Dry etching patterning of electrical and optical materials
AssigneeMassachusetts Institute of Technology
InventorsMichael W. Geis, Nikolay N. Efremow, Stella W. Pang
Life of this patent
Estimating the term…
Abstract
A new anisotropic dry etching system using a hot jet tube to heat and dissociate non-reactive source gas to form a directed flux of reactive specie or radicals for etching materials through openings in a resist or a reusable stencil of SiN.sub.x wherein x is in the range of 1.5 to 0.5. Si and GaAs may be etched using Cl.sub.2, F.sub.3, Br.sub.2 or SF.sub.6 source gasses. Pb or Hg, Cd, Te may be etched using n-butane, dimethyl ether or acetone as a source gas for CH.sub.3 radicals. The tube may be formed of tungsten or where fluorine is used as a source gas, an irridium tube is preferred. Alternatively, a tube formed of rhenium or an alloy of rhenium and tungsten is preferred for some applications.
Claims24
Apparatus for etching a first material through openings formed in a mask, comprising:
- (a) a source of feed gas containing species which are chemically reactive with respect to said first material when dissociated from said gas by heating;
- (b) a reusable stencil mask over said first material and formed of a second material which is not chemically reactive with respect to said species;
- (c) heater means for heating said feed gas to a temperature which dissociates said gas and forms species of said gas which react with said first material to etch said first material without substantially etching said second material.
Apparatus for etching a first material through openings formed in a second material, comprising:
- (a) a source of feed gas containing radicals which, when separated by thermal energy, are chemically reactive with said first material and chemically unreactive with said second material;
- (b) heater means for heating said gas to a temperature which dissociates said gas and forms said radicals of said gas which react with said first material to etch said first material without substantially etching said second material;
- and wherein the heater means comprises a hollow heatable tube having a distal and proximal end, the distal end of which is directed at the openings and the proximal end of which is coupled to said source of feed gas;
- and wherein said tube is formed of a metal from the group comprising irridium or rhenium or an alloy thereof.
A method for anisotropic etching of substrate material through openings formed in a mask comprising the steps of:
- (a) providing a source of gas containing radicals which, when heated, dissociate said radicals being capable of volatilizing said substrate material but not said mask material;
- (b) heating said gas to dissociate said radicals and directing said heated gas toward said openings to volatilize said material using a rhenium or irridium hot metal tube having a proximal end coupled to said gas source and an open distal end facing said openings.
Dependencies are inferred from the claim text.