Bg. Malm et al., Influence of transient enhanced diffusion of the intrinsic base dopant profile on SiGeHBT DC and HF characteristics, SOL ST ELEC, 44(10), 2000, pp. 1747-1752
The influence of transient enhanced boron out-diffusion from the intrinsic
base, caused by excess silicon interstitials created during the extrinsic b
ase implantation, has been investigated for a non-selective SiGe HBT proces
s. Devices with different designs of the extrinsic base region were fabrica
ted, where some designs allowed part of the epitaxial base to be implanted
with a high boron dose, hereby increasing the number of silicon interstitia
ls close to the intrinsic device. These devices showed a marked degradation
of DC characteristics and HF performance. 2D-device simulations were used
to investigate the sensitivity in DC and HF parameters to vertical base pro
file changes. Good agreement was obtained between measured and simulated DC
and HF characteristics. (C) 2000 Published by Elsevier Science Ltd. Ail ri
ghts reserved.