Methods and apparatus for detecting pattern dependent charging on a workpiece in a plasma processing system
US5869877A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Apr 23, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3011
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A charge monitoring apparatus measures an electrical charge deposited on a multiple-layered workpiece, such as a semiconductor wafer, in a plasma processing system. The apparatus includes a charge collection electrode (CCE), a non-conducting patterned layer and a voltage or current sensor. The patterned layer is provided on the CCE and includes a plurality of openings that extend through the patterned layer to the conducting surface of the CCE. The openings create a topology having an adequate aspect ratio to cause electron shading to occur during plasma processing of the workpiece. The voltage or current sensor includes an EEPROM transistor that stores information regarding the amount of electrical charge that accumulates on the CCE during plasma processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.