AlxGa1−xAs(100) modulated structures

A425 Surface Science 174 (1986) 43-47 North-Holland, Amsterdam

SUPERLA’ITICE

43

STRUC-IXJRES GROWN BY METALORGANIC

E. TOKUMITSU, T. KATOH, C.P. SUNG, A. SANDHU, M. KONAGAI and K. TAKAHASHI Department of Physical Electronics, Tokyo 152, Japan

Tokyo Institute of Technology, Ohokayama,

Received

for publication

2 August

1985; accepted

16 November

MBE

R. KIMURA, Meguro-ku,

1985

The metalorganic molecular beam epitaxial (MOMBE) growth of GaAs and (GaA1)As using triethylgalhum (TEG) and triethylaluminum (TEA) has been studied. GaAs/GaAlAs multi quantum well (MQW) heterostructures were fabricated and it was found that the photoluminescence peak energy at room temperature agreed with calculated values. Furthermore, a new technique to grow a nipi superlattice structure was proposed and as a trial growth a n-GaAs/n+GaAs multilayer was prepared by applying an alternating ionization voltage to hydrogen.

Surface Science 174 (1986) 48-54 North-Holland, Amsterdam

48

A MOLECULAR STATICS AND DYNAMICS STUDY OF EPITAXIAL GROWTH FRONTS * A. KOBAYASHI, Sun-Mok PAIK, K.E. KHOR ** and S. DAS SARMA Department Received

of Physics and Astronomy,

29 July 1985; accepted

University of Maryland

for publication

ColIege Park, Maryland 20742, USA

13 September

1985

We study the MBE growth process employing both an energetics calculation and a molecular dynamics simulation. The importance of various growth parameters: lattice-constant ratio, relative orientation, and relative displacement is examined by calculating the total energy of a model fcc(lll)/bcc(llO) system. Using a molecular dynamics method, the actual motion of a large number of atoms at the growth front is monitored and the temperature dependence of the diffusion constant is obtained for various substrate potentials and surface coverages.

Surface Science 174 (1986) 55-64 North-Holland, Amsterdam

55

THE TEMPORAL BEI-IAVIOUR OF REFLECTION-HIGH-ENERGY-ELECI’RON-DIFFRACTION AND IMPLICATIONS FOR GROWTH KINETICS DURING MOLECULAR BEAM EPITAXIAL GROWTH OF GaAs / AI,Ga , _ x As( 100) MODULATED STRUCTURES

INTENSITY

*

T.C. LEE, M.Y. YEN, P. CHEN + and A. MADHUKAR Department of Materials Science, Universiry of Southern California, Los Angeles, California 90089-0241, USA Received

3 August

1985; accepted

for publication

25 December

1985

We present some results of a systematic examination of the reflection-high-energy-ekctron-diffraction (RHEED) intensity behaviour of static GaAs(100) surfaces, and during molecular beam epitaxial (MBE) growth of GaAs and ALAS on such surfaces. The growth condition dependent role

A426 of surface kinetic processes in controlling the nature of the surfaces and interfaces is emphasized which, amongst other things, shows the need for two different optimum arsenic pressures for the growth of good normal and inverted interfaces in modulated structures, under most growth conditions. For the customary practise of forming interfaces during continuous growth of alternate layers, an example of special growth condition requiring only one optimum arsenic pressure is presented. The significance of the individual layer thicknesses and the total thickness of the modulated structure in controlling the quality of normal and inverted interfaces formed at the chosen growth conditions is revealed through a comparison of the RHEED dynamics during growth of (GaAs),/(AlAs), and (GaAs),/(AIAs), superlattices.

65

Surface Science 174 (1986) 65-70 North-Holland, Amsterdam

PHOTOLUMINESCENCE AND ABSORPTION LINEWIDTH OF EXTREMELY FLAT GaAs-AIAs QUANTUM WELLS PREPARED BY MOLECULAR BEAM EPITAXY INCLUDING INTERRUPTED DEPOSITION FOR ATOMIC LAYER SMOOTHING M. TANAKA, H. SAKAKI, J. YOSHINO and T. FURUTA Institute of Industrial Science, University Received

27 July 1985: accepted

of Tokyo, Roppongi 7-22-1, Minato-ku, Tokyo 106, Japan

for publication

1 November

1985

GaAs-AlAs quantum well (QW) structures with extremely flat interfaces are prepared by our new growth procedure and their photoluminescence (PL) and absorption linewidths are studied at various temperatures. The PL linewidths of our QWs measured at 77 and 4.2 K are found to be the narrowest that have ever been published, and indicate the effective interface roughness to be less than 0.19 atomic layer. Excellent correlation was found to exist between the PL and absorption lineshapes, suggesting the validity of estimating interface roughness from the PL linewidths.

71

Surface Science 174 (1986) 71-75 North-Holland, Amsterdam

REDUCTION OF WELL WIDTH FLUCTUATION IN AlGaAs-GaAs SINGLE QUANTUM WELL BY GROWTH INTERRUPTION DURING MOLECULAR BEAM EPITAXY T. FUKUNAGA, K.L.I. KOBAYASHI and H. NAKASHIMA Optoelectronics Joint Research Laboratory, 1333 Kamikodanaka, Nakahara-ku, Kawasaki 2/l, Japan Received

27 July 1985; accepted

for publication

10 November

1985

A few sharp exciton lines in photoluminescence (PL) spectra below 4.2 K are observed for single quantum wells grown with 2 min interruption at heterointerfaces during molecular beam epitaxial (MBE) growth. This phenomenon depends on MBE growth rate and is well correlated with the behavior of reflection high-energy electron diffraction (RHEED) intensity. PL and RHEED results are explained by the monolayer terrace formation mechanisms during MBE growth.