JPH10284373A - Charged particle beam aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform highly accurate pattern exposure without deteriorating the throughput, by optimizing the temperature of a wafer carried into an exposure chamber. SOLUTION: In an exposure chamber 10, a pattern is put to projection- exposure on a wafer W placed on a stage in vacuum by using electronic beams. The exposure chamber 10 is connected to an intermediate chamber 30 via a loader chamber 20. Before carrying the wafer W into the intermediate chamber 30, the wafer W is heated in a thermostatic chamber 50, and the temperature in the thermostatic chamber 50 is controlled to be higher than that in the exposure chamber 10. The water W is carried into the intermediate chamber 30 in atmospheric air, and the wafer W is carried out from the intermediate chamber 30 to the loader chamber 20 in vacuum. The wafer W is carried into the exposure chamber 10 in the loader chamber 20 in vacuum. When the intermediate chamber 30 is evacuated, the temperature of the water W is reduced due to adiabatic expansion, however, since the wafer W is previously heated, the temperature of the water W becomes the temperature set for the exposure chamber 10. Therefore, alignment and exposure can be performed immediately after the wafer W is carried into the exposure chamber 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam exposure apparatus for projecting and exposing a pattern on a sensitive substrate such as a wafer using an electron beam or an ion beam.

[0002]

2. Description of the Related Art In an electron beam exposure apparatus, a wafer on which a resist is applied is fixed on a wafer stage in an exposure chamber to perform pattern projection exposure. By the way, in order to carry a wafer under atmospheric pressure into an exposure chamber in a vacuum state, it is necessary to use an intermediate chamber for receiving the wafer in an atmospheric state and carrying the wafer into the exposure chamber in a vacuum state. That is, after the wafer is carried into the intermediate chamber in the atmospheric pressure state, the intermediate chamber is evacuated, and when the intermediate chamber is in a vacuum state, the gate valve provided between the intermediate chamber and the exposure chamber is opened to remove the wafer. It is transported on the stage in the exposure chamber.

However, since the evacuation of the intermediate chamber is rapidly performed, the temperature of the air in the intermediate chamber decreases due to adiabatic expansion. As a result, the wafer cools and shrinks. When the wafer is transferred into the exposure chamber in a state where the shrinkage has occurred and the pattern exposure is performed, during the exposure, the temperature of the wafer increases gradually until it reaches the temperature in the exposure chamber and gradually expands, and the pattern exposed on the wafer is exposed. Is patterned at a position shifted from a position to be exposed. Also,
Not only is the exposure position shifted, but also a pattern magnification error occurs.

In such a case, conventionally, exposure is performed by the following method in order to realize highly accurate exposure. (1) After the wafer is transferred to the wafer stage in the exposure chamber, exposure is performed after the temperature of the wafer reaches the set temperature of the exposure chamber. (2) When the wafer is evacuated in an intermediate chamber or the like, heat is applied to the wafer by a heating means such as a lamp to shorten the time required to reach a set temperature.

[0005]

However, (1)
In the case of the method (1), the time required to reach the set temperature becomes longer due to poor heat transfer characteristics in a vacuum. Improving exposure accuracy and throughput is an important issue in a charged particle beam exposure apparatus, but this method has a drawback that throughput is reduced.

On the other hand, even in the case of the method (2), the throughput is reduced since the wafer is heated once after being carried into the intermediate chamber. In addition, since the amount of heat applied to the wafer needs to be controlled very finely, very complicated control is required. Conventionally, since the temperature is not always confirmed to have finally reached the set value by monitoring the wafer temperature or the like but is controlled by the heating time or the like, the heating means changes over time (for example, When a change in the amount of light of a lamp occurs, exposure may be started before the temperature is sufficiently stabilized, and there is a problem that exposure accuracy is greatly affected. Also, a large-scale device is required to prevent the lamp from heating other parts of the device.

An object of the present invention is to provide a charged particle beam exposure apparatus capable of optimizing the temperature of a sensitive substrate carried into an exposure chamber and performing high-precision pattern exposure without lowering the throughput. .

[0008]

A description will be given with reference to the drawings showing an embodiment of the present invention. (1) Explained in association with FIGS. 1 and 2, the invention of claim 1 comprises: an exposure chamber 10 for projecting and exposing a pattern on a sensitive substrate mounted on a stage using a charged particle beam; The sensitive substrate is loaded, and the sensitive substrate is exposed in a vacuum to the exposure chamber 1.
The present invention is applied to a charged particle beam exposure apparatus having an intermediate chamber 30 which is carried into the apparatus. The above-described object is achieved by providing the temperature control device 50 for adjusting the temperature of the sensitive substrate before the sensitive substrate is carried into the intermediate chamber 30. (2) It is preferable that the temperature control device 50 heat the sensitive substrate so that the temperature of the sensitive substrate becomes higher than the set temperature in the exposure chamber by the temperature decrease of the sensitive substrate when the intermediate chamber 30 is evacuated. (3) As the temperature control device, a thermostatic bath 50 that stores the storage container 40 that stores a plurality of sensitive substrates conveyed from the previous process and that holds the sensitive substrates at a predetermined temperature can be used. (4) As a temperature controller, a thermostatic plate 9 for heating a sensitive substrate conveyed and placed from a previous process and holding the substrate at a predetermined temperature.
0 (FIGS. 3 and 4) can be used.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to the embodiment.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment Hereinafter, a first embodiment in which the present invention is applied to an electron beam exposure apparatus that projects and exposes a pattern on a wafer with an electron beam will be described with reference to FIGS. . FIG. 1 is a view for explaining an electron beam exposure apparatus according to the present invention. The electron beam exposure apparatus includes an electron gun, an electron beam projection optical system, a deflector, a wafer stage on which a wafer W is mounted, and XY coordinates of the wafer stage. An exposure chamber 10 having an interferometer or the like for measuring a position; a loader chamber 20 connected to the exposure chamber 10 via a gate valve G1 for loading and unloading a wafer W in a vacuum state; and a loader chamber via a gate valve G2. The intermediate chamber 30, which is connected to the chamber 20 and to the atmosphere through the gate valve G3, is loaded with the wafer W in the atmosphere, and is unloaded to the loader chamber 20 in a vacuum state, and stacks a plurality of wafers W. And a robot arm 60 for transferring the wafer W between the constant temperature bath 50 and the intermediate chamber 30, and a temperature controlled air into the constant temperature bath 50. Constituted by the constant-temperature air supply device 70 for feeding.

FIG. 2 is a view for explaining a constant temperature bath 50. The constant temperature bath 50 includes a bath main body 51, an elevating table 52 on which the carrier 40 is placed, and a door 53 for carrying the carrier 40 in and out. Prepare. An opening 51a is opened in the tank body 51, and the robot arm 60 is inserted through the opening 51a.
Accesses the thermostatic chamber 50, and the carrier 40 and the intermediate chamber 3
One wafer W is transferred between the two. The tank body 5
In FIG. 1, an inlet 51b for guiding the temperature-controlled air generated by the constant temperature air supply device 70 from above and a discharge port 51c for discharging the introduced air to the constant temperature air supply device 70 are formed. ing. The carrier 40 may be carried by a worker by opening the door 53, or may be carried by a robot.

As is well known, the constant-temperature air supply device 70 controls the supply of air to a desired temperature and supplies the air to the constant-temperature bath 50 via conduits 71 and 72 as shown in FIG. .

A procedure for carrying the wafer W to the electron beam exposure apparatus having the above-described structure and exposing the wafer W will be described. First, the gate valves G1 and G2 are closed, and the exposure chamber 10 and the loader chamber 20 are closed.
Is set to a predetermined vacuum state, and the gate valve G3 is kept open. The conditioned air set to a desired temperature by the constant temperature air supply device 70 is supplied to the constant temperature bath 50 from the inlet 51a, and a downflow of the conditioned air toward the lower outlet 51b occurs in the constant temperature bath 50. The wafer W stacked on the carrier 40 is heated by the conditioned air. When the intermediate chamber 30 is rapidly evacuated, the temperature drops due to adiabatic expansion, and the wafer W
Temperature also decreases. Therefore, the wafer W after the temperature is lowered
The temperature of the wafer W in the thermostat 50 is set to be higher (for example, 3 degrees higher) than the temperature set in the exposure chamber 10 so that the temperature of the exposure chamber 10 becomes the temperature set in the exposure chamber 10.

The robot arm 60 moves the carrier 40 to 1
The wafer W is transported to the intermediate chamber 30 while holding the wafers W. The gate valve G3 is closed and the intermediate chamber 30 is evacuated. At this time, the wafer W is cooled and contracted by the adiabatic expansion, but the wafer W is preliminarily heated, and the temperature of the wafer W at this time is substantially equal to the set temperature of the exposure chamber 10. Open the gate valve G2 and load the wafer W into the loader chamber 20.
And the gate valve G2 is closed. Gate valve G
1 is opened to transfer the wafer W from the loader chamber 20 onto the wafer stage in the exposure chamber 10. After the gate valve G1 is closed and alignment before exposure is performed, the pattern formed on the reticle is projected onto the wafer W by the projection optical system and the deflector.
Exposure to the right place. At this time, since the temperature of the wafer W has previously been set in the exposure chamber 10, alignment and exposure can be performed immediately after the gate valve G1 is closed.

During exposure, the next wafer W is similarly transferred to the first transfer system in the loader chamber 20, and the gate valve G2 is closed. When the exposure is completed, the gate valve G1 is opened, the exposed wafer W is transferred to the second transfer system of the loader chamber 20, the wafer W of the first transfer system is transferred to the exposure chamber 10, and the gate valve G1 is opened. Close and start alignment and exposure. Also in this case, since the wafer W is controlled to an appropriate temperature in the constant temperature bath 50 and is thus controlled in advance to the set temperature of the exposure chamber 10 when it is carried into the exposure chamber 10, the alignment is performed immediately after the gate valve G1 is closed. And exposure.

During transfer of the wafer W between the loader chamber 20 and the exposure chamber 10, the intermediate chamber 30 is evacuated by closing the gate valve G3. The gate valve G2 of the loader chamber 20 is opened to transfer the exposed wafer W of the second transfer system to the intermediate chamber 30. The gate valve G2 is closed, the intermediate chamber 30 is returned to the atmospheric pressure, and the gate valve G3 is opened. The exposed wafer W in the intermediate chamber 30 is gripped by the robot arm 60 and transferred to the carrier 40. Thereafter, the transfer and exposure of the wafer W are sequentially performed in the same manner.

As described above, in the present embodiment, the carrier 40 in which a plurality of wafers W are stacked is accommodated in the constant temperature chamber 50, and the temperature of the wafer W is set higher than the temperature set in the exposure chamber 10, so that the intermediate chamber 30 Wafer W
Is set to the set temperature of the exposure chamber 10, so that when the wafer W is carried into the exposure chamber 10, the wafer W is already controlled to the installation temperature in the exposure chamber 10, so that alignment and alignment before the start of exposure can be performed. Exposure can be started immediately after the wafer is loaded, and the throughput is improved.

-Second Embodiment- FIGS. 3 and 4 are views for explaining a second embodiment. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and differences will be mainly described. In the first embodiment, a case where a plurality of wafers W are stacked on the carrier 40 and handled (batch processing) has been described, but in the second embodiment, wafers W are handled one by one (single wafer processing). It is.

The wafer W is transferred from the previous process and transferred from the upper surface of the transfer device 80. A constant temperature plate 90 is provided at the end of the transfer device 80, and the wafer W stands by on the constant temperature plate 90 when the transfer is completed. As shown in FIG.
A flow path 91 through which constant-temperature water flows is formed therein, and a constant-temperature water supply device 100 that supplies hot water whose temperature has been adjusted is connected to the flow path 90 via conduits 101 and 102. The temperature of the hot water is adjusted such that the temperature of the wafer W is, for example, 3 degrees higher than the temperature set in the exposure chamber 10 as described above.

In the second embodiment, the wafer W heated on the constant temperature plate 90 is transferred to the robot arm 60.
The wafer W is transferred from the loader chamber 20 to the exposure chamber 10 in the same manner as in the first embodiment. The exposed wafer W is transferred from the exposure chamber 10 to the loader chamber 2.
0 to the intermediate chamber 30 and the robot arm 60
At a carry-out device (not shown).

In the second embodiment, the same operation and effect as those in the first embodiment can be obtained.

In the first embodiment, a plurality of wafers are stacked and accommodated in a constant temperature bath together with a carrier to heat the wafers. In the second embodiment, one wafer is directly transferred to a constant temperature plate. In the case where a single wafer is accommodated in a wafer case and transferred, the present invention is also applied to a case where the wafer case is heated in a constant temperature bath or heated on a constant temperature plate. Can be applied.

The constant-temperature bath heats the wafer by introducing constant-temperature air. However, a heater is installed in the constant-temperature bath to heat the wafer, or a pipe through which hot water flows is disposed in the constant-temperature bath. Or various heating methods can be adopted. In addition, although the description has been made with respect to a wafer as a sensitive substrate, the present invention can be applied to an apparatus for projecting and exposing a circuit pattern on a glass substrate for liquid crystal. Further, although the loader chamber 20 is provided between the intermediate chamber 30 and the exposure chamber 10, the loader chamber 20 can be omitted.

In the comparison between the constituent elements of the claims and the elements of the embodiment, the carrier 40 corresponds to a storage container, and the wafer W corresponds to a sensitive substrate. In addition, thermostat 5
0 and the constant temperature plate 90 correspond to a temperature control device.

[0025]

As described above, according to the present invention, in a charged particle beam exposure apparatus having an intermediate chamber for transferring a sensitive substrate to and from an exposure chamber, the temperature of the intermediate chamber is reduced when the intermediate chamber is evacuated. Since the sensitive substrate is pre-heated before being loaded into the intermediate chamber so that the temperature of the sensitive substrate becomes the set temperature in the exposure chamber, processing relating to exposure can be executed immediately after being loaded into the exposure chamber. And throughput is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a charged particle beam exposure apparatus according to a first embodiment of the present invention;

FIG. 2 is a view showing the inside of the thermostat of FIG. 1;

FIG. 3 is a block diagram showing a schematic configuration of a charged particle beam exposure apparatus according to a second embodiment of the present invention.

FIG. 4 is a view for explaining an example of the thermostat of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exposure room 20 Loader room 30 Intermediate room 40 Carrier 50 Constant temperature bath 60 Robot arm 70 Constant temperature air supply device 80 Transfer device 90 Constant temperature plate 100 Constant temperature water supply device W Wafer

Claims (4)

[Claims] An exposure chamber for projecting and exposing a pattern on a sensitive substrate mounted on a stage by using a charged particle beam, a sensitive substrate is carried in an atmospheric state, and the sensitive substrate is carried in the exposure chamber in a vacuum state. A charged particle beam exposure apparatus, comprising: a temperature controller for adjusting the temperature of the sensitive substrate before carrying the sensitive substrate into the intermediate chamber. 2. The charged particle beam exposure apparatus according to claim 1, wherein the temperature control device is configured to adjust the temperature of the sensitive substrate by an amount corresponding to a temperature decrease of the sensitive substrate when the intermediate chamber is evacuated. A charged particle beam exposure apparatus, wherein heating is performed so as to be higher than a set temperature. 3. The charged particle beam exposure apparatus according to claim 1, wherein the temperature control device accommodates a container for accommodating a plurality of sensitive substrates conveyed from a previous process, and stores the sensitive substrates. A charged particle beam exposure apparatus characterized in that the apparatus is a constant temperature bath for holding at a predetermined temperature. 4. The charged particle beam exposure apparatus according to claim 1, wherein the temperature adjustment device is a constant temperature plate that heats a sensitive substrate conveyed and placed from a previous process and holds the substrate at a predetermined temperature. A charged particle beam exposure apparatus.