Forming B_1-xC_x Semiconductor Layers by Chemical Vapor Deposition

Authors

Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

August 1997

Comments

United States Patent Number: 5,658,834

Abstract

Active semiconductor devices including heterojunction diodes and thin film transistors are formed by PECVD deposition of a boron carbide thin film on an N-type substrate. The boron to carbon ratio of the deposited material is controlled so that the film has a suitable band gap energy. Boron carbides such as B_4.7C, B_7.2C and B₁₉C have suitable band gap energies between 0.8 and 1.7 eV. The stoichiometry of the film can be selected by varying the partial pressure of precursor gases, such as nido pentaborane and methane. The precursor gas or gases are energized. e.g., in a plasma reactor. The heterojunction diodes retain good rectifying properties at elevated temperature, e.g., up to 400° C.