US4935092A
Expired / Lapsed
US
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Method of growing CaF2 film
Assignee: Sanyo Electric Co Ltd
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Filing: 1988-10-06
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Granted: 1990-06-19
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Expires: 2008-10-06
Abstract
Abstract The invention relates to a method of growing a single crystal CaF 2 film on a single crystal Si substrate having a principal plane of (100). According to the invention, the substrate temperature is first set at 550°-600° C. to grow a first CaF 2 film (first stage) and the substrate temperature is then raised to 750° C. or higher to grow a second CaF 2 film on the first CaF 2 film (second stage), thus the growth of the CaF 2 films is performed separately in two stages. Since, in the second stage, the growth of CaF 2 film is possible even at higher substrate temperature, the method of growing according to the invention makes it possible to grow a single crystal CaF 2 film with flat surface morphology and excellent crystal quality.
Inventors
- 👤 Yoshihiro Morimoto
- 👤 Kiyoshi Yoneda
- 👤 Shoji Sudo
- 👤 Shoichiro Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:37
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/12; Y; Y10; Y10S; Y10S117/00; Y10S117/901; Y10S117/902
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
66 words
A method of growing a CaF 2 film comprising; growing on a single crystal Si substrate with a principle plane of (100) a first single crystal CaF 2 film at the substrate temperature of about 550° to 600° C. and growing on the first single crystal CaF 2 film a second single crystal CaF 2 film at the substrate temperature of about 750° C. of higher.
Claim 2
Independent Claim
66 words
A method of growing a CaF 2 film comprising; growing on a single crystal Si substrate with a principle plane of (100) a first single crystal CaF 2 film at the substrate temperature of about 550° to 600° C. and growing on the first single crystal CaF 2 film a second single crystal CaF 2 film at the substrate temperature of about 750° C. of higher.
Claim 3
Dependent Claim
29 words
A method of growing a CaF 2 film as claimed in claim 1, wherein the thickness of said first single crystal CaF 2 film is 42 nm or more.
Claim 4
Dependent Claim
32 words
A method of growing a CaF 2 film as claimed in claim 1, wherein the total thickness of said first and second single crystal CaF 2 films is 100 nm or more.
Claim 5
Dependent Claim
47 words
A method of growing a CaF 2 film as claimed in claim 1, wherein the thickness of said first single crystal CaF 2 film is 42 nm or more and the total thickness of said first second single crystal CaF 2 films is 100 nm or more.
Claim 6
Dependent Claim
31 words
A method of grwoing a CaF 2 film as claimed in claim 1, wherein the substrate temperature when growing said second single crystal CaF 2 film is 800° C. or higher.
Claim 7
Independent Claim
83 words
A method of growing a CaF 2 film comprising; growing on a single crystal Si substrate with a principle plane of (100) a first single crystal CaF 2 film at the substrate temperature of about 550° to 600° C., applying a heat treatment to the substrate with said first single crystal CaF 2 film grown thereon, and growing on said first single crystal CaF 2 film a second single crystal CaF 2 film at the substrate temperature of about 750° C. or higher.
Claim 8
Independent Claim
83 words
A method of growing a CaF 2 film comprising; growing on a single crystal Si substrate with a principle plane of (100) a first single crystal CaF 2 film at the substrate temperature of about 550° to 600° C., applying a heat treatment to the substrate with said first single crystal CaF 2 film grown thereon, and growing on said first single crystal CaF 2 film a second single crystal CaF 2 film at the substrate temperature of about 750° C. or higher.
Claim 9
Dependent Claim
29 words
A method of growing a CaF 2 film as claimed in claim 6, wherein the thickness of said first single crystal CaF 2 film is 42 nm or more.
Claim 10
Dependent Claim
30 words
A method of growing CaF 2 film as claimed in claim 6, wherein the total thickness of said first and second single crystal CaF 2 films is 100 or more.
Claim 11
Dependent Claim
48 words
A method of growing a CaF 2 film as claimed in claim 6, wherein the thickness of said first single crystal CaF 2 film is 42 nm or more and the total thickness of said first and second single crystal CaF 2 films is 100 nm or more.
Claim 12
Dependent Claim
31 words
A method of growing a CaF 2 film as claimed in claim 6, wherein the substrate temperature when growing said second single crystal CaF 2 film is 800° C. of higher.
Claim 13
Dependent Claim
25 words
A method of growing a CaF 2 film as claimed in claim 6, wherein the temperature of said heat treatment is 800° C. or higher.
Claim 14
Dependent Claim
25 words
A method of growing a CaF 2 film as claimed in claim 11, wherein the temperature of said heat treatment is 850° C. or higher.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |