Patent DE120833C successfully refreshed from Google Patents.
US5645684A
Expired / Lapsed
US
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Multilayer high vertical aspect ratio thin film structures
Assignee: University of California
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Filing: 1995-06-07
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Granted: 1997-07-08
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Expires: 2015-06-07
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. Various material properties may be varied within the structures to produce electrical, mechanical or electromechanical devices.
Inventors
- 👤 Christopher G. Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:04
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; B01D67/0069; B01D67/0072; B01D67/0081; B01D67/0083; B01D69/00; B01D69/02; B01D69/12; B01D71/00; B01D71/02; B01D71/0213; 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; B01D2325/26; B81C2201/00; B81C2201/03; B81C2201/032; B81C2203/00; B81C2203/07; B81C2203/0707; B81C2203/0728
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
72 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; filling a first portion of said mold with a material having properties; filling a second portion of said mold with a material having properties at least one of which is different from the material filling said first portion of said mold; and etching said sacrificial thin film layer.
Claim 2
Independent Claim
72 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; filling a first portion of said mold with a material having properties; filling a second portion of said mold with a material having properties at least one of which is different from the material filling said first portion of said mold; and etching said sacrificial thin film layer.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein said step of providing a mold includes providing a first substrate and anisotropically etching 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
46 words
The method of claim 2 wherein after said step of coating the mold with a sacrificial layer, a second substrate is provided coated with a sacrificial layer patterned with anchoring holes, and said second substrate is bonded to said first substrate to provide a mold cavity.
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 1 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
30 words
The method of claim 1 wherein at least one of said steps of filling a first and a second portion of the mold is carried out by chemical vapor deposition.
Claim 15
Dependent Claim
16 words
The method of claim 13 wherein said chemical vapor deposition is chemical vapor deposition of silicon.
Claim 16
Dependent Claim
13 words
The method of claim 1 further including a step of reusing said mold.
Claim 17
Dependent Claim
23 words
The method of claim 1 wherein said material of said first portion and said material of said second portion have different electrical conductivity.
Claim 18
Dependent Claim
25 words
The method of claim 1 wherein said material of said first portion and said material of said second portion have different electronic energy band structure.
Claim 19
Dependent Claim
23 words
The method of claim 1 wherein said material of said first portion and said material of said second portion have different residual stress.
Claim 20
Dependent Claim
23 words
The method of claim 1 wherein said material of said first portion and said material of said second portion have different dopant concentrations.
Claim 21
Dependent Claim
22 words
The method of claim 1 wherein said material of said first portion is a reinforcement for said material of said second portion.
Claim 22
Dependent Claim
28 words
The method of claim 1 wherein at least one of said steps of filling a first and a second portion of the mold is carried out by plating.
Claim 23
Dependent Claim
59 words
The method of claim 1 further comprising after filling said second portion, filling a third portion of said mold with a material having properties at least one of which is different from the material filling said first portion of said mold, and at least one of which is different from the material filling said second portion of said mold.
Claim 24
Dependent Claim
54 words
The method of claim 22 wherein filling said first, second and third portions is carried out by thin film deposition, and no patterning is performed between the filling of the first, second and third portions and the mold has a variable wall-to-wall spacing whereby a micromechanical element with variable controlled material properties is formed.
Claim 25
Dependent Claim
79 words
A thin film structure, comprising: a network of members shaped as ribs or tubes having a thickness and wherein an extent of said thin film structure in any direction is greater than about twice said thickness, a first portion of said structure being composed of a material having properties, and a second portion of said structure being composed of material having properties at least one of which is different from the material composing said first portion of said structure.
Claim 26
Dependent Claim
79 words
A thin film structure, comprising: a network of members shaped as ribs or tubes having a thickness and wherein an extent of said thin film structure in any direction is greater than about twice said thickness, a first portion of said structure being composed of a material having properties, and a second portion of said structure being composed of material having properties at least one of which is different from the material composing said first portion of said structure.
Claim 27
Dependent Claim
17 words
The structure of claim 24 having a lowest extent between about 5 microns and about 250 microns.
Claim 28
Dependent Claim
24 words
The structure of claim 24 or 25 wherein said thin film structure has a film thickness between about 5 microns and about 15 microns.
Claim 29
Dependent Claim
17 words
The structure of claim 24 wherein said members form substantially rigid portions connected by substantially flexible links.
Claim 30
Dependent Claim
15 words
The structure of claim 27 wherein said substantially rigid portions are networks of said members.
Claim 31
Dependent Claim
10 words
The structure of claim 28 wherein said networks are honeycomb-shaped.
Claim 32
Dependent Claim
18 words
The structure of claim 27 wherein said substantially rigid portions and said substantially flexible links form a machine.
Claim 33
Dependent Claim
13 words
The structure of claim 30 wherein said machine is powered by an actuator.
Claim 34
Dependent Claim
15 words
The structure of claim 31 wherein said actuator dilates as a result of ohmic heating.
Claim 35
Dependent Claim
23 words
The structure of claim 24 wherein said material of said first portion and said material of said second portion have different electrical conductivity.
Claim 36
Dependent Claim
25 words
The structure of claim 24 wherein said material of said first portion and said material of said second portion have different electronic energy band structure.
Claim 37
Dependent Claim
23 words
The structure of claim 24 wherein said material of said first portion and said material of said second portion have different residual stress.
Claim 38
Dependent Claim
23 words
The structure of claim 24 wherein said material of said first portion and said material of said second portion have different dopant concentration.
Claim 39
Dependent Claim
22 words
The structure of claim 24 wherein said material of said first portion is a reinforcement for said material of said second portion.
Claim 40
Dependent Claim
60 words
The structure of claim 24 wherein a third portion of said structure is composed of a material having properties at least one of which is different from the material of which said first portion of said structure is composed, and at least one of which is different from the material of which said second portion of said structure is composed.
Claim 41
Dependent Claim
47 words
A thin film structure, comprising: a network of members shaped as ribs or tubes having a thickness and a bimorph for lifting said network out of a mold and wherein an extent of said thin film structure in any direction is greater than about twice said thickness.
Claim 42
Dependent Claim
47 words
A thin film structure, comprising: a network of members shaped as ribs or tubes having a thickness and a bimorph for lifting said network out of a mold and wherein an extent of said thin film structure in any direction is greater than about twice said thickness.
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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) | 2000-07-07 | 2001-01-06 | 2001-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-07 | 2005-01-06 | 2005-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-07 | 2009-01-06 | 2009-07-08 | $7700.00 | Window Closed / Lapsed |