Direct regrowth of thin strained silicon films on planarized relaxed silicon–germanium virtual substrates

We discuss a method for fabricating strained Si layers via deposition directly onto planarized relaxed SiGe virtual substrates, a process termed direct regrowth (DRG). We show that a trade-off exists between surface roughness and cleanliness of the Si/SiGe interface. Using this knowledge, we discuss process requirements to ensure that strained Si wafers produced via direct regrowth are free of interfacial contamination, exhibit ultra-low surface roughness, and feature abrupt Si/SiGe interfacial transitions. Finally, we show that metal-oxide-semiconductor field-effect transistors produced on strained Si channels fabricated via direct regrowth exhibit excellent device performance, suggesting the viability of the DRG process for manufacture of high quality strained Si wafers.