Material or article handling – Device for emptying portable receptacle – Nongravity type
Reexamination Certificate
1999-05-14
2001-11-20
Werner, Frank E. (Department: 3652)
Material or article handling
Device for emptying portable receptacle
Nongravity type
C414S416030, C414S217000, C414S937000, C414S939000, C414S754000, C118S719000, C294S001200, C432S239000
Reexamination Certificate
active
06318948
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a substrate transfer apparatus for transferring a substrate such as a semiconductor wafer and an LCD substrate, and relates to a substrate processing apparatus.
In manufacturing processes of semiconductor devices and LCDs, a substrate is transferred sequentially to each of process sections by use of the substrate transfer apparatus. In each process section, a plurality of substrates are processed simultaneously. For example, in the photolithographic process of a semiconductor device, a wafer is transferred to a coating unit, in which a photoresist coating film is formed on the surface of the wafer, transferred to a light exposure unit, in which the photoresist coating film is pattern-exposed, and transferred to a development unit to develop the pattern-exposed photoresist coating film.
As an example of the transfer apparatus, an apparatus for transferring a wafer while holding it by vacuum-adsorption, is disclosed in Japanese Patent Application KOKAI Publication No. 6-85042. In the conventionally-used apparatuses, a wafer is vacuum-adsorbed by a vacuum chuck at a center portion of the rear surface thereof, so that particles (derived from the vacuum chuck) may possibly attach to the center portion of the rear surface of the wafer. If the wafer having particles attached on the rear surface is loaded into the light exposure unit, the accuracy of alignment between the wafer and an optical lens decreases, with the result that a pattern latent image cannot be formed on the photoresist film with a high accuracy.
On the other hand, the substrate transfer apparatuses disclosed in US Patent Publications Nos. 5,664,254 and 5,700,127 have an arm holder for holding a wafer in contact with a peripheral portion of the rear surface of the wafer. The arm holder has a contact support portion having a self-alignment means which allows the wafer to directly align upon reception. The diameter of the contact support portion of this type is formed slightly larger than that of the wafer. This is made in order to take out the wafer smoothly and securely from a cassette even if the wafer is placed at a position slightly away from a desired setting position in the cassette.
Incidentally, according to the SEMI (Semiconductor Equipment and Material International) standard, a silicon wafers of 200 mm (8 inch) and 300 mm (12 inch) diameter may have allowances (differences in size) of ±0.2 mm and ±0.5 mm, respectively. On the other hand, according to the JEIDA (Japan Electronic Industry Development Association) standard, a silicon wafer of 200 mm (8 inch) diameter may have an allowance of ±0.5 mm (Glade I) or ±1.0 mm (Grade II) and a silicon wafer of 300 mm (12 inch) diameter may have an allowance of ±0.2 mm. Therefore, the arm holder must have a contact support portion sufficiently large to support the wafer formed within such an allowance. To attain this, in the conventional contact support portion, an additional space clearance is added to the allowance for the wafer size. Consequently, if a wafer formed in a minimum diameter within the allowance range specified by the standard, is supported, a clearance produced between the contact support portion and the wafer results in 2 mm or more.
Since the wafer is loosely held by the arm holder as mentioned, it moves around on the arm holder during the transfer process. It follows that the member of the contact support portion is rubbed with the wafer, possibly producing particles. Furthermore, when the wafer is transferred from the substrate transfer apparatus to another apparatus, alignment operation of the wafer must be repeated again in said another apparatus. More specifically, it is necessary to align the wafer in every process unit and a transfer apparatus of the light exposure apparatus. However, if an alignment means is newly installed to another transfer apparatus, the apparatus is enlarged and complicated, giving a large foot print of the apparatus.
BRIEF SUMMARY OF THE INVENTION
An Object of the present invention is to provide a substrate transfer apparatus capable of reducing an amount of particles generated during the substrate transfer and requiring no substrate alignment in an apparatus other than the substrate transfer apparatus, and provide a substrate processing apparatus having a small foot print.
According to the present invention, there is provided an apparatus for transferring a substrate comprising:
an arm holder moving into and out of a cassette while a substrate is mounted thereon;
a forward and backward driving mechanism for moving the arm holder forward and backward; and
a contact support member for supporting the substrate in contact with a lower surface peripheral portion of the substrate placed on the arm holder.
The contact support member comprises
a first defining portion for defining a front end of the substrate placed on the arm holder; and
a second defining portion facing the first defining portion, for defining a rear end of the substrate placed on the arm holder.
It is preferable that the first defining portion consist of a single stepped portion, and the second defining portion consist of upper and lower steps continuously formed. When the arm holder is retreated by the forward and backward driving mechanism, the rear end of the substrate is slid down from the upper stepped portion of the second defining portion to the lower stepped portion.
The lower stepped portion of the second defining portion is located nearer the stepped portion of the first defining portion than the upper stepped portion of the second defining portion. Furthermore, the upper stepped portion of the second defining portion is present in substantially the same plane as the stepped portion of the first defining portion.
It is preferable that the substrate transfer apparatus further comprise a transfer base table for movably supporting the arm holder and a contact member attached to the transfer base table.
When the arm holder is retreated by the forward and backward driving mechanism, the rear end of the substrate placed on the arm holder comes into contact with the contact member, and thereby the rear end of the substrate is slid down from the upper stepped portion of the second defining portion to the lower stepped portion.
The distance from the lower stepped portion of the second defining portion and the stepped portion of the first defining portion corresponds to the length of the diameter of the substrate plus allowance.
It is preferable that the substrate transfer apparatus further comprise a push mechanism for moving the second defining portion toward the first defining portion. In this case, it is further preferable that a press member be attached to the second defining portion, for pressing an upper portion of the rear end of the substrate.
According to the present invention, there is provided an apparatus for processing substrate comprising:
a process section for processing resist of a substrate;
a cassette section for receiving the substrate together with a cassette and transferring the substrate to/from the process section;
an interface section for transferring the substrate to/from another apparatus and transferring the substrate to/from the process section; and
a substrate transfer apparatus arranged in at least one of the cassette section and the interface section, for transferring the substrate.
The substrate transfer apparatus comprises
an arm holder moving into and out of a cassette while a substrate is mounted thereon;
a forward and backward driving mechanism for moving the arm holder forward and backward; and
a contact support member for supporting the substrate in contact with a lower surface peripheral portion of the substrate placed on the arm holder.
The contact support member comprises:
a first defining portion for defining a front end of the substrate placed on the arm holder; and
a second defining portion facing the first defining portion, for defining a rear end of the substrate placed on the arm holder.
Additional objects and advant
Ueda Issei
Yamaguchi Tadayuki
Rader & Fishman & Grauer, PLLC
Tokyo Electron Limited
Werner Frank E.
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