Si/Ge<sub>x</sub>Si/sub 1-x/ heterojunction bipolar transistors with the Ge<sub>x</sub>Si/sub 1-x/ base formed by Ge ion implantation in Si

S. Lombardo, A. Pinto, V. Raineri, Peter J. Ward, Giuseppe La Rosa, Giuseppe Privitera, S. U. Campisano

IEEE Electron Device Letters · 1996 · 21 citations · 10 references

Concepts

Abstract

We have fabricated n-p-n, Si/Ge/sub 2/Si/sub 1-x/ heterojunction bipolar transistors (HBTs) with the Ge/sub x/Si/sub 1-x/ base formed by high-dose Ge implantation followed by solid phase epitaxy. The fabrication technology is a standard self-aligned, double polysilicon process scheme for Si with the addition of the high-dose Ge implantation. The transistors are characterized by a 60 mn-wide neutral base with a Ge concentration peak of /spl ap/8 at.% at the base-collector junction. The HBTs show good electrical characteristics and compared to Si homojunction transistors show lower base resistance, larger values of current gain, and a lower emitter-to-collector transit time.

References

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