Title :
Control of a III-V epitaxial MOCVD process using ultraviolet absorption concentration monitoring
Author :
Flynn, Monique S Gaffney ; Smith, Roy S. ; Abraham, Patrick ; DenBaars, Steven P.
Author_Institution :
Litton Guidance & Control Syst., Woodland Hills, CA, USA
Abstract :
Metalorganic chemical vapor deposition (MOCVD) is a promising technology for the growth of epitaxial semiconductors. It has traditionally lacked real-time growth monitoring and control, which limits the precise reproducibility needed for high performance devices. Two complementary control approaches are investigated experimentally. The first is a feedforward disturbance rejection strategy using ultrasonic concentration measurements to reject source gas bubbler disturbances. The second is a feedback system using an ultraviolet absorption sensor for real-time monitoring of reaction chamber gas concentrations. Postgrowth X-ray analysis of InP/GaInAs superlattice test devices is used to evaluate control system performance
Keywords :
III-V semiconductors; MOCVD; computerised monitoring; feedback; feedforward; process control; real-time systems; vapour phase epitaxial growth; III-V epitaxial MOCVD process; concentration monitoring; disturbance rejection; epitaxial growth; feedback; feedforward; metalorganic chemical vapor deposition; real-time system; superlattice test; ultraviolet absorption; Chemical technology; Chemical vapor deposition; Electromagnetic wave absorption; Feedback; Gas detectors; III-V semiconductor materials; MOCVD; Monitoring; Reproducibility of results; Ultrasonic variables measurement;
Conference_Titel :
Control Applications, 1999. Proceedings of the 1999 IEEE International Conference on
Conference_Location :
Kohala Coast, HI
Print_ISBN :
0-7803-5446-X
DOI :
10.1109/CCA.1999.807757
