Title :
Improved reliability of AlGaAs/GaAs heterojunction bipolar transistors with a strain-relaxed base
Author :
Sugahara, H. ; Nagano, J. ; Nittono, T. ; Ogawa, K.
Author_Institution :
NTT LSI Lab., Kanagawa, Japan
Abstract :
The authors reveal a key to improving the life of MOCVD-grown AlGaAs/GaAs heterojunction bipolar transistors with carbon-doped base. In addition to presenting new findings on current gain degradation properties, it is shown that the importance of lattice strain relaxation in a carbon-doped base layer. Indium was incorporated into C-doped GaAs to relax strain by controlling the lattice constant in the base layer, which was slightly shrunk by carbon doping. Although lifetime testing is still underway, the median life is estimated to be longer than 2.8 /spl times/ 10/sup 6/ hours and 1.1 /spl times/ 10/sup 5/ hours where the collector current density is 10 kA/cm/sup 2/and 50 kA/cm/ /sup 2/, respectively.<>
Keywords :
III-V semiconductors; aluminium compounds; crystal defects; failure analysis; gallium arsenide; heterojunction bipolar transistors; life testing; semiconductor device reliability; semiconductor device testing; AlGaAs-GaAs; GaAs:C; GaAs:C,In; III-V semiconductors; MOCVD-grown; current gain degradation properties; epilayer structure; failure analysis; heterojunction bipolar transistors; improved reliability; lattice strain relaxation; lifetime testing; strain-relaxed base; Capacitive sensors; Degradation; Doping; Gallium arsenide; Heterojunction bipolar transistors; Indium; Lattices; Life estimation; Life testing; Strain control;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1993. Technical Digest 1993., 15th Annual
Conference_Location :
San Jose, CA, USA
Print_ISBN :
0-7803-1393-3
DOI :
10.1109/GAAS.1993.394489
