Atomie Layer Epitaxy ia a Rotating Disk Reactor

1991 ◽  
Vol 240 ◽  
Author(s):  
H. Liu ◽  
P. A. Zawadzki ◽  
P. E. Norris
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Atomic Layer ◽  
Rotating Disk ◽  
Atomic Layer Epitaxy ◽  
Process Window ◽  
Phase Reaction ◽  
Gas Phase Reactions ◽  
Group Iii ◽  
Reaction Complex

ABSTRACTCurrent difficulties of Atomic Layer Epitaxy (ALE) include relatively low growth rates and narrow process windows. Gas phase reaction, complex behavior of valve switching and purging times are suggested as the major causes [1,2]. We have used a movable X-shaped mechanical barrier to divide the growth chamber into four zones. Each zone supplies either source gas or purging hydrogen. If the barrier is positioned 0.5–2 mm from the wafer carrier, it can efficiently shear off the boundary layer and therefore reduce gas phase reactions. The substrate, constantly rotating beneath the barrier, is alternately exposed to group III or V sources by purging zones. The result is that process times are significantly reduced, saturated growth rate of 1 μm/hour is obtained and a relatively wide process window is observed. It was found that the growth mode was not purely ALE, due to source gas mixing which contributes an additional, possible kinetically limited, component of growth rate. However, this was also found to result in uniform film.

The role of surface and gas phase reactions in atomic layer epitaxy

1989 ◽  
Vol 19 (1-2) ◽  
pp. 137-147 ◽  
Author(s):  
P.D. Dapkus ◽  
S.P. DenBaars ◽  
Q. Chen ◽  
W.G. Jeong ◽  
B.Y. Maa
Keyword(s):  
Gas Phase ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Gas Phase Reactions

MOVPE GaN Gas-Phase Chemistry for Reactor Design and Optimization

1996 ◽  
Vol 449 ◽  
Author(s):  
S. A. Safvi ◽  
J. M. Redwing ◽  
A. Thon ◽  
J. S. Flynn ◽  
M. A. Tischler ◽  
...  
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Growth Rates ◽  
Operating Conditions ◽  
Gas Phase Reactions ◽  
Group V ◽  
Group Iii ◽  
Design And Optimization ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

ABSTRACTThe results of gas phase decomposition studies are used to construct a chemistry model which is compared to data obtained from an experimental MOVPE reactor. A flow tube reactor is used to study gas phase reactions between trimethylgallium (TMG) and ammonia at high temperatures, characteristic to the metalorganic vapor phase epitaxy (MOVPE) of GaN. Experiments were performed to determine the effect of the mixing of the Group III precursors and Group V precursors on the growth rate, growth uniformity and film properties. Growth rates are predicted for simple reaction mechanisms and compared to those obtained experimentally. Quantification of the loss of reacting species due to oligmerization is made based on experimentally observed growth rates. The model is used to obtain trends in growth rate and uniformity with the purpose of moving towards better operating conditions.

Gas-phase-reaction-controlled atomic-layer-epitaxy of silicon

1998 ◽  
Vol 16 (2) ◽  
pp. 679-684 ◽  
Author(s):  
Eiji Hasunuma ◽  
Satoshi Sugahara ◽  
Shinji Hoshino ◽  
Shigeru Imai ◽  
Keiji Ikeda ◽  
...  
Keyword(s):  
Gas Phase ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Phase Reaction ◽  
Gas Phase Reaction

Homogeneous Oxidation of Hydrogen in Catalytic Mini/Microchannels

2011 ◽  
Author(s):  
Azad Qazi Zade ◽  
Metin Renksizbulut ◽  
Jacob Friedman
Keyword(s):  
Gas Phase ◽  
Surface Reactions ◽  
Operating Conditions ◽  
Planar Geometry ◽  
Channel Height ◽  
Phase Reaction ◽  
Gas Phase Reactions ◽  
Radical Chain ◽  
Oxidation Of Hydrogen ◽  
Volume Method

Gas phase reaction effects in the catalytic oxidation of hydrogen on platinum-coated minichannels and microchannels are investigated numerically in planar geometry. The main objective of this work is to identify the relative importance of the gas phase and surface reactions under different operating conditions. A collocated finite-volume method is used to solve the governing equations. Detailed gas phase and surface reaction mechanisms along with a multi-component diffusion model are used. As the channel size is reduced, heat and radical losses to the walls can significantly alter the combustion behavior. While catalytic walls help in sustaining the gas phase reactions at very small length scales by reducing the heat losses to the walls owing to heat release associated with the surface reactions, they may inhibit homogeneous reactions by extracting radicals due to typically high absorption rates of such species at the walls. Thus, the radical chain mechanisms can be significantly altered by the presence of wall reactions, and the build-up of radical pools in the gas phase, which lead to homogeneous ignition, can be suppressed as a consequence. In the present study, the effects of two key parameters, i.e. channel height and the inlet mass flux on the interaction of gas phase and surface reactions will be explored. In each case, the limiting values beyond which the gas-phase reactions become relatively negligible compared to surface reactions will be identified for hydrogen/air mixtures.

Atomic layer epitaxy of device quality GaAs with a 0.6 μm/h growth rate

1991 ◽  
Vol 59 (12) ◽  
pp. 1440-1442 ◽  
Author(s):  
P. C. Colter ◽  
S. A. Hussien ◽  
A. Dip ◽  
M. U. Erdoǧan ◽  
W. M. Duncan ◽  
...  
Keyword(s):  
Growth Rate ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy

A Study on Film Precursors in SiH4 Thermal CVD by use of Trench Coverage Measurements

1989 ◽  
Vol 146 ◽  
Author(s):  
Akimasa Yuuki ◽  
Takaaki Kawahara ◽  
Yasuji Matsui ◽  
Kunihide Tachibana
Keyword(s):  
Gas Phase ◽  
Phase Reaction ◽  
Reaction Products ◽  
Gas Phase Reactions ◽  
Cross Sectional ◽  
Thermal Cvd ◽  
Silane Molecule ◽  
Cross Sectional Profile ◽  
Sticking Probabilities ◽  
Sectional Profile

ABSTRACTThe precursors of Si film in SiH4 low pressure thermal CVD are studied by use of the trench coverage analysis. The cross sectional profile of the film deposited in a trench is simulated by a direct Monte-Carlo method using the composition of the precursors and their sticking probabilities as adjustable parameters. A comparison with the experimental results[1] shows that the trench coverage profiles are well reproduced by the model where two kinds of precursors deposit independently with respective sticking probabilities of almost zero and unity. The former is silane molecule, and the latter is radicals produced by gas phase reactions. The deposition rate due to radicals can be estimated from the comparison. Considering the sticking probability and the SiH4 pyrolysis reactions, it is concluded that H3SiSiH is one of ate dominant film precursors in gas phase reaction products.

Determination of growth parameters for atomic layer epitaxy using reflectance difference spectroscopy

1996 ◽  
Vol 74 (S1) ◽  
pp. 85-88 ◽  
Author(s):  
R. Arès ◽  
C. A. Tran ◽  
S. P. Watkins
Keyword(s):  
Growth Rate ◽  
Growth Parameters ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Gas Flows ◽  
Difference Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reflectance Difference Spectroscopy

Reflectance difference spectroscopy (RDS) has been used to monitor the anisotropy of the surface of InAs and GaAs grown by atomic layer epitaxy (ALE). Saturation of the RDS signal is observed when the surface is fully covered with one monolayer of the impinging surface species. This property is used to optimize the growth interruptions for the ALE cycle. Good correlation of the RDS saturation is observed with growth-rate measurements obtained by X-ray diffraction (XRD). When exposure times are sufficiently long for saturation to be observed in the RDS signal, a growth rate of one monolayer per cycle (1 ML/cycle) is achieved. In principle all the different growth parameters such as exposure and purge times as well as gas flows can be determined in a few cycles performed on a single substrate. Without RDS the same results would require several growth runs and time consuming X-ray characterization.

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