US5660680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabrication of high vertical aspect ratio thin film structures
Assignee: Ob Realty LLC
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Filing: 1994-03-07
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Granted: 1997-08-26
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Expires: 2014-03-07
Abstract
Abstract This invention relates to the area of microelectromechanical systems in which electronic circuits and mechanical devices are integrated on the same silicon chip. The method taught herein allows the fabrication of thin film structures in excess of 150 microns in height using thin film deposition processes. Wafers may be employed as reusable molds for efficient production of such structures.
Inventors
- 👤 Christopher G. Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:24
CPC Classifications
B; B81; B81C; B81C1/00; B81C1/00015; B81C1/00222; B81C1/00246; A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0019; A61K9/0024; A61K9/0087; A61K9/0097; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1692; B01D39/20; B01D67/00; B01D67/0039; B01D67/0053; B01D67/0058; B01D67/006; B01D67/0062; B01D67/0072; B01D67/0081; B01D67/0083; B01D69/00; B01D69/02; B01D71/00; B01D71/02; B01D71/0213; B81B; B81B1/00; B81B1/002; B81B1/004; B81C99/00; B81C99/0075; B81C99/0085; C; C23; C23C; C23C16/00; C23C16/01; G; G03; G03F; G03F7/00; B01D2323/00; B01D2323/24; B01D2325/00; B01D2325/04; B01D2325/08; B81C2201/00; B81C2201/03; B81C2201/032; B81C2203/00; B81C2203/07; B81C2203/0707; B81C2203/0728; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/131; Y10T428/24; Y10T428/24149; Y10T428/24479; Y10T428/2457; Y10T428/24744
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
67 words
A method of fabrication of a micromechanical element, comprising: providing a mold having a depth; coating said mold with a sacrificial thin film layer; growing a structural thin film on said sacrificial thin film layer, without having first patterned said sacrificial thin film layer, so the thickness of said structural thin film is less than the depth of said mold; and etching said sacrificial thin film layer.
Claim 2
Independent Claim
67 words
A method of fabrication of a micromechanical element, comprising: providing a mold having a depth; coating said mold with a sacrificial thin film layer; growing a structural thin film on said sacrificial thin film layer, without having first patterned said sacrificial thin film layer, so the thickness of said structural thin film is less than the depth of said mold; and etching said sacrificial thin film layer.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said step of providing a mold includes providing a first substrate and anisotropically etching substantially vertical trenches in said first substrate.
Claim 4
Dependent Claim
52 words
The method of claim 2 wherein said first substrate is a silicon substrate and said etching of vertical trenches includes coating said first substrate with a masking layer, patterning said masking layer to expose the silicon in the areas where trenches are to be etched, and etching said trenches using plasma etching.
Claim 5
Dependent Claim
31 words
The method of claim 3 wherein said step of providing a mold further includes smoothing walls of said trenches by growing thermal oxide on them and etching said thermal oxide away.
Claim 6
Dependent Claim
27 words
The method of claim 3 or 4 wherein said step of providing a mold further includes growing a layer of low temperature oxide (LTO) on said mold.
Claim 7
Dependent Claim
42 words
The method of claim 2 wherein said step of providing a mold further includes providing a second substrate and bonding said second substrate to said first substrate to provide a mold cavity for tubing manifold or for an enclosed vessel with ports.
Claim 8
Dependent Claim
15 words
The method of claim 6 wherein said bonding is anodic bonding or hydrophilic thermal bonding.
Claim 9
Dependent Claim
30 words
The method of claim 6 wherein at least one of said first substrate and said second substrate has at least one orifice, for providing a mold cavity for a port.
Claim 10
Dependent Claim
25 words
The method of claim 11 wherein said step of coating said mold with a sacrificial thin film layer is carried out by chemical vapor deposition.
Claim 11
Dependent Claim
24 words
The method of claim 9 wherein said step of coating said mold with a sacrificial thin film layer includes growing a phosphosilicate glass layer.
Claim 12
Dependent Claim
27 words
The method of claim 10 wherein said step of coating said mold with a sacrificial thin film layer further includes growing a chemical vapor deposited oxide layer.
Claim 13
Dependent Claim
32 words
The method of claim 1 wherein said step of coating said mold with a sacrificial thin film layer includes growing a silicon layer by chemical vapor deposition and oxidizing said silicon layer.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein said step of growing a structural thin film is carried out by chemical vapor deposition.
Claim 15
Dependent Claim
20 words
The method of claim 13 wherein said step of growing a structural thin film includes growing a silicon thin film.
Claim 16
Dependent Claim
31 words
The method of claim 1 further including, before etching said sacrificial thin film layer, lapping and polishing said mold coated with said sacrificial thin film layer and said structural thin film.
Claim 17
Dependent Claim
26 words
The method of claim 15 further including, after growing said sacrificial thin film layer and before growing said structural layer, anodizing a portion of said mold.
Claim 18
Dependent Claim
58 words
The method of claim 15 further including, after said lapping and polishing, coating a lapped and polished surface of said mold with an additional sacrificial layer, bonding a single crystal plate to said lapped and polished surface of said mold, anchoring said single crystal plate to said structural thin film, and patterning said single crystal plate into islands.
Claim 19
Dependent Claim
15 words
The method of claim 17 further including fabricating electronic devices on said single crystal plate.
Claim 20
Dependent Claim
14 words
The method of claim 17 further including lapping and polishing said single crystal plate.
Claim 21
Dependent Claim
51 words
The method of claim 19 wherein said anchoring includes etching anchor holes through said single crystal plate and said additional sacrificial layer, filling said anchor holes and coating said single crystal plate with an anchor material, and removing a top layer of said anchor material to expose said single crystal plate.
Claim 22
Dependent Claim
13 words
The method of claim 11 further including a step of reusing said mold.
Claim 23
Independent Claim
67 words
A method of fabrication of a micromechanical element, comprising: providing a first substrate and anisotropically etching substantially vertical trenches in said first substrate to form a mold having a depth; coating said mold with a sacrificial thin film layer; forming a structural thin film having a thickness less than the depth of said mold on said sacrificial thin film layer; and etching said sacrificial thin film layer.
Claim 24
Independent Claim
67 words
A method of fabrication of a micromechanical element, comprising: providing a first substrate and anisotropically etching substantially vertical trenches in said first substrate to form a mold having a depth; coating said mold with a sacrificial thin film layer; forming a structural thin film having a thickness less than the depth of said mold on said sacrificial thin film layer; and etching said sacrificial thin film layer.
Claim 25
Independent Claim
105 words
A method of fabrication of a micromechanical element comprising: providing a mold having a cavity of a given depth; coating said mold with a sacrificial thin film layer; growing a structural thin film on said sacrificial thin film layer so the thickness of said structural thin film is less than the depth of said cavity and without having first patterned said sacrificial thin film layer; etching said sacrificial thin film layer; and etching at least one passageway leading to said cavity from a back of said mold and connecting said at least one passageway to a source of pressure at said back of said mold.
Claim 26
Independent Claim
105 words
A method of fabrication of a micromechanical element comprising: providing a mold having a cavity of a given depth; coating said mold with a sacrificial thin film layer; growing a structural thin film on said sacrificial thin film layer so the thickness of said structural thin film is less than the depth of said cavity and without having first patterned said sacrificial thin film layer; etching said sacrificial thin film layer; and etching at least one passageway leading to said cavity from a back of said mold and connecting said at least one passageway to a source of pressure at said back of said mold.
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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) | 2000-08-25 | 2001-02-24 | 2001-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-25 | 2005-02-24 | 2005-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-25 | 2009-02-24 | 2009-08-26 | $7700.00 | Window Closed / Lapsed |