GaAs THIN FILMS AND METHODS OF MAKING AND USING THE SAME

Shannon Boettcher

Patent

Atlas literature

Patent

US 9,368,670

GaAs THIN FILMS AND METHODS OF MAKING AND USING THE SAME

Shannon Boettcher

Drawings

Patent drawings and their descriptions. Click a drawing to enlarge it.

FIG. 1

FIG. 1 is a schematic of an exemplary close-spaced vapor transport method.

FIG. 2

FIG. 2 is a photographic image of an exemplary close-spaced vapor transport 15 apparatus.

FIG. 3

performance graph

FIG. 3 is a graph of SIMS depth proﬁles of two exemplary n-GaAs thin ﬁlms grown from diﬀerently-doped GaAs:Te sources on GaAs:Si substrates; the Te depth …

FIG. 4

performance graph

FIG. 4 is a graph of photoelectrochemical J-E curves of n-GaAs thin ﬁlms and control wafers; the curves are labeled with the corresponding sample's free …

FIG. 5

performance graph

FIG. 5 is a graph of photoelectrochemical J-E curves of p-GaAs thin ﬁlms and control wafers; the curves are labeled with the corresponding sample's free …

FIG. 6

performance graph

FIG. 6A is a graph of quantum eﬃciency as a function of applied bias of a p-GaAs thin ﬁlm measured in non-aqueous I-/13- under 850 nm illumination provided by …

FIG. 7

performance graph

FIG. 7 is a graph illustrating min t measurements obtained using photoelectrochemical (PEC) analysis of n-GaAs thin ﬁlms.

FIG. 8

performance graph

FIG. 8 is a graph illustrating min t measurements obtained using PEC on p-GaAs thin ﬁlms. 5

FIG. 9

performance graph

FIG. 9A) and a graph illustrating total impedance and phase angle response to DC voltage wherein each curve represents a diﬀerent DC bias.

FIG. 10

FIGS. 10A and 1 0 B illustrate representative Mott-Schottky plots for a representative p- GaAs thin ﬁlm (

FIG. 11

performance graph

FIG. 11 is a graph of Hall mobilities of n-GaAs thin ﬁlms made using an embodiment of the present disclosure as a function of N o and N A, wherein solid curves …

FIG. 12

performance graph

FIG. 12 is a graph of Hall mobilities of p-GaAs thin ﬁlms made using an embodiment of 15 the present disclosure as a function of N o and N A, wherein solid …

FIG. 13

FIG. 13B) of a GaAs thin ﬁlm deposited on a Si-doped n+-GaAs substrate. 20

FIG. 14

performance graph

FIG. 14 is a graph of EBIC decays with linear ﬁts used to extract L o values from passivated GaAs thin ﬁlms measured with low accelerating voltages of 2-5 keV.

FIG. 15

FIG. 15 is a schematic of an exemplary electron beam induced current (EBIC) technique, wherein Xis the separation between the excitation source and the …

FIG. 16

performance graph

FIG. 16 is a graph of the observed EBIC decay constant as a function of Vao, wherein the dashed line indicates L o predicted by spectral response using the G a …

FIG. 17

performance graph

FIG. 17 is a graph of L o measured by EBIC on the same CSVT GaAs thin ﬁlm before and after passivation by Na₂S, wherein the dashed line indicates the L o …

FIG. 18

performance graph

FIG. 18 is a graph comparing L o obtained by spectral response and EBIC techniques.

FIG. 19

performance graph

FIG. 19 is a graph of current as a function of voltage illustrating results obtained from of a representative GaAs pn junction thin ﬁlm device.

FIG. 20

performance graph

FIG. 20 is a graph of internal quantum eﬃciency (in t) as a function of wavelength illustrating results obtained from analysis of representative pn junction …

FIG. 21

performance graph

FIG. 21 is graph of internal quantum eﬃciency at various etch depths for a representative pn junction GaAs thin ﬁlm device illustrating that response improves …

FIG. 22

performance graph

FIG. 22 is a graph of light and dark IV curves for a device formed from a pn junction 10 GaAs thin ﬁlm.

FIG. 23

performance graph

FIG. 23 is a graph of concentration as a function of depth illustrating a SIMS proﬁle of Ge and Zn measured on a pn junction GaAs thin ﬁlm device which shows …

FIG. 24

performance graph

FIG. 24 is a graph of carrier concentration determined by capacitance-voltage proﬁling of a pn junction GaAs thin ﬁlm device from which the level of …

FIG. 25

FIG. 26

FIG. 27

FIG. 28

FIG. 29

FIG. 30

FIG. 30 9B). We ﬁt the impedance vs voltage response to an equivalent circuit (

Claims

Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.

4 independent · 18 dependent

1
IndependentGaAsGaAs
A method comprising: forming a GaAs thin ﬁlm on a deposition substrate by the steps of providing a GaAs powder source; providing a dopant source; and using vapor transport with a chemical transport agent to deposit the GaAs thin ﬁlm on the deposition substrate, the GaAs thin ﬁlm having Hall mobilities of 1000-4200 cm2V-1s-1 for an n-type GaAs thin ﬁlm and/or 50-240 cm2V -1s-1 for a p-type GaAs thin ﬁlm.
1. 2
  Dependent← claim 1GaAs
  The method of claim 1, wherein the GaAs thin ﬁlm is epitaxial.
2. 3
  Dependent← claim 1dopant source (S, Se, Cd, Ge, Si, C, Te, Zn)
  The method of claim 1, wherein the dopant source is selected from S, Se, Cd, Ge, Si, C, Te, Zn, or combinations thereof.
3. 4
  Dependent← claim 1chemical transport agent (H2, H₂O, I2, HCl)
  The method of claim 1, wherein the chemical transport agent is selected from H2, H₂ 0, 12, H CI, or combinations thereof.
4. 5
  Dependent← claim 1GaAs
  The method of claim 1, wherein the vapor transport comprises aqueous vapor 20 transport.
6
IndependentGaAsH₂O
A method comprising: providing a doped GaAs powder source; depositing a GaAs thin ﬁlm on a deposition substrate from the doped GaAs powder 25 source using a chemical transport agent in a vapor transport apparatus, the chemical transport agent comprising a carrier gas and H₂ 0, the H₂₀ concentration being 10 ppm to 12,000 ppm during the deposition; and wherein the GaAs thin ﬁlm is capable of producing a photocurrent ranging from 15 mA cm- 2 to 25 mA cm⁻² under 100 m W cm⁻² AM 1.5G illumination.
1. 7
  Dependent← claim 6dopant source (S, Se, Cd, Ge, Si, C, Te, Zn)
  The method of claim 6, wherein the doped GaAs powder comprises S, Se, Cd, Ge, Si, C, Te, Zn, or combinations thereof.
2. 8
  Dependent← claim 6GaAs
  The method of claim 6, wherein the GaAs thin ﬁlm comprises a dopant concentration ranging from 1016 cm⁻³ to 1019 cm -3.
3. 9
  Dependent← claim 6GaAs
  The method of claim 6, wherein the GaAs thin ﬁlm is epitaxial.
10
IndependentGaAsGaAs
A method comprising: combining a solid GaAs powder with a dopant to form a source composition; depositing a GaAs thin ﬁlm on a deposition substrate, from the source composition, using a chemical transport agent in a vapor transport system, in the absence of a toxic gas; and wherein the GaAs thin ﬁlm has an L o value of 2 p m to 3 p m or 5 p m to 8 pm.
1. 11
  Dependent← claim 10dopant source (S, Se, Cd, Ge, Si, C, Te, Zn)
  The method of claim 10, wherein the dopant is selected from S, Se, Cd, Ge, Si, C, Te, Zn, or combinations thereof.
2. 12
  Dependent← claim 10chemical transport agent (H2, H₂O, I2, HCl)
  15 12. The method of claim 10, wherein the chemical transport agent is selected from H2, H₂ 0, 12, H CI, and combinations thereof.
13
IndependentGaAsGaAs
A method comprising making a GaAs thin ﬁlm on a deposition substrate using a close-spaced vapor transport system, by: 20 providing a source composition comprising GaAs and a dopant powder mixture; maintaining a heat source positioned proximate the source composition, at a temperature ranging from 600 ° C to 950 °C; providing the deposition substrate positioned from 0.5 mm to 1.5 mm from the source composition; 25 maintaining the deposition substrate at a temperature that is 5 ° C to 200 C lower than the temperature of the heat source thereby producing a thermal gradient between the source composition and the deposition substrate; exposing the source composition to a chemical transport agent in the close-spaced vapor transport system to produce a vapor-phase GaAs precursor composition; and 30 depositing the GaAs thin ﬁlm on the deposition substrate using the thermal gradient to facilitate deposition of the vapor-phase GaAs precursor composition.
1. 14
  Dependent← claim 13GaAs
  The method of claim 13, wherein the GaAs thin ﬁlm is an epitaxial ﬁlm.
2. 15
  Dependent← claim 13GaAs
  The method of claim 13, wherein the GaAs thin ﬁlm is a polycrystalline ﬁlm.
3. 16
  Dependent← claim 13
  The method of claim 13, wherein the source composition is exposed to the chemical transport agent at atmospheric pressure.
4. 17
  Dependent← claim 13chemical transport agent (H2, H₂O, I2, HCl)
  The method of claim 13, wherein the chemical transport agent is selected from H2, H₂ 0, 12, H CI, and combinations thereof.
5. 18
  Dependent← claim 13H₂O
  The method of claim 13, wherein the chemical transport agent is H 2 and H₂ 0.
6. 19
  Dependent← claim 13GaAs
  The method of claim 13, wherein the GaAs thin ﬁlm is deposited on the deposition substrate at a rate of 10 nm per minute to 10 m per minute.
7. 20
  Dependent← claim 13dopant source (S, Se, Cd, Ge, Si, C, Te, Zn)
  The method of claim 13, wherein the dopant is selected from S, Se, Cd, Ge, Si, 15 C, Te, Z n, or combinations thereof.
8. 21
  Dependent← claim 13
  The method of claim 13, wherein the dopant
9. 22
  Dependent← claim 13GaAsTe powder and/or Zn powder
  The method of claim 13, wherein the GaAs ranging from 1 016 cm⁻³ to 1 019 cm -3.-31-is Te powder and/or Zn powder. thin ﬁlm comprises a dopant 20 concentration

Materials

Materials described outside the worked examples.

GaAs thin film

GaAs

Deposited Thin Film

Source Material

dopant source (S, Se, Cd, Ge, Si, C, Te, Zn)

Process steps

Additional fabrication and treatment steps described in the patent.

Close Spaced Vapor Transport

Step 1

Temperature

600, 950°C

Process details

pressure:atmospheric (per claim 16)

deposition rate:

Characterization

Measurements and analyses referenced in the patent, with their drawing references.

device performance measurement

Device Performance Measurement

FIG. 3 is a graph of SIMS depth proﬁles of two exemplary n-GaAs thin ﬁlms grown from diﬀerently-doped GaAs:Te sources on GaAs:Si substrates; the Te depth …

Figure references

FIG. 3

GaAs

Reported properties

Performance values and ranges asserted in the specification or claims.

Property	Value	Material
Hall mobility, n-type GaAs thin film	1000–4200	GaAs
Hall mobility, p-type GaAs thin film	50–240

Why these are connected

Related documents with shared materials, methods, properties, or citations.

GaAs THIN FILMS AND METHODS OF MAKING AND USING THE SAME | Matter42 Literature