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

Paper EM-FrM7
Real-time Thickness and Compositional Control of Ga1-xInxP Growth using P-Polarized Reflectance

Friday, October 29, 1999, 10:20 am, Room 608

Session: In Situ Monitoring and Growth
Presenter: V. Woods, North Carolina State University
Authors: V. Woods, North Carolina State University
K. Ito, North Carolina State University
I. Lauko, North Carolina State University
N. Dietz, North Carolina State University
Correspondent: Click to Email
Advances in the engineering and design of advanced electro-optical materials require sensors and control strategies that allow tight control over thickness and composition. In response to this demand, we developed p-polarized reflectance (PR) as a real time optical characterization technique, and demonstrate its sensitivity during heteroepitaxial GaP/GaInP growth under pulsed chemical beam epitaxy (PCBE) conditions. For closed loop control, we applied nonlinear control algorithms (based on nonlinear Kalman filtering) that utilizes the PR signals to control thickness and composition during heteroepitaxial growth of GaxIn1-xP on Si (001). A reduced order surface kinetics (ROSK) model has been formulated to describe the decomposition process of organometallic precursors and the time-dependency of the molar concentrations of the precursors fragments. These data are linked to compute the composition and thickness increase per time unit, utilizing the monitored PR signal for validation. This allows to establish feedback control algorithms, able to control both the growth rate and composition of GaxIn1-xP heterostructures.