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US4770738A
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Electro hydrodynamic method for the preparation of a thin semiconductor film
Assignee: BOC Group Ltd
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Filing: 1986-10-14
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Granted: 1988-09-13
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Expires: 2006-10-14
Abstract
Abstract A method of preparing a thin film of a semiconductor material on a substrate, in which charged microdroplets of the semiconductor material or a constituent thereof are generated by electrohydrodynamic (EHD) extraction of the droplets from a meniscus forced at an elongate tip of a nozzle containing the material in a molten state, the EHD extraction occurring under the influcence of a high electric field produced by an extractor electrode adjacent the tip of the nozzle. The microdroplets are then accelerated away from the elongate tip of the nozzle to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets. The two-dimensional beam is directed onto the trailing edge of a target carried on a moving substrate such that a film of the semiconductor material is formed on the substrate by deposition of the microdroplets on the trailing edge of the moving target.
Inventors
- 👤 Jean J. A. Robillard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:41
CPC Classifications
C; C30; C30B; C30B15/00; C30B15/08; C23; C23C; C23C26/00; C23C26/02; C30B15/007; C30B29/00; C30B29/60; C30B29/605; Y; Y10; Y10S; Y10S117/00; Y10S117/914; Y10S117/915
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
143 words
A method of preparing a thin film of a semiconductor material on a substrate, comprising: generating charged microdroplets of the semiconductor material or a constituent thereof by electrohydrodynamic (EHD) extraction of the said droplets from a meniscus formed at an elongate tip of a nozzle containing the material in a molten state, the EHD extraction occurring under the influence of a high electric field produced by an extractor electrode adjacent the tip of the nozzle, accelerating the microdroplets so generated away from the elongate tip of the nozzle to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets, and directing the two-dimensional beam onto the trailing edge of a target carried on a moving substrate such that a film of the semiconductor material is formed on the substrate by deposition of the microdroplets on the trailing edge of the moving target.
Claim 2
Independent Claim
143 words
A method of preparing a thin film of a semiconductor material on a substrate, comprising: generating charged microdroplets of the semiconductor material or a constituent thereof by electrohydrodynamic (EHD) extraction of the said droplets from a meniscus formed at an elongate tip of a nozzle containing the material in a molten state, the EHD extraction occurring under the influence of a high electric field produced by an extractor electrode adjacent the tip of the nozzle, accelerating the microdroplets so generated away from the elongate tip of the nozzle to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets, and directing the two-dimensional beam onto the trailing edge of a target carried on a moving substrate such that a film of the semiconductor material is formed on the substrate by deposition of the microdroplets on the trailing edge of the moving target.
Claim 3
Dependent Claim
54 words
A method according to claim 1, wherein the semiconductor material is a compound semiconductor, and a separate blanket of microdroplets is formed in respect of different constituents of the compound semiconductor, the separate blankets either being merged prior to impact on the said trailing edge of the target, or meeting at the trailing edge.
Claim 4
Dependent Claim
32 words
A method according to claim 1 wherein the target is a monocrystalline seed crystal of the semiconductor material and the thin film of semiconductor material is substantially monocrystalline or at least polycrystalline.
Claim 5
Dependent Claim
59 words
A method according to claim 3, further including forming a separate blanket of a semiconductor doping material, the blanket of doping material and the blanket of semiconductor material or a constituent thereof either being merged prior to impact on the said trailing edge of the target, or meeting at the trailing edge, whereby a doped semiconductor film is produced.
Claim 6
Dependent Claim
24 words
A method according to claim 1, wherein the elongate tip of the nozzle includes a single elongate opening at which the meniscus is formed.
Claim 7
Dependent Claim
31 words
A method according to claim 1, wherein the elongate tip of the nozzle includes a linear array of a plurality of individual openings at each of which a meniscus is formed.
Claim 8
Dependent Claim
30 words
The method of claim 1, wherein a voltage is applied between the extractor electrode and the nozzle of between 2 and 20 kV to provide the said high electric field.
Claim 9
Dependent Claim
30 words
The method of claim 5, wherein the width of the single nozzle opening, or the width of each individual nozzle opening, is from 10 -3 cm to 8×10 -3 cm.
Claim 10
Dependent Claim
22 words
The method of claim 1, wherein the target on the moving substrate is negatively biased with respect to the positively charged microdroplets.
Claim 11
Dependent Claim
26 words
The method of claim 1, wherein additional heating is provided at the trailing edge of the target by directing an electron beam along the trailing edge.
Claim 12
Dependent Claim
20 words
The method of claim 1, which is carried out in a vacuum chamber at 10 -5 to 10 -6 Torr.
Claim 13
Dependent Claim
30 words
The method of claim 6, wherein the width of the single nozzle opening, or the width of each individual nozzle opening, is from 10 -3 cm to 8×10 -3 cm.
Claim 14
Dependent Claim
23 words
A method according to claim 1, and further including the step of focusing the two-dimensional blanket prior to being positioned on said substrate.
Claim 15
Independent Claim
170 words
A method of preparing a thin film of a semiconductor material on a substrate, comprising: generating charged microdroplets of the semiconductor material or a constituent thereof by electrohydrodynamic (EHD) extraction of the said droplets from a meniscus formed at an elongate tip of a nozzle containing the material in a molten state, the EHD extraction occurring under the influence of a high electric field produced by an extractor electrode adjacent the tip of the nozzle; accelerating the microdroplets so generated away from the elongate tip of the nozzle and focusing the microdroplets to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets; directing the two-dimensional beam onto the trailing edge of a target carried on a moving subsrate such that a film of the semiconductor material is formed on the substrate by deposition of the microdroplets on the trailing edge of the moving target; and heating said trailing edge of said target by directing an electron beam along the trailing edge for promoting epitaxial growth of said microdroplets.
Claim 16
Independent Claim
170 words
A method of preparing a thin film of a semiconductor material on a substrate, comprising: generating charged microdroplets of the semiconductor material or a constituent thereof by electrohydrodynamic (EHD) extraction of the said droplets from a meniscus formed at an elongate tip of a nozzle containing the material in a molten state, the EHD extraction occurring under the influence of a high electric field produced by an extractor electrode adjacent the tip of the nozzle; accelerating the microdroplets so generated away from the elongate tip of the nozzle and focusing the microdroplets to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets; directing the two-dimensional beam onto the trailing edge of a target carried on a moving subsrate such that a film of the semiconductor material is formed on the substrate by deposition of the microdroplets on the trailing edge of the moving target; and heating said trailing edge of said target by directing an electron beam along the trailing edge for promoting epitaxial growth of said microdroplets.
Claim 17
Dependent Claim
43 words
A method according to claim 14, wherein said step of accelerating and focusing the microdroplets to form a two-dimensional ribbon-like beam or blanket of the charged microdroplets is achieved by ion optic lenses, including an insulator ring for mounting a doublet lens system.
Claim 18
Dependent Claim
51 words
A method according to claim 14, wherein the semiconductor material is a compound semiconductor, and a separate blanket of microdroplets is formed from different constituents of the compound semiconductor, the separate blankets either being merged prior to impact on the trailing edge of the target, or meeting at the trailing edge.
Claim 19
Dependent Claim
32 words
A method according to claim 14, wherein the target is a monocrystalline seed crystal of the semiconductor material and the thin film of semiconductor material is substantially monocrystalline or at least polycrystalline.
Claim 20
Dependent Claim
58 words
A method according to claim 15, further including forming a separate blanket of a semiconductor doping material, the blanket of doping material and the blanket of semiconductor material or a constituent thereof either being merged prior to impact on the trailing edge of the target, or meeting at the trailing edge, whereby a doped semiconductor film is produced.
Claim 21
Dependent Claim
24 words
A method according to claim 14, wherein the elongate tip of the nozzle includes a single elongate opening at which the menicus is formed.
Claim 22
Dependent Claim
31 words
A method according to claim 14, wherein the elongate tip of the nozzle includes a linear array of a plurality of individual openings at each of which a meniscus is formed.
Claim 23
Dependent Claim
29 words
The method of claim 14, wherein a voltage is applied between the extractor electrode and the nozzle of between 2 and 20 kV to provide the high electric field.
Claim 24
Dependent Claim
30 words
The method of claim 14, wherein the width of the single nozzle opening, of the width of each individual nozzle opening, is from 10 -3 cm to 8×10 -3 cm.
Claim 25
Dependent Claim
22 words
The method of claim 14, wherein the target on the moving substrate is negatively biased with respect to the positively charged microdroplets.
Claim 26
Dependent Claim
20 words
The method of claim 14, which is carried out in a vacuum chamber at 10 -5 to 10 -6 Torr.
Claim 27
Dependent Claim
16 words
A method according to claim 14, wherein a tungsten filament and anode heat the trailing edge.
Claim 28
Dependent Claim
30 words
The method of claim 14, wherein the width of the single nozzle opening, or the width of each individual nozzle opening, is from 10 -3 cm to 8×10 -3 cm.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |