On the optimization and reliability of ohmic and Schottky contacts to InAlAs/InGaAs HFET

Author

Heedt, C. ; Gottwald, P. ; Buchali, F. ; Prost, W. ; Kunzel, H. ; Tegude, F.J.

Author_Institution

Duisburg Univ., Germany

fYear

1992

fDate

21-24 April 1992

Firstpage

238

Lastpage

241

Abstract

Performance and reliability issues of contacts to lattice matched HFETs (heterostructure field-effect transistors) grown by MBE (molecular-beam epitaxy) on InP are addressed. Based on the idea that both Ni and Ge should be very close to the semiconductor surface, a novel Au-Ge-Ni superlattice ohmic-contact metallization has been developed (R/sub C/<0.1 Omega -mm). The leakage current of reverse-biased Schottky contacts is studied experimentally and theoretically. It is shown by both methods that the undoped barrier layer thickness has a superior influence in comparison to the barrier height Phi /sub B/. If Schottky contacts are thermally stressed in the atmosphere (T=200 degrees C), a dramatic increase of leakage is observed while the barrier height Phi /sub B/ remains unchanged.<>

Keywords

III-V semiconductors; Schottky effect; aluminium compounds; electrical contacts; field effect transistors; gallium arsenide; germanium; gold; indium compounds; metallic superlattices; metallisation; nickel; ohmic contacts; reliability; vapour phase epitaxial growth; 200 degC; Au-Ge-Ni; InAlAs-InGaAs-InP; InP; barrier height; heterostructure field-effect transistors; lattice matched HFETs; leakage current; molecular-beam epitaxy; optimization; reliability; reverse-biased Schottky contacts; semiconductor surface; superlattice ohmic-contact metallization; thermally stressed; undoped barrier layer; HEMTs; Indium phosphide; Lattices; Leakage current; MODFETs; Metallic superlattices; Metallization; Molecular beam epitaxial growth; Schottky barriers; Semiconductor superlattices;

fLanguage

English

Publisher

ieee

Conference_Titel

Indium Phosphide and Related Materials, 1992., Fourth International Conference on

Conference_Location

Newport, RI, USA

Print_ISBN

0-7803-0522-1

Type

conf

DOI

10.1109/ICIPRM.1992.235595

Filename

235595