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EP0044372A2
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Fabrication and use of a high aspect ratio, high resolution collimating mask for ion beam growth of semiconductor devices
Assignee: International Business Machines Corp
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Filing: 1981-01-23
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Granted: —
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Expires: 2001-01-23
Abstract
Abstract A high aspect ratio collimating mask (2) for use in ion beam epitaxy or ion implantation doping is formed through the use of damage-trail-forming materials which are irradiated through a mask and then etched. The high aspect ratio is obtained in part by the sequential formation of a plurality of spaced mask plates. The mask is useful in producing large scale integrated circuits by localized ion implantation (10) during epitaxial growth (7) of a crystal wafer (1). In apparatus for use of the collimating mask (2), the crystal wafer (1) is held perpendicular to the plurality of discrete parallel ion beams (10) emitted through the collimating mask (2).
Inventors
- 👤 Praveen Chaudhari
- 👤 Ned J. Chou
- 👤 Ralph Feder
- 👤 Alan B. Fowler
- 👤 James A. Vanvechten
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:54
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/20; H; H10; H10P; H10P30/00; H10P30/20; H10P30/22; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/944
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
149 words
The process of making a multi-aperture, high aspect ratio collimating mask, characterized by the steps of: forming on a first thin plate (34) of damage-trail-forming material a preliminary mask (35) of particle-arresting material configured to leave unmasked regions where openings are to be formed, irradiating said first plate through said preliminary mask with particles (36) having sufficient energy to pass through said first plate with negligible deflection and form damage trails (37) therethrough, etching said first plate (34) to enlarge said damage trails, mounting a second thin plate (38) of damage-trail-forming material spaced from and superimposed with said first plate, irradiating said second plate (38) through said preliminary mask and the enlarged damage trails in said first plate, with particles (36) energized sufficiently to pass through said second plate with negligible deflection and form damage trails (40) therethrough, and etching said second plate (38) to enlarge said damage trails.
Claim 2
Dependent Claim
149 words
The process of making a multi-aperture, high aspect ratio collimating mask, characterized by the steps of: forming on a first thin plate (34) of damage-trail-forming material a preliminary mask (35) of particle-arresting material configured to leave unmasked regions where openings are to be formed, irradiating said first plate through said preliminary mask with particles (36) having sufficient energy to pass through said first plate with negligible deflection and form damage trails (37) therethrough, etching said first plate (34) to enlarge said damage trails, mounting a second thin plate (38) of damage-trail-forming material spaced from and superimposed with said first plate, irradiating said second plate (38) through said preliminary mask and the enlarged damage trails in said first plate, with particles (36) energized sufficiently to pass through said second plate with negligible deflection and form damage trails (40) therethrough, and etching said second plate (38) to enlarge said damage trails.
Claim 3
Dependent Claim
29 words
The process as defined in claim 1 wherein said damage-trail-forming material is selected from the group consisting of A1 2 0 3 , Si0 2 , mica and garnet.
Claim 4
Dependent Claim
16 words
The process, as defined in claim 1 or 2, wherein said particle--arresting material (35) comprises gold.
Claim 5
Dependent Claim
41 words
The process, as defined in any of claims 1-3, wherein said damage--trail-forming material is sapphire with the plates thereof having a thickness of about 10 pm, and wherein the energy of said irradiation is in the order of 1 MeV protons.
Claim 6
Dependent Claim
27 words
The process, as defined in claim 3 or 4, wherein said particle--arresting material comprises gold and said preliminary mask (35) has a thickness of about 10 pm.
Claim 7
Dependent Claim
42 words
The process, as defined in any of claims 1-5, wherein said plates (29, 30) each have a thickness of about 10 pm, the openings therethrough (31, 32) are etched to about 100 nm, and the spacing (L) therebetween is about 1 cm.
Claim 8
Dependent Claim
64 words
The process of forming multiple circuit devices during epitaxial growth of a wafer, characterized by: passing a beam of doping ions through a collimating mask (2) having a plurality of openings therethrough of an aspect ratio of at least 10 5 for forming a plurality of discrete parallel ion beams (10), and directing said plurality of beams to a wafer (1) undergoing epitaxial growth.
Claim 9
Dependent Claim
64 words
The process of forming multiple circuit devices during epitaxial growth of a wafer, characterized by: passing a beam of doping ions through a collimating mask (2) having a plurality of openings therethrough of an aspect ratio of at least 10 5 for forming a plurality of discrete parallel ion beams (10), and directing said plurality of beams to a wafer (1) undergoing epitaxial growth.
Claim 10
Dependent Claim
78 words
The process of forming multiple circuit devices by ion implantation doping through means of a collimated beam, characterized by: passing a beam of doping ions through a collimating mask (2) having a plurality of openings therethrough of an aspect ratio of at least 10 5 for forming a plurality of discrete parallel ion beams (10), and directing said plurality of beams to a wafer (1); annealing said wafer to remove whatever damage is caused by said ion implantation.
Claim 11
Dependent Claim
78 words
The process of forming multiple circuit devices by ion implantation doping through means of a collimated beam, characterized by: passing a beam of doping ions through a collimating mask (2) having a plurality of openings therethrough of an aspect ratio of at least 10 5 for forming a plurality of discrete parallel ion beams (10), and directing said plurality of beams to a wafer (1); annealing said wafer to remove whatever damage is caused by said ion implantation.
Claim 12
Dependent Claim
31 words
A process as defined in claim 7 or 8, wherein said directing step comprises moving said ion beams (10) collectively relative to said wafer (1) in accordance with a predetermined pattern.
Claim 13
Dependent Claim
117 words
Apparatus for executing a process, as defined in any of claims 7-9, characterized in that the apparatus comprises an ion source (8) provided with a high aspect ratio, high resolution collimating mask (2) for forming a plurality of discrete parallel ion beams (10) in a given axial direction, at least one other source (6, 18) of a beam of matter (7) of substantially uniform intensity distribution crossing said plurality of discrete parallel ion beams (10) at an angle to said axial direction, and a sample holder (4) disposed for holding a semiconductor wafer (1) in the crossing area of said discrete beams (10) and said uniform beam (7), said wafer being held perpendicular to said axial direction.
References Cited (Backward Citations)
No citation records indexed.
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