Photography – Fluid-treating apparatus – Fluid application to one side only of photographic medium
Reexamination Certificate
2000-06-06
2001-10-30
Rutledge, D. (Department: 2851)
Photography
Fluid-treating apparatus
Fluid application to one side only of photographic medium
C414S940000
Reexamination Certificate
active
06309116
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-162562, filed Jun. 9, 1999; and No. 11-350144, filed Dec. 9, 1999, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing system for processing a substrate such as a semiconductor wafer in accordance with a photo-lithographic process.
In a manufacturing process of a semiconductor device, a semiconductor wafer is coated with a resist, and then the resist coating film is baked, exposed to light, and developed. Such a manufacturing process is carried out by using a substrate processing system (coating/developing system) disclosed in U.S. Pat. No. 5,664,254. In this system, resist coating, baking, and developing treatments excluding a light-exposure treatment are applied to a wafer. The process units are vertically stacked in multiple stages. A wafer is transferred to each of the process units by a main transfer arm mechanism which moves up and down along a transfer space arranged at the center of the system.
In the near future, the diameters of the wafers are planned to be changed from 8-inches to 12-inches (300 mm). When a large-size wafer is processed in accordance with a conventional system, the apparatus having quite a large footprint is required. In addition, the transfer arm must be moved horizontally for a long distance to transfer the large-size wafer, in other words, the moving stroke of the transfer arm becomes excessively long. As a result, the main transfer arm mechanism itself is enlarged more than required. Furthermore, the conventional system has a problem of a low maintainability since a maintenance operation must be applied from the outside the system.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a substrate processing system for processing a large substrate with a high throughput, characterized in that a transfer mechanism has a compact size with a small footprint, and excellent maintainability.
According to the present invention, there is provided a substrate processing system for processing a substrate in accordance with a photolithographic process, comprising:
a cassette section;
a process section having a plurality of process units each processing a substrate;
main transfer arm means arranged in a transfer space surrounded by the process section and the cassette section, for transporting substrates one by one not only between a cassette of the cassette section and each of the plurality of process units but also between the plurality of process units; and
a loop transfer path movably supporting the main transfer arm means in a lower portion of the transfer space and guiding the main transfer arm means so as to face each of the process units or the cassette section.
According to the present invention, the distance from the main transfer arm mechanism to each of the process units is shortened by a radius of the loop transfer path. It is therefore possible to smoothly load a large substrate into the process unit. As a result, the throughput increases. In addition, since the foot print of the system is reduced, the main transfer arm means is prevented from being enlarged.
Furthermore, according to the present invention, it is possible to increase the transfer space itself. Therefore, the maintainability of the main transfer arm mechanism and the process unit can be improved.
In the case where the cassette section has a plurality of cassette tables vertically stacked in multiple stages and the process section has a plurality of process units vertically stacked in multiple stages, the main transfer arm means comprises
a holder for holding the substrate;
a loop moving mechanism for moving the holder along the loop transfer path;
an up-and-down moving mechanism for moving the holder up and down; and
a back-and-forth moving mechanism for moving the holder back and forth.
The loop transfer path has a pair of support guide rails; and
a monorail having a rectangular sectional shape and interposed between the pair of support guide rails.
The loop moving mechanism comprises a cart having an upside-down U-letter sectional shape;
a plurality of wheels attached to the lower portion of the cart and driven to rotate on the support guide rails;
at least one pair of moving rollers attached to a depressed portion of the cart in contact with a side surface of the monorail;
a plurality of follower rollers driven to rotate on the monorail; and
a motor for initiating rotation of the driving roll.
The main transfer arm means comprises
a cylindrical support;
a plurality of holders for holding the substrate;
an up-and-down moving mechanism for moving the plurality of holders up and down in the cylindrical support;
a loop moving mechanism for moving the plurality of holders together with the cylindrical support along the loop transfer path; and
a plurality of back-and-forth moving mechanisms for independently moving the holders back and forth.
Each of the plurality of process units has a substrate loading/unloading port formed facing up so as to face the transfer space.
The process section comprises
a coating unit for applying a resist solution to the substrate;
a developing unit for developing a resist film applied on the substrate; and
a thermal processing unit for applying a heat treatment to the substrate.
It is preferable that the system of the present invention should further comprise a clean-air supply mechanism for supplying a down-flow of clean air into a space formed between adjacent process units. As the clean air supply mechanism, it is desirable to use an air cleaning unit having a fan filter unit (FFU) and an alkaline substance removing mechanism.
The system of the present invention may further comprise an interface section for transferring the substrate to/from a light exposure apparatus and for transferring the substrate to/from a washing apparatus.
The interface section is desirably arranged near the transfer space and in a position accessible by the main transfer arm means.
FIG. 1
shows a schematic structure of a conventional substrate transfer system. A main transfer arm mechanism
200
has a transfer table
203
having two holders
201
,
202
capable of holding the wafer W in upper and lower portions and a liftable rotating mechanism
204
for moving the transfer table
203
up and down and rotating it by an angle of &thgr;. The holders
201
,
202
can be moved back and forth by a moving mechanism (not shown) housed in the transfer table
203
, in the direction indicated by a double-headed arrow
210
.
However, since a single main transfer arm mechanism
200
transports the wafer W between various process units and loads/unloads the wafer W into/from various process units in the conventional system, the wafer W is not transferred between the process units
206
at the same time as the wafer W is loaded/unloaded into/from the various process units
206
. As a result, it is impossible to reduce the time required for coating/developing the wafer W.
Furthermore, if the up-and-down movement, rotation of the transfer table
203
, and back-and-forth movement of the holders
201
,
202
are performed by the main transfer arm mechanism
200
, the burden on the main transfer arm mechanism becomes significantly high, with the result that the transfer of the wafer W is delayed.
When the wafer is exposed to light in a light-exposure apparatus, the wafer is first mounted on the delivery table, and then, the wafer is transferred to a wafer holder used exclusively for transferring the wafer from the delivery table to the light-exposure apparatus. While the wafer remains on the delivery table, if another wafer is delivered there, the wafer holder cannot transfer the newly transferred wafer to the delivery table. Therefore, the transfer of the wafer is further delayed.
The present inventors conducted intensive studies to solve the aforementioned problems. As a result, they made the present invention.
Inada Hiroichi
Kudou Hiroyuki
Mahara Koji
Ueda Issei
Fulbright & Jaworski L.L.P.
Rutledge D.
Tokyo Electron Limited
LandOfFree
Substrate processing system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Substrate processing system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Substrate processing system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2578346