Semiconductor treatment system and method for exchanging and treating substrate

• US 5,564,889 A
• Filed: 06/17/1994
• Issued: 10/15/1996
• Est. Priority Date: 06/18/1993
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Kyushu Limited (Tokyo Electron Limited), Tokyo Electron Limited
• Inventors: Araki, Shinichiro
• Primary Examiner(s): Underwood, Donald W.
• Application Number:
  US08/262,329
• Time in Patent Office: 851 Days
• Field of Search: 414/222, 414/749, 414/729, 414/935, 414/937, 294/907
• US Class Current: 414/806
• CPC Class Codes: H01L 21/68707 the wafers being placed on a robot blade, or gripped by a gripper for conveyance
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling

Abstract

A resist coating system for semiconductor wafers has a treatment unit and a transfer unit. The treatment unit has a plurality of treatment sections, and a transfer robot moves along the treatment sections. The transfer robot has a vertically movable driving block and first, and second and third arms for holding the semiconductor wafers, which are vertically arranged on the driving block and supported by the same such that they can advance and retreat independent of one another, and an adiabatic plate supported by the driving block between the third arm and the first and second arms. The third arm is used to take each wafer out of a cooling section, which is one of the treatment section. The wafer exchange in each treatment section is performed by means of two of the first through third arms. An arm for taking from the treatment section a wafer having been treated is operated in synchronism with another arm for inserting into the section a wafer to be treated.

Claims

1. A method of exchanging target substrates, employed in a semiconductor treatment system which has a station for mounting each substrate, and a transfer apparatus provided with a base vertically movable among upper, intermediate and lower levels, and upper and lower arms for transferring the substrates, said upper and lower arms being vertically arranged on said base and supported by said base such that they can advance and retreat independent of each other, said station being formed such that each substrate can be transferred between said station and one of said upper and lower arms by moving said one of said arms in horizontal and vertical directions,

wherein said upper level of said base is set such that one of the substrates can be kept out of contact with said station when said lower arm is positioned above said station together with said one of the substrates,

said intermediate level of said base is set such that said lower arm can be kept out of contact with one of the substrates when said lower arm is positioned under said one of the substrates which is placed on said station, and also such that one of the substrates can be kept out of contact with said station when said upper arm is positioned above said station together with said one of the substrates, and

said lower level of said base is set such that said upper arm can be kept out of contact with one of the substrates when it is positioned under said one of the substrates placed on said station,

said method comprising, so as to remove a first substrate, which is one of the substrates and mounted on said station, from said station by said upper arm, and to transfer a second substrate, which is one of the substrates and supported by said lower arm, from said lower arm onto said station, the steps of:

positioning said base at said lower level with said upper and lower arms positioned in retreat positions;

advancing said upper arm to a position under said first substrate while said base being positioned at said lower level;

moving said base up to said upper level after positioning said upper arm under said first substrate, thereby raising said first substrate from said station by said upper arm;

retreating said upper arm with said first substrate and advancing said lower arm with said second substrate while said base being positioned at said upper level;

moving said base down to said intermediate level after positioning said lower arm above said station, thereby transferring said second substrate from said lower arm onto said station;

retreating said lower arm after transferring said second substrate onto said station; and

confirming by an optical sensor as to whether said upper arm holds said first substrate while retreating said upper arm and advancing said lower arm, wherein said optical sensor comprises means for emitting light and means for receiving said light which are fixed relative to said base and connected to each other through an optical axis intersecting movement paths of said first and second substrates, and wherein said first substrate on said upper arm is sensed by said optical sensor when said optical axis intersects said first substrate on said upper arm and does not intersect said second substrate on said lower arm.

2. The method according to claim 1, wherein said retreat of said lower arm is initiated while said base being positioned at said intermediate level.

3. The method according to claim 1, wherein said retreat of said upper arm and said advance of said lower arm are performed substantially in synchronism.

4. The method according to claim 1, wherein an opening is formed in said lower arm such that said first substrate on said upper arm is sensed by said optical sensor when said optical axis intersects both of said opening of said lower arm and said first substrate on said upper arm at a same time.

5. A method of exchanging target substrates, employed in a semiconductor treatment system which has a station for mounting each substrate, and a transfer apparatus provided with a base vertically movable among upper, intermediate and lower levels, and upper and lower arms for transferring the substrates, said upper and lower arms being vertically arranged on said base and supported by said base such that they can advance and retreat independent of each other, said station being formed such that each substrate can be transferred between said station and one of said upper and lower arms by moving said one of said arms in horizontal and vertical directions,

wherein said upper level of said base is set such that one of the substrates can be kept out of contact with said station when said lower arm is positioned above said station together with said one of the substrates,

said intermediate level of said base is set such that said lower arm can be kept out of contact with one of the substrates when said lower arm is positioned under said one of the substrates which is placed on said station, and also such that one of the substrates can be kept out of contact with said station when said upper arm is positioned above said station together with said one of the substrates, and

said lower level of said base is set such that said upper arm can be kept out of contact with one of the substrates when it is positioned under said one of the substrates placed on said station,

said method comprising, so as to remove a first substrate, which is one of the substrates and mounted on said station, from said station by said lower arm, and to transfer a second substrate, which is one of the substrates and supported by said upper arm, from said upper arm onto said station, the steps of:

positioning said base at said intermediate level with said upper and lower arms positioned in retreat positions;

advancing said lower arm to a position under said first substrate while said base being positioned at said intermediate level;

moving said base up to said upper level after positioning said lower arm under said first substrate, thereby raising said first substrate from said station by said lower arm;

retreating said lower arm with said first substrate and advancing said upper arm with said second substrate while said base being positioned at said upper level;

moving said base down to said lower level after positioning said upper arm above said station and also after retreating said lower arm, thereby transferring said second substrate from said upper arm onto said station;

retreating said upper arm after transferring said second substrate onto said station; and

confirming by an optical sensor as to whether said lower arm holds said first substrate while retreating said lower arm and advancing said upper arm, wherein said optical sensor comprises means for emitting light and means for receiving said light which are fixed relative to said base and connected to each other through and optical axis intersecting movement paths of said first and second substrates, and wherein said first substrate on said lower arm is sensed by said optical sensor when said optical axis intersects said first substrate on said lower arm and does not intersect said second substrate on said upper arm.

6. The method according to claim 5, wherein said retreat of said upper arm is initiated while said base being positioned at said lower level.

7. The method according to claim 5, wherein said retreat of said lower arm and said advance of said upper arm are performed substantially in synchronism.

8. The method according to claim 5, wherein an opening is formed in said upper arm such that said first substrate on said lower arm is sensed by said optical sensor when said optical axis intersects both of said opening of said upper arm and said first substrate on said lower arm at a same time.

9. A method of exchanging target substrates, employed in a semiconductor treatment system which has a station for mounting each substrate, and a transfer apparatus provided with a base vertically movable among upper, intermediate, and lower levels, and upper and lower arms for transferring the substrates, said upper and lower arms being vertically arranged on said base and supported by said base such that they can advance and retreat independent of each other, said station being formed such that each substrate can be transferred between said station and one of said upper and lower arms by moving said one of said arms in horizontal and vertical directions,

wherein said upper level of said base is set such that one of the substrates can be kept out of contact with said station when said lower arm is positioned above said station together with said one of the substrates,

said intermediate level of said base is set such that said lower arm can be kept out of contact with one of the substrates when said lower arm is positioned under said one of the substrates which is placed on said station, and also such that one of the substrates can be kept out of contact with said station when said upper arm is positioned above said station together with said one of the substrates, and

said lower level of said base is set such that said upper arm can be kept out of contact with one of the substrates when it is positioned under said one of the substrates placed on said station,

said method comprising, so as to remove a first substrate, which is one of the substrates and mounted on said station, from said station by said lower arm, and to transfer a second substrate, which is one of the substrates and supported by said upper arm, from said upper arm onto said station, the steps of:

positioning said base at said intermediate level with said upper and lower arms positioned in retreat positions;

advancing said lower arm to a position under said first substrate and advancing said upper arm with said second substrate while said base being positioned at said intermediate level;

moving said base up to said upper level after positioning said lower arm under said first substrate, thereby raising said first substrate from said station by said lower arm;

retreating said lower arm with said first substrate while said base being positioned at said upper level;

moving said base down to said lower level after positioning said upper arm above said station and also after retreating said lower arm, thereby transferring said second substrate from said upper arm onto said station; and

retreating said upper arm after transferring said second substrate onto said station.

10. The method according to claim 9, wherein said retreat of said upper arm is initiated while said base being positioned at said lower level.

11. The method according to claim 9, wherein said advance of said lower arm and said advance of said upper arm are performed substantially in synchronism.

12. The method according to claim 9, further comprising the step of confirming by an optical sensor as to whether said lower arm holds said first substrate while retreating said lower arm, wherein said optical sensor comprises means for emitting light and means for receiving said light which are fixed relative to said base and connected to each other through an optical axis intersecting movement paths of said first and second substrates, and wherein said first substrate on said lower arm is sensed by said optical sensor when said optical axis intersects said first substrate on said lower arm and does not intersect said second substrate on said upper arm.

13. The method according to claim 12, wherein an opening is formed in said upper arm such that said first substrate on said lower arm is sensed by said optical sensor when said optical axis intersects both of said opening of said upper arm and said first substrate on said lower arm at a same time.