US4601971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunnel cathode mask for electron lithography and method for manufacturing and operating it
Assignee: Siemens AG
•
Filing: 1983-07-14
•
Granted: 1986-07-22
•
Expires: 2003-07-14
Abstract
Abstract A mask for corpuscular lithography permits a short exposure time for generating structures on semiconductor wafers, and provides a cost reduction of such structure generation. The mask has a tunnel cathode in corpuscle-emitting regions.
Inventors
- 👤 Burkhard Lischke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:33
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/312; B; B82; B82Y; B82Y10/00; B82Y40/00; H01J37/00; H01J37/02; H01J37/04; H01J37/06; H01J37/073; H01J37/30; H01J37/317; H01J37/3174; H01J37/3175; H01J2237/00; H01J2237/30; H01J2237/317; H01J2237/3175; H01J2237/31777; H01J2237/31781; H01J2237/31783; Y; Y10; Y10S; Y10S430/00; Y10S430/143
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
54 words
In a mask for electron projection corpuscular lithography, the improvement comprising providing the mask as a tunnel cathode having a sandwich structure with an insulating region through which electrons tunnel in corpuscle-emitting regions and non-corpuscle emitting regions of the mask, and an absorber means being provided at the non-corpuscle emitting regions for absorbing electrons.
Claim 2
Dependent Claim
54 words
In a mask for electron projection corpuscular lithography, the improvement comprising providing the mask as a tunnel cathode having a sandwich structure with an insulating region through which electrons tunnel in corpuscle-emitting regions and non-corpuscle emitting regions of the mask, and an absorber means being provided at the non-corpuscle emitting regions for absorbing electrons.
Claim 3
Dependent Claim
17 words
The mask according to claim 1 wherein a structure comprising metal-insulator-metal is provided in the corpuscle-emitting regions.
Claim 4
Dependent Claim
18 words
The mask according to claim 1 wherein a structure comprising doped semiconductor-dielectricmetal is provided in the corpuscle-emitting regions.
Claim 5
Dependent Claim
15 words
The mask according to claim 1 wherein at least one absorber consists of a metal.
Claim 6
Dependent Claim
16 words
The mask according to claim 2 wherein at least one absorber region consists of a dielectric.
Claim 7
Independent Claim
137 words
A method for adjusting a position of a mask for electron projection corpuscular lithography having a tunnel cathode in corpuscle-emitting regions of the mask, comprising the steps of: providing the mask as a tunnel cathode with a sandwich construction of a first metal, an absorber region, and a second metal; providing adjusting marks formed of first and second adjustment mark metals spaced by an insulator as a part of the mask which are electrically insulated from the first and second metals and which each also form tunnel cathodes; and adjusting the mask by energizing the adjusting mark tunnel cathodes while the tunnel cathode for the actual lithography is not energized and using electrons emitted from the adjustment marks to adjust the position of the mask, whereby thereafter the tunnel cathode for the actual lithography may be energized.
Claim 8
Independent Claim
137 words
A method for adjusting a position of a mask for electron projection corpuscular lithography having a tunnel cathode in corpuscle-emitting regions of the mask, comprising the steps of: providing the mask as a tunnel cathode with a sandwich construction of a first metal, an absorber region, and a second metal; providing adjusting marks formed of first and second adjustment mark metals spaced by an insulator as a part of the mask which are electrically insulated from the first and second metals and which each also form tunnel cathodes; and adjusting the mask by energizing the adjusting mark tunnel cathodes while the tunnel cathode for the actual lithography is not energized and using electrons emitted from the adjustment marks to adjust the position of the mask, whereby thereafter the tunnel cathode for the actual lithography may be energized.
Claim 9
Dependent Claim
32 words
In a mask for electron projection corpuscular lithography, the improvement comprising a tunnel cathode in corpuscle-emitting regions of the mask, and wherein a structure comprising metal-insulator-superconductor is provided at said corpuscle-emitting regions.
Claim 10
Dependent Claim
32 words
In a mask for electron projection corpuscular lithography, the improvement comprising a tunnel cathode in corpuscle-emitting regions of the mask, and wherein a structure comprising metal-insulator-superconductor is provided at said corpuscle-emitting regions.
Claim 11
Independent Claim
162 words
A method for manufacturing a mask for electron projection corpuscular lithography, comprising the steps of: forming a tunnel cathode by providing a first metal layer, an insulating layer on a surface of the first metal layer, absorber regions at portions of the mask at which electron emission is not to occur, and a second metal layer overlying the insulating layer and the absorber regions, said second metal layer being sufficiently thin and the insulator being sufficiently thin so as to permit tunnel cathode electron emission from the first metal through the insulator and through the second metal onto a surface to be lithographed, the absorber regions being sufficiently thick to absorb emitted electrons; and forming said absorber region prior to application of the second metal layer by radiating regions at which it is desired to form the absorber regions so that absorber regions are grown thereat due to contamination with carbon in a vacuum in which the absorber regions are being grown.
Claim 12
Independent Claim
162 words
A method for manufacturing a mask for electron projection corpuscular lithography, comprising the steps of: forming a tunnel cathode by providing a first metal layer, an insulating layer on a surface of the first metal layer, absorber regions at portions of the mask at which electron emission is not to occur, and a second metal layer overlying the insulating layer and the absorber regions, said second metal layer being sufficiently thin and the insulator being sufficiently thin so as to permit tunnel cathode electron emission from the first metal through the insulator and through the second metal onto a surface to be lithographed, the absorber regions being sufficiently thick to absorb emitted electrons; and forming said absorber region prior to application of the second metal layer by radiating regions at which it is desired to form the absorber regions so that absorber regions are grown thereat due to contamination with carbon in a vacuum in which the absorber regions are being grown.
Claim 13
Independent Claim
167 words
A method for manufacturing a mask for electron projection corpuscular lithography, comprising the steps of: forming a tunnel cathode by providing a first metal layer, an insulating layer on a surface of the first metal layer, absorber regions at portions of the mask at which electron emission is not to occur, and a second metal layer overlying the insulating layer and between the absorber regions and the first metal layer, said second metal layer being sufficiently thin and the insulator being sufficiently thin so as to permit tunnel cathode electron emission from the first metal through the insulator and through the second metal onto a surface to be lithographed, the absorber regions being sufficiently thick to absorb emitted electrons; and forming said absorber regions after application of the second metal layer by radiating regions at which it is desired to form the absorber regions so that absorber regions are grown thereat due to contamination with carbon in a vacuum in which the absorber regions are being grown.
Claim 14
Independent Claim
167 words
A method for manufacturing a mask for electron projection corpuscular lithography, comprising the steps of: forming a tunnel cathode by providing a first metal layer, an insulating layer on a surface of the first metal layer, absorber regions at portions of the mask at which electron emission is not to occur, and a second metal layer overlying the insulating layer and between the absorber regions and the first metal layer, said second metal layer being sufficiently thin and the insulator being sufficiently thin so as to permit tunnel cathode electron emission from the first metal through the insulator and through the second metal onto a surface to be lithographed, the absorber regions being sufficiently thick to absorb emitted electrons; and forming said absorber regions after application of the second metal layer by radiating regions at which it is desired to form the absorber regions so that absorber regions are grown thereat due to contamination with carbon in a vacuum in which the absorber regions are being grown.
Claim 15
Dependent Claim
131 words
A mask for electron projection corpuscular lithography, comprising: a first metal layer; an insulating layer on a surface of the first metal layer; a second relatively thinner metal layer on the insulating layer except for portions of the mask at which electron emission is not to occur from the mask, said locations having absorbing regions; the insulating layer and the second metal layer being sufficiently thin so as to provide a tunnel cathode effect such that when a potential is applied between the first and second metal layers, electrons will pass through the insulating layer and the second layer so as to be available for lithographing a desired surface; and the absorber region being sufficiently thick so as to absorb electrons passing through the insulating layer from the first metal layer.
Claim 16
Dependent Claim
131 words
A mask for electron projection corpuscular lithography, comprising: a first metal layer; an insulating layer on a surface of the first metal layer; a second relatively thinner metal layer on the insulating layer except for portions of the mask at which electron emission is not to occur from the mask, said locations having absorbing regions; the insulating layer and the second metal layer being sufficiently thin so as to provide a tunnel cathode effect such that when a potential is applied between the first and second metal layers, electrons will pass through the insulating layer and the second layer so as to be available for lithographing a desired surface; and the absorber region being sufficiently thick so as to absorb electrons passing through the insulating layer from the first metal layer.
Claim 17
Dependent Claim
144 words
A mask for electron projection corpuscular lithography, comprising: a first metal layer; an insulating layer on a surface of the first metal layer; a second relatively thinner metal layer on the insulating layer; portions of the mask at which electron emission is not to occur having absorbing regions on a surface of the second metal layer opposite portions of the insulating layer; and the insulating layer and the second metal layer being sufficiently thin so as to provide a tunnel cathode effect wuch that when a potential is applied between the first and second metal layers, electrons will pass through the insulating layer and the second metal layer so as to be available for lithographing a desired surface; and the absorber regions being sufficiently thick so as to absorb electrons passing through the insulating layer and second metal layer from the first metal layer.
Claim 18
Dependent Claim
144 words
A mask for electron projection corpuscular lithography, comprising: a first metal layer; an insulating layer on a surface of the first metal layer; a second relatively thinner metal layer on the insulating layer; portions of the mask at which electron emission is not to occur having absorbing regions on a surface of the second metal layer opposite portions of the insulating layer; and the insulating layer and the second metal layer being sufficiently thin so as to provide a tunnel cathode effect wuch that when a potential is applied between the first and second metal layers, electrons will pass through the insulating layer and the second metal layer so as to be available for lithographing a desired surface; and the absorber regions being sufficiently thick so as to absorb electrons passing through the insulating layer and second metal layer from the first metal layer.
Claim 19
Independent Claim
95 words
A method for electron projection corpuscular lithography, comprising the steps of: providing first and second metal layers with an insulator therebetween and wherein the insulator and the second metal layer are sufficiently thin so as to permit a tunnel cathode electron emission at desired regions for lithographing a surface, and wherein at other regions from which electron emission is not to occur, providing an absorber region of thickness sufficient to prevent tunnel cathode emission when a voltge is applied across metal layers M1 and M2 sufficient to cause tunnel cathode emission at the desired regions.
Claim 20
Independent Claim
95 words
A method for electron projection corpuscular lithography, comprising the steps of: providing first and second metal layers with an insulator therebetween and wherein the insulator and the second metal layer are sufficiently thin so as to permit a tunnel cathode electron emission at desired regions for lithographing a surface, and wherein at other regions from which electron emission is not to occur, providing an absorber region of thickness sufficient to prevent tunnel cathode emission when a voltge is applied across metal layers M1 and M2 sufficient to cause tunnel cathode emission at the desired regions.
References Cited (Backward Citations)
US3922546A
Cited
US4137458A
Cited
DE2840553A1
Cited
US4197332A
Cited
US4194123A
Cited
US4274035A
Cited
US4377627A
Cited
US4331505A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |