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Indexed by:期刊论文

Date of Publication:2017-08-01

Journal:PLASMA SCIENCE & TECHNOLOGY

Included Journals:Scopus、SCIE、EI

Volume:19

Issue:8,SI

ISSN No.:1009-0630

Key Words:atomic layer etching; multi-scale model; tailored bias voltage waveforms; ion energy and angular distributions

Abstract:Plasma atomic layer etching is proposed to attain layer-by-layer etching, as it has atomic-scale resolution, and can etch monolayer materials. In the etching process, ion energy and angular distributions (IEADs) bombarding the wafer placed on the substrate play a critical role in trench profile evolution, thus importantly flexibly controlling IEADs in the process. Tailored bias voltage waveform is an advisable method to modulate the IEADs effectively, and then improve the trench profile. In this paper, a multi-scale model, coupling the reaction chamber model, sheath model, and trench model, is used to research the effects of bias waveforms on the atomic layer etching of Si in Ar/Cl-2 inductively coupled plasmas. Results show that different discharge parameters, such as pressure and radio-frequency power influence the trench evolution progress with bias waveforms synergistically. Tailored bias waveforms can provide nearly monoenergetic ions, thereby obtaining more anisotropic trench profile.