Carbon diffusion in undoped, n‐type, and p‐type GaAs

The effects of background doping, surface encapsulation, and As4 overpressure on carbon diffusion have been studied by annealing samples with 1000 A p‐type carbon doping spikes grown within 1 μm layers of undoped (n−), Se‐doped (n+), and Mg‐doped (p+) GaAs. The layers were grown by low‐pressure metalorganic chemical vapor deposition using CCl4 as the carbon doping source. Two different As4 overpressure conditions were investigated: (1) the equilibrium pAs4 over GaAs (no excess As), and (2) pAs4 ∼2.5 atm. For each As4 overpressure condition, both capless and Si3N4‐capped samples of the n−‐, n+‐, and p+‐GaAs crystals were annealed simultaneously (825 °C, 24 h). Secondary‐ion mass spectroscopy was used to measure the atomic carbon depth profiles. The carbon diffusion coefficient is always low, but depends on the background doping, being highest in Mg‐doped (p+) GaAs and lowest in Se‐doped (n+) GaAs. The influence of surface encapsulation (Si3N4) and pAs4 on carbon diffusion is minimal.

[1]  T. Kuech,et al.  Mechanism of carbon incorporation in MOCVD GaAs , 1984 .

[2]  Y. Homma,et al.  Analysis of carbon and oxygen in GaAs using a secondary ion mass spectrometer equipped with a 20 K‐cryopanel pumping system , 1985 .

[3]  Y. Mori,et al.  Carbon incorporation in metalorganic chemical vapor deposition (Al,Ga)As films grown on (100), (311)A, and (311)B oriented GaAs substrates , 1987 .

[4]  C. Ramasastry,et al.  Effect of Heavy Doping on the Self-Diffusion of Germanium , 1957 .

[5]  N. Holonyak,et al.  Carbon‐doped AlxGa1−xAs‐GaAs quantum well lasers , 1988 .

[6]  D. Kisker,et al.  13C isotopic labeling studies of growth mechanisms in the metalorganic vapor phase epitaxy of GaAs , 1988 .

[7]  J. Hutchby,et al.  Growth and diffusion of abrupt zinc profiles in gallium arsenide and heterojunction bipolar transistor structures grown by organometallic vapor phase epitaxy , 1988 .

[8]  D. Tennant,et al.  Investigation of carbon incorporation in GaAs using13C-enriched trimethylarsenic and13Ch4 , 1988 .

[9]  Baraff,et al.  Electronic structure, total energies, and abundances of the elementary point defedts in GaAs. , 1985, Physical review letters.

[10]  G. L. Pearson,et al.  Properties of vacancy defects in GaAs single crystals , 1975 .

[11]  M. B. Das.  High-frequency performance limitations of millimeter-wave heterojunction bipolar transistors , 1988 .

[12]  P. Enquist.  Secondary ion mass spectroscopy depth profiles of heterojunction bipolar transistor emitter-base heterojunctions grown by low pressure OMVPE , 1988 .

[13]  Herbert Kroemer,et al.  Heterostructure bipolar transistors: What should we build? , 1983 .

[14]  H. Reiss.  Chemical Effects Due to the Ionization of Impurities in Semiconductors , 1953 .

[15]  G. Scilla,et al.  Controlled carbon doping of GaAs by metalorganic vapor phase epitaxy , 1988 .

[16]  M. Ilegems.  Beryllium doping and diffusion in molecular‐beam epitaxy of GaAs and AlxGa1−xAs , 1977 .

[17]  Brian T. Cunningham,et al.  Heavy carbon doping of metalorganic chemical vapor deposition grown GaAs using carbon tetrachloride , 1989 .