CHALLENGES FOR A SI/GE HETERODEVICE TECHNOLOGY

Previous results reported for Si-based devices like the SiGe heterobipolar transistor (SiGe HBT), the n- and p-channel SiGe modulation doped field effect transitor (SiGe MODFET or MOSFET) and SiGe optoelectronic devices point to the outstanding potential of this novel heterosystem. Enhanced speed, distinctly above 100 GHz can be envisaged, high gains or transconductances and low noise. This performance will extend the application area of the conventional Si-microelectronic. The technology for Si/Ge heterodevices is on a minor development revel. Inspite of a basic compatibility with Si-technology, SiGe introduces additional constraints, mainly due to a large lattice mismatch and to the requirement of nm-thin layers with atomically sharp junctions. Here actual Si/Ge technologies will be reviewed covering growth, layout aspects and device processes. Effects on the device performance will be discussed. Challenging technological activities concerning thermal budget, implantation, etching, passivation wait for a solution.