TY  - JOUR
AU  - Khanduri, G. M. 
AU  - Panwar, B. S. 
PY  - 2004
TI  - Study of Cutoff Frequency of High Collector Current Density in SiGe Single-Heterojunction Bipolar Transistor
JF  - American Journal of Applied Sciences
VL  - 1
IS  - 3
DO  - 10.3844/ajassp.2004.236.239
UR  - https://thescipub.com/abstract/ajassp.2004.236.239
AB  - The cutoff frequency performance of an NPN Si/SiGe/SiGe Single-heterojunction bipolar transistor (SiGe SHBT) at high collector current densities has been analyzed using a 2-dimensional MEDICI device simulator. A conventional NPN Si/SiGe/Si Double-heterojunction bipolar transistor (SiGe DHBT) having uniform 14%Ge in the base region has been investigated for comparison. The analysis shows the formation of a retarding potential barrier for minority carrier electrons at the basecollector heterojunction of the DHBT structure. Whereas, the base-collector homojunction of the SiGe SHBT structure, having a uniform 14%Ge profile in its base and collector, inhibits the formation of such a retarding potential barrier. The SHBT structure with a base-collector homojunction shows an Improved cutoff frequency at a high collector current density in comparison with conventional SiGe DHBT, which makes it more promising for high speed, scaled down, field-specific applications.