MIT Department of Electrical Engineering & Computer Science

February 14, 1995
3:30 Reception, 4:00 Lecture
Room 34-101, 50 Vassar Street

Title: Advances and Applications of Mismatched Semiconductor Materials

Eugene A. Fitzgerald
Massachusetts Institute of Technology
Cambridge, Massachusetts

Because Si VLSI is the dominant circuit platform, there is an increasing desire for a wider range of optoelectronic and electronic devices with different characteristics to be integrated with conventional Si circuits. The ability to combine GeSi, GaAs, and InGaP with Si, for example, would allow the integration of visible emitters, III-V FETs, and GeSi FETs with Si VLSI. However, the introduction of dislocations in the structures to relieve the lattice mismatch degrades material quality and reliability. Recent advances in controlling dislocations in mismatched heterostructures will be described. This successful dislocation engineering has resulted in record hole and electron mobilities in strained Ge(Si)/GeSi/Si structures and the successful integration of InGaP LEDs with Si.