Production and treatment of Si1-xGex films by excimer laser assisted techniques [Producción y tratamiento de películas de Si1-xGex mediante técnicas asistidas por láser de excímero]

Heterostructures of Si1-xGex alloys on Si (100) have been achieved using two different excimer laser techniques. The first one, the Laser Induced Chemical Vapour Deposition (LCVD), was used in order to deposit germanium on Si (100) substrates via photolysis of GeH4 as precursor gas. The resulting films show a very homogeneous and amorphous structure as determined by HREM, XRD and Raman analysis. These deposited amorphous germanium films and a part of their underlaying Si (100) substrate were melted using the second technique, the Pulsed Laser Induced Epitaxy (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 concentration profile from the number of pulses.