Atomic Layer Epitaxy: modeling Of Growth Parameters for Device Quality GaAs.

1989 ◽  
Vol 145 ◽  
Author(s):  
E. Colas ◽  
R. Bhat ◽  
G. C. Nihous
Keyword(s):  
Initial Conditions ◽  
Growth Parameters ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Impurity Incorporation ◽  
Gas Concentration ◽  
Group Iii ◽  
Sequential Group

AbstractDevice quality GaAs was grown in a conventional Organometallic Chemical Vapor Deposition (OMCVD) reactor, using sequential group III and V reactant gas exposures typical of Atomic Layer Epitaxy (ALE). The importance of gas phase concentration transients during the ALE cycles was revealed by systematic investigations of the effect of the sequences used, for the cycles, on impurity incorporation as well as on the growth rates. In this study, we attempt to quantify the effects of such transients by solving the diffusion equation for the reactant gases, with initial conditions specific to ALE. We used this model to calculate the time dependence of the reactant gas concentration at the growing surface. This quantitative study gives us new insights into the ALE technique and confirms that the V/II ratio at the substrate surface can be controlled by the choice of the gas sequence.

A Model for Indium Incorporation in the Growth of InGaN Films

1996 ◽  
Vol 449 ◽  
Author(s):  
E. L. Piner ◽  
F. G. McIntosh ◽  
J. C. Roberts ◽  
K. S. Boutros ◽  
M. E. Aumer ◽  
...  
Keyword(s):  
Metalorganic Chemical Vapor Deposition ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Reaction Pathways ◽  
Balance Model ◽  
Mass Balance Model ◽  
Structural And Optical Properties ◽  
Indium Metal

ABSTRACTThe development of high quality indium based III-nitride compounds is lagging behind the corresponding aluminum and gallium based compounds. Potential problems confronting the growth of epitaxial and double heterostructure InGaN will be discussed. A mass balance model is presented describing the competing reaction pathways occurring during the growth of indium containing compounds. Atomic layer epitaxy and metalorganic chemical vapor deposition grown InGaN films will be used to explain this model. Also, the growth parameters leading to the attainment of high InN percentages, reduced indium metal formation, and improved structural and optical properties of indium containing nitrides will be discussed.

Low Pressure Diamond Growth Using a Secondary Radical Source

1992 ◽  
Vol 282 ◽  
Author(s):  
Terttu I. Hukka ◽  
Robin E. Rawles ◽  
Mark P. D'Evelyn
Keyword(s):  
Substrate Surface ◽  
Thermal Dissociation ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Diamond Growth ◽  
Hydrogen Atoms ◽  
Cycle Times ◽  
Novel Method ◽  
Precursor Molecules

ABSTRACTA novel method for chemical vapor deposition and atomic layer epitaxyusing radical precursors under medium vacuum conditions is being developed. Fluorine atoms are generated by thermal dissociation in a hot tube and abstract hydrogen atoms from precursor molecules injected immediately downstream of the source, generating radicals with completechemical specificity. The radical precursors are then transported to the growing substrate surface under nearly collision-free conditions. To date we have grown diamond films from CCl3 or CH3 radicals together with atomic hydrogen, generated by injecting CHCI3 or CH4 and H2 into the F atom stream at reactor pressures between 10−4 and 10−2 Torn This approach should be ideal for low-temperature growth and atomic layer epitaxy: growth rates remain relatively high because activation energies for radical reactions are typically small and because the cycle times for atomic layer epitaxy can be reduced to die msec range by fast gas-stream switching, and contamination and segregation are minimized by keeping the surface “capped” by chemisorbed intermediates.

Laser Assisted Atomic Layer Epitaxy-A Vehicle to Optoelectronic Integration

1991 ◽  
Vol 222 ◽  
Author(s):  
Q. Chen ◽  
J. S. Osinski ◽  
C. A. Beyler ◽  
M. Cao ◽  
P. D. Dapkus ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Growth Parameters ◽  
Growth Parameter ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Gain Medium ◽  
Atomic Layer Epitaxy ◽  
Small Areas ◽  
Wide Range ◽  
Optoelectronic Integration

ABSTRACTTwo implementations of laser assisted atomic layer epitaxy(LALE) for selective area growth of GaAs using trimethylgallium and AsH3 as precursors are described. A wide range of growth parameters lead to self-limiting monolayer/cycle growth which is suited for precise layer thickness control. By combining LALE with conventional metalorganic chemical vapor deposition, A10.3Ga0.7As/GaAs double heterostructures including LALE GaAs have been grown, permitting electrical and optical characterization to be performed on the thin and small areas of the LALE deposits. The information is used in a growth parameter optimization process resulting in device quality GaAs. Quantum well lasers with active region grown by LALE are demonstrated for the first time. The application of LALE to optoelectronic integration is demonstrated by depositing small area quantum wells as the gain medium in an otherwise transparent waveguide.

The Growth of AIGaAs/GaAs Heterostructures By Atomic Layer Epitaxy

1987 ◽  
Vol 102 ◽  
Author(s):  
S. P. Denbaars ◽  
A. Hariz ◽  
C. Beyler ◽  
B. Y. Maa ◽  
Q. Chen ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Active Regions ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
High Quality ◽  
Monolayer Growth ◽  
Low Threshold ◽  
Kinetics Of

ABSTRACTThe kinetics of atomic layer epitaxy (ALE) of GaAs utilizing trimethylgallium and arsine are described. The results show that saturated monolayer growth can be achieved-in the temperature range 445°C -485°C and that high quality materials can be grown.. Hybrid A1GaAs/GaAs heterostructures have been grown utilizing ALE for the active regions and conventional metalorganic chemical vapor deposition (MOCVD) for the confining regions that yield high quality quantum wells and low threshold quantum well lasers.

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.

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.

scholarly journals Deposition of Zinc Selenide by Atomic Layer Epitaxy for Multilayer X-Ray Optics

1989 ◽  
Vol 161 ◽  
Author(s):  
J.K. Shurtleff ◽  
D.D. Allred ◽  
R.T. Perkins ◽  
J.M. Thorne
Keyword(s):  
Chemical Vapor ◽  
Atomic Layer ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Atomic Layer Epitaxy ◽  
Ray Optics ◽  
X Ray ◽  
Vapor Deposition Technique ◽  
Number Of Cycles

ABSTRACTThin film deposition techniques currently being used to produce multilayer x-ray optics (MXOs) have difficulty producing smooth, uniform multilayers with d-spacings less than about twelve angstroms. We are investigating atomic layer epitaxy (ALE) as an alternative to these techniques.ALE is a chemical vapor deposition technique which deposits an atomic layer of material during each cycle of the deposition process. The thickness of a film deposited by ALE depends only on the number of cycles. Multilayers deposited by ALE should be smooth and uniform with precise d-spacings which makes ALE an excellent technique for producing multilayer x-ray optics.We have designed and built an ALE system and we have used this system to deposit ZnSe using diethyl zinc and hydrogen selenide.

OPTICAL PROPERTIES OF CdTe/ZnTe ULTRATHIN QUANTUM WELLS GROWN BY ATOMIC LAYER EPITAXY

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1667-1670 ◽  
Author(s):  
M. GARCÍA-ROCHA ◽  
I. HERNÁNDEZ-CALDERÓN
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Diffusion Length ◽  
Substrate Surface ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Low Temperature Photoluminescence

Ultrathin quantum wells (UTQWs) of CdTe within ZnTe barriers were successfully grown by atomic layer epitaxy (ALE) on GaAs(001) substrates. ALE growth of CdTe was performed by alternate exposure of the substrate surface to individual fluxes of Cd and Te. Two different samples with 2-monolayer (ML) (substrate temperature Ts= 270° C ) and 4 ML (Ts = 290° C ) CdTe QWs were grown. Low temperature photoluminescence (PL) experiments exhibited intense and sharp peaks associated to the 2 ML QWs at 2.26 eV. In the case of the nominally 4-ML-thick QW the PL spectrum presented an intense peak around 2.13 eV and two weak features around 2.04 and 1.91 eV. The first peak is attributed to ~ 3 ML QW and the second one to ~ 4 ML QW. The dominance of the 3 ML peak is mainly attributed to Cd loss in the QW due to its substitution by Zn atoms. Due to a high diffusion length of the photogenerated carriers in the barriers, quite weak signals from the ZnTe barriers were observed in both cases. Room temperature (RT) photoreflectance (PR) spectra showed contributions from the CdTe UTQWs, the ZnTe barriers, and the GaAs substrate.

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