Sidewall smoothing in high aspect ratio/deep etching using a discrete gas switching method
US6924235B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2003 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Aug 12, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67069
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved method for introducing gases into an alternating plasma etching/deposition chamber is provided by the present invention. To minimize the introduction of pressure pulses into the alternating etching/deposition chamber when the deposition and etchant gas supplies are switched on and off, a mass flow controller is used to provide a relatively constant flow of gas. A gas bypass or a gas exhaust is provided such that when a gas inlet to the alternating etching/deposition chamber is closed an alternative path is provided for the flow of gas from the mass flow controller. The provision of a bypass or exhaust maintains the pressure of the gas received from the mass flow controller at a substantially constant level. The elimination or minimization of a pressure pulse of the gas helps increase the smoothness of the walls of high aspect ratio features etched in a silicon substrate in the alternating etching/deposition chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.