JPS62147726A - electron beam equipment - Google Patents

Abstract

PURPOSE:To rapidly and continuously treat a sample by communicating a preliminary exhaust chamber and a sample chamber with the atmosphere via a passage for passing the sample, and blocking the passage by a holder which holds the sample. CONSTITUTION:A holder 28 continuously introduced into a sample chamber 37 is conveyed from the atmosphere into a preliminary exhaust chamber 25. In this case, the leakage air from between a vacuum chamber wall 47 and the holder 28 and the air around a wafer 60 are exhausted by a vacuum pump 29. A differential exhaust is achieved between preliminarily exhaust chambers 25, 27 and the chamber 37 to perform a predetermined vacuum degree in the chamber 27. The holder introduced into the chamber 37 is placed on a stage 38, drawn by an electron beam, and a pattern width is measured, and the holder pressed toward a preliminarily exhaust chamber 40 is removed through a preliminarily exhaust 42 into the atmosphere. Thus, samples can be continuously and rapidly conveyed from the atmosphere into the sample chamber held in high vacuum and conveyed out from the sample chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electron beam apparatus +1, and particularly to an apparatus for rapidly and continuously loading and unloading a sample into a vacuum system.

[Background of the invention]

A conventional electron beam lithography apparatus has a structure as described in Japanese Patent No. 60-959241 (FIG. 1) for carrying in wafers. The exposure sample 1 is placed in the sample preparation chamber 5 under atmospheric pressure. Next, after evacuating the sample preparation chamber 5 with the oil rotary pump 9, the turbo molecular pump 7 and the oil rotary pump 8 are used to further increase the vacuum level to about 10''B~10-BT.
get orr. Thereafter, the gate valve 4 is closed and the sample 1 is carried into the sample chamber 2.

However, according to this delivery method, the preliminary chamber must be evacuated from atmospheric pressure to high vacuum, which takes about 10 minutes.
This requires about a minute, and it is impossible to continuously transport the sample into the sample chamber.

This was one of the factors that worsened throughput.

In order to solve this problem, recently Japanese Patent Application Publication No. 60-89922
The method described in Figure 2 was proposed. In other words, the wafer is not placed in a vacuum, the gap between the wafer surface and each vacuum chamber is kept small, and most of the air flowing in from the gap is evacuated from the first and second vacuum chambers. This method keeps the chamber in a high vacuum.

However, this method has the serious drawback that a large amount of dust adheres to the wafer because air flows continuously over the wafer.

[Purpose of the invention]

An object of the present invention is to provide an apparatus that can overcome these problems and process samples quickly and continuously.

[Summary of the invention]

A problem with conventional devices is that the pre-evacuation chamber must be evacuated from atmospheric pressure to a high vacuum.

Furthermore, in the method disclosed in Japanese Patent Application Laid-Open No. 60-89922, the wafer is placed adjacent to a vacuum system and placed in atmospheric pressure, so that contamination of the wafer is unavoidable.

In order to solve these two problems, one idea is to maintain the degree of vacuum in the pre-evacuation chamber at a near-steady state at all times, and through this, transport the sample into and out of the sample chamber maintained at a high vacuum state. It will be done. The device structure for maintaining vacuum in this method is as follows.

The atmosphere is communicated with the pre-exhaust chamber and the sample chamber through a communication path for the sample to pass through, and a holder holding the sample blocks these communication paths.The holder is continuously carried into the sample chamber for processing. After this is completed, transport it out in the same way.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. 3.4.5. In FIG. 3, cathode 31. Electrode; 32° electromagnetic lens 3
3.35 The wafer 60 held by the holder 28 is carried in and out of the sample chamber 37 of the electron beam mirror consisting of the differential exhaust ports 34 and 36.

38 is a stage for moving the holder, and 39 is a vacuum pump for evacuating the sample chamber 37. The configuration on the wafer loading side consists of preliminary evacuation chambers 25, 27, respective evacuation vacuum pumps 29, 30, and gate valves 24, 26. Similarly, the wafer unloading side consists of preliminary evacuation chambers 40, 42, vacuum pumps 44, 45, and gate valves 41, 43. In FIG. 4, 46 is a notch for holding the wafer. In FIG. 5, 47 is 1" (a cross section of the cavity wall, and a communication path 48 is formed by the vacuum chamber wall, and the communication path is closed to the holder 28 holding the wafer 60. Differential exhaust glass is the third
In the figure, the atmosphere, the preliminary exhaust chamber 25, and the preliminary exhaust chamber 25
and 27, preliminary exhaust chamber 27 and sample chamber 37. Sample chamber 37 and preliminary exhaust chamber 40° preliminary exhaust chambers 40 and 42. Preliminary exhaust chamber 42
There are a total of 6 locations, including in the atmosphere and in the atmosphere.

Next, the operation will be explained. Sample chamber 3 continues from the left side in Figure 5.
The holder 28 pushed into the holder 7 is first carried into the preliminary exhaust chamber 25 from the atmosphere. At this time, as shown in FIG. 5, leaks from between the vacuum chamber wall 47 and the holder 28 and air around the wafer 60 are evacuated by a vacuum pump 29. As a result, the degree of vacuum in the pre-evacuation chamber 25 is 10-” Torr.
It will be about.

A similar differential evacuation is performed between the preliminary evacuation chambers 25 and 27 and the sample chamber 37. Pre-exhaust chamber 27 is 10-1
0' Torr, sample chamber 37 is 10-8 to 10''-7T
A vacuum degree of o, rr is achieved. The holder introduced into the sample chamber 37 is placed on the stage 38, and drawing with an electron beam, pattern width 411J length, etc. are performed.

Thereafter, the holder pushed out toward the preliminary exhaust chamber 40 is taken out into the atmosphere through the preliminary exhaust 42.

Due to leakage from the atmosphere side, the preliminary exhaust chamber 42 is 10-2
Torr, and the pre-evacuation chamber 40 has a vacuum degree of 10-'Torr. When stopping wafer loading and unloading, the gate valves 24, 26, 41.4:3 are closed to isolate the vacuum system from the atmosphere.

In this example, we measured a field emission cathode that requires ultra-high vacuum, and adopted a differential pumping structure using 36, 34 and electrode 32 to maintain the electron gun chamber at an ultra-high vacuum of 10-10 Torr. are doing. However, in hot cathodes and ion sources that do not require ultra-high vacuum, the preliminary evacuation chamber can be omitted as shown in FIG.

FIG. 7 shows an embodiment in which a wafer 60 is carried in and carried out through one prefer 11 exhaust chamber 58.

The row of holders on the left side of the figure are holders that are carried into the right sample chamber 59, and the lower holders are holders that are carried out into the atmosphere on the left side. By adopting this structure, 1
The wafer can be carried into the high-vacuum sample chamber using two pre-evacuation chambers 58 and a pre-evacuation vacuum pump.

In these embodiments, the length of the communication path through which the holder passes is made longer than the diameter of the notch 46 for installing the wafer, so that air leakage can be effectively suppressed.

〔Effect of the invention〕

According to the present invention, the degree of vacuum in each pre-evacuation chamber is mostly in a steady state, and the vacuum pump most suitable for each degree of vacuum can be selected. The loading and unloading speeds to the sample chamber are limited by the exhaust speeds in the preliminary exhaust chamber and the sample chamber, so by increasing these exhaust speeds, the loading and unloading speeds can be increased, and the number of preliminary exhaust chambers can also be reduced to 0. You can set up as many rooms as you need. As a result, it is possible to continuously and rapidly carry samples into and out of the atmosphere into the sample chamber maintained at a high vacuum.

Further, since the influence of wind pressure due to exhaust air on the sample is only during loading and unloading, the morphology PI' on the sample is minor, including the problem of adhesion of dust etc. to the sample.

ff1li condolence explanation of the drawings No. 11*l shows the exhaust system configuration of the conventional device 1II8, Fig. 2
The figures are a cross-sectional view showing an example of another conventional device, Figure 1 is a cross-sectional view showing the configuration of an embodiment of the present invention, Figures 41 and 4 are perspective views of the holder, and Figure 5 shows the difference. Cross-sectional view of the dynamic exhaust section, No. 6
The figure is a sectional view showing the configuration of this embodiment, and FIG. 7 is a horizontal sectional view of the preliminary exhaust chamber.

DESCRIPTION OF SYMBOLS 1... Sample, 2... Sample chamber, 3... Charge optical mirror body, 4... Gate valve, 5... Preliminary exhaust chamber, 6...
・First exhaust valve, 7...Turbo molecular bomb (TMP), 8...Turbo molecular pump back pressure generation oil rotary pump (RP), 9...Preliminary exhaust chamber exhaust oil 107 rotation pump, 10... expansion container, 11... second
Exhaust valve, 12...Third exhaust valve, 1 piece 3.
...Fourth exhaust valve, 14...First vacuum chamber, 15...Second vacuum chamber, 16...Third
vacuum chamber, 17... gap sensor, 18
... Wafer, 19... Notch, 20... Stage, 21... X stage, 22... X stage, 2
3...Y stage, 24...gate valve, 25.
...First preliminary exhaust chamber on the loading side.

26...Gate valve, 27...Carry-in side second preliminary exhaust chamber, 28...Holder, 29...Vacuum pump,
30... Vacuum pump, 31... Cathode, 32 Yu electrode,
33...Condenser lens, 34...Blanking aperture, 35...Objective lens, 36...Difference between the electron mirror and the sample chamber! Exhaust room, 37...Sample chamber, 38...
・Stage, 39...Vacuum pump for exhausting the sample chamber, 4
o... First preliminary exhaust chamber on the carry-out side, 41... Gate valve, 42... Second preliminary exhaust chamber on the carry-out side, 43...
Gate valve, 44... Vacuum pump, 45... Vacuum pump, 46... Wafer installation notch, 47...
・Preliminary exhaust chamber wall, 48... communication passage, 49... game 1
to valve, 5o... stage, 51... ion source,
52... Electrode, 53... Deflector, 54... Electrostatic lens, 55... Sample chamber, 56... Vacuum pump, 57
...Gate valve, 58...Preliminary exhaust chamber, 59...
-Sample chamber, 60...wafer.

Claims (1)

[Claims] 1. An electron beam device that controls an electron beam and irradiates it onto a sample, comprising: a sample chamber in which the sample is placed; a communication path with the atmosphere side for carrying in the sample; and the sample chamber. An electron beam apparatus comprising: a holder having a structure for closing the communication path and holding a sample in order to maintain a vacuum. 2. In the electron beam according to claim 1, the holder is provided with a notch for holding the sample, and the communicating path has a length that can completely cover the notch, and a plurality of communicating paths are provided. An electron beam device comprising a structure that allows the holder to pass through the communication path continuously without gaps.