Plasma processing method and equipment used therefor
US5827435A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 26, 1995 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Oct 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A plasma processing method is provided which suppresses the charge accumulation on a processing object such as a semiconductor substrate. An alternating excitation signal in the form of pulses for exciting the plasma is supplied to a reaction gas contained in a plasma chamber, each pulse having an on-period t.sub.on for supplying the excitation signal and an off-period t.sub.off for stopping the excitation signal. The off period ranges from 10 to 100 .mu.sec. The on-period may be determined as needed. An alternating bias signal for biasing the processing object is also applied to the object in the chamber. The bias signal has a frequency of at most 600 kHz. As a result, an increased number of positive and negative ions impinge the object thus increasing the processing rate and reducing the charge accumulation compared to prior art processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.