Real time optical characterization of gas flow dynamics in high-pressure chemical vapor deposition

Abstract

While low-pressure chemical vapor deposition (CVD) methods offer excellent pathways for many compound semiconductors, these growth techniques possess limitations in the growth of high quality compounds with large thermal decomposition pressure such as InN and related materials. To study and extend the growth towards elevated pressures a high-pressure CVD system with integrated real time optical characterization techniques has been established. The built-in real time monitoring techniques allow the characterization of gas flow kinetics, precursor decomposition kinetics, as well as the crucial steps of nucleation and film formation. In this contribution, we report the characterization of process parameter under which the thin film growth process can be maintained under laminar flow condition. Laser light scattering has been proven as the most robust optical tool to characterize the onset of turbulence. Hence, it allows the mapping the pressure and flowing regime under which laminar flow can be maintained.