skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Selective etching of silicon carbide films

Abstract

A method of etching silicon carbide using a nonmetallic mask layer. The method includes providing a silicon carbide substrate; forming a non-metallic mask layer by applying a layer of material on the substrate; patterning the mask layer to expose underlying areas of the substrate; and etching the underlying areas of the substrate with a plasma at a first rate, while etching the mask layer at a rate lower than the first rate.

Inventors:
; ;
Publication Date:
Research Org.:
The Regents of the University of California, Oakland, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1176038
Patent Number(s):
7,151,277
Application Number:
10/613,508
Assignee:
The Regents of the University of California (Oakland, CA) OSTI
DOE Contract Number:
9782
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Gao, Di, Howe, Roger T., and Maboudian, Roya. Selective etching of silicon carbide films. United States: N. p., 2006. Web.
Gao, Di, Howe, Roger T., & Maboudian, Roya. Selective etching of silicon carbide films. United States.
Gao, Di, Howe, Roger T., and Maboudian, Roya. Tue . "Selective etching of silicon carbide films". United States. doi:. https://www.osti.gov/servlets/purl/1176038.
@article{osti_1176038,
title = {Selective etching of silicon carbide films},
author = {Gao, Di and Howe, Roger T. and Maboudian, Roya},
abstractNote = {A method of etching silicon carbide using a nonmetallic mask layer. The method includes providing a silicon carbide substrate; forming a non-metallic mask layer by applying a layer of material on the substrate; patterning the mask layer to expose underlying areas of the substrate; and etching the underlying areas of the substrate with a plasma at a first rate, while etching the mask layer at a rate lower than the first rate.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 19 00:00:00 EST 2006},
month = {Tue Dec 19 00:00:00 EST 2006}
}

Patent:

Save / Share:
  • Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C{sub 60} precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C{sub 60} with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C{sub 60} on silicon dioxide at surface temperatures less than 1250 K. 5 figs.
  • Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C.sub.60 precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C.sub.60 with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C.sub.60 on silicon dioxide at surface temperatures less than 1250 K.
  • The method is described for depositing a single crystalline, epitaxial SiC film on a single crystalline Si substrate which comprises, in combination, the steps of (a) treating the surface of the single crystalline silicon substrate to remove the surface layer of SiO[sub 2] from said silicon substrate; followed by (b) heating said substrate to temperature in the range of from about 600 to about 1,000 C and flowing a gaseous stream comprising a compound composed of Si, H and C over said heated substrate, to thereby deposit a single crystalline epitaxial SiC film onto said substrate, wherein said compound containsmore » Si and C in 1:1 atomic ratio.« less
  • For high-temperature processing and device applications, refractory materials, such as silicon carbide (SiC) and tungsten (W), are actively considered or evaluated as the basic semiconductor and metallization materials for future generations of integrated circuits. In order to pattern fine lines in SiC and W thin films, a selective and anisotropic etching technique needs to be developed for future device applications. Therefore, the etching process including basic mechanisms and process requirement have been chosen as the overall research goals of this project. Reactive ion etching (RIE) of SiC thin films in a variety of fluorinated gas plasmas, such as SF{sub 6},more » CBrF{sub 3} and CHF{sub 3} mixed with oxygen was investigated in depth. The best anisotropic profile was observed by using CHF{sub 3} gas in the RIE mode. A typical DC bias, -300V, is concluded from etching experiments to determine the dependence of SiC etch rate and physical reaction under RIE mode. Reactive ion etching of tungsten (W) thin film was also investigated by using the different fluorinated gas plasmas, such as CF{sub 4}, SF{sub 6}, CBrF{sub 3} and CHF{sub 3} mixed with oxygen. The obtaining of anisotropic etching profiles in W etching was suggested and the mechanisms were also studied.« less
  • For high temperature processing and device applications refractory materials, silicon carbide (SiC) and tungsten (W), are considered or evaluated as the basic semiconductor and metallization materials for integrated circuits. In order to pattern fine lines in SiC and W thin films, a selective and anisotropic etching technique is needed. First, materials properties, such as crystallinity, conductivity, refractive index, optical bandgap, etc., of sputtered silicon carbide (SiC) and tungsten (W) thin films have been investigated in conjunction with the rapid thermal annealing (RTA) technique. The RTA temperature dependence of the optical bandgap of SiC thin films has been obtained. High crystallinitymore » W thin of low resistivity films were obtained using by RTA. Reactive ion etching (RIE) of SiC thin films in a variety of fluorinated gas plasmas, such as SF{sub 6}, CBrF{sub 3} and CHF{sub 3} mixed with oxygen has been investigated in depth. The emission spectra and induced DC bias of the RF plasma were monitored to explore the etching mechanisms. A SiC:Si etch ratio higher than unity was obtained for the first time by using CBrF{sub 3}/75%O{sub 2} and CHF{sub 3}/90%O{sub 2} at 200W, 20 sccm, 20mTorr plasma conditions. The best anisotropic profile was observed by using CHF{sub 3} gas in the RIE mode. A typical DC bias, -300V, is concluded from etching experiments to determine the dependence of SiC etch rate and physical reaction under RIE mode. RIE of tungsten (W) thin film was investigated by using the different fluorinated gas plasmas, such as CF{sub 4}, SF{sub 6}, CBrF{sub 3} and CHF{sub 3} mixed with oxygen. We have achieved our goal of selective patterning of tungsten films over SiC, Si, SiO{sub 2}, which required in order to use W in SiC device applications. A very good W:Si and W:SiO{sub 2} selective ratio, 4:1 and 4.8:1, were observed by using CHF{sub 3}/70%O{sub 2} gases under different Plasma conditions.« less