US4877504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods for fabricating electro-optically active niobium dioxide (NbO2)
Assignee: Honeywell Inc
•
Filing: 1987-08-19
•
Granted: 1989-10-31
•
Expires: 2007-08-19
Abstract
Abstract A reactive ion-beam sputtering technique for fabricating NbO 2 crystalline thin films suitable for use in these electro-optic devices.
Inventors
- 👤 James C. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:36
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/17; C; C23; C23C; C23C14/00; C23C14/0021; C23C14/0036; C23C14/06; C23C14/08; C23C14/083; C23C14/22; C23C14/34; C23C14/46
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
151 words
A method of forming an electro-optically switchable niobium dioxide (NbO 2 ) crystalline thin film on a solid substrate by reactive ion-beam sputtering in a hermetic chamber, comprising: placing a niobium (Nb) target in said chamber; grounding said target; placing said substrate in said chamber; providing an oxidizing background atmosphere in said chamber; evacuating said chamber to a pressure sufficient for said sputtering process; heating said substrate to a temperature sufficient to allow said crystalline thin film to form on said substrate; generating an ion-beam from a source; directing said ion-beam onto said target so that Nb atoms are sputtered from said target; controlling the spread of said ion-beam as said beam travels from said source to said target; and positioning said substrate so that the majority of said Nb atoms sputtered from said target strike said substrate, thereby forming said electro-optically switchable thin film of NbO 2 on said substrate.
Claim 2
Independent Claim
151 words
A method of forming an electro-optically switchable niobium dioxide (NbO 2 ) crystalline thin film on a solid substrate by reactive ion-beam sputtering in a hermetic chamber, comprising: placing a niobium (Nb) target in said chamber; grounding said target; placing said substrate in said chamber; providing an oxidizing background atmosphere in said chamber; evacuating said chamber to a pressure sufficient for said sputtering process; heating said substrate to a temperature sufficient to allow said crystalline thin film to form on said substrate; generating an ion-beam from a source; directing said ion-beam onto said target so that Nb atoms are sputtered from said target; controlling the spread of said ion-beam as said beam travels from said source to said target; and positioning said substrate so that the majority of said Nb atoms sputtered from said target strike said substrate, thereby forming said electro-optically switchable thin film of NbO 2 on said substrate.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said pressure sufficient for said sputtering process is less than 10 -3 T.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said substrate is heated to approximately 600° C.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said controlling the spread of said ion-beam includes injecting electrons into said ion-beam.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said ion-beam is comprised of argon ions.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein said oxidizing atmosphere is comprised of O 2 and argon.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein the current density of said ion beam at said target is approximately 1 mA/cm 2 .
Claim 9
Dependent Claim
22 words
The method of claim 1 further including depositing an NbO 2 layer on said substrate at a rate of approximately 1 Å/sec.
Claim 10
Dependent Claim
16 words
The method of claim 1 wherein said ion-beam has an energy of approximately 1200 electron volts.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein the target to substrate distance is approximately 15 cm.
References Cited (Backward Citations)
US3962062A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |