JPS60130826A - Charged beam drawing method - Google Patents

Abstract

PURPOSE:To enable to draw a higher-precision pattern by a method wherein the drawing is performed with a beam irradiation amount less than a beam irradiation amount to be required for forming the pattern and the beam irradiation amount to be required is obtained by repeating the drawing plural times, and at the same time, an equalization of the irradiation positions is performed. CONSTITUTION:Assuming that the beam irradiation amount to be required for drawing a pattern is D, the drawing is performed first with an irradiation amount of D/n (n>=2) and drawings of (n) times are performed by repeating the drawing. In this case, the first drawing is performed at a place deviated by (a) microns from the finally stable place, the second drawing to the fourth drawing are respectively performed at each different place deviated by a/2 microns, a/4 microns and a/8 microns, and the fifth drawing and hereinafter are assumed to roughly stabilize. For example, when the number (n) of times of the drawing is supposed to be n=5, the first drawing place becomes a position as indicated by a solid line in the vicinity of the drawing starting position 1 and the fifth drawing place becomes a position as indicated by a one-dotted chain line in the vicinity of the drawing end position 5. The position deviation error between the first and fifth drawing positions becomes a/8 microns. Accordingly, the mechanical micromotion, the expansion and contraction due to temperature change, the current fluctuation and position fluctuation of charged beam, the various drifts, the influence of noise, etc., are significantly reduced by equalization. As a result, a higher-precision pattern is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a drawing method using a drawing apparatus using a charged beam.

[Prior art and its problems]

A charged beam drawing method using an ion beam, an ion beam, or the like is expected to be a device capable of drawing fine patterns, and is also put into practical use. However, various problems have become apparent when attempting to draw so-called submicron patterns of less than 1" Ω.Especially, due to the characteristics and sensitivity of the resist, it is difficult to draw fine patterns. This means that a large amount of irradiation!t is required.As a result of this, the following problems arise: ■The substrate to be drawn is heated due to the high irradiation amount.■The drawing time becomes long, so ■-1 The influence of various drifts. ■-2 Mechanical movement of the board (, ■-3 Effects of expansion and contraction due to temperature changes in the device and board, etc.), resulting in a decrease in accuracy. Conventionally, to avoid this, the precision + fltl It is necessary to arrange a large number of markers on a registration storage tank, that is, on a substrate to be drawn, and to frequently perform positioning and correction using the markers with a drawing beam.

This results in a decrease in the area that can be treated and an increase in drawing time.

[Purpose of the invention]

This invention is an improvement on the drawbacks of the conventional method mentioned above.

The purpose of this invention is to provide a method for drawing high-precision bangs. 5. [Summary of the Invention] The present invention solves the above-mentioned problems by analyzing the temperature difference.

By taking advantage of the fact that the influence of mechanical micro-movement is thick (appears) at a relatively early stage of drawing, and that other important factors occur relatively randomly, we focused on the fact that various causes of accuracy deterioration can be reduced by so-called averaging. It was done by

In other words, when drawing one figure, the required dose is D(p C
7 cm 2 ), drawing is first performed with a dose of D/n (n) 2 ), and this is repeated to perform drawing n times. The writing time is usually determined by the irradiation power, which is determined by the characteristics of the beam source barrel, so even if you write n times, the overhead will only increase by 4 + AE *, but the overall result will not be much larger (this Considering the following points, it is within an acceptable range.

〔Effect of the invention〕

The present invention eliminates various causes of deterioration of batting accuracy, particularly mechanical micro-movement and expansion/contraction due to temperature changes.

Loading beam current fluctuations, position fluctuations, and various drifts.

The effects of noise, etc. are greatly reduced by averaging, and as a result, highly accurate bangs can be obtained.

[Embodiments of the invention]

1 is used in one embodiment of the present invention. A configuration diagram of a Nariko beam drawing device is shown.

The baton data to be drawn is stored in the magnetic disk 16 or the memory of the computer 17, and sent to the drawing device via the control interface 11 at the time of drawing.

The present invention is not different from conventional systems in terms of system configuration, drawing procedure, etc. The difference is that since the beam irradiation amount is 1/n, the beam flow/deflection speed controls the same operation as writing n times using the same baton data.

FIG. 2 schematically shows the effects of the present invention. In general, shadows 4 due to mechanical tremors and temperature changes often appear exponentially. As shown in the figure, the first drawing is performed at a location 8 microns away from the final stable location, and the second drawing is at a/2
It is assumed that the third time the deviation is a/4 micron, the fourth time the deviation is a/8 micron, and the fifth and subsequent times are almost stable. According to this drawing method, for example, if n=5, Figure 2
If you draw a rectangle like the one shown in , there will be a black line (solid line) near the drawing start position, and 11 lines < single-dot chain @) near the end position.
It becomes Samurai Ia as shown in , and its positional deviation error is V8
Becomes micro□kron.

On the other hand, according to the conventional method λ, this becomes ■ and ■ (red dotted line) and A
The difference will be a micron.

In other words, by adopting this drawing method, the accuracy has been significantly improved (8 times). Increasing n improves the degree of i-goodness, but since the overhead increase of 6 minutes is also proportional to n,
There is naturally an optimal value of n7)≦. Usually n is 4 to 10
It is efficient.

In this method, even if the beam position changes instantaneously due to noise or the like, as long as the beam position is reflected at the i-opening point, the ratio will be 1/n, which will have virtually no effect.

[Other embodiments of the invention]

Instead of drawing the same figure n times overlappingly, a mechanism is added to skip the first m times (man) of a prespecified figure. This makes it difficult to use the light #J variable in the rusk scan method, which is usually difficult.

Alternatively, in the pasta scan method 1, it is possible to simplify the control of the irradiation time tn.

[Brief explanation of the drawing]

The first diagram is a configuration diagram showing the configuration of a quadruple beam lithography device 4, which is one of the charged beam lithography devices, and the second diagram is an explanatory diagram showing the effects of the present invention. DESCRIPTION OF SYMBOLS 1...High voltage power supply, 2...Vibration isolation stand, 3...Auto feeder, 4...Stage, 5...Electron gun, 6...
- Electromagnetic lens, 7... Blanking electrode, 8... Deflection electrode, 9... Laser length measurement system, 10... Motor,
ll...Control interface, 12...Operation panel, 1:lk, 14...Display terminal, 15...
Magnetic tape device, 16...Magnetic disk device, 17.
・It's a machine in total.

Claims (2)

[Claims] (1) In a charged beam lithography system, lithography is performed using a trowel with a smaller amount of beam irradiation than the irradiation layer required to form a dimensional tan, and by repeating this several times, the required beam irradiation layer is obtained and the irradiation position is A charged beam 4 seedling drawing method characterized in that an average of 1 hit is performed. (2) The charged beam lithography system has a stage continuous movement I# type raster scan method, and the number of times specified for each figure is