JPH0638393B2 - Substrate exchange device - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a substrate exchange apparatus such as an electron beam drawing apparatus.

[Prior art and its problems]

A substrate exchanging device such as an electron beam drawing device has conventionally set a substrate on a substrate holder in advance on a jig and, as shown in FIG. 4, can store a plurality of substrate holders 25 (hereinafter referred to as a holder magazine). It is inserted into the sample chamber 1 such as an electron beam drawing device, and the gate valve 3
The substrate holder 25 is loaded in the sample chamber 1 by the holder transfer device 52 by the holder transfer device 52, returned to the holder magazine 53 after drawing, and then the holder 51 is used by the lifter 51. The operation of lifting the magazine 53 step by step and loading the unprocessed substrate 4 together with the substrate holder 25 into the sample chamber 1 by the holder transfer device 52 is repeated. In FIG. 4, 2 is a drawing stage, 27 and 33 are vacuum exhaust devices, and 54 is a door for loading and unloading the substrate holder.

As described above, conventionally, the work of attaching / removing the substrate 4 to / from the substrate holder 25 and the work of inserting / removing it from / into the holder magazine 53 are manually performed, which takes a long time. Variation occurs due to adiabatic expansion of the post-vacuum chamber 50 during vacuum exhaust. This variation causes a temperature difference from the temperature of the drawing stage 2 in the sample chamber 1 and causes thermal deformation during drawing, which deteriorates drawing accuracy.

[Object of the Invention]

The present invention eliminates the temperature difference between the temperature of the drawing stage and the temperature of the drawing stage caused by the temperature variation of the substrate holder during insertion into the holder magazine and the temperature change of the substrate holder due to adiabatic expansion during vacuum evacuation in the vacuum chamber. The purpose is to prevent thermal deformation of the and eliminate the deterioration of drawing accuracy.

[Outline of Invention]

The present invention for achieving the above object is to provide a vacuum sample chamber in an electron beam drawing apparatus or the like, a preliminary chamber connected to the sample chamber and evacuated in the same manner as the sample chamber, and a gate valve in the preliminary chamber. Load / unload station having a vacuum chamber that is connected to the sample chamber through the open / closed atmosphere and a substrate holder that detachably holds the substrate to be processed in the sample chamber are alternately provided between the sample chamber and the preliminary chamber. Between the means for transferring, the substrate cassette arranged in the vacuum chamber of the loading / unloading station and capable of accommodating a plurality of substrates, and between the substrate cassette also provided in the vacuum chamber and the substrate holder in the spare chamber. And a substrate cassette arranged in a vacuum chamber of a load / unload station.
Each substrate is transferred to the substrate holder in the preliminary chamber and sent to the sample chamber, and after drawing, the drawn substrate is separated from the substrate holder returned to the preliminary chamber and placed in the substrate cassette placed in the vacuum chamber of the load / unload station. It is intended to be stored. As a result, the substrate holder is always in the vacuum chamber without contacting the atmosphere, and the temperature change can be minimized.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. A sample chamber 1 such as an electron beam drawing apparatus is evacuated to vacuum, and a substrate holder 25 holding a substrate 4 is placed on a drawing stage 2 inside the sample chamber 1, and an electron optical lens barrel (EOS) is installed.
The electron beam is scanned by 24, and drawing is performed on the substrate 4. The substrate holder 25 is exchanged by the holder transfer device 18 between the drawing stage 2 in the sample chamber 1 and the moving stage 22 in the preliminary chamber 5 with the gate valve 3 opened. The holder transfer device 18 is the same as the conventionally used holder transfer device 52 shown in FIG. 4, and a detailed description thereof will be omitted. During drawing, the gate valve 3 is closed and the vacuum tightness of the sample chamber 1 with respect to the preliminary chamber 5 is maintained. Details of the moving stage 22 are shown in FIG. The moving stage 22 includes a motor 21 and a ball screw 23.
Pitch P of the holding portion of the substrate holder 25 by a driving device such as
Just move the shuttle. There are two holding portions of the substrate holder 25 on the moving stage 22, A and B. A holds the drawn substrate holder 25, and B holds the substrate holder 25 holding the loaded substrate. FIG. 3 shows that the substrate holder 25 located at the position B is placed in the sample chamber 1 by the holder transport device 1.
8 shows a state in which the substrate 4 has been transferred and becomes “empty”, and the drawn substrate holder 25 at the position A shows a state in which the substrate 4 is separated and is discharged to the unload station 19.
After the substrate 4 is unloaded, the “empty” substrate holder 25 is moved from the position A to the position B by the moving device 31 at the pitch P.
Then, the entire moving stage 22 is moved in the direction of the load station 12 by the pitch P by a driving device such as the motor 21 and the ball screw 23. Board holder 25
The substrate 4 is clamped to the substrate holder 25 by a spring (not shown) provided in the substrate holder 25, and the release mechanism 7, 7'presses the spring to release it. Therefore, when the substrate 4 is loaded or unloaded on the substrate holder 25, the release mechanism 7 or 7'is operated and the clamp is opened. The load station 12 and the unload station 19 have almost the same structure, and the difference between the function of sending the substrate 4 to the substrate holder 25 on the moving stage 22 and the function of taking it in is the same. Is shown with a dash ('). Gate valve 8
And 8'connect the spare chamber 5 and the load station 12 or the unload station 19 and are opened only when the substrate 4 is exchanged. The substrate cassettes 9 and 9'contain the unprocessed substrate 4 or the drawn substrate 4 and are placed on the elevator 10 or 10 'and moved up and down. Substrate carrier plate 1
1 receives a substrate 4 from a substrate cassette 9 and a substrate holder 25
For loading, and for the substrate carrying plate 11 'to take the substrate 4 from the substrate holder 25 to the substrate cassette 9'via motors 14 and 14' and ball screws 15 and 15 'along the guide rails 13 and 13', respectively. Moving. Three
4, 34 'are drive motors for the elevators 10, 10', and 20, 20 'are ball screws. The load station 12 and the unload station 19 described above are both housed in the vacuum chamber 6 or 6'and evacuated by the vacuum exhaust device 55. The doors 56 and 56 'are used for attaching and detaching the substrate cassettes 9 and 9', and are always closed during operation.

Next, the operation of the present apparatus will be described. When the substrate cassettes 9 and 9'for the unprocessed substrate and the drawn substrate are first removed and the new substrate cassette is set, the vacuum exhaust device 55 is stopped and the vacuum is removed. This is done by returning the chambers 6 and 6'to the atmosphere and then opening the doors 56 and 56 '. The substrate cassette 9 accommodating the unprocessed substrate 4 and the "empty" substrate cassette 9'are set on the cassette lifter 10 of the load station 12 and the cassette lifter 10 'of the unload station 19, respectively, and the doors 56 and 56' are set. Close and seal, and activate vacuum pump 55. When the vacuum chambers 6 and 6'become in a certain vacuum state, the cycle operation is started. Of course, during the above work, the gate valves 3, 8 and 8'are closed, the vacuum exhaust devices 33 and 27 are operating, and the sample chamber 1 and the preliminary chamber 5 are kept in a constant vacuum state. The moving stage 22 in the preliminary chamber 5 is moving to the load station 12 side, the gate valve 8 is opened, the release mechanism 7 is operated to unclamp, and the substrate transfer plate 11 is advanced to hold the unprocessed substrate 4 in the holder. It is loaded on the substrate holder 25 in the section B, the substrate carrying plate 11 is retracted, and the gate valve 8 is closed. Next, move stage 22 to unload station 1
9, the gate valve 3 is opened, the substrate carrier 25 is sent to the drawing stage 2 of the sample chamber 1 by the holder transfer device 18, the holder transfer device 18 is retracted, the gate valve 3 is closed, and drawing is started. . Holder holding part A
Since the substrate holder 25 in FIG. 2 is “empty”, the unloading operation is omitted and the moving device 31 is operated to operate the substrate holder 2
5 is moved to the holder holding part B, and the moving stage 22 is moved to the load station 12 side. The above-described substrate 4 loading operation is performed on the substrate holder 25 in the holder holding section B, and the completion of drawing of the substrate holder 25 in the sample chamber 1 is awaited. When drawing is completed, the gate valve 3 is opened, and the drawn substrate holder 25 is taken from the drawing stage 2 to the holder holding part A of the moving stage 22 by the holder transfer device 18, and then the moving stage 22 is unloaded at the unload station 19. The substrate holder 2 in the holder holding part B by moving to the side
5 into the sample chamber and gate valve 3 after the feeding is completed
After closing, the release mechanism 7'is operated to unload the drawn substrate 4 in the holder holding part A to unclamp the substrate 4, the gate valve 8'is opened, and the substrate transfer plate 11 is opened. ′ Is operated to store the drawn substrate 4 in the substrate cassette 9 ′. Next, the gate valve 8'is closed, the "empty" substrate holder 25 is moved to the holder holding portion B, and the moving stage 22 is moved to the load station side. The above operation is repeated below. The cassette lifters 10 and 10 'move the substrate cassettes 9 and 9'up and down by one pitch each time the substrate 4 is loaded or unloaded. When the substrate cassette 9 becomes "empty" and the substrate cassette 9'is full, the cycle operation for one lot is completed.

As described above, the substrate holder is located in either the sample chamber or the preliminary chamber and is constantly evacuated,
The temperature difference between the substrate holder and the drawing stage in the sample chamber can be eliminated.

It should be noted that when the substrate is set in the load station, it is thermally affected because it is placed in the vacuum chamber from the atmosphere,
A material having a low expansion is generally used, the heat capacity is small, and the deformation in the sample chamber is extremely smaller than that of the substrate holder.

In the above-described embodiment, the example in which the two substrate holders 25 are placed on the moving stage 22 and the load station 12 and the unload station 19 are separately provided, but the present invention is not limited to this. Various modifications can be made such that one substrate holder 25 can be mounted on one of them, or one station can be used for both loading and unloading.

〔The invention's effect〕

Without exposing the substrate holder to the atmosphere, the temperature change can be minimized by keeping the temperature constant in the vacuum chamber and the temperature difference from the drawing stage can be eliminated to prevent the drawing accuracy from decreasing.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a plan view, FIG. 2 is a sectional view taken along line AA, and FIG. 3 is a sectional view taken along line BB. FIG. 4 is a plan view showing a conventional technique. 1 ... Sample chamber, 2 ... Drawing stage, 3, 8, 8 '...
Gate valve, 4 ... Substrate, 5 ... Preliminary chamber, 6, 6 ',
50 ... Vacuum chamber, 7, 7 '... Release mechanism,
9, 9 '... substrate cassette, 10, 10' ... cassette lifter, 11, 11 '... substrate transport plate, 12 ... load station, 13, 13', 36, 37, 38 ... guide, 14, 14 ', 21, 34 ... Motor, 15, 1
5 ', 20, 20', 23 ... Ball screw, 18 ... Holder transfer device, 19 ... Unload station, 22
...... Movement stage, 24 ・ ・ ・ EOS, 25 ・ ・ ・ Substrate holder, 27,33,55 ・ ・ ・ Vacuum exhaust device, 28 ・ ・ ・ Surface plate, 31 ・ ・ ・ Movement device, 51 ・ ・ ・ Lifter, 52 ・ ・ ・ Holder transfer device , 53 ... Substrate holder magazine, 54, 5
6,56 '... Door

Claims (2)

[Claims] 1. A vacuum sample chamber in an electron beam drawing apparatus and the like, a preliminary chamber connected to the sample chamber and evacuated in the same manner as the sample chamber, and connected to the preliminary chamber via a gate valve. A load / unload station having a vacuum chamber that can be opened to the atmosphere, and means for alternately transferring a substrate holder that detachably holds a substrate to be processed in the sample chamber, between the sample chamber and the auxiliary chamber A substrate cassette disposed in the vacuum chamber of the load / unload station and capable of accommodating a plurality of substrates; and the substrate between the substrate cassette also provided in the vacuum chamber and a substrate holder in the spare chamber. Substrate exchanging device comprising means for transferring the substrate. 2. A structure in which substrates are transferred one by one from a substrate cassette for loading to a substrate holder and sent into a sample chamber, and after the substrates are processed, they are stored in a separately provided substrate cassette for unloading. Claim 1 characterized by
Substrate exchanging device according to item.