In-Situ Monitoring for Nano-Structure Growth in MOVPE

This chapter describes the advances achieved in the last decades for in-situ monitoring of gas phase epitaxial growth (MOVPE) with resolution down to the atomic scale. By spatial resolution electron diffraction would be the tool of choice. However, by mean free path arguments it cannot be applied in the gasphase environment of MOVPE. Optical in-situ techniques on the other hand, easy to setup, have been developed to such a level in the last decades that monolayer resolution is now possible. Even a simple single wavelength reflectance measurement can determine growth rates, composition and temperature. In-situ analysis on the submonolayer scale is routinely possible using Reflectance Anisotropy Spectroscopy (RAS). RAS is best suited to follow online the epitaxial growth evolution of surfaces, revealing surface structure and stochiometry as a function of time (ms). Doping profiling has been achieved as well by combining reflectance and RAS. The chapter closes with an outlook to the ultimate surface tool, the most recent application of a scanning tunneling microscope in MOVPE.