Title :
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
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;
Conference_Titel :
Indium Phosphide and Related Materials, 1992., Fourth International Conference on
Conference_Location :
Newport, RI, USA
Print_ISBN :
0-7803-0522-1
DOI :
10.1109/ICIPRM.1992.235595
