scholarly journals Properties of AlN/GaN Heterostructures Grown at Low Growth Temperatures with Ammonia and Dimethylhydrazine

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1412
Author(s):  
Caroline E. Reilly ◽  
Nirupam Hatui ◽  
Thomas E. Mates ◽  
Pratik Koirala ◽  
Adedapo A. Oni ◽  
...  
Keyword(s):  
Electronic Materials ◽  
Chemical Vapor ◽  
High Electron ◽  
X Ray Diffraction ◽  
Electron Gases ◽  
Flow Modulation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Rate Versus ◽  
Sheet Charge

The integration of different electronic materials systems together has gained increasing interest in recent years, with the III-nitrides being a favorable choice for a variety of electronic applications. To increase flexibility in integration options, growing nitrides material directly on semi-processed wafers would be advantageous, necessitating low temperature (LT) growth schemes. In this work, the growth of AlN and GaN was conducted via metalorganic chemical vapor deposition (MOCVD) using both NH3 and DMHy as N-precursors. The relationships between growth rate versus temperature were determined within the range of 300 to 550 °C. The growth of AlN/GaN heterostructures was also investigated herein, employing flow modulation epitaxy MOCVD at 550 °C. Subsequent samples were studied via atomic force microscopy, X-ray diffraction, TEM, and Hall measurements. Two-dimensional electron gases were found in samples where the LT AlN layer was grown with NH3, with one sample showing high electron mobility and sheet charge of 540 cm2/V∙s and 3.76 × 1013 cm−2, respectively. Inserting a LT GaN layer under the LT AlN layer caused the mobility and charge to marginally decrease while still maintaining sufficiently high values. This sets the groundwork towards use of LT nitrides MOCVD in future electronic devices integrating III-nitrides with other materials.

scholarly journals Influence of the growth parameters of TiO2 thin films deposited by the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Deposition Parameters

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.

HETERO-GROWTH OF (100) ORIENTATED ZNO FILMS ON SILICON BY SS-CVD

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4250-4254 ◽  
Author(s):  
JIAN-GUO LU ◽  
ZHI-ZHEN YE ◽  
HAN-HONG CHEN ◽  
JING-YUN HUANG ◽  
BING-HUI ZHAO
Keyword(s):  
Texture Coefficient ◽  
Zinc Acetate Dihydrate ◽  
Chemical Vapor ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Lower Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
First Time ◽  
Lower Growth Temperature

ZnO films with (100) preferred orientation are reported for the first time. ZnO films were synthesized on Si(100) substrate by solid-source chemical vapor deposition (SS-CVD) using zinc acetate dihydrate (solid) as a precursor. The structural properties were investigated by X-ray diffraction and atomic force microscopy. Results show that a lower growth temperature and a higher deposition rate will facilitate the formation of (100) texture. The texture coefficient for (100) plane is 3.28.

Influence of Ammonia on the Fabrication of Aligned Carbon Nanotubes Using Thermal CVD

2011 ◽  
Vol 467-469 ◽  
pp. 312-315
Author(s):  
Gang Li ◽  
Wen Ming Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Vertical Alignment ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Aligned Carbon Nanotubes ◽  
20 Nm

Ultra-thin (20 nm) nickel catalyst films were deposited by sputtering on SiO2/Si substrates. At the pretreatments, ammonia (NH3) was conducted for different time in a thermal chemical vapor deposition (CVD) system. Pretreated samples were characterized using atomic force microscopy (AFM). After the pretreatment, acetylene was introduced into the chamber for 10 min, samples were characterized using scanning electron micrograph (SEM) and X-ray diffraction (XRD). It was concluded that NH3 pretreatment was very crucial to control the surface morphology of catalytic metals and thus to achieve the vertical alignment of carbon nanotubes (CNTs). With higher density of the Ni particles, better alignment of the CNTs can be obtained due to steric hindrance effect between neighboring CNTs.

Growth of Diamond Films Using C3F8AND H2in A New System

1994 ◽  
Vol 349 ◽  
Author(s):  
Ping Huangfu ◽  
Zengsun Jin ◽  
Xianyi Lu ◽  
Guangtian Zou ◽  
Huaxian Xiao ◽  
...  
Keyword(s):  
Synthetic Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Surface Pretreatment ◽  
Force Microscopy ◽  
Atomic Force ◽  
Single Crystal Diamond ◽  
New System

ABSTRACTIn the present study, the new system used C3F8and H2 as source gases. Filament-assisted chemical vapor deposition was utilized. Continuous diamond films were grown on the Si and Mo substrates without any surface pretreatment. The results of scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and atomic force microscopy measurements indicate that the films deposited on the Mo substrates are of high quality. Homoepitaxial diamond films were grown on the high pressure synthetic single crystal diamond substrates. The results show that in our experimental conditions epitaxial films were easily grown on the (111) synthetic diamond substrates and sometimes epitaxial filmse also grown on the (100) synthetic diamond substrates.

scholarly journals Synthesis of ultrasmooth nanostructured diamond films by microwave plasma chemical vapor deposition using a He/H2/CH4/N2gas mixture

2006 ◽  
Vol 21 (10) ◽  
pp. 2675-2682 ◽  
Author(s):  
S. Chowdhury ◽  
Damon A. Hillman ◽  
Shane A. Catledge ◽  
Valery V. Konovalov ◽  
Yogesh K. Vohra
Keyword(s):  
Gas Flow ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Emission ◽  
X Ray Diffraction ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Flow Ratio

Ultrasmooth nanostructured diamond (USND) films were synthesized on Ti–6Al–4V medical grade substrates by adding helium in H2/CH4/N2plasma and changing the N2/CH4gas flow from 0 to 0.6. We were able to deposit diamond films as smooth as 6 nm (root-mean-square), as measured by an atomic force microscopy (AFM) scan area of 2 μm2. Grain size was 4–5 nm at 71% He in (H2+ He) and N2/CH4gas flow ratio of 0.4 without deteriorating the hardness (∼50–60 GPa). The characterization of the films was performed with AFM, scanning electron microscopy, x-ray diffraction (XRD), Raman spectroscopy, and nanoindentation techniques. XRD and Raman results showed the nanocrystalline nature of the diamond films. The plasma species during deposition were monitored by optical emission spectroscopy. With increasing N2/CH4feedgas ratio (CH4was fixed) in He/H2/CH4/N2plasma, a substantial increase of CN radical (normalized by Balmer Hαline) was observed along with a drop in surface roughness up to a critical N2/CH4ratio of 0.4. The CN radical concentration in the plasma was thus correlated to the formation of ultrasmooth nanostructured diamond films.

Characterization of Planar Interdigital Micro Supercapacitor with PECVD Graphene as Electrodes at Low Temperature

2017 ◽  
Vol 889 ◽  
pp. 191-194
Author(s):  
Hafzaliza Erny Zainal Abidin ◽  
Azrul Azlan Hamzah ◽  
Mohd Ambri Mohamed ◽  
Burhanuddin Yeop Majlis
Keyword(s):  
Energy Storage ◽  
Gas Sensing ◽  
Cardiac Pacemaker ◽  
Chemical Vapor ◽  
High Specific Surface Area ◽  
High Electron ◽  
Graphene Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Interdigital Electrodes

Graphene has recently gained much interest in applications such as energy storage, catalysis and gas sensing. In terms of energy storage, micro supercapacitor has attracted a lot of interest in fields such as bioMEMS, biomedical implants such as cardiac pacemaker and the promising field of powering small electronic devices. In this paper, the structure of the micro supercapacitor PECVD graphene on electrodes consists of SiO2 substrate, graphene on Nickel (Ni) electrodes, with Polypyrrole (Ppy), graphene and Polyvinyl Alcohol (PVA) layers. To improve performance, graphene is one of the more promising material being investigated for micro supercapacitor electrodes due to several advantages such as high specific surface area and high electron mobility. Graphene was then grown on the Ni electrodes using the Plasma- Enhanced Chemical Vapor Deposition (PECVD) process. The graphene growth structure on the interdigital electrodes of micro supercapacitor was characterized by Raman Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray (EDX) and Atomic Force Microscopy (AFM). A Raman spectrum of graphene growth on interdigital electrode has identified three peaks which are the D band, G band and 2D band. The broad peaks at 1340 cm-1 and 1580 cm-1 correspond to the D and G bands, respectively.

Low Temperature Chemical Vapor Deposition of 3C-SiC on Si Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 201-204 ◽  
Author(s):  
Christian Förster ◽  
Volker Cimalla ◽  
Oliver Ambacher ◽  
Jörg Pezoldt
Keyword(s):  
Gas Phase ◽  
Vapor Deposition ◽  
Growth Process ◽  
Chemical Vapor ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force

In the present work an UHVCVD method was developed which allows the epitaxial growth of 3C-SiC on Si substrates at temperatures below 1000°C. The developed method enable the growth of low stress or nearly stress free single crystalline 3C-SiC layers on Si. The influence of hydrogen on the growth process are be discussed. The structural properties of the 3C-SiC(100) layers were studied with reflection high-energy diffraction, atomic force microscopy, X-ray diffraction and the layer thickness were measured by reflectometry as well as visible ellipsometry. The tensile strain reduction at optimized growth temperature, Si/C ratio in the gas phase and deposition rate are demonstrated by the observation of freestanding SiC cantilevers.

Growth of Ultra-High Density 3C-SiC Nanowires via Single Source CVD

2011 ◽  
Vol 1350 ◽  
Author(s):  
Kasif Teker ◽  
Joseph A. Oxenham
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor ◽  
Iron Film ◽  
X Ray Diffraction ◽  
Lower Efficiency ◽  
Force Microscopy ◽  
High Temperature Electronics ◽  
Sic Nanowires ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACTSilicon carbide (SiC) nanostructures attract interest due to their applications in optoelectronic devices, sensors, and high-power/high temperature electronics. The synthesis of SiC nanowires by chemical vapor deposition using hexamethyldisilane (HMDS) as a source material on SiO2/Si substrate has been investigated. Various catalyst materials, including iron (film and nanoparticles), nickel (film and nanoparticles), and cobalt nanoparticles have been used. The growth runs have been carried out at temperatures between 900 and 1100°C under H2 as carrier gas. 3C-SiC nanowires have successfully been grown at even lower temperatures despite the lower efficiency of source decomposition at low temperatures. The SiC nanowire diameters are in the range of 8 nm to 60 nm, as determined by transmission electron microscopy (TEM). In general, the efficiency of nanowire growth has increased with temperature except the growth on Ni film, which has occasionally resulted in SiC flowers. Higher nanowire density at high temperatures can be attributed to more efficient decomposition of the source at higher temperatures. Further, optical properties of the nanowires have been studied by Fourier transform infrared spectroscopy (FTIR). The fabricated nanowires have also been characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray diffraction (XRD).

Epitaxial Growth of Single Crystalline Ge Films on GaAs Substrates for CMOS Device Integration

2008 ◽  
Vol 1068 ◽  
Author(s):  
Hock-Chun Chin ◽  
Ming Zhu ◽  
Ganesh Samudra ◽  
Yee-Chia Yeo
Keyword(s):  
High Resolution ◽  
Epitaxial Growth ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Gate Stack ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
First Time

ABSTRACTWe report a novel chemical vapor deposition (CVD) process for epitaxial growth of Ge film on GaAs substrate. The resultant layer exhibits device level quality, as shown by high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, high-resolution X-ray diffraction (HRXRD). In addition, atomic force microscopy (AFM) scanning indicates low RMS surface roughness of 5 Å. Secondary ion mass spectrometry (SIMS) reveals negligible out-diffusion of Ga and As into the Ge epilayer. By employing silane passivation, Ge p-MOSFET with TaN/HfO2 gate stack was fabricated on Ge/GaAs heterostructure for the first time, showing excellent output and pinch-off characteristics. A GaAs channel n-MOSFET was also fabricated, using similar SiH4 treatment during gate stack formation. These results reveal a potential solution to integrate Ge p-channel and GaAs n-channel MOSFET for advanced CMOS applications.

Low-temperature growth of HfO2 dielectric layers by Plasma-Enhanced CVD

2003 ◽  
Vol 786 ◽  
Author(s):  
M. Losurdo ◽  
M.M. Giangregorio ◽  
M. Luchena ◽  
P. Capezzuto ◽  
G. Bruno ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Growth Dynamics ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Interface Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dielectric Layers

ABSTRACTHfO2 dielectric layers have been grown on p -type Si(100) by plasma enhanced chemical vapor deposition (PE-CVD), using Ar-O2 plasmas and hafnium(IV) tetra-t -butoxide as precursors. In-situ control of the plasma phase is carried out by optical emission spectroscopy (OES) and quadrupolar mass spectrometry (QMS).Structural and optical properties of the HfO2 layers and of the HfO2/Si interface are investigated by spectroscopic ellipsometry (SE) in the photon energy range 1.5–6.0 eV‥ SE data are corroborated by results obtained from glancing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).The effect of the substrate temperature (RT-250°C) and precursor flow on the thickness of interfacial SiO2 layer and on the HfO2 microstructure is investigated. The growth dynamics of HfO2 film and SiO2 interface layer is also discussed.

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