Title :
Ohmic contacts with different metal structures for lattice matched InP based heterostructures
Author :
Lamarre, P. ; McTaggart, R. ; Pulley, M. ; Huang, J. ; Jackson, G.
Author_Institution :
Raytheon Co., Lexington, MA, USA
Abstract :
AuGeNiAu and PdGeAu contacts to InP based high electron mobility transistor (HEMT) structures are examined. Standard, non-recessed, transmission line model (TLM) structures do not accurately represent contact resistance when there is high interfacial resistance between InGaAs and InAlAs. A mathematical model using distributed resistance is reviewed. Three new TLM structures derived from the model are shown and new methods for measuring contact resistance are given. Different metal schemes were evaluated and different layer thicknesses within a given metal scheme were also compared using statistically designed experiments. PdGeAu was found to be consistently better for ohmic contacts than AuGeNiAu. The optimum thicknesses found in the PdGeAu system were 150Å of Pd and 500Å of Ge
Keywords :
III-V semiconductors; aluminium compounds; contact resistance; gallium arsenide; germanium alloys; gold alloys; high electron mobility transistors; indium compounds; nickel alloys; ohmic contacts; palladium alloys; semiconductor-metal boundaries; 150 Å; 500 Å; HEMT; InP-InAlAs-InGaAs-AuGeNiAu; InP-InAlAs-InGaAs-PdGeAu; contact resistance; distributed resistance; interfacial resistance; lattice matched heterostructures; layer thicknesses; ohmic contacts; optimum thicknesses; semiconductors; transmission line model structures; Contact resistance; Electrical resistance measurement; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; Lattices; MODFETs; Mathematical model; Ohmic contacts;
Conference_Titel :
Indium Phosphide and Related Materials, 1993. Conference Proceedings., Fifth International Conference on
Conference_Location :
Paris
Print_ISBN :
0-7803-0993-6
DOI :
10.1109/ICIPRM.1993.380642
