Fine Pattern Etching of Silicon Substrates Using Atmospheric Line-Shaped Microplasma Source

Abstract

An atmospheric line-shaped microplasma source was developed for fine pattern etching, and the dependence of the etching properties on the substrate temperature and the distance between the two outer gas outlets was investigated. There was a sudden increase of the etching rate and a decrease of top width when the substrate temperature was 300°C or more. Auger electron spectroscopy (AES) analysis indicates that oxidation on the line shoulder caused the top width to decrease. By decreasing the distance between the two outer gas outlets from 3 mm to 650 µm, the top width decreased from 441 µm to 234 µm. The gas flow simulation result revealed that there exists a firing limit of SF6 partial pressure from 0.1% to 0.2% in the configuration.

Current status of microplasma research

“…Several results on the high-speed, direct etching of Si up to hundreds of micrometers per minute have been reported [13,45,46]. A three-dimensional process has also been reported, in which a VHF microplasma jet is mounted on a machine tool with three movable axes [47].…”

Annealing performance improvement of elongated inductively coupled plasma torch and its application to recovery of plasma-induced Si substrate damage

“…Contamination from electrodes and plasma instability are also a concern. Atmospheric line-shaped plasma [30][31][32] and plate plasma 33) have been developed, but they are not of sufficiently high temperature to enable instantaneous thermal processing.…”

Microfabrication of plasma nanotorch tips for localized etching and deposition

“…In [1][2][3][4] a tungsten carbide needle tube electrode with inner hole diameter of 150 µm; silica discharge tube with 0.7 mm diameter, line shape microplasma source with inner gas outlet dimension of 130 µm, and UHF inductively coupled quartz-glass discharge capillary of 100 µm inner diameter was used. These tips function as miniaturized version of plasma spray and cutting nozzles [5].…”