AVS 45th International Symposium
    Electronic Materials and Processing Division Tuesday Sessions
       Session EM+SE-TuM

Paper EM+SE-TuM5
Mg Doping Studies of ECR-MBE GaN Thin Films

Tuesday, November 3, 1998, 9:40 am, Room 316

Session: Critical Issues in Widebandgap Semiconductors
Presenter: I.E. Berishev, University of Houston
Authors: I.E. Berishev, University of Houston
E. Kim, University of Houston
O. Kameli, University of Houston
D. Starikov, University of Houston
A. Bensaoula, University of Houston
Correspondent: Click to Email
MBE of GaN is a rapidly progressing ultra high vacuum growth technique that allows the growth of high purity materials, at lower temperatures, in a clean and well characterized environment, and at high enough growth rates. Much of the recent work however was performed using RF nitrogen sources instead to previously popular ECR sources. Lower deposition rates for ECR sources being the major reason. In all growth technologies, p-type doping remains an issue for GaN device structures fabrication such as LED, LD, FET, etc. As grown p-type MBE GaN layers were however successively realized by several groups. In our study a modified ASTEX ECR source, allowing optically active GaN thin films at growth rates up to 1 micron per hour, was utilized in an MBE environment. Using this nitrogen source, Mg doping studies of GaN were undertaken. The effects of growth parameters and ECR source design on the Mg incorporation and its electrical activity were characterized by SIMS, electrochemical profiling, and photo-luminescence. The background concentration and major impurities are identified by time of flight SIMS. A direct correlation exists between Mg incorporation and the ECR power, nitrogen flow, Mg cell temperature, growth temperature and ECR exit aperture size. Using an optimized process, SIMS show sharp profiles between doped and undoped layers can be obtained. This work was supported by funds from a NASA cooperative agreement #NCC8-127 to SVEC, a Texas Advanced Research Program Grant # 1-1-27764, and a Texas Advanced Technology Program Grant # 1-1-32061.