Title: Manufacture of silicon-based devices having disordered sulfur-doped surface layers

Abstract

The present invention provides methods of fabricating a radiation-absorbing semiconductor wafer by irradiating at least one surface location of a silicon substrate, e.g., an n-doped crystalline silicon, by a plurality of temporally short laser pulses, e.g., femtosecond pulses, while exposing that location to a substance, e.g., SF.sub.6, having an electron-donating constituent so as to generate a substantially disordered surface layer (i.e., a microstructured layer) that incorporates a concentration of that electron-donating constituent, e.g., sulfur. The substrate is also annealed at an elevated temperature and for a duration selected to enhance the charge carrier density in the surface layer. For example, the substrate can be annealed at a temperature in a range of about 700 K to about 900 K.

Inventors:

Carey, III, James Edward ^[1]; Mazur, Eric ^[2]

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+ Show Inventor Affiliations

1. (Newton, MA)
2. Concord, MA

Issue Date:

Tue Apr 08 00:00:00 EDT 2008

Research Org.:

President and Fellows of Harvard College (Cambridge, MA)

Sponsoring Org.:

USDOE

OSTI Identifier:

1014531

Patent Number(s):

7354792

Application Number:

10/950,248

Assignee:

President and Fellows of Harvard College (Cambridge, MA)

Patent Classifications (CPCs):

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

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H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES

H01L21/02686 - {Pulsed laser beam}
H01L21/268 - using electromagnetic radiation, e.g. laser radiation
H01L31/02363 - {of the semiconductor body itself, e.g. textured active layers}
H01L31/0288 - characterised by the doping material
H01L31/1804 - {comprising only elements of Group IV of the Periodic System}
H01L31/1864 - {Annealing}

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

Y02E10/547 - Monocrystalline silicon PV cells

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02P - CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

Y02P70/50 - Manufacturing or production processes characterised by the final manufactured product

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DOE Contract Number:  

FC36-01GO11051

Resource Type:

Patent

Country of Publication:

United States

Language:

English