JPS61296714A - Charged-beam exposure apparatus - Google Patents

Abstract

PURPOSE:To form a pattern with a high accuracy by eliminating the out-of-focus and the position discrepancy of the pattern caused by the leakage of digital signals. CONSTITUTION:A signal (a) is a control signal which is expected to cause a leakage of a high frequency component in a charged-beam polarization amplifier 9 which has a harmful influence on the charged-beam of an electron optical system (EOS) 1 and a high frequency component, i.e. a differential signal, of this signal is obtained by a differential circuit 4. A signal (c) is obtained from the differential signal (b) by an absolute value circuit 3 and a gate operation is applied to an original blanking signal (d) by a gate circuit 10 with the signal (c). A glanking amplifier 2 is driven on a signal (e) to blank the charged-beam. Moreover, the blanking signal can be extended to the extent of the exposure reduced by this method as shown by dot lines in the figure (e) so that the reduction of the exposure can be avoided.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention uses a charged beam such as an electron beam to
In recent years, in order to achieve high precision, high throughput, and high speed, devices that draw I patterns have been using control circuits such as high precision deflection amplifiers including D-A converters to achieve high speed.
It has become necessary to place them closer to the charged beam path.

However, at the same time, the digital signal containing many high-frequency components also approaches the charged beam at the same time as the high-precision deflection amplifier. A problem arose in that patterning was not possible.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a charged beam exposure apparatus capable of eliminating pattern blurring or positional shift due to digital signal leakage.

[Summary of the invention]

In order to achieve the above object, the present invention applies blanking to the charged beam using a differential value of a signal that is expected to be accompanied by leakage that affects the charged beam.

〔Effect of the invention〕

By carrying out the present invention, it is possible to eliminate pattern blurring and positional deviation due to leakage of digital signals, so that highly accurate pattern formation can be performed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows a configuration diagram of an embodiment of the present invention, and FIG. 2 shows its operation. In the figure, a is the electron optical system (EO8)
This is a control signal that is expected to cause leakage of the high frequency component of the charged beam deflection amplifier 9 that adversely affects the charged beam of No. 1, and a differential signal of this signal containing the high frequency component is obtained by the differentiating circuit 4 (b in the figure). Further, from this differential signal, the absolute value circuit 3 obtains a signal as shown in C in the figure, and this signal is used to sigate the original blanking signal (d in the figure) by the gate circuit 10, resulting in a signal as shown in e in the figure. The blanking amplifier 2 is driven with a signal to blank the charged beam.

The parts indicated by 5 and 6 in Fig. 2 were originally charged beams ON.
This is a portion with a high frequency component of the state, and 7 is a portion with a high frequency component of the charged beam OFF state.

Further, by extending the blanking signal as indicated by the dotted line e in the figure by the amount of exposure reduced by the above method, it is possible to eliminate the reduction in the amount of exposure. For example, the blanking control circuit 8 that generates the blanking signal counts the number of times the blanking signal is gated by the gate circuit 10 (counts the signal C), and generates the blanking signal d according to the counted value. This is achieved by delaying.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining one embodiment of the present invention, and FIG. 2 is a timing diagram of signals of various parts of the apparatus shown in FIG. 1... Electron optical system, 2... Blanking amplifier, 3
... Absolute value circuit, 4... Differential circuit, 5.6.7...
- Portion containing high frequency components, 8... Blanking control circuit, 9... Deflection amplifier, 10... Gate circuit, a.
... Deflection amplifier control signal with high frequency components, b...
Output signal of the differentiation circuit, C... output signal of the absolute value circuit,
d...Blanking signal, e...Blanking signal after ° correction, f...Influence of signal a on the charged beam. Representative Patent Attorney Kensuke Chika (1 person) 2nd
figure

Claims (2)

[Claims] (1) In a charged beam exposure apparatus having at least a deflection control circuit that generates a digital signal and a circuit that converts the digital signal into an analog signal, the device includes means for generating a differential signal of the digital signal, and a means for generating a differential signal of the digital signal; A charged beam exposure apparatus comprising means for generating a beam blanking signal. (2) In the charged beam exposure apparatus according to claim 1, means for generating a blanking signal sufficient to compensate for the decreased exposure amount by a signal for blanking the charged beam according to the differential signal. A charged beam exposure apparatus comprising: