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Title: Crystallization and doping of amorphous silicon on low temperature plastic

Abstract

A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate is disclosed. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900 C), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180 C for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180 C) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide. 5 figs.

Inventors:
; ; ;
Issue Date:
OSTI Identifier:
6988232
Patent Number(s):
5346850 A
Application Number:
PPN: US 7-968561
Assignee:
Univ. of California, Oakland, CA (United States) PTO; EDB-94-152892
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Resource Relation:
Patent File Date: 29 Oct 1992
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON; CRYSTAL DOPING; CRYSTALLIZATION; AMORPHOUS STATE; CARRIER MOBILITY; ELECTRIC CONDUCTIVITY; LASERS; SUBSTRATES; ELECTRICAL PROPERTIES; ELEMENTS; MOBILITY; PHASE TRANSFORMATIONS; PHYSICAL PROPERTIES; SEMIMETALS; 360601* - Other Materials- Preparation & Manufacture; 360602 - Other Materials- Structure & Phase Studies

Citation Formats

Kaschmitter, J.L., Truher, J.B., Weiner, K.H., and Sigmon, T.W. Crystallization and doping of amorphous silicon on low temperature plastic. United States: N. p., 1994. Web.
Kaschmitter, J.L., Truher, J.B., Weiner, K.H., & Sigmon, T.W. Crystallization and doping of amorphous silicon on low temperature plastic. United States.
Kaschmitter, J.L., Truher, J.B., Weiner, K.H., and Sigmon, T.W. Tue . "Crystallization and doping of amorphous silicon on low temperature plastic". United States.
@article{osti_6988232,
title = {Crystallization and doping of amorphous silicon on low temperature plastic},
author = {Kaschmitter, J.L. and Truher, J.B. and Weiner, K.H. and Sigmon, T.W.},
abstractNote = {A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate is disclosed. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900 C), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180 C for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180 C) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide. 5 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {9}
}