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Title: On compensation and impurities in state-of-the-art GaN epilayers grown on sapphire

Book ·
OSTI ID:395020
; ;  [1];  [2]; ;  [3]
  1. Naval Research Lab., Washington, DC (United States). Lab. for Advanced Material Synthesis
  2. Hewlett-Packard, San Jose, CA (United States)
  3. National Inst. of Standards and Technology, Gaithersburg, MD (United States)

A comparison between 300 K electron transport data for state-of-the-art wurtzite GaN grown on sapphire substrates and corresponding theoretical calculations shows a large difference, with experimental mobility less than the predicted mobility for a given carrier concentration. The comparison seems to imply that GaN films are greatly compensated, but the discrepancy may also be due to the poorly known values of the materials parameters used in the calculations. In this work, recent analysis of transport and SIMS measurements on silicon-doped GaN films are shown to imply that the compensation, N{sub A}/N{sub D}, is less than 0.3. In addition, the determination of an activation energy of 34 meV in a GaN film doped to a level of 6 {times} 10{sup 16} cm{sup {minus}3} suggests either that a second, native donor exists in the doped films at a level of between 6 {times} 10{sup 16} cm{sup {minus}3} and 1 {times} 10{sup 17} cm{sup {minus}3}, or that the activation energy of Si in GaN is dependent on the concentration, being influenced by impurity banding or some other physical effect. GaN films grown without silicon doping are highly resistive.

OSTI ID:
395020
Report Number(s):
CONF-951155-; ISBN 1-55899-298-7; TRN: IM9648%%97
Resource Relation:
Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Gallium nitride and related materials; Ponce, F.A. [ed.] [Xerox Palo Alto Research Center, CA (United States)]; Dupuis, R.D. [ed.] [Univ. of Texas, Austin, TX (United States)]; Nakamura, S. [ed.] [Nichia Chemical Industries, Tokushima (Japan)]; Edmond, J.A. [ed.] [Cree Research, Inc., Durham, NC (United States)]; PB: 993 p.; Materials Research Society symposium proceedings, Volume 395
Country of Publication:
United States
Language:
English