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Title: Method for producing silicon thin-film transistors with enhanced forward current drive

Abstract

A method for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates.

Inventors:
 [1]
  1. (San Jose, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
871664
Patent Number(s):
5773309
Assignee:
Regents of University of California (Oakland, CA) LLNL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; producing; silicon; thin-film; transistors; enhanced; forward; current; drive; fabricating; amorphous; film; tfts; polycrystalline; surface; channel; region; particularly; adapted; top-gate; advantages; leakage; accomplished; selectively; crystallizing; selected; pulsed; excimer; laser; create; layer; gate-insulator; created; polysilicon; increased; mobility; compared; device; operation; currents; achieved; reverse; relatively; transistor; exhibits; inherent; example; pixel; switch; active-matrix; liquid; crystal; display; improve; refresh; rates; leakage currents; film transistors; current drive; particularly adapted; silicon layer; amorphous silicon; polycrystalline silicon; crystalline silicon; liquid crystal; producing silicon; leakage current; excimer laser; silicon surface; drive current; crystal display; channel region; fabricating amorphous; insulator surface; thin-film transistors; forward current; film transistor; enhanced forward; selected region; active-matrix liquid; drive currents; /438/117/148/

Citation Formats

Weiner, Kurt H. Method for producing silicon thin-film transistors with enhanced forward current drive. United States: N. p., 1998. Web.
Weiner, Kurt H. Method for producing silicon thin-film transistors with enhanced forward current drive. United States.
Weiner, Kurt H. Thu . "Method for producing silicon thin-film transistors with enhanced forward current drive". United States. https://www.osti.gov/servlets/purl/871664.
@article{osti_871664,
title = {Method for producing silicon thin-film transistors with enhanced forward current drive},
author = {Weiner, Kurt H.},
abstractNote = {A method for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {1}
}

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