US4463028A
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Method for preparing composite or elementary semi-conducting polycrystalline films
Assignee: L'ETAT BELGE REPRESENTE PAR LE SECRETAIRE GENERAL DES SERVICES de la PROGRAMMATION de la POLITIQUE SCIENTIFIQUE
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Filing: 1981-08-03
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Granted: 1984-07-31
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Expires: 2001-08-03
Abstract
Abstract There is described a method for preparing polycrystalline semi-conducting films comprised of two elements respectively from Groups III and V, or Groups II and VI of the Periodic Table, by irradiating with a laser beam a film which is comprised of at least two layers from elements selected with a stoichiometric ratio, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method is comprised of irradiating said film with a structured laser beam to cause crystallizing into crystallites which are regularly aligned and with a size at least equal to the thickness of the resulting film.
Inventors
- 👤 Lucien D. Laude
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:20
CPC Classifications
C; C30; C30B; C30B1/00; C30B1/02; C30B1/06; C30B1/08; C30B1/023; C30B29/00; C30B29/10; C30B29/40; Y; Y10; Y10S; Y10S148/00; Y10S148/093; Y10S148/094
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
136 words
Method for preparing polycrystalline semi-conducting films comprised of two elements from Groups III and V, respectively, or Groups II and VI, respectively, of the Periodic Table, by irradiating with a laser beam a film, said film being comprised of at least two layers each of which is formed from one of said elements selected in a stoichiometric ratio, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method is comprised of irradiating said film with a structured laser beam to cause crystallizing of said elements into crystallites which are regularly aligned and which have a size at least equal to the thickness of the resulting film, wherein said laser beam is structured by passing the beam through an optical means which is so arranged as to cause interference fringes.
Claim 2
Dependent Claim
136 words
Method for preparing polycrystalline semi-conducting films comprised of two elements from Groups III and V, respectively, or Groups II and VI, respectively, of the Periodic Table, by irradiating with a laser beam a film, said film being comprised of at least two layers each of which is formed from one of said elements selected in a stoichiometric ratio, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method is comprised of irradiating said film with a structured laser beam to cause crystallizing of said elements into crystallites which are regularly aligned and which have a size at least equal to the thickness of the resulting film, wherein said laser beam is structured by passing the beam through an optical means which is so arranged as to cause interference fringes.
Claim 3
Dependent Claim
23 words
Method as defined in claim 1, in which said film is comprised of alternating layers from said elements selected with a stoichiometric ratio.
Claim 4
Dependent Claim
94 words
Method for preparing polycrystalline elementary semi-conducting films by irradiating with a laser beam an elementary amorphous semi-conducting film, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method comprises irradiating said film with a structured laser beam to cause crystallizing said semi-conducting film into crystallites which are regularly aligned and which have a size at least equal to the thickness of the resulting film, wherein said laser beam is structured by passing the beam through an optical means which is so arranged as to cause interference fringes.
Claim 5
Dependent Claim
94 words
Method for preparing polycrystalline elementary semi-conducting films by irradiating with a laser beam an elementary amorphous semi-conducting film, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method comprises irradiating said film with a structured laser beam to cause crystallizing said semi-conducting film into crystallites which are regularly aligned and which have a size at least equal to the thickness of the resulting film, wherein said laser beam is structured by passing the beam through an optical means which is so arranged as to cause interference fringes.
Claim 6
Dependent Claim
25 words
Method as defined in claim 1 or 3, in which said non-crystalline substrate is cleaned by ionic bombardment with a neutral gas, such as argon.
Claim 7
Dependent Claim
23 words
Method as defined in claim 1 or 3, in which said crystallites have a size larger than the thickness of the resulting film.
Claim 8
Dependent Claim
22 words
Method as defined in claim 1, in which said optical means causing interference fringes is comprised of an etched quartz optic grating.
Claim 9
Dependent Claim
41 words
Method as defined in claim 6, in which the number of etched lines in the quartz optic grating and the spacing grating-film have such values that the laser beam causes a regular crystallizing over the whole surface area with aligned crystallites.
Claim 10
Dependent Claim
24 words
Method as defined in claim 7, in which the number of lines in the optic grating varies between 1000 and 6000 to the cm.
Claim 11
Dependent Claim
15 words
Method as defined in claim 7, in which the spacing grating-film is about 1 mm.
Claim 12
Dependent Claim
20 words
Method as defined in claim 1, in which the optical means causing interference fringes is comprised of a Fresnel's lens.
Claim 13
Dependent Claim
34 words
Method as defined in claim 1, in which the optical means causing interference fringes is comprised of a metal screen or grid having a regular mesh lying at right angle to the beam axis.
Claim 14
Dependent Claim
30 words
Method as defined in claim 1 or 3, in which said laser beam irradiating the film operates in pulsed mode with an energy between 50 and 100 mJ/cm 2 .
Claim 15
Dependent Claim
30 words
Method as defined in claim 1 or 3, in which said laser beam irradiating the film operates in continuous mode with an energy between 1 and 5 J/cm 2 .
Claim 16
Dependent Claim
19 words
Method as defined in claim 1 or 3, in which said laser beam is made homogeneous before being structured.
Claim 17
Dependent Claim
76 words
Method as defined in claim 14, in which said laser beam is made homogeneous by passing through a quartz cylinder-like rod which is bent twice at right angle along opposite directions, coated with a metal layer, and the input and output surfaces thereof being polished, in parallel relationship together and at right angle to the rod axis, the diameter of said rod varying from the input to the output surface by a factor of about 2.
Claim 18
Dependent Claim
31 words
Method as defined in claim 1 or 3, in which the film thickness lies between 1 and 2 microns, and the laser beam is comprised of a pulsed ruby laser beam.
Claim 19
Dependent Claim
28 words
Method as defined in claim 1 or 3, in which the film thickness lies between 2 and 25 microns, and the laser beam is a continuous laser beam.
Claim 20
Dependent Claim
22 words
Method as defined in claim 1 or 3, in which the protective layer is comprised of silicon monooxide or indium-doped tin oxide.
Claim 21
Dependent Claim
77 words
Method as defined in claim 1, in which the elements from Groups III and V, or II and VI of the Periodic Table are deposited over a non-crystalline substrate in alternating layers with a thickness varying between 50 and 2000 Å depending on the nature of the element, by means of an electron gun, with stoichiometric ratios, the last layer being coated with a protective layer, the thickness of the various layers being controlled by vibrating quartz.
Claim 22
Dependent Claim
56 words
Method as defined in claim 19, in which the thicknesses from two different elementary layers which are directly adjacent to one another, each vary between 50 and 200 Å and are retained constant over the whole thickness of the total film, so as to obtain a homogeneous and regular piling of both said different elementary layers.
Claim 23
Dependent Claim
26 words
Method as defined in claim 20, in which the thickness of the elementary layers is reduced progressively over the substrate as said layers are being deposited.
Claim 24
Dependent Claim
48 words
Method as defined in claim 21, in which the first sandwiches have a thickness in the range from 0.1 to 0.5 microns, and the last sandwich has a thickness in the range of 150 Å, each sandwich being formed by two different elementary layers which are directly adjacent.
Claim 25
Dependent Claim
19 words
Method as defined in claim 20, in which the last layer being deposited is comprised of the less-absorbing element.
Claim 26
Dependent Claim
37 words
Method as defined in claim 1, in which the elements from Groups III and V are selected respectively among those element couples which comprise aluminum and antimony, aluminum and arsenic, gallium and arsenic, and indium and phosphorus.
Claim 27
Dependent Claim
31 words
Method as defined in claim 1, in which the elements from Groups II and VI are selected respectively among those element couples which comprise cadmium and sulfur, and cadmium and tellurium.
Claim 28
Dependent Claim
15 words
Method as defined in claim 3, in which the element used is silicon or germanium.
Claim 29
Dependent Claim
22 words
Method as defined in claim 3, in which said optical means causing interference fringes is comprised of an etched quartz optic grating.
Claim 30
Dependent Claim
20 words
Method as defined in claim 3, in which the optical means causing interference fringes is comprised of a Fresnel's lens.
Claim 31
Dependent Claim
34 words
Method as defined in claim 3, in which the optical means causing interference fringes is comprised of a metal screen or grid having a regular mesh lying at right angle to the beam axis.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-31 | 1988-01-30 | 1988-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-31 | 1992-01-30 | 1992-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-31 | 1996-01-30 | 1996-07-31 | $7700.00 | Window Closed / Lapsed |