Dopant and As4/Ga Flux Ratio Influence on the Electrical and Structural Properties of LT GaAs

1994 ◽  
Vol 340 ◽  
Author(s):  
S. P. O'Hagan ◽  
M. Missous
Keyword(s):  
Substrate Temperature ◽  
Pressure Ratio ◽  
Flux Ratio ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Strong Function ◽  
X Ray ◽  
Undoped Material ◽  
Hall Effect Measurements ◽  
P Type

ABSTRACTDouble crystal x-ray diffraction and Hall effect measurements have been performed on GaAs layers grown by molecular beam epitaxy at low substrate temperature (200-250°C). The concentration of excess As incorporated in undoped material is found to be a strong function of growth temperature but not of As4/Ga beam equivalent pressure ratio at a given temperature. Doping with Si or Be at concentrations of 1019cm−3 or greater has resulted in significant reduction of excess As concentration in layers grown at 250'C. This effect is seen to diminish with reducing substrate temperature. The effect is not seen when Se is used as the doping source. Reducing As overpressure in the presence of such a high doping concentrations has led to highly electrically active n- and p-type layers grown at 250'C.

Properties of Sputter Deposited ZnO Films Co-doped with Lithium and Phosphorus

2013 ◽  
Vol 1494 ◽  
pp. 77-82
Author(s):  
T. N. Oder ◽  
A. Smith ◽  
M. Freeman ◽  
M. McMaster ◽  
B. Cai ◽  
...  
Keyword(s):  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Hall Effect Measurements ◽  
Sputter Deposited ◽  
P Type ◽  
Post Deposition ◽  
Co Doped

ABSTRACTThin films of ZnO co-doped with lithium and phosphorus were deposited on sapphire substrates by RF magnetron sputtering. The films were sequentially deposited from ultra pure ZnO and Li3PO4 solid targets. Post deposition annealing was carried using a rapid thermal processor in O2 and N2 at temperatures ranging from 500 °C to 1000 °C for 3 min. Analyses performed using low temperature photoluminescence spectroscopy measurements reveal luminescence peaks at 3.359, 3.306, 3.245 eV for the co-doped samples. The x-ray diffraction 2θ-scans for all the films showed a single peak at about 34.4° with full width at half maximum of about 0.17°. Hall Effect measurements revealed conductivities that change from p-type to n-type over time.

Nitrogen-Doping Induced Optical Bandgap Widening of P-Type Cu2O Flms

2009 ◽  
Vol 1217 ◽  
Author(s):  
Yoshitaka Nakano ◽  
Shu Saeki ◽  
Takeshi Morikawa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Optical Bandgap ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
N Doping ◽  
Hall Effect Measurements ◽  
Optical Bandgap Energy ◽  
P Type

AbstractWe have investigated the effect of N doping into Cu2O films deposited by reactive magnetron sputtering. With increasing N-doping concentration up to 3 at.%, the optical bandgap energy is enlarged from ˜2.1 to ˜2.5 eV with retaining p-type conductivity as determined by optical absorption and Hall-effect measurements. Additionally, photoelectron spectroscopy in air measurements shows an increase in the valence and conduction band shifts with N doping. These experimental results demonstrate possible optical bandgap widening of p-type N-doped Cu2O films, which is a phenomenon that is probably associated with significant structural changes induced by N doping, as suggested from x-ray diffraction measurements.

Formation and Characteristics of CoSi2 Layers Synthesized by Mevva Implantation

1996 ◽  
Vol 438 ◽  
Author(s):  
S. P. Wong ◽  
Qicai Peng ◽  
W. Y. Cheung ◽  
W. S. Guo ◽  
J. B. Xu ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Ion Beam ◽  
Metal Vapor ◽  
Vacuum Arc ◽  
Strong Temperature Dependence ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Hall Effect Measurements ◽  
Large Peak ◽  
P Type

AbstractIon beam synthesis of CoSi2 layers in Si by MEVVA (Metal Vapor Vacuum Arc) implantation has been performed under various conditions. The formation and characteristics of these CoSi2 layers have been studied by XTEM, RBS, AFM, X-ray diffraction, ellipsometry, electrical and Hall effect measurements. It was found that a higher substrate temperature during implantation results in an as-implanted Co distribution closer to the surface and hence the formation of a shallower CoSi2 layer after annealing. Buried CoSi2 layers of good crystal quality and low resistivity CoSi2 can be formed by MEVVA implantation and annealing under appropriate conditions. A strong temperature dependence of the Hall coefficient showing a large peak at around 100K was observed for the CoSi2 layers formed in p-type Si substrates but not in n-type substrates. The properties and their dependence on the processing conditions, in particular, the substrate temperature during implantation, are presented and discussed.

Characterization of p-type 4H-SiC epitaxial layer grown on (11-20) substrate

2001 ◽  
Vol 680 ◽  
Author(s):  
Kazutoishi Kojima ◽  
Toshiyuki Ohno ◽  
Mituhiro Kushibe ◽  
Koh Masahara ◽  
Yuuki Ishida ◽  
...  
Keyword(s):  
Boron Concentration ◽  
Hole Mobility ◽  
Crystalline Quality ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hall Effect Measurements ◽  
P Type ◽  
Incorporation Efficiency

ABSTRACTGrowth and characterization of p-type 4H-SiC epitaxial layers grown on (11-20) substrates are reported. P-type 4H-SiC epilayers with smooth surface morphology have been grown on (11-20) substrates by low-pressure, hot-wall type CVD with SiH4–C3H8–H2–TMA system. The doping concentration can be controlled in the range from about 1×1016cm−3 to 1×1019cm−3. Anisotropy of the crystalline quality is observed by x-ray diffraction measurement. P-type epilayers, in which near band-gap emissions are dominated and D-A pair peak is not observed, are obtained. Hole mobility of (11-20) epilayers is smaller than that of (0001) epilayers probably due to the lack of crystalline quality compared to (0001) epilayers. The results of both low-temperature photoluminescence and the temperature dependence of Hall effect measurements indicate that the boron concentration as undoped impurity in (11-20) epilayer is lower than that of (0001) epilayer. This may be caused by the smaller incorporation efficiency of boron into (11-20) epilayer than that of (0001) epilayer.

Formation and Characteristics of CoSi2 Layers Synthesized by Mevva Implantation

1996 ◽  
Vol 439 ◽  
Author(s):  
S. P. Wong ◽  
Qicai Peng ◽  
W. Y. Cheung ◽  
W. S. Guo ◽  
J. B. Xu ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Ion Beam ◽  
Metal Vapor ◽  
Vacuum Arc ◽  
Strong Temperature Dependence ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Hall Effect Measurements ◽  
Large Peak ◽  
P Type

AbstractIon beam synthesis of CoSi2 layers in Si by NIEVVA (Metal Vapor Vacuum Arc) implantation has been performed under various conditions. The formation and characteristics of these CoSi2 layers have been studied by XTEM, RBS, AFM, X-ray diffraction, ellipsometry, electrical and Hall effect measurements. It was found that a higher substrate temperature during implantation results in an as-implanted Co distribution closer to the surface and hence the formation of a shallower CoSi2 layer after annealing. Buried CoSi2 layers of good crystal quality and low resistivity CoSi2 can be formed by MEVVA implantation and annealing under appropriate conditions. A strong temperature dependence of the Hall coefficient showing a large peak at around 100K was observed for the CoSi2 layers formed in p-type Si substrates but not in n-type substrates. The properties and their dependence on the processing conditions, in particular, the substrate temperature during implantation, are presented and discussed.

scholarly journals Electrical and Structural properties of Copper Oxide (CuO) thin films on Plastic substrate deposited by spray pyrolysis technique

2019 ◽  
Vol 7 (2) ◽  
pp. 14-18 ◽  
Author(s):  
Mohammad G. Faraj ◽  
Askander K. Kaka ◽  
Halo D. Omar
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Substrate Temperature ◽  
Copper Oxide ◽  
Hall Effect ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hall Effect Measurements

In this paper, copper oxide (CuO) thin films were deposited on polyimide (PI) Plastic substrates with spray pyrolysis technique with different temperatures (i.e. 250–300 °C). All the deposited films were characterized by X-ray diffraction (XRD) and Hall Effect measurements for the Structural and electrical properties. Effects of substrate temperature on the structural and electrical characteristics of the films were studied. The X-ray diffraction patterns’ results reveal that the all of CuO films have a face centered cubic structure. The crystallite grain size was calculated using Scherrer formula and it is found that the substrate temperature (300 0C) has maximum crystallite grain size (81.2 nm). Hall Effect measurements showed that all the films are of p-type conductivity. Depending on the substrate temperature, Hall measurement showed that the electrical resistivity and the carrier concentration varied in the range 77.4 Ω.cm to 52.7 Ω.cm and  6.3 x1015 cm-3 to  10.1 x1015 cm-3.

InP Layers Grown by Molecular Beam Epitaxy at Low Substrate Temperature

1991 ◽  
Vol 241 ◽  
Author(s):  
K. Xie ◽  
C. R. Wie ◽  
G. W. Wicks
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Double Crystal ◽  
X Ray ◽  
Hall Effect Measurements ◽  
Phosphorus Source ◽  
Substrate Temperatures

ABSTRACTInP layers were grown on semi-insulating InP wafer by molecular beam epitaxy (MBE) at low substrate temperatures (<200° C), using solid phosphorus source. We use x-ray diffraction, double crystal x-ray rocking curve, Auger electron spectroscopy, and temperature-dependent Van der Pauw and Hall effect measurements to characterize the as-grown and annealed InP layers. It is found that the InP layer is in poly-crystal state with excess P over 7 at%. The layers became single crystal after annealing above 400°C. The resistivity of the InP layer decreased from 60 Ωcm for an as-grown sample to 0.82 Ωcm after 400°C RTA annealing. The different role of excess P as compared to the role played by excess As in LT-GaAs is discussed based on the P properties.

Epitaxial Ge Films on Si Substrates

1987 ◽  
Vol 91 ◽  
Author(s):  
J.S. Mccalmont ◽  
D. Robinson ◽  
K.M. Lakin ◽  
H.R. Shanks
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Film Growth ◽  
Dopant Concentration ◽  
Source Material ◽  
Cluster Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
P Type

ABSTRACTThin films of germanium have been prepared using an ultrahigh vacuum ionized-cluster beam (ICB) system. The dopant concentration of the films was varied by alloying the germanium source material with aluminum, a p-type dopant. X-ray diffraction analysis of the films has shown that an epitaxial (100) germanium film can be deposited on a (100) silicon substrate with a substrate temperature as low as 300°C. The results confirm that ICM deposition can be used to prepare epitaxial germanium films, but ionization of the clusters does not appear to affect the film growth.

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

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