Epitaxial Growth of Thin Ge Films on [001] Gaas by Laser Photochemical Vapor Deposition from GeH4

1987 ◽  
Vol 101 ◽  
Author(s):  
V. Tavitian ◽  
C. J. Kiely ◽  
J. G. Eden
Keyword(s):  
Growth Rate ◽  
Film Thickness ◽  
Vapor Deposition ◽  
Epitaxial Film ◽  
Film Growth ◽  
Cross Sectional ◽  
Parallel Geometry ◽  
193 Nm ◽  
Photochemical Vapor Deposition ◽  
Substrate Temperatures

ABSTRACTEpitaxial Ge films have been grown on [001] GaAs for substrate temperatures (Ts) as low as 285°C by photodissociating GeH4 at 193 nm in parallel geometry. For a laser fluence of ~15 mJ - cm-2, the film growth rate varies from 0.6 to ~5 nm - min-1, depending upon Ts and gas pressure. Plan and cross-sectional TEM studies of the Ge/GaAs bicrystal demonstrate that the 400–700 A thick Ge films are single crystal and epitaxial with the substrate. The present limitation on epitaxial film thickness appears to be imposed by reduced adatom mobility at the temperatures investigated.

Laser Photochemical Vapor Deposition of Ge Films (300 ≤ T ≤ 873 K) from GeH4: Roles of Ge2H6 and Ge

1986 ◽  
Vol 75 ◽  
Author(s):  
K. K. King ◽  
V. Tavitian ◽  
D. B. Geohegan ◽  
E. A. P. Cheng ◽  
S. A. Piette ◽  
...  
Keyword(s):  
Activation Energy ◽  
Laser Radiation ◽  
Vapor Deposition ◽  
Film Growth ◽  
Uv Laser ◽  
Cvd Growth ◽  
Excimer Laser Radiation ◽  
Parallel Geometry ◽  
Photochemical Vapor Deposition ◽  
Substrate Temperatures

AbstractThe photochemical growth of polycrystalline and amorphous Ge films on SiO2, GaAs and NaCl by photodissociating GeH4 with excimer laser radiation in parallel geometry is reported. For substrate temperatures (TS) below the pyrolytic threshold for GeH4 (553 K), two distinct regions of film growth are observed. In the 425< TS < 553 K range, the ultraviolet (UV) laser “seeds” the reactor with Ge2H6 which readily pyrolyzes at the surface, forming several monolayers of Ge which subsequently catalyze the pyrolysis of GeH4. The activation energy (Ea) in this region is the same as that for the normal CVD growth of Ge from GeH4 (Ea = 0.9 eV). If, however, the laser is pulsed throughout the film growth run, Ea falls by a factor of at least 2 and growth is observed for TS as low as 300 K. In this laser sustained region, film growth ceases in the absence of UV laser radiation. These results clearly demonstrate the ability of a UV laser to alter the reactor chemistry and dictate the species responsible for film growth.

Photo Modified Growth of GaAs by Chemical Beam Epitaxy

1998 ◽  
Vol 510 ◽  
Author(s):  
R. Jothilingam ◽  
T. Farrell ◽  
T.B. Joyce ◽  
P.J. Goodhew
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Electrical Power ◽  
Xenon Lamp ◽  
Chemical Beam Epitaxy ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Substrate Temperatures ◽  
Laser Reflectometry

AbstractWe report the photo modified growth of GaAs by chemical beam epitaxy at substrate temperatures in the range 335 to 670°C using triethygallium (TEG) and arsine. A mercury-xenon lamp (electrical power 200 W) provided the irradiation for the photoassisted growth. The growth was monitored in real time by laser reflectometry (LR) using a 670 nm semiconductor laser, and the optically determined growth rate agreed with that obtained from the layer thickness measured by cross sectional transmission electron microscopy. The observed photo-enhancement of the growth rate at low substrate temperatures and inhibition at high substrate temperatures is thermal in origin, consistent with raising the substrate temperature by 10±3°C. Cross sectional transmission electron microscopy showed that the photoassisted layers are essentially free from dislocations

Defects and Their Control in SiO2 Films Prepared by D2 –Lamp Photochemical Vapor Deposition

1988 ◽  
Vol 131 ◽  
Author(s):  
Hidehiko Nonaka ◽  
Kazuo Arai ◽  
Shingo Ichimura
Keyword(s):  
Vapor Deposition ◽  
Defect Formation ◽  
Film Growth ◽  
Film Surface ◽  
Formation Mechanisms ◽  
Silica Films ◽  
Activated Oxygen ◽  
Surface Modified ◽  
Photochemical Vapor Deposition ◽  
Vacuum Uv

ABSTRACTAmorphous silica films deposited from the mixture of gases (Si2 H6 and Si2F6) by deutrium-lamp CVD were studied by IR, vacuum UV, EPR and Auger electron (AE) spectrometries. The F-doping enhanced the film growth and removed defects in the film such as -H, -OH, and E' centers. A model on deposition and defect formation mechanisms was proposed based on the thermodynamic Stabilities of resultant HF in the reactions. The AES study showed that the film surface modified by activated oxygen had an increased hardness against electron beams.

A Study of Nucleation and Growth in MOCVD: The Growth of Thin Films of Alumina

2000 ◽  
Vol 648 ◽  
Author(s):  
M.P. Singh ◽  
S. Mukhopadhayay ◽  
Anjana Devi ◽  
S.A. Shivashankar
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Film Growth ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Cross Sectional ◽  
Alumina Films ◽  
Pressure Chemical

AbstractWe have studied the nucleation and growth of alumina by metalorganic chemical vapor deposition (MOCVD). The deposition of alumina films was carried out on Si(100) in a horizontal, hot-wall, low pressure chemical vapor deposition (CVD) reactor, using aluminum acetylacetonate{Al(acac)3}as the CVD precursor. We have investigated growth of alumina films as a function of different CVD parameters such as substrate temperature and total reactor pressure during film growth. Films were characterized by optical microscopy, X-ray diffractometry (XRD), scanning electron microscopy (SEM), cross-sectional SEM, and secondary ion mass spectrometry (SIMS) compositional depth profiling. The chemical analysis reveals that the carbon is present throughout the depth of the films.

A STUDY OF ALUMINA THIN FILMS GROWN BY LOW PRESSURE MOCVD: XPS AND AES

2002 ◽  
Vol 16 (08) ◽  
pp. 1261-1267 ◽  
Author(s):  
M. P. SINGH ◽  
S. A. SHIVASHANKAR ◽  
T. SHRIPATHI
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Alumina Film ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Low Pressure Mocvd ◽  
Substrate Temperatures

We have studied the chemical composition of alumina ( Al 2 O 3) films grown on Si(100) at different substrate temperatures by metalorganic chemical vapor deposition (MOCVD) using aluminium acetylactonate { Al(acac) 3} as the precursor. We have found that the resulting films of Al 2 O 3 contain substantial amounts of carbon. X-ray photoelectron spectroscopy (XPS) was employed to study the chemical state of carbon present in such films. The XPS spectrum reveals that the carbon present in Al 2 O 3 film is graphitic in nature. Auger electron spectroscopy (AES) was employed to study the distribution of carbon in the Al 2 O 3 films. The AES depth profile reveals that carbon is present throughout the film. The AES study on Al 2 O 3 films corroborates the XPS findings. An investigation of the Al 2 O 3/ Si (100) interface was carried out using cross-sectional transmission electron microscopy (XTEM). The TEM study reveals textured growth of alumina film on Si(100), with very fine grains of alumina embedded in an amorphous carbon-containing matrix.

On the optimization of a dc arcjet diamond chemical vapor deposition reactor

1996 ◽  
Vol 11 (3) ◽  
pp. 694-702 ◽  
Author(s):  
S. W. Reeve ◽  
W. A. Weimer ◽  
D. S. Dandy
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Methyl Radical ◽  
Chemical Kinetic Model ◽  
Model Calculations ◽  
Chemical Vapor Deposition Reactor

Based on results from chemical kinetic model calculations, a method to improve diamond film growth in a dc arcjet chemical vapor deposition reactor has been developed. Introducing the carbon source gas (CH4) into an Ar/H2 plasma in close proximity to the substrate produced diamond films exhibiting simultaneous improvements in quality and mass deposition rates. These improvements result from a reduced residence time of the methane in the plasma which inhibits the hydrocarbon chemistry in the gas from proceeding significantly beyond methyl radical production prior to encountering the substrate. Improvements in growth rate were modest, increasing by only a factor of two. Optical emission actinometry measurements indicate that the flux of atomic hydrogen across the stagnation layer to the substrate is mass diffusion limited. Since diamond growth depends upon the flux of atomic H to the substrate, these results suggest that under the conditions examined here, a low atomic H flux to the substrate poses an upper limit on the attainable diamond growth rate.

Reaction Kinetics of Epitaxial Silicon Deposition at 220-400°C Using Remote Plasma-Enhanced Chemical Vapor Deposition

1989 ◽  
Vol 165 ◽  
Author(s):  
B. Anthony ◽  
T. Hsu ◽  
L. Breaux ◽  
S. Banerjee ◽  
A. Tasch
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Reaction Kinetics ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Epitaxial Silicon ◽  
Remote Plasma ◽  
Inert Carrier ◽  
Substrate Temperatures ◽  
Kinetics Of

AbstractIn this paper the reaction kinetics of Remote Plasma-enhanced Chemical Vapor Deposition (RPCVD) are investigated. Growth rate characterization has been performed for substrate temperatures of 220 – 400°C, r-f powers from 4 – 8 W, and silane flow rates of 10 – 30 sccm. Growth rate has been found to increase exponentially with r-f power, which is, as yet, unexplained. An approximate square root dependence of growth rate on silane partial pressure agrees with the theory of Claasen et. Al for Chemical Vapor Deposition (CVD) of silicon from silane with an inert carrier gas. From an Arrhenius plot of the temperature dependence of growth rate, we note a change of slope at ∼300°C which we have attributed to the behavior of hydrogen at the silicon surface.

Laser Photochemical Vapour Deposition of Epitaxial Ge Films on GaAs from GeH4 Using NH3 as a Sensitiser

1988 ◽  
Vol 129 ◽  
Author(s):  
C.J. Kiely ◽  
C. Jones ◽  
V. Tavitian ◽  
J.G. Eden
Keyword(s):  
Growth Rate ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Film Growth ◽  
Hydrogen Abstraction ◽  
Auger Spectroscopy ◽  
Hydrogen Atoms ◽  
Production Of Hydrogen ◽  
Substrate Temperatures ◽  
Secondary Ion

ABSTRACTThe viability of ammonia as a sensitiser for the epitaxial growth of Ge on GaAs by laser photochemical vapour deposition (LPVD) has been investigated. Specifically NH3/GeH4/He (0.8/5/95 sccm, 5.5 Torr total pressure) mixtures have been irradiated by a 193nm ArF excimer laser in parallel geometry for substrate temperatures, Ts<400°C. As evidenced by a dramatic acceleration in Ge film growth rate, the NH3 efficiently couples the laser radiation to the GeH4 precursor molecule. The microstructures of LPVD Ge films grown with and without NH3 have been examined by TEM, and the epitaxial nature of both types of films has been verified, although some subtle differences are noted. Chemical analysis of the deposited films has been carried out using Auger spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy. Our results show that there is little or no nitrogen incorporation into the Ge films grown in the presence of NH3, and that hydrogen contamination in our films is minimal. The beneficial effect of NH3 on the growth rate of LPVD Ge films is attributed to the photolytic production of hydrogen atoms which efficiently decompose GeH4 by hydrogen abstraction collisions.

Sign in / Sign up

Export Citation Format

Share Document