Growth and properties of AlxGa1–xN epitaxial layers

AlxGa1–xN layers up to x = 0.45 are grown on sapphire substrates with different orientations via vapour phase reaction of NH3 with the chlorides of Ga and Al. Epitaxial growth with good crystalline perfection is observed on (0001)- and (1102)-oriented substrates. Indications to the existence of a cubic sphalerite phase in AlxGa1–xN are found. All undoped layers are n-type conducting with electron concentrations above 1019 cm−3 and show a tendency to lower electron concentrations with rising x. The electron mobility depends strongly on the growth conditions. Optical transmission measurements show the expected increase of the band gap with x. Photoluminescence spectra of undoped layers are dominated by a structure near 3.46 eV independent of x. Some results for Zn-doped samples are also given. AlxGa1–xN-Schichten bis zu x = 0,45 werden auf Saphirsubstraten unterschiedlicher Orientierung uber die Gasphasenreaktion von NH3 mit den Chloriden des Ga und Al abgeschieden. Epitaktisches Wachstum mit guter Kristallperfektion ergibt sich auf (0001)- und (1102)-orientierten Substraten. Es werden Hinweise auf die Existenz einer kubischen Sphaleritphase in AlxGa1–xN gefunden. Alle Schichten sind n-leitend mit Elektronenkonzentrationen oberhalb 1019 cm−3 und zeigen eine Tendenz zu niedrigeren Elektronenkonzentrationen mit wachsendem x. Die Elektronenbeweglichkeit hangt stark von den Zuchtungsbedingungen ab. Optische Transmissionsmessungen zeigen den erwarteten Anstieg in der Breite der verbotenen Zone mit wachsendem x. Photolumineszenzspektren undotierter Schichten werden von einer Struktur nahe 3,46 eV beherrscht, die unabhangig von x ist. Einige Ergebnisse fur Zn-dotierte Proben werden ebenfalls mitgeteilt.

[1]  R. Madar,et al.  Growth anisotropy in the GaN/Al2O3 system , 1977 .

[2]  Heinz Schulz,et al.  Crystal structure refinement of AlN and GaN , 1977 .

[3]  B. Etlinger,et al.  Method of growing of p-type GaN in nonequilibrium conditions , 1977 .

[4]  L. Däweritz,et al.  Vapour-phase epitaxial growth of Ga1−xAlxN on sapphire , 1976 .

[5]  J. Hutchby,et al.  Photoluminescence of ion‐implanted GaN , 1976 .

[6]  Masatoshi Sano,et al.  Epitaxial Growth of Undoped and Mg-Doped GaN , 1976 .

[7]  G. A. Slack,et al.  Growth of high purity AlN crystals , 1976 .

[8]  R. F. Rutz.  Ultraviolet electroluminescence in AlN , 1976 .

[9]  R. Madar,et al.  High pressure solution growth of GaN , 1975 .

[10]  D. Redfield.  Transport properties of electrons in energy band tails , 1975 .

[11]  H. Grimmeiss,et al.  Optical investigations of Zn, Hg and Li doped GaN , 1974 .

[12]  A. Tempel,et al.  Cubic phase gallium nitride by chemical vapour deposition , 1974 .

[13]  A. Shintani,et al.  Kinetics of the epitaxial growth of GaN using Ga, HCl and NH3 , 1974 .

[14]  C. C. Wang,et al.  Epitaxial growth and piezoelectric properties of A1N, GaN, and GaAs on sapphire or spinel , 1973 .

[15]  V. S. Ban,et al.  Mass Spectrometric Studies of Vapor‐Phase Crystal Growth II . , 1971 .

[16]  J. C. Phillips,et al.  New Set of Tetrahedral Covalent Radii , 1970 .

[17]  A. Noreika,et al.  Growth Characteristics of AlN Films Pyrolytically Deposited on Si , 1968 .

[18]  P. J. Dean,et al.  Lattice Vibration Spectra of Aluminum Nitride , 1967 .

[19]  M. Cardona.  Band parameters of semiconductors with zincblende, wurtzite, and germanium structure , 1963 .

[20]  D. W. Pashley.  THE STUDY OF EPITAXY IN THIN SURFACE FILMS , 1956 .

[21]  H. Neumann,et al.  Epitaxial growth and electrical properties of GaN-AlN solid solutions , 1977 .

[22]  H. Neumann.  Electrical properties of n‐Type GaN , 1977 .

[23]  Steven G. Louie,et al.  Self-consistent electronic states for reconstructed Si vacancy models , 1976 .

[24]  J. Pankove.  Optical properties of GaN , 1975 .

[25]  W. Seifert,et al.  Influence of Growth Temperature and Substrate Material on the Properties of Epitaxial GaN , 1974 .

[26]  J. Pankove,et al.  GaN yellow-light emitting diodes , 1973 .

[27]  J. Pankove,et al.  Epitaxially grown AlN and its optical band gap , 1973 .

[28]  Jacques I. Pankove,et al.  Luminescence in GaN , 1973 .

[29]  K. Lauterjung.  Landolt-Börnstein, Zahlenwerte und Funktionen aus Naturwissenschaft und Technik , 1969 .