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Title: Method for enhancing the solubility of dopants in silicon

Abstract

A method for enhancing the equilibrium solid solubility of dopants in silicon, germanium and silicon-germanium alloys. The method involves subjecting silicon-based substrate to biaxial or compression strain. It has been determined that boron solubility was largely enhanced (more than 100%) by a compressive bi-axial strain, based on a size-mismatch theory since the boron atoms are smaller than the silicon atoms. It has been found that the large enhancement or mixing properties of dopants in silicon and germanium substrates is primarily governed by their, and to second order by their size-mismatch with the substrate. Further, it has been determined that the dopant solubility enhancement with strain is most effective when the charge and the size-mismatch of the impurity favor the same type of strain. Thus, the solid solubility of small p-type (e.g., boron) as well as large n-type (e.g., arsenic) dopants can be raised most dramatically by appropriate bi-axial (compressive) strain, and that solubility of a large p-type dopant (e.g, indium) in silicon will be raised due to size-mismatch with silicon, which favors tensile strain, while its negative charge prefers compressive strain, and thus the two effects counteract each other.

Inventors:
; ;
Issue Date:
Research Org.:
The Regents of the University of California, Oakland, CA (United States),; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1174513
Patent Number(s):
6,627,522
Application Number:
09/945,878
Assignee:
The Regents of the University of California (Oakland, CA) OSTI
DOE Contract Number:  
W-7405-ENG48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Sadigh, Babak, Lenosky, Thomas J., and De La Rubia, Tomas Diaz. Method for enhancing the solubility of dopants in silicon. United States: N. p., 2003. Web.
Sadigh, Babak, Lenosky, Thomas J., & De La Rubia, Tomas Diaz. Method for enhancing the solubility of dopants in silicon. United States.
Sadigh, Babak, Lenosky, Thomas J., and De La Rubia, Tomas Diaz. Tue . "Method for enhancing the solubility of dopants in silicon". United States. https://www.osti.gov/servlets/purl/1174513.
@article{osti_1174513,
title = {Method for enhancing the solubility of dopants in silicon},
author = {Sadigh, Babak and Lenosky, Thomas J. and De La Rubia, Tomas Diaz},
abstractNote = {A method for enhancing the equilibrium solid solubility of dopants in silicon, germanium and silicon-germanium alloys. The method involves subjecting silicon-based substrate to biaxial or compression strain. It has been determined that boron solubility was largely enhanced (more than 100%) by a compressive bi-axial strain, based on a size-mismatch theory since the boron atoms are smaller than the silicon atoms. It has been found that the large enhancement or mixing properties of dopants in silicon and germanium substrates is primarily governed by their, and to second order by their size-mismatch with the substrate. Further, it has been determined that the dopant solubility enhancement with strain is most effective when the charge and the size-mismatch of the impurity favor the same type of strain. Thus, the solid solubility of small p-type (e.g., boron) as well as large n-type (e.g., arsenic) dopants can be raised most dramatically by appropriate bi-axial (compressive) strain, and that solubility of a large p-type dopant (e.g, indium) in silicon will be raised due to size-mismatch with silicon, which favors tensile strain, while its negative charge prefers compressive strain, and thus the two effects counteract each other.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2003},
month = {9}
}

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