Lift pin for dechucking substrates
US5900062A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1995 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Dec 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6833
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A lift pin 95 for dechucking a substrate 15 held to a chuck 50 by residual electrostatic charge, the substrate being processed in a plasma formed using RF currents, is described. The lift pin 95 comprises (a) a movable elongated member 110 having a tip 115 suitable for lifting and lowering the substrate 15 off the chuck 50, and capable of forming an electrically conductive path between the substrate 15 and a current sink 105. The electrically conductive path comprises at least one of the following: (1) a frequency selective filter capable of filtering RF currents flowing therethrough so that substantially no RF currents flow through the filter; or (2) a resistor having a resistance sufficiently elevated to reduce the voltage caused by RF currents flowing therethrough, by at least about 50%. The lift pin 95 allows the residual electrostatic charge in the substrate 15 to be discharged to the current sink 105 substantially without allowing RF currents, used to form a plasma in the process chamber and to attract the plasma to the substrate, from flowing to the current sink 105.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.