Load port door assembly with integrated wafer mapper
US6396072B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 2000 |
| Grant date | May 28, 2002 |
| Priority date | — |
| Expiry date | Apr 3, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67772
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A load port interface for determining the presence or absence of wafers in a cassette, i.e. a wafer mapper, is integrated with a port closure assembly in a load port interface separating a process environment from an operator environment. A cover plate and a door are arranged in an L-shape, with both members being able to seal the port in a bulkhead of the load port interface. In one configuration, the cover plate seals the port, while door panel members rest horizontally on the operator side of the bulkhead. In this position, a wafer stack, W, inside of a cassette may be placed on the inside door panel, with the top of the wafer stack, W, being open. As the door is raised from the horizontal position to a vertical position, the wafer stack, W, is rotated through an opening in the bulkhead so that the wafer stack, W, is now on the process side. The wafer mapper features a moveable trolley connected to, or within, the door. The trolley can move parallel to the wafer stack, W, under control of a stepper motor and examine each row of the stack, counting wafers as light is reflected or scattered from the edges of the wafers. Each wafer may be optically probed through a window in a cove…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.