Real-time spectroscopic ellipsometry as a characterization tool for oxide molecular beam epitaxy

A real-time spectroscopic ellipsometer (RTSE) was designed and implemented on an oxide molecular beam epitaxy (MBE) system. The RTSE was designed as a complementary tool to the other existing in situ deposition monitors on th e MBE. To quantify how the RTSE complemented the other tools las well as to determine its limitations), the RTSE was used to characterize the depositi on of (111)-oriented Y2O3 on (111) Si and (110)-oriented Y2O3 on (100) Si. Results from computer modeling of the RTSE data subsequent to deposition sh owed excellent agreement with atomic absorption flux measurements, quartz c rystal monitor flux measurements, refection high energy electron diffractio n measurements, and Rutherford backscattering spectroscopy. From the RTSE m easurements, growth rates and microstructures were determined and verified by ex situ techniques. In addition, the sticking coefficient of yttrium to Y2O3 was found to be 1.00 +/-0.07. Also, the temperature dependent optical properties of the Y2O3 films were measured at 25 and at 730 degreesC. Nearl y bulk values were found, indicating the high quality films deposited via t his method. (C) 2001 American Vacuum Society.