US5587090A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple level mask for patterning of ceramic materials
Assignee: Texas Instruments Inc
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Filing: 1994-04-04
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Granted: 1996-12-24
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Expires: 2014-04-04
Abstract
Abstract A novel multiple level mask (e.g. tri-level mask 36) process for masking achieves a desired thick mask with substantially vertical walls and thus improves the ion milling process of ceramic materials (e.g. BST). An embodiment of the present invention is a microelectronic structure comprising a ceramic substrate, an ion mill mask layer (e.g. photoresist 42) overlaying the substrate, a dry-etch-selective mask layer (e.g. TiW 40) overlaying the ion mill mask layer, the dry-etch-selective mask layer comprising a different material than the ion mill mask layer, a top photosensitive layer (38) overlaying the dry-etch-selective mask layer, the top photosensitive layer comprising a different material than the dry-etch-selective mask layer, and a predetermined pattern formed in the top photosensitive layer, the dry-etch-selective mask layer and the ion mill mask layer. The predetermined pattern has substantially vertical walls in the ion mill mask layer.
Inventors
- 👤 James F. Belcher
- 👤 Steven N. Frank
- 👤 John P. Long
- 👤 Jeanee Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:48
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/53; C04B41/5338; C04B41/80; C04B41/91; H; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H10F39/184; H10F39/1843; H10N; H10N15/00; H10N15/10; C04B2111/00; C04B2111/00474; C04B2111/00844; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
174 words
A method of forming a microelectronic structure, said method comprising steps: (a) providing a ceramic substrate; (b) chemical vapor depositing a parylene mask layer on said ceramic substrate; (c) forming a dry-etch-selective mask layer on said parylene mask layer, said dry-etch-selective mask layer comprising a different material than said parylene mask layer; (d) forming a top photosensitive layer on said dry-etch-selective mask layer, said top photosensitive layer comprising a different material than said dry-etch-selective mask layer; (e) forming a pattern in said top photosensitive layer using photolithography; (f) forming said pattern in said dry-etch-selective mask layer using said top photosensitive layer as a first etch mask: (g) forming said pattern in said parylene mask layer using said dry-etch-selective mask layer as a second etch mask, said parylene mask layer having vertical walls; and (h) ion milling said pattern in said ceramic substrate using said parylene mask layer as a third etch mask, whereby the vertical walls of the parylene mask layer allow vertical walls and/or deep trenches to be formed in the ceramic substrate.
Claim 2
Independent Claim
174 words
A method of forming a microelectronic structure, said method comprising steps: (a) providing a ceramic substrate; (b) chemical vapor depositing a parylene mask layer on said ceramic substrate; (c) forming a dry-etch-selective mask layer on said parylene mask layer, said dry-etch-selective mask layer comprising a different material than said parylene mask layer; (d) forming a top photosensitive layer on said dry-etch-selective mask layer, said top photosensitive layer comprising a different material than said dry-etch-selective mask layer; (e) forming a pattern in said top photosensitive layer using photolithography; (f) forming said pattern in said dry-etch-selective mask layer using said top photosensitive layer as a first etch mask: (g) forming said pattern in said parylene mask layer using said dry-etch-selective mask layer as a second etch mask, said parylene mask layer having vertical walls; and (h) ion milling said pattern in said ceramic substrate using said parylene mask layer as a third etch mask, whereby the vertical walls of the parylene mask layer allow vertical walls and/or deep trenches to be formed in the ceramic substrate.
Claim 3
Dependent Claim
21 words
The method according to claim 1, wherein said ceramic substrate is selected from the group consisting of: oxides, nitrides and carbides.
Claim 4
Dependent Claim
14 words
The method according to claim 1, wherein said ceramic substrate is barium strontium titanate.
Claim 5
Dependent Claim
29 words
The method according to claim 1, said method further comprising forming a lift-off layer on said ceramic substrate before said step of chemical vapor depositing said parylene mask layer.
Claim 6
Dependent Claim
25 words
The method according to claim 4, said method further comprising dissolving said lift-off layer after said step of etching said pattern in said ceramic substrate.
Claim 7
Dependent Claim
13 words
The method according to claim 4, wherein said lift-off layer is soluble polyimide.
Claim 8
Dependent Claim
23 words
The method according to claim 4, wherein said lift-off layer is selected from the group consisting of: polyimide thinner, epoxy, photoresist and wax.
Claim 9
Dependent Claim
17 words
The method according to claim 1, wherein said dry-etch-selective mask layer is a metal or metal compound.
Claim 10
Dependent Claim
13 words
The method according to claim 1, wherein said dry-etch-selective mask layer is TiW.
Claim 11
Dependent Claim
31 words
The method according to claim 1, wherein said dry-etch-selective mask layer is selected from the group consisting of: SiO 2 , spin on glass, Si 3 N 4 , and cermets.
Claim 12
Dependent Claim
12 words
The method according to claim 1, wherein said pattern is a grid.
Claim 13
Dependent Claim
39 words
The method according to claim 1, said method further comprising removing said top photosensitive layer, said dry-etch-selective mask layer and said parylene mask layer from said ceramic substrate, after said step of etching said pattern in said ceramic substrate.
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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) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |