sizes can be handled on the same sample stage, an excellent effect is achieved in that the mechanism for holding the wafer on the sample stage can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of the present invention, Fig. 2 is a plan view of a sample stage according to an embodiment/example of the present invention, Fig. 3 is a sectional view taken along the In-IU line of Fig. 2, and Fig. 4 is beam adjustment. A block diagram showing the jig height adjustment device. Figure 5 (Δ) is the output waveform diagram of the detectors 28Δ and 28B, Figure (B) is its differential waveform diagram, and Figure 6 is the software configuration of the control circuit 40Δ. 3: Wafer 10, ■0A: Sample stage 14: Arm insertion groove 16: Wafer transfer arm 18, +8' Electrostatic chuck plate 22.22A, actuator 24: Beam adjustment jig 26: Marks 28A, 28B, detector

Claims (1)

[Claims] A sample stage (10) on which a wafer is placed; a beam adjustment jig (24) having a beam adjustment pattern formed on one side; Beam adjustment jig (24
), and an actuator (22) that slightly drives the surface of the sample table in a direction perpendicular to the wafer mounting surface of the sample stage, and a signal that corresponds to the spot shape of the electron beam (EB) irradiated to the beam adjustment pattern. a detection means (28) for outputting an output; and a detection means for irradiating the beam adjustment pattern with an electron beam (EB) whose focus has been adjusted by irradiating a mark on a wafer placed on the sample stage (10); Based on the detection signal from (28), the pattern surface is detected by the electron beam (
Move the actuator (EB) to the focus position (EB).
An electron beam exposure apparatus comprising: a control means (40) for controlling 22).