Patent US5254202A successfully refreshed from Google Patents.
US5254202A
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US
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Fabrication of laser ablation masks by wet etching
Assignee: International Business Machines Corp
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Filing: 1992-04-07
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Granted: 1993-10-19
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Expires: 2012-04-07
Abstract
Abstract Tantalum (or hafnium) oxide layers, alternated with silicon oxide layers in a dielectric stack reflector type mask for high power laser ablation, are wet etched at a high temperature with a highly caustic solution, preferably potassium hydroxide, to provide a much increased manufacturing yield in comparison with known processes such as ion milling. High feature density is achieved through the use of a resist which is built in two patterning steps. Preferably, a chromium layer is deposited and covered with an organic resist which is patterned by an optical or electron beam exposure. The chromium is then etched by means of the resist mask to form a resist for the caustic wet etch of the tantalum (or hafnium) oxide either separately or together with silicon oxide layers of the dielectric stack reflector mask to be used in the laser ablation process at high power.
Inventors
- 👤 Leon H. Kaplan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:17
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/5353; C04B41/80; C04B41/91; G; G03; G03F; G03F1/00; G03F1/54; G03F1/68; G03F1/80; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24331; Y10T428/24802; Y10T428/24917; Y10T428/24926
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
32 words
A process including the step of selectively etching, using a resist pattern, at least one of hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C.
Claim 2
Dependent Claim
32 words
A process including the step of selectively etching, using a resist pattern, at least one of hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C.
Claim 3
Dependent Claim
18 words
A process as recited in claim 1, wherein said highly caustic solution is a solution of potassium hydroxide.
Claim 4
Dependent Claim
23 words
A process as recited in claim 2, wherein said solution has a concentration of potassium hydroxide in the range of 50%-60% by weight.
Claim 5
Dependent Claim
22 words
A process as recited in claim 3, wherein said temperature is approximately 100° C. and said concentration is approximately 55% by weight.
Claim 6
Dependent Claim
37 words
A process as recited in claim 1, including the further steps of applying a metal layer to said at least one of hafnium oxide and tantalum oxide, and patterning said metal layer to form said resist pattern.
Claim 7
Dependent Claim
57 words
A product including pairs of layers of silicon oxide and at least one of hafnium oxide and tantalum oxide, said product made by a process including the step of: selectively etching, using a resist pattern, said at least one of said hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C.
Claim 8
Dependent Claim
57 words
A product including pairs of layers of silicon oxide and at least one of hafnium oxide and tantalum oxide, said product made by a process including the step of: selectively etching, using a resist pattern, said at least one of said hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C.
Claim 9
Dependent Claim
18 words
A product as recited in claim 6, wherein said highly caustic solution is a solution of potassium hydroxide.
Claim 10
Dependent Claim
23 words
A product as recited in claim 7, wherein said solution has a concentration of potassium hydroxide in the range of 50%-60% by weight.
Claim 11
Dependent Claim
22 words
A product as recited in claim 8, wherein said temperature is approximately 100° C. and said concentration is approximately 55% by weight.
Claim 12
Dependent Claim
37 words
A product as recited in claim 6, including the further steps of applying a metal layer to said at least one of hafnium oxide and tantalum oxide, and patterning said metal layer to form said resist pattern.
Claim 13
Dependent Claim
67 words
A product made by a process including the steps of: applying a metal layer to at least one of hafnium oxide and tantalum oxide; patterning said metal layer to form a resist pattern; selectively etching, using said resist pattern, said at least one of said hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C., wherein said metal layer is chromium.
Claim 14
Dependent Claim
67 words
A product made by a process including the steps of: applying a metal layer to at least one of hafnium oxide and tantalum oxide; patterning said metal layer to form a resist pattern; selectively etching, using said resist pattern, said at least one of said hafnium oxide and tantalum oxide with a highly caustic solution at a temperature above 65° C., wherein said metal layer is chromium.
Claim 15
Dependent Claim
15 words
A product as recited in claim 6, wherein said product is a laser ablation mask.
Claim 16
Dependent Claim
33 words
A method as recited in claim 5, wherein said step of applying said metal layer includes the step of applying chromium to said at least one of said hafnium oxide and tantalum oxide.
Claim 17
Dependent Claim
31 words
A method as recited in claim 1, further including a step of forming pairs of layers of silicon oxide and said at least one of said hafnium oxide and tantalum oxide.
Claim 18
Dependent Claim
70 words
A patterned reflector, comprising: a plurality of pairs of layers, each of said pairs of layers comprising a layer of silicon oxide and at least one of hafnium oxide and tantalum oxide; and a patterned layer of metal, said metal being resistant to etching with a highly caustic solution at a temperature above 65° C., said plurality of pairs of layers being patterned in accordance with said patterned metal layer.
Claim 19
Dependent Claim
70 words
A patterned reflector, comprising: a plurality of pairs of layers, each of said pairs of layers comprising a layer of silicon oxide and at least one of hafnium oxide and tantalum oxide; and a patterned layer of metal, said metal being resistant to etching with a highly caustic solution at a temperature above 65° C., said plurality of pairs of layers being patterned in accordance with said patterned metal layer.
Claim 20
Dependent Claim
28 words
A patterned reflector according to claim 15, wherein said patterned metal layer and said at least one of said hafnium oxide and tantalum oxide have openings etched therein.
Claim 21
Dependent Claim
27 words
A patterned reflector according to claim 15, further comprising a substrate, said at least one of said hafnium oxide and tantalum oxide being applied to said substrate.
Claim 22
Dependent Claim
12 words
A patterned reflector according to claim 17, wherein said substrate comprises quartz.
Claim 23
Dependent Claim
12 words
A patterned reflector according to claim 15, wherein said metal is chromium.
Claim 24
Dependent Claim
15 words
A patterned reflector according to claim 15, wherein said highly caustic solution is potassium hydroxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-18 | 1997-04-19 | 1997-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-18 | 2001-04-19 | 2001-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-18 | 2005-04-19 | 2005-10-19 | $7700.00 | Window Closed / Lapsed |