US5852346A
Expired / Lapsed
US
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Forming luminescent silicon material and electro-luminescent device containing that material
Assignee: University of Surrey
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Filing: 1997-09-15
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Granted: 1998-12-22
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Expires: 2017-09-15
Abstract
Abstract A process is provided for forming a silicon material which exhibits room temperature photoluminescence and/or electroluminescence. It comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate and subsequently annealing the substrate at an elevated temperature for a period such as to bring about Si nanocrystal formation, the nanocrystals being dispersed through the SiO 2 substrate. Photoluminescence of visible light from the resulting substrate is induced on irradiation of the substrate with e.g. ultraviolet light, and the substrate can also be incorporated into an electroluminescent device. The process is characterised by the features of implanting silicon ions at a dose from 1×10 17 /cm 2 to less than that required to produce saturation and by the use of an implantation energy of 100 keV or more. The resulting silicon nanocrystals dispersed through the SiO 2 substrate have an average particle size of about 30 Å.
Inventors
- 👤 Takuya Komoda
- 👤 Peter Layton Francis Hemment
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:57
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/22; C23C14/48; C23C14/58; C23C14/5806; C23C14/584; H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/822; H10H20/826; H10H20/8262; H10H20/8264
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
119 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a sufficient time to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate, said crystals exhibiting photoluminescence and/or electroluminescence, and said process being characterized in that silicon ions are implanted at an energy of at least 100 keV and at a dose of from 1×10 17 /cm 2 to less than that required to produce sputter-limited saturation, whereby there is produced a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 2
Dependent Claim
119 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a sufficient time to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate, said crystals exhibiting photoluminescence and/or electroluminescence, and said process being characterized in that silicon ions are implanted at an energy of at least 100 keV and at a dose of from 1×10 17 /cm 2 to less than that required to produce sputter-limited saturation, whereby there is produced a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 3
Dependent Claim
19 words
A process according to claim 1, wherein the silicon ions are implanted as an energy of about 200 keV.
Claim 4
Dependent Claim
50 words
The process of claim 1, wherein the implantation step comprises a first stage in which silicon ions are implanted into the SiO 2 substrate at a first energy and subsequent implantation stages in which the silicon ions are implanted into said substrate at other energies different from the first energy.
Claim 5
Dependent Claim
35 words
The process of claim 3 in which one implantation stage is carried out at an energy of about 150 keV and the other implantation stage is carried out at an energy of about 200 keV.
Claim 6
Dependent Claim
18 words
The process of claim 1, wherein the substrate is annealed at a temperature of 900° to 1300° C.
Claim 7
Dependent Claim
19 words
The process of claim 1, wherein the substrate is annealed for a period of 15 minutes to 6 hours.
Claim 8
Dependent Claim
16 words
The process of claim 1, wherein the substrate is annealed in an atmosphere of nitrogen gas.
Claim 9
Dependent Claim
27 words
A process of claim 1, wherein further annealing is carried out in the presence of hydrogen that modifies the microcrystals to cause them to exhibit increased luminescence.
Claim 10
Dependent Claim
157 words
A process of forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient time to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate and capable of exhibiting photoluminescence and/or electroluminescence, the process being characterized in that the thickness of the silicon dioxide layer is more than 100 nm-500 nm and the silicon dioxide layer is implanted with ions having an energy of at least 100 keV which is sufficient to penetrate the SiO 2 layer with a projection range equal to or more than half the thickness of the SiO 2 layer whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 11
Dependent Claim
157 words
A process of forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient time to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate and capable of exhibiting photoluminescence and/or electroluminescence, the process being characterized in that the thickness of the silicon dioxide layer is more than 100 nm-500 nm and the silicon dioxide layer is implanted with ions having an energy of at least 100 keV which is sufficient to penetrate the SiO 2 layer with a projection range equal to or more than half the thickness of the SiO 2 layer whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 12
Dependent Claim
16 words
The process of claim 8, wherein the hydrogen is present as a component of forming gas.
Claim 13
Dependent Claim
23 words
The process of claim 8, wherein the further annealing is carried out at a temperature from more than 400° C. to 1100° C.
Claim 14
Dependent Claim
17 words
The process of claim 8, wherein the further annealing is carried out for at least 1 hour.
Claim 15
Dependent Claim
20 words
The process of claim 1, wherein the SiO 2 is produced by oxidation of the surface of a silicon wafer.
Claim 16
Dependent Claim
18 words
The process of claim 1, wherein the SiO 2 is prepared in the form of a quartz plate.
Claim 17
Dependent Claim
186 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient time to bring about precipitation of silicon nanocrystals dispersed through the substrate and capable of producing photoluminescence and/or electroluminescence, the process being characterized in that silicon ions are implanted at a dose of from 1×10 17 /cm 2 to less than that required to produce saturation and at an energy of at least 100 keV, and in that the thickness of the layer is more than 100 nm and the projection range or ranges of the implanted ions are chosen so that all the silicon is deposited in the oxide layer at a depth or depths with a projected range which is greater than three times the standard deviation of the range whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 18
Dependent Claim
186 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient time to bring about precipitation of silicon nanocrystals dispersed through the substrate and capable of producing photoluminescence and/or electroluminescence, the process being characterized in that silicon ions are implanted at a dose of from 1×10 17 /cm 2 to less than that required to produce saturation and at an energy of at least 100 keV, and in that the thickness of the layer is more than 100 nm and the projection range or ranges of the implanted ions are chosen so that all the silicon is deposited in the oxide layer at a depth or depths with a projected range which is greater than three times the standard deviation of the range whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 19
Dependent Claim
131 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate, said crystals exhibiting photoluminescence and/or electroluminescence, and said process being characterized in that silicon ions are implanted at an energy of at least 100 keV and at a dose of from 1×10 17 /cm 2 to less than that required to produced sputter-limited saturation, whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 20
Dependent Claim
131 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate, said crystals exhibiting photoluminescence and/or electroluminescence, and said process being characterized in that silicon ions are implanted at an energy of at least 100 keV and at a dose of from 1×10 17 /cm 2 to less than that required to produced sputter-limited saturation, whereby there is produced a silicon material containing Si nanocrystals having an average particle size of about 30 Å which is capable of producing photoluminescence and/or electroluminescence.
Claim 21
Dependent Claim
143 words
A process of forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate and capable of exhibiting photoluminescence and/or electroluminescence, the process being characterized in that the thickness of the silicon dioxide layer is more than 100 nm-500 nm and the silicon dioxide layer is implanted with ions having an energy of at least 100 keV which is sufficient to penetrate the SiO 2 layer with a projection range equal to or more than half the thickness of the SiO layer, whereby there is produce a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 22
Dependent Claim
143 words
A process of forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the SiO 2 substrate and capable of exhibiting photoluminescence and/or electroluminescence, the process being characterized in that the thickness of the silicon dioxide layer is more than 100 nm-500 nm and the silicon dioxide layer is implanted with ions having an energy of at least 100 keV which is sufficient to penetrate the SiO 2 layer with a projection range equal to or more than half the thickness of the SiO layer, whereby there is produce a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 23
Dependent Claim
174 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the substrate and capable of producing photoluminescence and/or electroluminescence, the process being characterized in that silicon ions are implanted at a dose of from 1×10 17 /cm 2 to less than that required to produce saturation and at an energy of at least 100 keV, and in that the thickness of the layer is more than 100 nm and the projection range or ranges of the implanted ions are chosen so that all of the silicon is deposited in the oxide layer at a depth or depths with a projected range which is greater than three times the standard deviation of the range, whereby there is produced a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 24
Dependent Claim
174 words
A process for forming a luminescent silicon material which comprises the steps of implanting silicon ions into a silicon oxide (SiO 2 ) substrate, and annealing the substrate at an elevated temperature in an atmosphere comprising at least one of hydrogen and nitrogen for a period sufficient to bring about precipitation of silicon nanocrystals dispersed through the substrate and capable of producing photoluminescence and/or electroluminescence, the process being characterized in that silicon ions are implanted at a dose of from 1×10 17 /cm 2 to less than that required to produce saturation and at an energy of at least 100 keV, and in that the thickness of the layer is more than 100 nm and the projection range or ranges of the implanted ions are chosen so that all of the silicon is deposited in the oxide layer at a depth or depths with a projected range which is greater than three times the standard deviation of the range, whereby there is produced a silicon material which is capable of producing photoluminescence and/or electroluminescence.
Claim 25
Dependent Claim
30 words
The process of claim 18, in which the thickness of the silicon dioxide layer is about 500 nm and the projection range of the silicon ions is about 300 nm.
References Cited (Backward Citations)
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