AVS 46th International Symposium
    Electronic Materials and Processing Division Friday Sessions
       Session EM-FrM

Paper EM-FrM6
Integrated Real-time SE, RDS and QMS to Characterize and Optimize OMCVD Growth

Friday, October 29, 1999, 10:00 am, Room 608

Session: In Situ Monitoring and Growth
Presenter: K.A. Bell, North Carolina State University
Authors: K.A. Bell, North Carolina State University
M. Ebert, North Carolina State University
S.D. Yoo, North Carolina State University
K. Flock, North Carolina State University
D.E. Aspnes, North Carolina State University
Correspondent: Click to Email
We combine spectroscopic ellipsometry (SE) and reflectance-difference spectroscopy (RDS) in a single optical path with quadrupole mass spectrometry (QMS) on an OMCVD reactor to probe bulk and surface properties as well as ambient composition in real time during growth. This unique system enables us to characterize the complex parameter space of OMCVD and optimize growth conditions. Monitoring the optical response of the sample and gas phase species enables us to determine ideal growth parameters for our reactor and to characterize growth mechanisms. The optical spectrometer is a multichannel, parallel acquisition and processing system built around a commercial rotating-spindle OMCVD reactor and a custom photodiode array (PDA) detector that allows us to extract sample optical properties over a spectral range of 200 to 800 nm at a repetition rate of 2 Hz. Together with time-resolved QMS, we determine system-specific parameters necessary to calibrate temperature and characterize gas flow dynamics. The former has been done using reciprocal space analysis of SE data to extract sample critical point energies in real time with an accuracy of 0.5 meV corresponding to +/-1 degree in sample temperature. Monitoring the growth of GaP on Si(001) in real time, we observe a SE sensitivity to 0.1 Angstrom changes in thickness and a QMS sensitivity of 0.1% changes in ambient composition.