US5002899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical contacts on diamond
Assignee: Massachusetts Institute of Technology
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Filing: 1990-03-22
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Granted: 1991-03-26
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Expires: 2010-03-22
Abstract
Abstract A method for forming ohmic contacts on diamond substrates, where, by irradiating a diamond substrate with radiation having a wavelength in the neighborhood of 193 nm, regions of enhanced electrical conductivity may be formed without substantially heating the substrate surface. Metal films may be applied to obtain ohmic or Schottky type contacts on the irradiated sites. The invention may be used to form regions of anisotropic and isotropic enhanced conductivity. Regions of anisotropic conductivity may be employed as polarizing optical devices.
Inventors
- 👤 Michael W. Geis
- 👤 Mordechai Rothschild
- 👤 Daniel J. Ehrlich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:15
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0114; H10D64/012; H10D64/0121; H10D64/0122; H10P; H10P34/00; H10P34/40; H10P34/42
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
102 words
A method for forming an electrical contact on a diamond electrical component substrate by creating a region of enhanced conductivity in said diamond component substrate suitable as an electrical contact without substantially heating said electrical component substrate, comprising the steps of: selecting a prepared diamond electrical component substrate; placing said substrate in the beam path of a light source capable of providing light of approximately 193 nm wavelength; irradiating said substrate with said light from said source to create a substantially non-graphite region of sustained, enhanced conductivity in said substrate; and, employing said region as an electrical contact to said diamond substrate.
Claim 2
Independent Claim
102 words
A method for forming an electrical contact on a diamond electrical component substrate by creating a region of enhanced conductivity in said diamond component substrate suitable as an electrical contact without substantially heating said electrical component substrate, comprising the steps of: selecting a prepared diamond electrical component substrate; placing said substrate in the beam path of a light source capable of providing light of approximately 193 nm wavelength; irradiating said substrate with said light from said source to create a substantially non-graphite region of sustained, enhanced conductivity in said substrate; and, employing said region as an electrical contact to said diamond substrate.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein the intensity of said light is approximately 20 Mw/cm 2 .
Claim 4
Dependent Claim
18 words
The method of claim 1, wherein the intensity of said light is greater than 20 Mw/cm 2 .
Claim 5
Dependent Claim
15 words
The method of claim 2, wherein said light irradiates said crystal for approximately 10 nanoseconds.
Claim 6
Dependent Claim
16 words
The method of claim 1, wherein the source of said light is an ArF excimir laser.
Claim 7
Dependent Claim
16 words
The method of claim 2, wherein the source of said light is an ArF excimir laser.
Claim 8
Dependent Claim
20 words
The method of claim 5, wherein said laser provides a single pulse of said light approximately 10 nanoseconds in duration.
Claim 9
Dependent Claim
20 words
The method of claim 6, wherein said laser provides a single pulse of said light approximately 10 nanoseconds in duration.
Claim 10
Dependent Claim
31 words
The method of claim 1, further comprising the step of irradiating a plurality of adjacent regions such that said regions are in electrical contact forming a single region of enhanced conductivity.
Claim 11
Dependent Claim
28 words
The method of claim 1, further comprising the step of irradiating said region at least a second time so that said region is equally conductive in all directions.
Claim 12
Dependent Claim
28 words
The method of claim 9, further comprising the step of irradiating said region at least a second time so that said region is equally conductive in all directions.
Claim 13
Dependent Claim
17 words
The method of claim 10, further comprising the step of providing an electrical connection to said region.
Claim 14
Dependent Claim
24 words
The method of claim 1, further comprising the step of placing a metallic conductor on said irradiated region to form an ohmic type contact.
Claim 15
Dependent Claim
12 words
The method of claim 1, wherein said diamond substrate is p-type diamond.
Claim 16
Dependent Claim
12 words
The method of claim 1, wherein said diamond substrate is n-type diamond.
Claim 17
Dependent Claim
22 words
The method of claim 1 wherein said removing comprises removing said graphite during irradiation by control of the power and exposure time.
Claim 18
Dependent Claim
12 words
The method of claim 1 wherein said removing comprises washing said substrate.
Claim 19
Dependent Claim
14 words
The method of claim 1 wherein said removing comprises plasma treatment of said surface.
Claim 20
Dependent Claim
10 words
The method of claim 1 wherein said region is graphiteless.
Claim 21
Independent Claim
93 words
A method of forming a polarizing optical device comprising the steps of: selecting a prepared diamond substrate; placing said substrate in the beam path of a light source capable of providing light of approximately 193 nm wavelength; creating a polarizing region on said substrate by irradiating said substrate with said light from said source to produce a region of enhanced conductivity, said region being more conductive in a first direction than a second direction, and said region having the property of polarizing incident light; and employing said region as a polarizing optical device.
Claim 22
Independent Claim
93 words
A method of forming a polarizing optical device comprising the steps of: selecting a prepared diamond substrate; placing said substrate in the beam path of a light source capable of providing light of approximately 193 nm wavelength; creating a polarizing region on said substrate by irradiating said substrate with said light from said source to produce a region of enhanced conductivity, said region being more conductive in a first direction than a second direction, and said region having the property of polarizing incident light; and employing said region as a polarizing optical device.
Claim 23
Dependent Claim
17 words
The method of claim 20 wherein the intensity of said light is approximately 20 Mw/cm 2 .
Claim 24
Dependent Claim
15 words
The method of claim 1 wherein said light irradiates said crystal for approximately 10 nanoseconds.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-03-25 | 1994-09-24 | 1995-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-25 | 1998-09-24 | 1999-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-25 | 2002-09-24 | 2003-03-26 | $7700.00 | Window Closed / Lapsed |