Abstract
The etching characteristics of polycrystalline silicon (poly-Si) by short-time modulated electron cyclotron resonance (ECR) determined by using a Cl2 etchant were investigated. It was found that the poly-Si etching rate was improved by increasing the pulse interval of the microwaves to more than 50 μs for a 50% duty ratio and applying a 600 kHz rf bias to the substrate. A large amount of negative chlorine ions are generated in the afterglow which occurs for more than 50 μs in high-density, low-pressure plasmas. The low rf bias alternately accelerates both the negative and positive ions to the substrate surface. As a result, the pulse-time modulated ECR plasma can produce high rate and charge-free etching with a 600 kHz rf bias.
Original language | English |
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Pages (from-to) | 316-318 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 68 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1996 Dec 1 |
Externally published | Yes |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)