Structural characterization of Si1-xGex/Si strained superlattices and relaxed virtual substrates grown by chemical vapor deposition

We present SiGe/Si (001) heteroepitaxy performed in a commercial Chemical V apor Deposition (CVD) cold-wall vertical reactor using SiH4 and GeH4 as pre cursor gases. This versatile machine operates in a wide range of temperatur e and pressure, allowing both the Ultra High Vacuum (UHV) and the Low Press ure (LP)-CVD. The growth of Si0.71Ge0.29/Si strained superlattices (SLs) at 600 degrees C and Si0.75Ge0.25/Si relaxed pseudo-substrates at 700 degrees C is demonstrated using UHV and LP, respectively, and their structural pro perties are discussed. Finally, results of a first attempt of growing an un doped resonant tunneling like heterostructure onto a Si0.75Ge0.25 virtual s ubstrate (VS) are reported. (C) 2000 Elsevier Science B.V. All rights reser ved.