US4680243A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a mask for use in X-ray photolithography and resulting structure
Assignee: Micronix Corp
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Filing: 1985-08-02
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Granted: 1987-07-14
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Expires: 2005-08-02
Abstract
Abstract A method for manufacturing a mask (100) for use in x-ray photolithographic processes includes the step of coating a silicon wafer (10) with a layer of boron nitride (12). A masking substance (14) is used to coat one side of the boron nitride coated wafer, and the boron nitride is etched off of the other side of the wafer. The wafer (10) is then bonded to a pyrex ring (16) using a field assisted thermal bonding process. During the field assisted thermal bonding process, the silicon (11) is bonded directly to the pyrex (16). Then, a zirconium layer (24) is used to cover the mask and is selectively etched where it is desired to remove a circular portion of the silicon. Thereafter the silicon is subjected to a semianisotropic etch. The remaining structure includes a pyrex ring bonded to a silicon ring across which a layer of boron nitride is stretched. The layer of boron nitride is subjected to an annealing process and is then coated with an x-ray opaque material.
Inventors
- 👤 Alexander R. Shimkunas
- 👤 Barry Block
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:32
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22
Claims Analysis
Total Claims: 81
Claim 1
Independent Claim
55 words
A method for manufacturing a mask for use in a photolithograhic process, the method comprising the steps of: coating both surfaces of a wafer with layers of boron nitride; covering one surface of the boron nitride coated wafer with an etch stop; and removing a portion of the boron nitride with a sodium hypochlorite solution.
Claim 2
Independent Claim
55 words
A method for manufacturing a mask for use in a photolithograhic process, the method comprising the steps of: coating both surfaces of a wafer with layers of boron nitride; covering one surface of the boron nitride coated wafer with an etch stop; and removing a portion of the boron nitride with a sodium hypochlorite solution.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said step of depositing a layer of boron nitride is done using a low pressure chemical vapor deposition process.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said etch stop comprises a polyethylene disk.
Claim 5
Dependent Claim
22 words
The method of claim 3 further comprising the step of removing said polyethylene disk after said portion of boron nitride is removed.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said etch stop comprises a wax coated plastic sheet.
Claim 7
Independent Claim
95 words
A method for manufacturing a mask for use in a photolithographic process, the method comprising the steps of: covering both surfaces of a wafer with a layer of x-ray transparent material; providing a solid layer of material; covering one side of the coated wafer wth said solid layer of material, said solid layer of material serving as an etch stop, x-ray transparent material on the other side of the wafer remaining exposed, said step of covering one side being performed after said step of providing a solid layer; and etching the exposed x-ray transparent material.
Claim 8
Independent Claim
95 words
A method for manufacturing a mask for use in a photolithographic process, the method comprising the steps of: covering both surfaces of a wafer with a layer of x-ray transparent material; providing a solid layer of material; covering one side of the coated wafer wth said solid layer of material, said solid layer of material serving as an etch stop, x-ray transparent material on the other side of the wafer remaining exposed, said step of covering one side being performed after said step of providing a solid layer; and etching the exposed x-ray transparent material.
Claim 9
Independent Claim
35 words
A method for manufacturing a mask for use in a photolithographic process comprising the step of bonding a glass ring to a silicon substrate, said bonding being done with a field assisted thermal bonding process.
Claim 10
Independent Claim
35 words
A method for manufacturing a mask for use in a photolithographic process comprising the step of bonding a glass ring to a silicon substrate, said bonding being done with a field assisted thermal bonding process.
Claim 11
Independent Claim
43 words
A method for manufacturing a mask comprising the steps of: providing a wafer of crystalline material having one side covered by a x-ray transparent layer; covering a portion of said wafer with an etch stop; and subjecting said wafer to a semianisotropic etchant.
Claim 12
Independent Claim
43 words
A method for manufacturing a mask comprising the steps of: providing a wafer of crystalline material having one side covered by a x-ray transparent layer; covering a portion of said wafer with an etch stop; and subjecting said wafer to a semianisotropic etchant.
Claim 13
Dependent Claim
18 words
The method of claim 7 wherein said silicon substrate has a layer of boron nitride on one side.
Claim 14
Dependent Claim
27 words
The method of claim 7 wherein said field assisted thermal bonding process is accomplished by providing an electrical potential between said silicon substrate and said glass ring.
Claim 15
Dependent Claim
22 words
The method of claim 10 wherein said field assisted thermal bonding process is accomplished at a temperature between 340° and 350° C.
Claim 16
Dependent Claim
22 words
The method of claim 11 wherein a voltage of approximately 1300 volts is placed across said silicon substrate and said glass ring.
Claim 17
Dependent Claim
26 words
The method of claim 12 wherein said glass ring and said silicon substrate remain at a temperature between 340° and 350° C. for approximately 80 minutes.
Claim 18
Dependent Claim
17 words
The method of claim 12 wherein said voltage is applied at a corner of said glass ring.
Claim 19
Independent Claim
83 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a wafer of a first material having one side coated with a layer of x-ray transparent material; coating a portion of the surface of said wafer with a layer of zirconium, said layer of zirconium having an opening through which a portion of said first material is exposed; and etching said exposed portion of said first material, said layer of zirconium acting as an etch stop.
Claim 20
Independent Claim
83 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a wafer of a first material having one side coated with a layer of x-ray transparent material; coating a portion of the surface of said wafer with a layer of zirconium, said layer of zirconium having an opening through which a portion of said first material is exposed; and etching said exposed portion of said first material, said layer of zirconium acting as an etch stop.
Claim 21
Dependent Claim
14 words
The method of claim 15 wherein said silicon is etched with a KOH solution.
Claim 22
Dependent Claim
25 words
The method of claim 15 wherein said silicon wafer having one side coated with a layer of boron nitride is bonded to a glass ring.
Claim 23
Dependent Claim
22 words
The method of claim 17 wherein said silicon is bonded to a glass ring using a process of field assisted thermal bonding.
Claim 24
Dependent Claim
48 words
The method of claim 18 further comprising the steps of: depositing a second masking substance over a first portion of said layer of zirconium, said second masking substance serving as an etch stop, a second portion of said layer of zirconium remaining exposed; and removing said second portion.
Claim 25
Dependent Claim
14 words
The method of claim 19 wherein said second masking substance is a polyethylene ring.
Claim 26
Dependent Claim
27 words
The method of claim 20 further comprising the step of coating a portion of said layer of zirconium and said glass ring with a third masking substance.
Claim 27
Dependent Claim
34 words
The method of claim 21 wherein said third masking substance is Astrawax 23, said third masking substance protecting a portion of said silicon during said step of etching said exposed portion of said silicon.
Claim 28
Dependent Claim
48 words
The method of claim 15 wherein said silicon wafer is bonded to a glass ring, said step of etching comprises the step of applying a KOH solution to said exposed portion of said silicon, and said layer of zirconium protects said glass ring during said step of etching.
Claim 29
Independent Claim
49 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a silicon wafer having a layer of boron nitride coated on one side; covering a portion of said silicon wafer with an etch stop; and subjecting said wafer to a semianisotropic etchant.
Claim 30
Independent Claim
49 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a silicon wafer having a layer of boron nitride coated on one side; covering a portion of said silicon wafer with an etch stop; and subjecting said wafer to a semianisotropic etchant.
Claim 31
Dependent Claim
14 words
The method of claim 24 wherein said etchant comprises KOH and an oxidizing agent.
Claim 32
Dependent Claim
12 words
The method of claim 25 wherein said oxidizing agent is potassium chromate.
Claim 33
Dependent Claim
16 words
The method of claim 26 wherein said potassium chromate has a concentration of approximately 0.01 molarity.
Claim 34
Dependent Claim
40 words
A mask for use in photolithography comprising: a silicon ring; an x-ray transparent layer of material supported by said silicon ring; a glass ring bonded to said silicon ring, said bond being produced by a field assisted thermal bonding process.
Claim 35
Dependent Claim
40 words
A mask for use in photolithography comprising: a silicon ring; an x-ray transparent layer of material supported by said silicon ring; a glass ring bonded to said silicon ring, said bond being produced by a field assisted thermal bonding process.
Claim 36
Independent Claim
62 words
A method for manufacturing a mask comprising the steps of: bonding a substrate to a support structure with a field assisted thermal bond; coating said substrate with a layer of material; and removing a portion of said substrate, thereby leaving a membrane of said material affixed to the remaining portion of said substrate, said remaining portion being bonded to said support structure.
Claim 37
Independent Claim
62 words
A method for manufacturing a mask comprising the steps of: bonding a substrate to a support structure with a field assisted thermal bond; coating said substrate with a layer of material; and removing a portion of said substrate, thereby leaving a membrane of said material affixed to the remaining portion of said substrate, said remaining portion being bonded to said support structure.
Claim 38
Dependent Claim
23 words
The method of claim 29 wherein said substrate is a silicon wafer, said support structure is glass, and said material is boron nitride.
Claim 39
Dependent Claim
21 words
The method of claim 30 further comprising the step of forming a patterned layer of x-ray opaque material on said membrane.
Claim 40
Independent Claim
105 words
A method for manufacturing a mask comprising the steps of: bonding a substrate to a conductive member with a field assisted thermal bond, said member having a centrally located aperture therein; bonding said conductive member to a support structure with a field assisted thermal bond; coating at least one side of said substrate with a layer of x-ray transparent material; and removing a portion of said substrate, thereby leaving a membrane of said x-ray transparent material affixed to the remaining portion of said substrate, said remaining portion of said substrate being bonded to said conductive member, said conductive member being bonded to said support structure.
Claim 41
Independent Claim
105 words
A method for manufacturing a mask comprising the steps of: bonding a substrate to a conductive member with a field assisted thermal bond, said member having a centrally located aperture therein; bonding said conductive member to a support structure with a field assisted thermal bond; coating at least one side of said substrate with a layer of x-ray transparent material; and removing a portion of said substrate, thereby leaving a membrane of said x-ray transparent material affixed to the remaining portion of said substrate, said remaining portion of said substrate being bonded to said conductive member, said conductive member being bonded to said support structure.
Claim 42
Dependent Claim
27 words
The method of claim 32 wherein said conductive member is a metal ring, said support structure is a glass ring, and said substrate is a glass wafer.
Claim 43
Dependent Claim
44 words
A mask comprising: a glass ring; a metal ring bonded to said glass ring with a field assisted thermal bond; an x-ray transparent membrane affixed to said glass ring; and a support structure bonded to said metal ring with a field assisted thermal bond.
Claim 44
Dependent Claim
44 words
A mask comprising: a glass ring; a metal ring bonded to said glass ring with a field assisted thermal bond; an x-ray transparent membrane affixed to said glass ring; and a support structure bonded to said metal ring with a field assisted thermal bond.
Claim 45
Dependent Claim
30 words
The mask of claim 34 wherein said support structure is a glass ring, said mask further comprising a patterned x-ray opaque layer of material formed on said x-ray transparent membrane.
Claim 46
Independent Claim
37 words
A method for manufacturing a mask comprising the steps of: coating a substrate with a layer of x-ray transparent material; forming a conductive ring on said layer of x-ray transparent material on one side of said substrate;
Claim 47
Independent Claim
37 words
A method for manufacturing a mask comprising the steps of: coating a substrate with a layer of x-ray transparent material; forming a conductive ring on said layer of x-ray transparent material on one side of said substrate;
Claim 48
Dependent Claim
18 words
bonding said conductive ring to a support structure with a field assisted thermal bond; and removing said substrate.
Claim 49
Dependent Claim
18 words
bonding said conductive ring to a support structure with a field assisted thermal bond; and removing said substrate.
Claim 50
Dependent Claim
19 words
The method of claim 36 wherein said conductive ring is metal sputtered onto said layer of x-ray transparent material.
Claim 51
Dependent Claim
19 words
The method of claim 36 wherein said conductive ring is metal evaporated onto said layer of x-ray transparent material.
Claim 52
Dependent Claim
19 words
The method of claim 36 wherein said substrate is a wafer and said support structure is a glass ring.
Claim 53
Independent Claim
74 words
A method for manufacturing a mask comprising the steps of: coating a wafer of a first material with a layer of a second material, said second material being x-ray transparent; coating at least one side of said wafer with a layer of conductive material, said conductive material being x-ray transparent; field assisted thermal bonding said layer of conductive material to a support structure; and removing a portion of said first material within said wafer.
Claim 54
Independent Claim
74 words
A method for manufacturing a mask comprising the steps of: coating a wafer of a first material with a layer of a second material, said second material being x-ray transparent; coating at least one side of said wafer with a layer of conductive material, said conductive material being x-ray transparent; field assisted thermal bonding said layer of conductive material to a support structure; and removing a portion of said first material within said wafer.
Claim 55
Dependent Claim
13 words
The method of claim 40 wherein said support structure is a glass ring.
Claim 56
Dependent Claim
13 words
The method of claim 40 wherein said conductive material comprises indium tin oxide.
Claim 57
Independent Claim
46 words
A method for manufacturing a mask comprising the steps of: coating a substrate with a layer of x-ray transparent conductive material; forming a field assisted thermal bond between said x-ray transparent conductive material and a support structure; and removing at least a portion of said substrate.
Claim 58
Independent Claim
46 words
A method for manufacturing a mask comprising the steps of: coating a substrate with a layer of x-ray transparent conductive material; forming a field assisted thermal bond between said x-ray transparent conductive material and a support structure; and removing at least a portion of said substrate.
Claim 59
Dependent Claim
15 words
The method of claim 43 wherein said x-ray transparent conductive material is doped boron nitride.
Claim 60
Dependent Claim
13 words
The method of claim 44 wherein said boron nitride is doped with titanium.
Claim 61
Dependent Claim
20 words
A mask comprising: an x-ray transparent membrane; a support structure bonded to said membrane with a field assisted thermal bond.
Claim 62
Dependent Claim
20 words
A mask comprising: an x-ray transparent membrane; a support structure bonded to said membrane with a field assisted thermal bond.
Claim 63
Dependent Claim
12 words
The mask of claim 46 wherein said membrane comprises indium tin oxide.
Claim 64
Dependent Claim
19 words
The mask of claim 47 wherein said layer of indium tin oxide is affixed to a boron nitride layer.
Claim 65
Dependent Claim
12 words
The mask of claim 46 wherein said membrane comprises doped boron nitride.
Claim 66
Independent Claim
47 words
A method of making a mask comprising the steps of: forming an x-ray transparent layer on a substrate; etching away said substrate, thereby leaving an x-ray transparent membrane; and forming an x-ray opaque patterned layer on the surface of said membrane previously in contact with said substrate.
Claim 67
Independent Claim
47 words
A method of making a mask comprising the steps of: forming an x-ray transparent layer on a substrate; etching away said substrate, thereby leaving an x-ray transparent membrane; and forming an x-ray opaque patterned layer on the surface of said membrane previously in contact with said substrate.
Claim 68
Dependent Claim
22 words
The method of claim 50 wherein prior to removal of said substrate, said x-ray transparent layer is affixed to a support structure.
Claim 69
Dependent Claim
38 words
The method of claim 50 further comprising the step of forming at least one intermediate layer between said x-ray opaque patterned layer and said membrane, said intermediate layer facilitating adhesion of said x-ray opaque layer to said membrane.
Claim 70
Dependent Claim
34 words
The method of claim 50 further comprising the step of forming at least one intermediate layer between said x-ray opaque patterned layer and said membrane, said intermediate layer providing mechanical strength to said membrane.
Claim 71
Independent Claim
56 words
A method for forming a mask comprising the steps of: forming an x-ray transparent layer on both sides of a substrate; etching a portion of said x-ray transparent layer on one side of said substrate with a bead blast etch process, thereby exposing a portion of said substrate; and removing said exposed portion of said substrate.
Claim 72
Independent Claim
56 words
A method for forming a mask comprising the steps of: forming an x-ray transparent layer on both sides of a substrate; etching a portion of said x-ray transparent layer on one side of said substrate with a bead blast etch process, thereby exposing a portion of said substrate; and removing said exposed portion of said substrate.
Claim 73
Dependent Claim
17 words
The method of claim 54 further comprising the step of bonding said substrate to a support structure.
Claim 74
Dependent Claim
17 words
The method of claim 54 wherein sodium bicarbonate beads are used to etch said x-ray transparent layer.
Claim 75
Dependent Claim
13 words
The method of claim 54 wherein said x-ray transparent layer comprises boron nitride.
Claim 76
Dependent Claim
13 words
The method of claim 6 wherein said solid layer of material comprises polyethylene.
Claim 77
Dependent Claim
28 words
A mask comprising: an x-ray transparent membrane; intermediate material affixed to said membrane; and a support structure bonded to said intermediate material with a field assisted thermal bond.
Claim 78
Dependent Claim
28 words
A mask comprising: an x-ray transparent membrane; intermediate material affixed to said membrane; and a support structure bonded to said intermediate material with a field assisted thermal bond.
Claim 79
Independent Claim
102 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a substrate having a first side coated with a layer of x-ray transparent material, said substrate having a second side; coating a portion of the said second side of said substrate with a metal layer, said metal layer having an opening through which a portion of said substrate is exposed; and etching said exposed portion of said substrate, said metal layer acting as a mask during said step of etching said exposed portion, said metal being capable of resisting an alkali metal hydroxide etching solution.
Claim 80
Independent Claim
102 words
A method for manufacturing a mask for use in a photolithographic process comprising the steps of: providing a substrate having a first side coated with a layer of x-ray transparent material, said substrate having a second side; coating a portion of the said second side of said substrate with a metal layer, said metal layer having an opening through which a portion of said substrate is exposed; and etching said exposed portion of said substrate, said metal layer acting as a mask during said step of etching said exposed portion, said metal being capable of resisting an alkali metal hydroxide etching solution.
Claim 81
Dependent Claim
26 words
The method of claim 60 wherein said step of etching is accomplished by applying a KOH solution to said substrate, said KOH solution etching said 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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |