Title :
Low leakage and high speed InP/In0.53Ga0.47As/InP metamorphic double heterojunction bipolar transistors in GaAs substrates
Author :
Kim, Y.M. ; Griffith, Zach ; Rodwell, M.J.W. ; Gossard, A.C.
Abstract :
The paper presents low leakage and high speed InP/In0.53Ga0.47As/InP metamorphic double heterojunction bipolar transistors in GaAs substrates. Metamorphic HBT with improved fmax is resulted from high carbon base doping concentration. Carbon doping grading was used in base layer from 8e19/cm2 to 5e19/cm3. Pd (30 Å)/ Ti (200 Å)/ Pd (200 Å) / Au (400 Å) base ohmic contacts are used. These provide specific contact resistance well below 10-6 Ω cm2. The base-collector leakage current was found to be 1.2 nA at VCB=0.3 V. This leakage is comparable to 1.8 nA Icbo for lattice matched DHBT. The triple-mesa HBT was fabricated using optical projection lithography and selective wet etching.
Keywords :
III-V semiconductors; doping profiles; gallium arsenide; gold; heterojunction bipolar transistors; indium compounds; leakage currents; ohmic contacts; palladium; photolithography; sputter etching; titanium; 0.3 V; 1.2 nA; 1.8 nA; 200 Å; 30 Å; 400 Å; GaAs; InP-In0.53Ga0.47As/InP HBT; InP-InGaAs-InP:C; Pd-Ti-Au; carbon base doping concentration; contact resistance; lattice matched double HBT; low leakage current; metamorphic double heterojunction bipolar transistors; ohmic contacts; optical projection lithography; selective wet etching; triple-mesa HBT; Contact resistance; Doping; Double heterojunction bipolar transistors; Gallium arsenide; Gold; Heterojunction bipolar transistors; Indium phosphide; Lattices; Leakage current; Ohmic contacts;
Conference_Titel :
Semiconductor Device Research Symposium, 2003 International
Print_ISBN :
0-7803-8139-4
DOI :
10.1109/ISDRS.2003.1272129
