MOCVD of Wide Bandgap III-V Semiconductors by using Novel Precursors

1989 ◽  
Vol 162 ◽  
Author(s):  
Kwok-L. Ho ◽  
Klavs F. Jensen ◽  
Scott A. Hanson ◽  
John F. Evans ◽  
David C. Boyd ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Reaction ◽  
Chemical Vapor ◽  
Laser Interferometry ◽  
Wide Bandgap ◽  
Typical Sample ◽  
Steady State Kinetic ◽  
Surface Reaction Kinetics ◽  
State Kinetic

ABSTRACTThin films of aluminum nitride have been grown by metalorganic chemical vapor deposition (MOCVD) from diethylaluminum azide. Growth rates of AIN on Si(111) were monitored in-situ with laser interferometry. The growth rate was linear in the partial pressure of the reactant at high temperatures and sublinear at low temperatures. A simple surface reaction mechanism consistent with these observations has been proposed. Surface reaction kinetics and mechanism were further investigated by steady-state kinetic mass spectrometry. Parameters in the growth rate expression were determined by a nonlinear regression of growth rate data. A typical sample of AIN on B-plane sapphire showed a bandgap of about 5.2eV which was increased to 5.9eV upon annealing in nitrogen at atmosphere pressure.

MOCVD of GaN Using Diethylgalliumazide and Ammonia

1990 ◽  
Vol 204 ◽  
Author(s):  
Kwok-L. Ho ◽  
Klavs F. Jensen ◽  
Jen-W. Hwang ◽  
John F. Evans ◽  
Wayne L. Gladfelter
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Smooth Surface ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Laser Interferometry ◽  
Optical And Electrical Properties ◽  
Sapphire Substrates

ABSTRACTGaN thin films have been deposited on Si and sapphire substrates by metalorganic chemical vapor deposition (MOCVD) using diethylgalliumazide and ammonia. Films were grown in the temperature range of 500-750°C. Growth rates were monitored in situ using laser interferometry. The addition of ammonia enhanced the growth rate significantly. At high temperatures, gas-phase depletion of the precursor reduced the growth rate of GaN. Films grown on (0001)-oriented sapphire substrates at temperatures above 650°C were highly textured with smooth surface morphology. Optical and electrical properties of the films are discussed and compared to those of films grown using conventional Ga and N sources.

Deposition and Crystallisation Behaviour of Amorphous Silicon Thin Films Obtained by Pyrolysis of Disilane Gas at Very Low Pressure

1994 ◽  
Vol 345 ◽  
Author(s):  
T. Kretz ◽  
D. Pribat ◽  
P. Legagneux ◽  
F. Plais ◽  
O. Huet ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Electrical Conductance ◽  
Chemical Vapor ◽  
Crystalline Fraction ◽  
Silicon Thin Films ◽  
Crystallisation Behaviour

AbstractHigh purity amorphous silicon layers were obtained by ultrahigh vacuum (millitorr range) chemical vapor deposition (UHVCVD) from disilane gas. The crystalline fraction of the films was monitored by in situ electrical conductance measurements performed during isothermal annealings. The experimental conductance curves were fitted with an analytical expression, from which the characteristic crystallisation time, tc, was extracted. Using the activation energy for the growth rate extracted from our previous work, we were able to determine the activation energy for the nucleation rate for the analysed-films. For the films including small crystallites we have obtained En ∼ 2.8 eV, compared to En ∼ 3.7 eV for the completely amorphous ones.

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