PRODUCTION AND TREATMENT OF SI1-XGEX FILMS BY EXCIMER-LASER ASSISTED TECHNIQUES

Heterostructures of Si1-xGex alloys on Si (100) have been achieved usi ng two different excimer laser techniques. The first one, the Laser In duced Chemical Vapour Deposition (LCVD), was used in order to deposit germanium on Si (100) substrates via photolysis of GeH4 as precursor g as. The resulting films show a very homogeneous and amorphous structur e as determined by HREM, XRD and Raman analysis. These deposited amorp hous germanium films and a part of their underlaying Si (100) substrat e were melted using the second technique, the Pulsed Laser Induced Epi taxy (PLIE), inducing an epitactic recrystallization of a Si-Ge alloy. The analysis of the obtained alloys by HREM, XRD, and XPS, reveals a strong dependence of the crystal quality and of the germanium concentr ation profile from the number of pulses.