US4693758A
Expired / Lapsed
US
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Method of making devices in silicon, on insulator regrown by laser beam
Assignee: Hitachi Ltd
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Filing: 1985-10-04
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Granted: 1987-09-15
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Expires: 2005-10-04
Abstract
Abstract This invention relates to improvements in the SOS technology including the so-called laser annealing processing. According to this invention, a semiconductor layer of an SOS structure consists of the three layers of an interface layer made up of twins, a seed crystalline layer and a re-grown layer far thicker than the preceding two layers when viewed from the side of an insulating substrate. The re-grown layer is formed in such a way that a semiconductor layer deposited on the insulating substrate is irradiated with an electromagnetic wave, for example, pulsed ruby laser beam, which is absorbed substantially uniformly by a portion except the interface layer and the seed crystalline layer. According to this invention, the quality of the re-grown layer is improved, and the mobility of carriers is enhanced. As a result, the operating speed of a semiconductor device employing the SOS structure is raised, and the leakage current is reduced.
Inventors
- 👤 Yutaka Kobayashi
- 👤 Takaya Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:02
CPC Classifications
H; H10; H10D; H10D86/00; H10D30/00; H10D30/60; H10D30/67; H10D30/6758; H10D30/6759; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2921; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3258; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3438; H10P14/3441; H10P14/3442; H10P14/38; H10P14/3802; H10P14/3808; H10P14/3816; H10P34/00; H10P34/40; H10P34/42; Y; Y10; Y10S; Y10S117/00; Y10S117/903; Y10S117/904; Y10S438/00; Y10S438/967
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
169 words
A method of forming a single crystalline semiconductor layer comprising the steps of: (a) depositing a layer of semiconductor material on a main surface of an insulating substrate, said layer of semiconductor material comprising an interface sublayer adjacent said main surface of the insulating substrate and a single crystalline semiconductor sublayer formed continuously on the interface sublayer, the single crystalline semiconductor sublayer having an exposed surface not adjacent the interface sublayer, said interface sublayer being made up of an aggregate of single crystalline semiconductor grains, said single crystalline semiconductor sublayer having a predetermined orientation and (b) irradiating a portion of said single crystalline semiconductor sublayer with an electromagnetic wave which has energy and a wavelength required to re-grow said portion substantially uniformly, from the exposed surface of said single crystalline semiconductor sublayer; said portion being all of said single crystalline semiconductor sublayer other than a seed layer part of said single crystalline semiconductor sublayer, adjacent said interface sublayer, that is necessary for serving as a seed of the re-growth.
Claim 2
Independent Claim
169 words
A method of forming a single crystalline semiconductor layer comprising the steps of: (a) depositing a layer of semiconductor material on a main surface of an insulating substrate, said layer of semiconductor material comprising an interface sublayer adjacent said main surface of the insulating substrate and a single crystalline semiconductor sublayer formed continuously on the interface sublayer, the single crystalline semiconductor sublayer having an exposed surface not adjacent the interface sublayer, said interface sublayer being made up of an aggregate of single crystalline semiconductor grains, said single crystalline semiconductor sublayer having a predetermined orientation and (b) irradiating a portion of said single crystalline semiconductor sublayer with an electromagnetic wave which has energy and a wavelength required to re-grow said portion substantially uniformly, from the exposed surface of said single crystalline semiconductor sublayer; said portion being all of said single crystalline semiconductor sublayer other than a seed layer part of said single crystalline semiconductor sublayer, adjacent said interface sublayer, that is necessary for serving as a seed of the re-growth.
Claim 3
Dependent Claim
57 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein the wavelength, the energy and an irradiation period of said electromagnetic wave used in the step (b) are selected in a range sufficient for uniformly melting said portion and insufficient for heating said portion up to a boiling point of the semiconductor material.
Claim 4
Dependent Claim
33 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein the step (b) is performed a plurality of times until a mobility of carriers in the re-grown part increases.
Claim 5
Dependent Claim
57 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein said insulating substrate used in the step (a) is of single crystalline sapphire or single crystalline spinel and the semiconductor material is silicon grown from a vapor phase, and said electromagnetic wave used in the step (b) is a pulsed ruby laser beam.
Claim 6
Dependent Claim
34 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein the single crystalline semiconductor sublayer is made of silicon, and the orientation of the top main surface thereof is {111}.
Claim 7
Dependent Claim
24 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein said interface sublayer had a thickness of approximately 0.05 μm.
Claim 8
Dependent Claim
27 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein said irradiating is performed at an energy density of 1.5 J/cm 2 .
Claim 9
Dependent Claim
53 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein the orientation of the top main surface of the single crystalline semiconductor sublayer is {100} or {110}, and wherein the step (b) is performed such that the single crystalline semiconductor sublayer is under a tensile stress after the re-growth.
Claim 10
Dependent Claim
42 words
A method of forming a single crystalline semiconductor layer according to claim 1, wherein said electromagnetic wave used in step (b) is from a laser source selected from the group consisting of YAG laser, glass laser, CO 2 laser and Ar laser.
Claim 11
Dependent Claim
23 words
A method of forming a semiconductor layer according to claim 1, wherein the single crystalline semiconductor sublayer is thicker than the interface sublayer.
Claim 12
Dependent Claim
21 words
A method of producing a semiconductor layer according to claim 1, wherein said portion is thicker than said seed layer part.
Claim 13
Dependent Claim
29 words
A method of forming a semiconductor layer according to claim 1, wherein said portion of the single crystalline semiconductor sublayer is the bulk of the single crystalline semiconductor sublayer.
Claim 14
Dependent Claim
27 words
A method of forming a single crystalline semiconductor layer according to claim 3, wherein said electromagnetic wave used in the step (b) is a pulsed laser beam.
Claim 15
Dependent Claim
27 words
A method of forming a single crystalline semiconductor layer according to claim 3, wherein said irradiating is performed at an energy density of 1.5 J/cm 2 .
Claim 16
Dependent Claim
21 words
A method of forming a single crystalline semiconductor layer according to claim 3, wherein the step (b) is performed 2-4 times.
Claim 17
Dependent Claim
21 words
A method of producing a semiconductor layer according to claim 10, wherein said portion is thicker than said seed layer part.
Claim 18
Dependent Claim
21 words
A method of forming a single crystalline semiconductor layer according to claim 14, wherein the step (b) is performed 2-4 times.
Claim 19
Independent Claim
273 words
A method of producing a semiconductor device comprising the steps of: (a) depositing a layer of semiconductor material on a main surface of an insulating substrate, said layer of semiconductor material comprising an interface sublayer adjacent said main surface of the insulating substrate and a single crystalline silicon sublayer formed continuously on the interface sublayer, the single crystalline silicon sublayer having an exposed surface not adjacent the interface sublayer, said interface sublayer being made up of an aggregate of single crystalline silicon grains, said single crystalline silicon sublayer having an orientation of {100} or {110}, (b) irradiating a portion of said single crystalline silicon sublayer with an electromagnetic wave which has energy and a wavelength required to melt said portion substantially uniformly, from the exposed surface of said single crystalline silicon sublayer; said portion being all of said single crystalline silicon sublayer other than a seed layer within said single crystalline silicon sublayer, adjacent said interface sublayer, that is necessary for serving as a seed of re-growth, (c) re-growing the molten single crystalline silicon layer with said seed layer part as the seed, a temperature of said insulating substrate being held lower than that of said silicon layer at this time thereby to leave a tensile stress in at least the top main surface of the re-grown single crystalline silicon layer, and (d) subjecting an inner or surface part of said re-grown layer to at least one treatment of a manufacturing process of the desired semiconductor device under a temperature condition under which at least one of said re-grown layer and said insulating substrate is kept at a temperature of below 600° C.
Claim 20
Independent Claim
273 words
A method of producing a semiconductor device comprising the steps of: (a) depositing a layer of semiconductor material on a main surface of an insulating substrate, said layer of semiconductor material comprising an interface sublayer adjacent said main surface of the insulating substrate and a single crystalline silicon sublayer formed continuously on the interface sublayer, the single crystalline silicon sublayer having an exposed surface not adjacent the interface sublayer, said interface sublayer being made up of an aggregate of single crystalline silicon grains, said single crystalline silicon sublayer having an orientation of {100} or {110}, (b) irradiating a portion of said single crystalline silicon sublayer with an electromagnetic wave which has energy and a wavelength required to melt said portion substantially uniformly, from the exposed surface of said single crystalline silicon sublayer; said portion being all of said single crystalline silicon sublayer other than a seed layer within said single crystalline silicon sublayer, adjacent said interface sublayer, that is necessary for serving as a seed of re-growth, (c) re-growing the molten single crystalline silicon layer with said seed layer part as the seed, a temperature of said insulating substrate being held lower than that of said silicon layer at this time thereby to leave a tensile stress in at least the top main surface of the re-grown single crystalline silicon layer, and (d) subjecting an inner or surface part of said re-grown layer to at least one treatment of a manufacturing process of the desired semiconductor device under a temperature condition under which at least one of said re-grown layer and said insulating substrate is kept at a temperature of below 600° C.
Claim 21
Dependent Claim
41 words
A method of producing a semiconductor device according to claim 18, wherein the temperature condition in the step (d) is that at least one of said re-grown layer and said insulating substrate is at a temperature not higher than 400° C.
Claim 22
Dependent Claim
59 words
A method of producing a semiconductor device according to claim 18, wherein the manufacturing process of the semiconductor device in the step (d) includes a doping treatment in which a predetermined part of said re-grown layer is doped with predetermined impurity atoms, and a passivation treatment in which a predetermined exposed surface part of said re-grown layer is passivated.
Claim 23
Dependent Claim
33 words
A method of producing a semiconductor device according to claim 18, wherein the step (d) includes forming first and second MOS semiconductor elements, of opposite conductivity type, in said single crystalline silicon sublayer.
Claim 24
Dependent Claim
23 words
A method of producing a semiconductor device according to claim 18, wherein the single crystalline silicon sublayer is thicker than the interface sublayer.
Claim 25
Dependent Claim
21 words
A method of producing a semiconductor device according to claim 18, wherein said portion is thicker than the seed layer part.
Claim 26
Dependent Claim
29 words
A method of producing a semiconductor device according to claim 20, wherein said portion of the single crystalline silicon sublayer is the bulk of the single crystalline silicon sublayer.
Claim 27
Dependent Claim
53 words
A method of producing a semiconductor device according to claim 20, wherein the step (d) includes removing a part of the single crystalline silicon sublayer, including a part of the re-grown layer, so as to leave an island of the single crystalline silicon sublayer, said desired semiconductor device being formed in said island.
Claim 28
Dependent Claim
36 words
A method of producing a semiconductor device according to claim 21, wherein said first and second MOS semiconductor elements are first and second MOS transistors, whereby CMOS transistors are formed in the single crystalline silicon sublayer.
Claim 29
Dependent Claim
21 words
A method of producing a semiconductor device according to claim 22, wherein said portion is thicker than the seed layer part.
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) | 1990-09-14 | 1991-03-16 | 1991-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-14 | 1995-03-16 | 1995-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-14 | 1999-03-16 | 1999-09-15 | $7700.00 | Window Closed / Lapsed |