Automatic wafer centering method and apparatus
US11764093B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2021 |
| Grant date | Sep 19, 2023 |
| Priority date | — |
| Expiry date | Aug 10, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67167
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A substrate transport apparatus including a transport chamber, a drive section, a robot arm having an end effector at a distal end configured to support a substrate and being connected to the drive section generating at least arm motion in a radial direction extending and retracting the arm, an imaging system with a camera mounted in a predetermined location to image at least part of the robot arm, and a controller connected to the imaging system to image the arm moving to a predetermined repeatable position, the controller effecting capture of a first image of the robot arm proximate to the repeatable position decoupled from encoder data of the drive axis, wherein the controller calculates a positional variance of the robot arm from comparison of the first image with a calibration image, and from the positional variance determines a motion compensation factor changing the extended position of the robot arm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.