US4734152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry etching patterning of electrical and optical materials
Assignee: Massachusetts Institute of Technology
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Filing: 1987-07-13
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Granted: 1988-03-29
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Expires: 2007-07-13
Abstract
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 x wherein x is in the range of 1.5 to 0.5. Si and GaAs may be etched using Cl 2 , F 3 , Br 2 or SF 6 source gasses. Pb or Hg, Cd, Te may be etched using n-butane, dimethyl ether or acetone as a source gas for CH 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.
Inventors
- 👤 Michael W. Geis
- 👤 Nikolay N. Efremow
- 👤 Stella W. Pang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:34
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/246; H10P50/242; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/28; H10P50/282; H10P50/283; H10P50/286; H10P50/287; H10P50/69; H10P50/691; H10P52/00; H10P95/00; H10P95/70
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
101 words
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.
Claim 2
Dependent Claim
101 words
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.
Claim 3
Dependent Claim
44 words
The apparatus of claim 1 wherein the heater means comprises a heatable hollow tube having a proximal and distal 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.
Claim 4
Dependent Claim
12 words
The apparatus of claim 2 wherein the tube is formed of rhenium.
Claim 5
Dependent Claim
12 words
The apparatus of claim 2 wherein the tube is formed of irridium.
Claim 6
Dependent Claim
26 words
The apparatus of claim 2 wherein the tube is adapted to be resistively heated to a temperature in a range of 900 to 3000 degrees Kelvin.
Claim 7
Dependent Claim
22 words
The apparatus of claim 1 wherein the source gas is taken from the group comprising hydrogen, fluorine, chlorine, bromine, methane and ethane.
Claim 8
Dependent Claim
50 words
The apparatus of claim 2 wherein the tube is formed of metal from the group comprising rhenium and irridium, or an alloy thereof, the source gas is chlorine, the first material is GaAs and the second material is SiN x wherein x is in the range of 1.5 to 0.5.
Claim 9
Dependent Claim
38 words
The apparatus of claim 2 wherein the tube is formed of irridium, the source gas is fluorine or a compound containing fluorine, and the first material is silicon; and the temperature is between about 1750° and 2500° K.
Claim 10
Dependent Claim
26 words
The apparatus of claim 2 wherein the source gas is taken from the group comprising n-butane, dimethyl ether or acetone and the first material is lead.
Claim 11
Dependent Claim
140 words
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.
Claim 12
Dependent Claim
140 words
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.
Claim 13
Dependent Claim
24 words
The apparatus of claim 10 wherein the tube is adapted to be resistively heated by an encircling wire coil through which current is passed.
Claim 14
Dependent Claim
22 words
The apparatus of claim 10 wherein the source gas is taken from the group comprising: hydrogen, fluorine, chlorine, bromine, methane and ethane.
Claim 15
Dependent Claim
23 words
The apparatus of claim 10 wherein the source gas is chlorine, the first material is GaAs and the second material is a photoresist.
Claim 16
Dependent Claim
40 words
The apparatus of claim 10 wherein the source gas is fluorine or a compound containing fluorine, and the first material is silicon while the second material is SiO 2 ; and the temperature is between about 1750° and 3300° K.
Claim 17
Dependent Claim
38 words
The apparatus of claim 10 wherein the source gas is taken from the group comprising n-butane, Pb(CH 3 ) 4 , dimethyl ether or acetone and the first material is lead while the second material is a photoresist.
Claim 18
Dependent Claim
20 words
The apparatus of claim 10 wherein the source gas contains fluorine and the first material is tungsten or silicon nitride.
Claim 19
Dependent Claim
24 words
The apparatus of claim 10 wherein the source gas contains hydrogen and the first material is SiO 2 , Ge, Sn, Si or As.
Claim 20
Dependent Claim
23 words
The apparatus of claim 10 wherein the source gas contains Cl and CH 3 radicals and the first material is InP or InGaAs.
Claim 21
Dependent Claim
28 words
The apparatus of claim 10 wherein the source gas contains CH 3 radicals and the first material is HgCdTe or Pb, Zn, Sn, As, Se, Cd or Te.
Claim 22
Dependent Claim
25 words
The apparatus of claim 10 wherein the source gas contains Cl radicals and the first material is from the group comprising Si, AlGaAs, and GaAs.
Claim 23
Dependent Claim
28 words
The apparatus of claim 10 wherein the source gas contains H radicals and the first material is from the group comprising Ge, Sn, Si, As, SiO 2 .
Claim 24
Dependent Claim
23 words
The apparatus of claim 10 wherein the source gas contains oxygen radicals and the first material is from the group comprising organic photoresist.
Claim 25
Independent Claim
89 words
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.
Claim 26
Independent Claim
89 words
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.
Claim 27
Dependent Claim
27 words
The method of claim 23 wherein the mask is a reusable stencil formed of SiN x where "x" is in the range of about 1.5 to 0.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |