Influence of SiOx Capping Layer Quality on Impurity-Free Interdiffusion in GaAs/AlGaAs Quantum Wells

1999 ◽  
Vol 607 ◽  
Author(s):  
P.N.K. Deenapanray ◽  
H.H. Tan ◽  
C. Jagadish
Keyword(s):  
Chemical Vapor Deposition ◽  
Quantum Wells ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Capping Layer ◽  
Dielectric Layers ◽  
Free Vacancy

AbstractWe have investigated the influence of SiOx capping layer quality on impurity-free vacancy interdiffusion in GaAs/Al0.54Ga0.46As quantum wells. Dielectric layers were deposited by plasmaenhanced chemical vapor deposition, and properties of layers were changed by varying either the flow rate of silane or deposition temperature. The extent of intermixing in our samples is discussed in terms of the 0 content and incorporation of N in capping layers, and also on their porosity. We also report on the electrically active defects which are introduced in Si02 capped and annealed n-GaAs, and relate them to the intermixing process.

EFFECT OF CAPPING LAYER ON InxGa1-xN QUANTUM DOTS GROWN USING NNAD METHOD BY MOCVD

2009 ◽  
Vol 08 (01n02) ◽  
pp. 197-201
Author(s):  
HEON SONG ◽  
R. NAVAMATHAVAN ◽  
SEONG-MUK JEONG ◽  
SEON-HO LEE ◽  
JIN-SU KIM ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Capping Layer ◽  
Nitridation Time ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

In x Ga 1-x N quantum dots (QDs) were grown on GaN epitaxy using nitridation of nano-alloyed droplet (NNAD) method by metal-organic chemical vapor deposition (MOCVD) system. Before the In x Ga 1-x N QDs formation, In + Ga droplets were initially formed by the flow of TMI and TMG, which acts as a nucleation seed for the QDs growth. Density of the alloy droplets was increased with the increasing flow rate; however, droplet size was scarcely changed about 100–200 nm by flow rate. And In x Ga 1-x N QDs size can be easily changed by controlling the nitridation time or various factors. Also, the influence of GaN capping layer on the properties of In x Ga 1-x N QDs was discussed.

Control of the Intermixing of InGaAs/InGaAsP Quantum Well in Impurity Free Vacancy Disordering by Changing NH3 Flow Rate During the Growth of SiNx Capping Layer

1999 ◽  
Vol 607 ◽  
Author(s):  
W.J. Choi ◽  
H.T Yi ◽  
D.H. Woo ◽  
S. Lee ◽  
S.H. Kim ◽  
...  
Keyword(s):  
Quantum Well ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Quantum Well Intermixing ◽  
Capping Layer ◽  
Gas Ratio ◽  
Free Vacancy ◽  
Better Than ◽  
Reactive Gas

AbstractThe dependence of impurity free vacancy disordering (IFVD) of InGaAs/InGaAsP QW structure on the characteristics of dielectric capping layer was studied using SiNx film as capping layers. The characteristics of the SiNx capping layer were varied by changing the NH3 flow rate during SiNx deposition by plasma enhanced chemical vapor deposition (PECVD). The degree of quantum well intermixing (QWI) with SiNX capping layer grown at higher NH3 flow rate was larger than that with SiNx film grown at lower NH3 flow rate. This implies that QWI can be easily controlled by simply changing the reactive gas ratio in the growing process of SiN, capping layer. It was also shown that this method to control QWI is better than the method of using two different capping layers such as SiNx film and SiO2 film in order to get spatially selective QWI on the same substrate.

Deposition of SiO2:F:C Films With Low Dielectric Constant and With High Resistance to Annealing

1999 ◽  
Vol 606 ◽  
Author(s):  
J. Lubguban ◽  
Y. Kurata ◽  
T. Inokuma ◽  
S. Hasegawa
Keyword(s):  
Dielectric Constant ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
High Resistance ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Low Dielectric Constant ◽  
Rf Power ◽  
Low Dielectric

AbstractSiO2:F:C films were deposited using a plasma-enhanced chemical vapor deposition (PECVD) technique from SiH4/O2/CF4/CH4 mixtures. Increasing amount of carbon were introduced to the SiO2:F films by changing the CH4 flow rate, [CH4], while keeping constant other conditions such as rf power and deposition temperature, TD. It was found that the addition of CH4 decreases the dielectric constant, k; from 3.36 for [CH4] = 0 sccm to 2.95 for [CH4] = 8 sccm. For the [CH4] condition where the film has a lowest k, the deposition temperature and rf power were optimized by depositing films using different values of TD and rf power The k for films in the new series as well as the stress and water absorption was investigated. Results show that the dielectric constant further decrease up to 2.85. Some films were then annealed from 400 - 800 °C and it was found that the k for films deposited with higher [CH4] has a better stability with respect to annealing up to a temperature of 600 °C.

Preparation of Immobilized Nano-Columnar TiO2 Grains by Chemical Vapor Deposition

2008 ◽  
Vol 8 (5) ◽  
pp. 2680-2683 ◽  
Author(s):  
Hong-Hsin Huang
Keyword(s):  
Chemical Vapor Deposition ◽  
Critical Load ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Scratch Test ◽  
Rutile Phase ◽  
Columnar Grains ◽  
Excellent Adhesion

Nano-columnar TiO2 grains are prepared and immobilized by chemical vapor deposition using TiCl4, H2 and O2 at low temperature. The structure of TiO2 is analyzed by X-ray diffraction (XRD), the morphology is observed by scanning electron microscopy (SEM) and the adhesion is estimated by measuring the critical load in scratch test. Results show that the structure of TiO2 films depend on the deposition temperature changing from amorphous, anatase, rutile, and both anatase and rutile phases as prepared at temperatures of 200, 300, 400 and 500 °C, respectively. The nano-columnar TiO2 grains are formed in both rutile and anatase phases, while it could be only rutile phase by increasing TiCl4 flow rate. The morphologies of TiO2 changes from smooth to nano-columnar grains as the deposition temperature increased from 200 to 400 °C. Excellent adhesion strength of crystalline TiO2 was obtained and it could be improved by increasing the TiCl4 flow rate in range of 0.3–0.6 sccm, where the critical load of TiO2 increases from 17 to 21 N.

Chemical Vapor Deposition (CVD) of ZrC Coatings from ZrCl4-C3H6-H2

2011 ◽  
Vol 189-193 ◽  
pp. 648-652 ◽  
Author(s):  
Qiao Mu Liu ◽  
Li Tong Zhang ◽  
Zhi Xin Meng ◽  
Lai Fei Cheng
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Content ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Carbon Deposition ◽  
Rough Surfaces ◽  
Chemical Vapor ◽  
Deposition Mechanism ◽  
Spherical Structure

ZrC coatings were prepared by CVD using ZrCl4, C3H6, and H2as the precursors. The mechanisms responsible for the effects of deposition temperature, H2flow rate and inlet C/Zr ratio on the ZrC coatings were studied based on the deposition mechanism of ZrC. The results indicate that the ZrC morphologies change from a loose spherical structure to a cauliflower structure, then to a glassy structure as the deposition temperature increases from 1050°C to 1150°C, then to 1250°C. The carbon content in the ZrC coatings increases with increasing the deposition temperature. Higher inlet C/Zr ratio can lead to rough surfaces and higher carbon content. Reasonable H2concentration can inhibit carbon deposition, and lead to a cauliflower structure.

Low Temperature Preparation of High-Quality Pb(Zr,Ti)O3 Films by Metal Organic Chemical Vapor Deposition with High Reproducibility

2001 ◽  
Vol 688 ◽  
Author(s):  
Hiroshi Funakubo ◽  
Kuniharu Nagashima ◽  
Masanori Aratani ◽  
Kouji Tokita ◽  
Takahiro Oikawa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Process Window ◽  
High Quality ◽  
Low Temperature Preparation

AbstractPb(Zr,Ti)O3 (PZT) is one of the most promising materials for ferroelectric random access memory (FeRAM) application. Among the various preparation methods, metalorganic chemical vapor deposition (MOCVD) has been recognized as a most important one to realize high density FeRAM because of its potential of high-step-coverage and large-area-uniformity of the film quality.In the present study, pulsed-MOCVD was developed in which a mixture of the source gases was pulsed introduced into reaction chamber with interval. By using this deposition technique, simultaneous improvements of the crystallinity, surface smoothness, and electrical property of the film have been reached by comparing to the conventional continuous gas-supplied MOCVD. Moreover, this film had larger remanent polarization (Pr) and lower leakage current density. This is owing to reevaporation of excess Pb element from the film and increase of migration on the surface of substrate during the interval time.This process is also very effective to decrease the deposition temperature of the film having high quality. In fact, the Pr and the leakage current density of polycrystalline Pb(Zr0.35Ti0.65)O3 film deposited at 415 °C were 41.4 μC/cm2 and on the order of 10−7 A/cm2 at 200 kV/cm. This Pr value was almost the same as that of the epitaxially grown film deposited at 415 °C with the same composition corrected for the orientation difference. This suggests that the polycrystalline PZT film prepared by pulsed-MOCVD had the epitaxial-grade ferroelectric properties even through the deposition temperature was as low as 415 °C. Moreover, large “process window” comparable to the process window at 580 °C, above 150 °C higher temperature and was widely used condition, was achieved even at 395°C by the optimization of the deposition condition.

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