Wafer transfer system, wafer transfer method, cassette exchange system and cassette exchange method

Abstract

A cassette exchange system is provided. The cassette exchange system includes a wafer temporary storage apparatus, a first cassette base, a second cassette base and a moving apparatus. The wafer temporary storage apparatus includes a plurality of wafer carrier units. The first cassette base is suitable for carrying a first cassette, and the second cassette base is suitable for carrying a second cassette. The moving apparatus connects the first cassette base with the second cassette base. Also, the moving apparatus sequentially moves the first cassette base and the second cassette base to the wafer temporary storage apparatus to simultaneously transfer the wafers stored in the first cassette to the second cassette.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority benefit of Taiwan application serial no. 94107258, filed on Mar. 10, 2005. All disclosure of the Taiwan application is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a wafer transfer system, a wafer transfer method, a cassette exchange system and an exchange method thereof. [0004] 2. Description of the Related Art [0005] Because of the continuous high integration density of semiconductor devices of integrated circuits, manufacturing process accuracy becomes more and more important. Once minor errors occur during processes, the whole manufacturing process may fail. As a result, wafers are damaged and scraped, and costs thus increase. [0006] For a general semiconductor process, a semiconductor equipment is composed of several neighboring process chambers. By a wafer transfer system, wafers are transferred among diffe...

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Benefits of technology

[0010] Accordingly, the present invention is directed to a wafer transfer system and a wafer transfer method. According to the system and the method, costs resulting from scratching the wafer surface or backside during the wafer transfer can be avoided.

[0011] The present invention also is directed to a cassette exchange system and a cassette exchange method. According to the system and the method, wafer transfer efficiency is improved and costs resulting from scratching the wafer surface or backside during the wafer transfer can be avoided.

[0015] The wafer transfer system of the present invention includes the first sensor and the second sensor. Before the wafer is transferred, checking results from the sensors are apt to determining whether to unload the wafer in the cassette. Accordingly, the chance of scratching the wafer surface or backside during the wafer transfer is effectively reduced. In addition, the checking results may further detect component aging or distortion for warning purpose.

[0022] The cassette exchange system includes a plurality of wafer carrier units. All wafers in one cassette can be simultaneously transferred to another cassette. Accordingly, the wafer transfer efficiency is improved and the process time is reduced.

[0023] In addition, in one embodiment the first sensor and the second sensor are disposed on at least one of the wafer carrier units of the cassette exchange system. The checking results generated by the sensors determine whether to load or unload the wafers in the cassette before loading or unloading the wafers. Accordingly, the chance of scratching the wafer surface or backside during the wafer transfer is reduced. In addition, the checking results may further detect component aging or distortion for warning purpose.

Problems solved by technology

Once minor errors occur during processes, the whole manufacturing process may fail.

As a result, wafers are damaged and scraped, and costs thus increase.

The motions of a robot blade are complicated which include moving up or down, rotating, retracting and so on.

Note that during these steps, minor shift or displacement may cause the wafer transfer failed; or even the wafer may drop or slide so as to cause the wafer broken or scratched.

Due to the frequency of wafer transfers by the robot blade, transmission components may be aging, abraded or even distorted.

All of them result in the shift of the robot blade and deteriorate the accuracy of removing the wafer by the robot blade.

As a result, the robot blade may be in touch with the wafer or even scratch the wafer surface or backside or break the wafer.

These factors will increase the manufacturing costs.

This method increases the process time.

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