Cassette buffering within a minienvironment

Abstract

A SMIF interface is disclosed for buffering one or more cassettes within a minienvironment affixed to a process tool. The interface includes a load port formed of a port door and a port plate circumjacent thereabout, and a minienvironment mounted to port plate. The SMIF interface and / or process tool includes at least one shelf for storing a cassette after the load port separates the cassette from its transport pod. In operation, while a first cassette is located within the process tool, a second pod is seated on the load port, the cassette is separated from the pod and the cassette is stored on a storage shelf. When processing on the first cassette is completed, the second cassette is loaded into the processing tool. The first cassette is returned to the pod and removed from the load port. A cassette from a new pod is then seated on the load port, separated from its pod and stored on the storage shelf. This process continues until processing on each scheduled wafer lot is completed. By providing a buffer of cassettes within the minienvironment of the SMIF interface, the processing tool is no longer dependent on timely delivery of pods to the interface to ensure that the process tool does not sit idle.

Description

technical field [0001] The present invention relates to the transport of workpieces, such as semiconductor wafers, from storage and transport containers to process tools, and more particularly to a system that allows the containers to be buffered within an environmnt near the process tool. Background technique [0002] A SMIF system proposed by Hewlett-Packard is disclosed in US patents US4532970 and US4534389. The purpose of the SMIF system is to reduce the flow of particulate matter onto semiconductor wafers during wafer storage and transport during semiconductor wafer manufacturing. This is achieved by mechanically ensuring that the gaseous medium (eg, air or nitrogen) surrounding the flakes is substantially stationary relative to the flakes during storage and transport, and that particles do not pass from the surrounding environment into the middle of the flake environment. [0003] A SMIF system has three main parts: (1) a small volume hermetic container for storing an...

AI Technical Summary

Problems solved by technology

First, these buffers take up a lot of valuable space on the wafer processing line

Second, even if the in-place buffer can deliver the containers to a loadport in a timely manner, it still takes time to start loading the containers onto the loadport and to return the cassette to the container after the work in the cassette has been processed. Precious time separating the cartridge from the container

Additionally, tooling capable of supporting two load ports requires identical components for each load port, thus increasing cost and operational complexity

Additionally, the two load ports take up valuable additional space on the front end of the tooling

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