Effects of hydrogen additive on obtaining residue-free reactive ion etching of [beta]-SiC in fluorinated plasmas

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2221648· OSTI ID:6098018

Yih, P H; Steckl, A J ^[1]

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1. Univ. of Cincinnati, OH (United States). Dept. of Electrical and Computer Engineering

In this paper the authors discuss the formation and prevention of residues during long-term reactive ion etching (RIE) of [beta]-SiC thin films in a variety of fluorinated gas plasmas mixed with oxygen: CHF[sub 3], CF[sub 4], SF[sub 6], and NF[sub 3]. Without the addition of H[sub 2], all fluorinated plasmas produced significant residue for mixtures with O[sub 2] ranging from 0 to 90%. Only NF[sub 3] and CHF[sub 3] at 0% O[sub 2] showed a low level, or the absence, of residues. The introduction of a relatively small amount of H[sub 2] additive was observed to prevent residue formation in the etched region during the process. In CHF[sub 3] etching, [approximately]10% H[sub 2] was sufficient to prevent residues at all values of O[sub 2]%. A significantly larger (>10%) amount of H[sub 2] is required to prevent residue formation in CF[sub 4]/O[sub 2], SF[sub 6]/O[sub 2], and NF[sub 3]/O[sub 2] plasma. For these gases, the required H[sub 2] additive concentration increases as the oxygen decreases, reaching a maximum for 10% O[sub 2]. Optimum RIE conditions in different fluorinated gas plasmas are presented for SiC homojunction and heterojunction device fabrication. The effects of covering the powered electrode with graphite or Kapton sheets on residue formation and etch rates were investigated with a variety of fluorinated gas plasmas. The mechanisms of residue formation and prevention through the addition of H[sub 2] are discussed.

• OSTI ID: 6098018
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 140:6; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ADDITIVES
CARBIDES
CARBON COMPOUNDS
CARBON FLUORIDES
CATALYTIC EFFECTS
CONCENTRATION RATIO
DEPOSITION
ELEMENTS
ETCHING
FABRICATION
FLUORIDES
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN
MITIGATION
NITROGEN COMPOUNDS
NITROGEN FLUORIDES
NONMETALS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RESIDUES
SEMICONDUCTOR DEVICES
SILICON CARBIDES
SILICON COMPOUNDS
SULFUR COMPOUNDS
SULFUR FLUORIDES
SURFACE FINISHING