IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Thursday Sessions
       Session EL-ThA

Invited Paper EL-ThA1
In-situ Analysis, Monitoring and Control of III-V-Semiconductor Epitaxial Growth

Thursday, November 1, 2001, 2:00 pm, Room 124

Session: In-Situ Semiconductor Characterization
Presenter: W. Richter, TU Berlin, Germany
Correspondent: Click to Email
Epitaxial growth of semiconductor structures requires control of the growth process on the atomic scale. This, however, is difficult to achieve by just controlling macroscopic growth parameters like partial pressures (fluxes) and temperatures. It is thus desirable to have in real time microscopic information from the growing surface for a direct analysis and conseqently control on the ongoing growth process. Optical probes offer in this respect important advantages: they are in general non invasive, they can be fast in obtaining the needed information and finally they can be applied in all growth environments (vacuum or gasphase based growth methods). The "optical" disadvantage of having a low spatial resolution can be overcome quite often by extra "calibration" measurements with high resolution spatial probes like STM, AFM, LEED. I will discuss first the analysis of reconstructed surfaces by reflectance anisotropy (RAS). Simultaneous measurements in MBE and MOVPE together with theoretical calculations allow to correlate optical spectra with surface reconstructions. Based on these basic data it is possible to describe adsorption and desorption processes of the basic constituents (Group III and V elements). Moreover, growth in dependence of partial pressure and temperature can be described via different modes in a flux - temperature phase diagram, allowing thus to define the surface growth status nearly independent of the special epitaxial equipment. Monitoring and control of device growth seem to be now possible.