US6406638B1
Expired / Lapsed
US
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Method of forming vertical, hollow needles within a semiconductor substrate, and needles formed thereby
Assignee: University of California
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Filing: 2000-01-06
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Granted: 2002-06-18
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Expires: 2020-01-06
Abstract
Abstract A method of forming a needle includes the step of anisotropically etching a channel into the back side of a semiconductor substrate. The front side of the semiconductor substrate is then isotropically etched to form a vertical axial surface surrounding the channel. The resultant needle has an elongated body formed of a semiconductor material. The elongated body includes an axial surface positioned between a first end and a second end. The axial surface defines a channel between the first end and the second end. In one embodiment, the first end has a sloping tip with a single circumferential termination point.
Inventors
- 👤 Boris Stoeber
- 👤 Dorian Liepmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:28
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/32; B; B81; B81B; B81B1/00; B81B1/006
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
64 words
A method of forming a needle, said method comprising the steps of: anisotropically etching a channel into the back side of a semiconductor substrate; and isotropically etching the front side of said semiconductor substrate to form a vertical axial surface surrounding said channel, said vertical axial surface having a rounded cross-sectional profile between a tip of said needle and a base of said needle.
Claim 2
Independent Claim
64 words
A method of forming a needle, said method comprising the steps of: anisotropically etching a channel into the back side of a semiconductor substrate; and isotropically etching the front side of said semiconductor substrate to form a vertical axial surface surrounding said channel, said vertical axial surface having a rounded cross-sectional profile between a tip of said needle and a base of said needle.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said anisotropically etching step includes the step of deep reactive ion etching of said backside of said semiconductor substrate.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein said anisotropically etching step includes the step of forming a channel with a funnel region.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein said isotropically etching step includes the step of initially performing an anisotropic etch to alter a profile of said vertical axial surface.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein said isotropically etching step includes the step of deep reactive ion etching of said front side of said semiconductor substrate.
Claim 7
Dependent Claim
28 words
The method of claim 1 further comprising the step of depositing a protective material to cover an entire surface of said channel prior to said isotropically etching step.
Claim 8
Dependent Claim
10 words
A needle formed by the method of claim 1 .
Claim 9
Independent Claim
65 words
A method of forming a matrix of needles, said method comprising the steps of: anisotropically etching channels into the back side of a semiconductor substrate; and isotropically etching the front side of said semiconductor substrate to form vertical axial surfaces surrounding said channels, said vertical axial surfaces each having a rounded cross-sectional profile between a tip and a base of respective ones of said needles.
Claim 10
Independent Claim
65 words
A method of forming a matrix of needles, said method comprising the steps of: anisotropically etching channels into the back side of a semiconductor substrate; and isotropically etching the front side of said semiconductor substrate to form vertical axial surfaces surrounding said channels, said vertical axial surfaces each having a rounded cross-sectional profile between a tip and a base of respective ones of said needles.
Claim 11
Dependent Claim
18 words
The method of claim 8 further comprising the step of cutting said semiconductor substrate to produce individual needles.
Claim 12
Dependent Claim
9 words
Needles formed by the method of claim 9 .
Claim 13
Dependent Claim
17 words
The method of claim 8 further comprising step of utilizing said matrix of needles as a mold.
Claim 14
Dependent Claim
19 words
The method of claim 8 wherein said anisotropically etching step includes the step of anisotropically deep reactive ion etching.
Claim 15
Independent Claim
91 words
A method of forming a needle, said method comprising the steps of: anisotropically etching a channel into the back side of said semiconductor substrate with a channel mask; isotropically etching the front side of said semiconductor substrate to form a vertical axial surface surrounding said channel with a needle mask, wherein said channel mask and said needle mask are offset by a predetermined distance such that a plane at which a surface of said channel and said vertical axial surface intersects is unparallel to said front side of said semiconductor substrate.
Claim 16
Independent Claim
91 words
A method of forming a needle, said method comprising the steps of: anisotropically etching a channel into the back side of said semiconductor substrate with a channel mask; isotropically etching the front side of said semiconductor substrate to form a vertical axial surface surrounding said channel with a needle mask, wherein said channel mask and said needle mask are offset by a predetermined distance such that a plane at which a surface of said channel and said vertical axial surface intersects is unparallel to said front side of said semiconductor substrate.
Claim 17
Dependent Claim
17 words
The method of claim 13 wherein said predetermined distance is smaller than a dimension of said channel.
Claim 18
Dependent Claim
27 words
The method of claim 13 wherein the vertical axial surface has a rounded cross-sectional profile between a tip of said needle and a base of said needle.
Claim 19
Dependent Claim
21 words
The method of claim 13 wherein said anisotropically etching step includes the step of forming a channel with a funnel region.
Claim 20
Dependent Claim
27 words
The method of claim 13 wherein said isotropically etching step includes the step of performing an anisotropic etch to alter a profile of said vertical axial surface.
Claim 21
Dependent Claim
26 words
The method of claim 13 wherein said isotropically etching step includes the step of deep reactive ion etching of said front side of said semiconductor substrate.
Claim 22
Dependent Claim
30 words
The method of claim 13 further comprising the step of depositing a protective material to cover an entirety of said surface of said channel prior to said isotropically etching step.
Claim 23
Dependent Claim
10 words
A needle formed by the method of claim 13 .
Claim 24
Independent Claim
47 words
A method of forming a needle comprising: anisotropically etching a first side of a substrate to form a channel; and isotropically etching a second side of the substrate to form a vertical axial surface surrounding the channel, wherein the first side is opposite to the second side.
Claim 25
Independent Claim
47 words
A method of forming a needle comprising: anisotropically etching a first side of a substrate to form a channel; and isotropically etching a second side of the substrate to form a vertical axial surface surrounding the channel, wherein the first side is opposite to the second side.
Claim 26
Dependent Claim
12 words
The method of claim 21 wherein said channel is a close-ended channel.
Claim 27
Dependent Claim
19 words
The method of claim 22 further comprising etching the second side of the substrate to open the close-ended channel.
Claim 28
Dependent Claim
22 words
The method of claim 21 wherein the anisotropically etching step includes deep reactive ion etching of the first side of the substrate.
Claim 29
Dependent Claim
18 words
The method of claim 21 wherein the anisotropically etching step includes forming a channel with a funnel region.
Claim 30
Dependent Claim
20 words
The method of claim 21 wherein the channel extends from the first side to the second side of the substrate.
Claim 31
Dependent Claim
25 words
The method of claim 21 wherein the channel extends from the first side to a predetermined distance short of the second side of the substrate.
Claim 32
Dependent Claim
23 words
The method of claim 21 wherein the isotropically etching step includes initially performing an anisotropic etch to produce a steep vertical axial surface.
Claim 33
Dependent Claim
22 words
The method of claim 21 wherein the isotropically etching step includes deep reactive ion etching of the second side of the substrate.
Claim 34
Dependent Claim
64 words
The method of claim 21 wherein: the anisotropically etching step is performed with a first mask having a first center and a first centerline passing through the first center, the isotropically etching step is performed with a second mask having a second center and a second centerline passing through said second center, and the first centerline is a predetermined distance from the second centerline.
Claim 35
Dependent Claim
23 words
The method of claim 22 further comprising depositing oxide to cover an entire surface of the channel prior to the isotropically etching step.
Claim 36
Dependent Claim
10 words
A needle formed by the method of claim 26 .
Claim 37
Independent Claim
65 words
A method of forming a matrix of needles comprising: anisotropically etching a first side of a substrate to form a plurality of channels; and isotropically etching a second side of the substrate to form a plurality of vertical axial surfaces, each of the plurality of vertical axial surfaces surrounding one of the plurality of channels, wherein the first side is opposite to the second side.
Claim 38
Independent Claim
65 words
A method of forming a matrix of needles comprising: anisotropically etching a first side of a substrate to form a plurality of channels; and isotropically etching a second side of the substrate to form a plurality of vertical axial surfaces, each of the plurality of vertical axial surfaces surrounding one of the plurality of channels, wherein the first side is opposite to the second side.
Claim 39
Dependent Claim
17 words
The method of claim 33 wherein at least some of the plurality of channels are close-ended channels.
Claim 40
Dependent Claim
19 words
The method of claim 34 further comprising etching the second side of the substrate to open the close-ended channels.
Claim 41
Dependent Claim
14 words
The method of claim 33 further comprising cutting the substrate to produce individual needles.
Claim 42
Dependent Claim
9 words
Needles formed by the method of claim 36 .
Claim 43
Independent Claim
15 words
The method of 33 claim further comprising utilizing the matrix of needles as a mold.
Claim 44
Dependent Claim
16 words
The method of claim 33 wherein the anisotropically etching step includes anisotropically deep reactive ion etching.
Claim 45
Dependent Claim
16 words
The method of claim 33 wherein the isotropically etching step includes isotropically deep reactive ion etching.
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