US5096535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacturing segmented channel structures
Assignee: Xerox Corp
•
Filing: 1990-12-21
•
Granted: 1992-03-17
•
Expires: 2010-12-21
Abstract
Abstract In semiconductor technologies such as thermal ink jet printhead fabrication, there exists a need for the precise placement of channels in a substrate. Due to errors in plane alignment in semiconductor substrates, channel structures tend to widen dimensions, thus lowering precision. A one-step anisotropic etching process is disclosed for accurately making channel structures, as well as reservoir structures. Channel structures are formed by segmenting the channel, such that during the anisotropic etching, thin walls between the segments break down before the completion of the etch. Widening of channels is greatly reduced, thus increasing precision. During such a one-step process, larger structures, such as a reservoir, can be formed during the same step.
Inventors
- 👤 William G. Hawkins
- 👤 James F. O'Neill
- 👤 Roberto E. Proano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 00:29
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/16; B41J2/1621; B41J2/1635; B41J2/1601; B41J2/1604; B41J2/1626; B41J2/1628; B41J2/1629; B41J2/1631; B41J2/164; B41J2/1645; H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/644
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
95 words
A method of fabricating rectangular and large aspect ratio features in a substrate amenable to anisotropic etching processes, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; and anisotropically etching said exposed areas of said substrate for a period of time such that wall structures formed during said anisotropic etching step are substantially removed before said etching step is terminated.
Claim 2
Independent Claim
95 words
A method of fabricating rectangular and large aspect ratio features in a substrate amenable to anisotropic etching processes, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; and anisotropically etching said exposed areas of said substrate for a period of time such that wall structures formed during said anisotropic etching step are substantially removed before said etching step is terminated.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said substrate is formed from silicon.
Claim 4
Dependent Claim
17 words
The method of claim 2, wherein said planar surface of said substrate is the {100} planar surface.
Claim 5
Dependent Claim
17 words
The method of claim 2, wherein said planar surface of said substrate is the {110} planar surface.
Claim 6
Dependent Claim
23 words
The method of claim 1, wherein in said anisotropic etch step is in KOH and said period of time is approximately three hours.
Claim 7
Dependent Claim
15 words
The method of claim 1, wherein said segmented areas have dimensions of 50 μm×50 μm.
Claim 8
Dependent Claim
23 words
The method of claim 6, wherein in said etching steps, said wall structures have a thickness of between 8 μm and 10 μm.
Claim 9
Dependent Claim
21 words
The method of claim 6, wherein in said etching steps, said wall structures undercut 75% to 95% through the etch sequence.
Claim 10
Dependent Claim
21 words
The method of claim 1, wherein in said forming step, said etching mask is formed from Si 3 N 4 .
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein in said anisotropic etching step, said substrate is exposed to a concentration of KOH in a reaction chamber.
Claim 12
Dependent Claim
34 words
The method of claim 1 wherein in said anisotropic etching step wall structures formed during said anisotropic etching step are substantially removed after 90% of the period of time for said anisotropic etching step.
Claim 13
Independent Claim
114 words
A method of fabricating channels and a reservoir in a substrate amenable to anisotropic etching processes for a thermal ink jet printhead, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose broad and segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; and anisotropically etching said exposed areas of said substrate for a period of time such that said exposed broad area is completely etched through said substrate and wall structures formed during said anisotropic etching step are substantially removed before said etching step is driven to completion.
Claim 14
Independent Claim
114 words
A method of fabricating channels and a reservoir in a substrate amenable to anisotropic etching processes for a thermal ink jet printhead, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose broad and segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; and anisotropically etching said exposed areas of said substrate for a period of time such that said exposed broad area is completely etched through said substrate and wall structures formed during said anisotropic etching step are substantially removed before said etching step is driven to completion.
Claim 15
Dependent Claim
12 words
The method of claim 12, wherein said substrate is formed from silicon.
Claim 16
Dependent Claim
17 words
The method of claim 13, wherein said planar surface of said substrate is the {100} planar surface.
Claim 17
Dependent Claim
16 words
The method of claim 13, wherein said planar surface of said substrate is the {planar} surface.
Claim 18
Dependent Claim
19 words
The method of claim 12, wherein in said anisotropic etch step, said period of time is approximately three hours.
Claim 19
Dependent Claim
15 words
The method of claim 12, wherein said segmented areas have dimensions of 50 μm×50 μm.
Claim 20
Dependent Claim
23 words
The method of claim 17, wherein in said etching steps, said wall structures have a thickness of between 8 μm and 10 μm.
Claim 21
Dependent Claim
20 words
The method of claim 17, wherein in said etching steps, said wall structures have a thickness of approximately 9 μm.
Claim 22
Dependent Claim
21 words
The method of claim 12, wherein in said forming step, said etching mask is formed from Si 3 N 4 .
Claim 23
Dependent Claim
24 words
The method of claim 12, wherein in said anisotropic etching step, said substrate is exposed to a concentration of KOH in a reaction chamber.
Claim 24
Dependent Claim
34 words
The method of claim 12 wherein in said anisotropic etching step wall structures formed during said anisotropic etching step are substantially removed after 90% of the period of time for said anisotropic etching step.
Claim 25
Independent Claim
135 words
A method of fabricating channels and a reservoir in a substrate amenable to etching processes for a thermal ink jet printhead, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose broad and segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; removing said photoresist layer; anisotropically etching said exposed areas of said substrate for a period of time such that said exposed broad area is completely etched through said substrate and wall structures formed during said anisotropic etching step are substantially removed before said etching step is driven to completion; removing said etching mask; and coupling said substrate to a heater die to form a thermal ink jet printhead.
Claim 26
Independent Claim
135 words
A method of fabricating channels and a reservoir in a substrate amenable to etching processes for a thermal ink jet printhead, comprising: forming a patterned etching mask on a planar surface of a substrate; said etching mask being delineated to expose broad and segmented areas in said substrate, such that said plurality of segmented areas are separated by a plurality of wall structures in said etching mask; removing said photoresist layer; anisotropically etching said exposed areas of said substrate for a period of time such that said exposed broad area is completely etched through said substrate and wall structures formed during said anisotropic etching step are substantially removed before said etching step is driven to completion; removing said etching mask; and coupling said substrate to a heater die to form a thermal ink jet printhead.
References Cited (Backward Citations)
US4600934A
Cited
USRE32572E
Cited
US4786357A
Cited
US4829324A
Cited
US4863560A
Cited
US4915718A
Cited
US4899181A
Cited
US4875968A
Cited
US4957592A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-17 | 1995-09-16 | 1996-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-17 | 1999-09-16 | 2000-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-17 | 2003-09-16 | 2004-03-17 | $7700.00 | Window Closed / Lapsed |