Title :
Optimization of the doping levels in doubly doped InAlAs/InGaAs HEMTs
Author :
Kraus, S. ; Sexl, M. ; Bohm, G. ; Trankle, Gunther ; Weimann, G.
Author_Institution :
Walter Schottky Inst., Tech. Univ. Munchen, Garching, Germany
Abstract :
Delta-doped InAlAs/InGaAs-HEMTs were grown by MBE, lattice matched on InP-substrates. The ratio of upper doping to lower doping was varied from 1:0, 4:1, 2:1, 1:1 to 0:1, while total doping concentration was kept constant. By increasing the bottom doping concentration, the drain current is increased and the kink effect reduced. Ultimately the inversely doped transistor shows absolutely no kink and a very low output conductance of 25 mS/mm. These new results offer a better understanding of the kink effect, related to the band structure of the HEMTs and its dependence on doping
Keywords :
III-V semiconductors; aluminium compounds; band structure; doping profiles; gallium arsenide; high electron mobility transistors; indium compounds; semiconductor epitaxial layers; InAlAs-InGaAs; InP; InP-substrates; MBE; band structure; bottom doping concentration; delta-doping; doping levels; doubly doped HEMTs; drain current; inversely doped transistor; kink effect; output conductance; Charge carrier density; Doping; Electrons; Etching; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; MODFETs; Substrates;
Conference_Titel :
Compound Semiconductors, 1997 IEEE International Symposium on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7503-0556-8
DOI :
10.1109/ISCS.1998.711725
