LPCVD SiGe for heterojunction bipolar transistors

In this work SiGe Heterojunction Bipolar Transistors (HBTs) are grown using Low-Pressure Chemical Vapour Deposition (LPCVD). To date LPCVD has tended to produce higher quality material for device applications than Molecular Beam Epitaxy (MBE). However, the quality of MBE grown material continues to improve and in the long-term it will be throughput rather than material quality that will become the issue. The LPCVD technique is easily scalable and able to accommodate batches of wafers, MBE is not so easily scalable. Although both techniques are being researched to much the same extent, it remains to be seen which will become the dominant process when this technology comes to market. (5 pages)