Method and arrangement for producing an N-semiconductive indium sulfide thin layer

• US 8,143,145 B2
• Filed: 03/14/2009
• Issued: 03/27/2012
• Est. Priority Date: 04/01/2008
• Status: Expired due to Fees

• Current Assignee: Helmholtz-Zentrum Berlin FüR Materialien und Energie Gesellschaft Mit Beschrã¤Nkter Haftung (Bundesrepublik Deutschland)
• Original Assignee: Helmholtz-Zentrum Berlin FüR Materialien und Energie Gesellschaft Mit Beschrã¤Nkter Haftung (Bundesrepublik Deutschland)
• Inventors: Allsop, Nicholas, Fischer, Christian-Herbert, Gledhill, Sophie, Lux-Steiner, Martha Christina
• Primary Examiner(s): Ahmadi, Mohsen
• Application Number:
  US12/934,329
• Publication Number:
  US 20110081734A1
• Time in Patent Office: 1,109 Days
• Field of Search: 257/E21.269, 257/E21.274, 257/E21.308
• US Class Current: 438/478
• CPC Class Codes: C23C 16/305 Sulfides, selenides, or tellurides
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations

Abstract

A method of producing, at atmospheric pressure, an n-type semiconductive indium sulfide thin film on a substrate using an indium-containing precursor, hydrogen sulfide as a reactive gaseous precursor, and an inert carrier gas stream includes cyclically repeating first and second steps so as to produce an indium sulfide thin film of a desired thickness. The first method phase includes converting the indium-containing precursor to at least one of a dissolved and a gaseous phase, heating the substrate to a temperature in a range of 100° C. to 275° C., directing the indium containing precursor onto the substrate and supplying hydrogen sulfide to the indium-containing precursor in a mixing zone in an amount so as to provide an absolute concentration of hydrogen sulfide that is greater than zero and no greater than 1% by volume. The indium concentration of the indium-containing precursor is set so as to produce a compact In(OH_x,X_y,S_z)₃ film, where X=halide and x+y+2z=1 with z≠0. The second step includes setting a temperature of the substrate in a range of 18° C. and 450° C. and directing hydrogen sulfide onto the substrate in an absolute concentration up to 100%.

Claims

1. A method of producing an n-type semiconductive indium sulfide thin film on a substrate using an indium-containing precursor, hydrogen sulfide as a reactive gaseous precursor, and an inert carrier gas stream, the method being carried out at atmospheric pressure and comprising:

a) converting the indium-containing precursor to at least one of a dissolved and a gaseous phase,

heating the substrate to a temperature in a range of 100°

C. to 275°

C., and

directing the converted indium containing precursor onto the substrate and supplying hydrogen sulfide to the indium-containing precursor in an amount so as to provide an absolute concentration of hydrogen sulfide that is greater than zero and no greater than 1% by volume in a mixing zone,

wherein the indium concentration of the indium-containing precursor is set so as to produce a compact In((OH)_x,X_y,S_z)₃ film, where X=halide and x+y+2z=1 with z≠

0,

b) setting a temperature of the substrate in a range of 18°

C. and 450°

C., and

directing onto the substrate hydrogen sulfide in an absolute concentration up to 100%; and

cyclically repeating steps a) and b) so as to produce an indium sulfide thin film of a desired thickness.

2. The method as recited in claim 1, wherein the indium-containing precursor has a vapor pressure that facilitates the converting of the indium-containing precursor to the at least one of a dissolved and a gaseous phase.

3. The method as recited in claim 1, wherein the indium-containing precursor forms a volatile adduct with a solvent.

4. The method as recited in claim 1, wherein in step a) the indium-containing precursor and hydrogen sulfide are directed in a laminar flow over the substrate.

5. The method as recited in claim 1, wherein the converting the indium-containing precursor to at least one of a dissolved and a gaseous phase includes dissolving the indium containing precursor in a solvent so as to form a solution and atomizing the solution with at least one of an ultrasonic generator and a pneumatic atomizer so as to produce an aerosol of extremely fine droplets in air.

6. The method as recited in claim 1, wherein the converting the indium-containing precursor to at least one of a dissolved and a gaseous phase includes providing the indium-containing precursor as a solid and passing a solvent vapor over the indium-containing precursor so as to convert the indium-containing precursor to the gaseous phase.

7. The method as recited in claim 1, wherein the converting the indium-containing precursor to at least one of a dissolved and a gaseous phase includes dissolving the indium containing precursor in a solvent so as to form a solution and dripping the solution onto a heated surface so as to convert the indium-containing precursor to the gaseous phase.

8. The method as recited in claim 1, wherein the indium-containing precursor includes at least one of a halide salt of indium and a solvent adduct of the halide salt.

9. The method as recited in claim 8, wherein the β

-diketonate is indium acetylacetonate (In(acac)₃).

10. The method as recited in claim 8, wherein the halide salt is indium chloride InCl₃.

11. The method as recited in claim 1, wherein the indium-containing precursor includes a β

-diketonate.

12. The method as recited in claim 1, wherein the solvent includes at least one of an alcohol and a ketone.

13. The method as recited in claim 1, wherein the solvent includes at least one of an ethanol and an acetone.

14. The method as recited in claim 1, wherein the carrier gas stream is N₂.

15. The method as recited in claim 1, wherein a vicinity surrounding the heated substrate is at room temperature.

16. The method as recited in claim 1, further comprising preheating at least one of the hydrogen sulfide and a mixture of the hydrogen sulfide, indium-containing precursor and carrier gas stream.

17. The method as recited in claim 1, wherein the substrate includes at least one of TiO₂, CuInS₂, CuGaSe₂, a chalcopyrite, metal and glass.

18. The method as recited in claim 1, further comprising performing an in-situ optical concentration measurement so as to determine concentrations of constituent fractions of aerosols directed to the substrate.

19. The method as recited in claim 1, further comprising performing an in-situ optical reflectance measurement so as to determine a thickness of the produced indium sulfide thin film.