Dual cassette load lock

Abstract

A workpiece loading interface is included within a workpiece processing system which processes workpieces, typically wafers, in a vacuum. The workpiece loading interface includes two separate chambers. Each chamber may be separately pumped down. Thus, while a first cassette of wafers, from a first chamber is being accessed, a second cassette of wafers may be loaded in the second chamber and the second chamber pumped down. Each chamber is designed to minimize intrusion to a clean room. Thus a door to each chamber has a mechanism which, when opening the door, first moves the door slightly away from an opening in the chamber and then the door is moved down parallel to the chamber. After the door is opened, a cassette of wafers is lowered through the opening in a motion much like a drawbridge. The cassette may be pivoted within the chamber when the position from which wafers are accessed from the cassette differs from the position from which the cassette is lowered out of the chamber.

Description

BACKGROUND [0001] The present invention relates to a front end loading interface used in the loading of workpieces in semiconductor processing equipment. [0002] Semiconductor processing equipment often has a plurality of chambers in which processing occurs. Arm assemblies or other robotic devices are generally used to move workpieces, generally wafers from a wafer queuing station to various chambers for processing. When the processing is finished the wafer is returned to the queuing station. For an example of prior art processing equipment, see U.S. Pat. No. 4,715,921 issued to Maher, et al. for a Ouad Processor. [0003] Semiconductor processing is typically done in a vacuum. Therefore, a wafer queuing station into which is placed a cassette of wafers to be processed must be pumped down before the wafers may be accessed. This significantly increases the time the semiconductor processing equipment is idle while waiting for a cassette of processed wafers to be exchanged for a cassette ...

AI Technical Summary

Benefits of technology

"The present invention provides a workpiece loading interface for a workpiece processing system that includes two separate chambers that can be separately pumped down. This allows for faster processing of wafers through the system. The chambers are designed to minimize intrusion to a clean room, and the cassette of wafers can be easily replaced with an automated device. The cassette can be pivoted within the chamber to access wafers from different positions. These features improve the efficiency and flexibility of the workpiece processing system."

Problems solved by technology

This significantly increases the time the semiconductor processing equipment is idle while waiting for a cassette of processed wafers to be exchanged for a cassette of unprocessed wafers and subsequent pumping down of the wafer queuing station.

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