Abnormal Rectifying Characteristics of a Mg Doped GaN Schottky Diode

2003 ◽  
Vol 764 ◽  
Author(s):  
Jae Wook Kim ◽  
Byung Kyu Cho ◽  
Jhang Woo Lee ◽  
Phil W. Yu
Keyword(s):  
Low Temperature ◽  
Series Resistance ◽  
Deep Level ◽  
Sample Surface ◽  
Current Level ◽  
Doping Profile ◽  
Acceptor State ◽  
Equivalent Circuit Analysis ◽  
Zero Bias ◽  
Temperature Range

AbstractElectrical properties of Ti/Al Schottky junctions formed on p-GaN layers are investigated using Hall, I-V and C-V measurements in the temperature range of 82∼500K. All data exhibit extremely strong low temperature carrier freeze out effects, assured by huge decreases of the Hall concentration, zero-bias capacitance and also diode current level as the temperature decreases below ∼150K. The dramatic decrease of current level at the low temperature range indicates that tunneling plays a more important role for the low temperature conduction and the junction shows ohmic-like I-V characteristics due to large series resistance. The barrier height estimated with the thermionic model varies with a strong temperature dependency from 1.21eV at 500K to 0.24eV at 82K. High frequency equivalent circuit analysis indicates that the corrected capacitance still shows a strong frequency dependency even after compensating the series resistance effect due to the slow response of Mg acceptor state. The transition frequency of the acceptor state, which is proportional to the emission rate of the deep level, is estimated to be 142KHz at room temperature. Low frequency C-V measurements provide a proper doping profile, revealing the ∼15nm thin layer with a high doping spike of ∼8×1018/cm3 near the sample surface and the constantly doped bulk layer with a doping level of ∼1017/cm3.

scholarly journals Electrical characterization of low temperature plasma epitaxial Si grown on highly doped Si substrates

2020 ◽  
Vol 11 ◽  
pp. 4
Author(s):  
Cyril Leon ◽  
Sylvain Le Gall ◽  
Marie-Estelle Gueunier-Farret ◽  
Jean-Paul Kleider ◽  
Pere Roca i Cabarrocas
Keyword(s):  
Low Temperature ◽  
Deep Level ◽  
Chemical Vapour ◽  
Electrical Characterization ◽  
Deposition Process ◽  
Doping Profile ◽  
Epitaxial Silicon ◽  
Temperature Plasma ◽  
Doping Density ◽  
Si Substrates

Epitaxial silicon layers were grown on highly doped c-Si substrates using the plasma-enhanced chemical vapour deposition process (PECVD) at low temperature (175 °C). The transport and defect-related properties of these epi-Si layers were characterized by current density-voltage (J–V) and capacitance–voltage (C–V) techniques. The results show that the epi-Si layers exhibit a non-intentional n-type doping with a low apparent doping density of about 2 × 1015 cm−3. The admittance spectroscopy technique is used to investigate the presence of deep-level defects in the structure. An energy level at 0.2 eV below the conduction band has been found with a density in the range of 1015 cm−3 which may explain the observed apparent doping profile.

Defect Evolution in Ion Irradiated 6H-SiC Epitaxial Layers

2005 ◽  
Vol 483-485 ◽  
pp. 485-488 ◽  
Author(s):  
Alfonso Ruggiero ◽  
M. Zimbone ◽  
Fabrizio Roccaforte ◽  
Sebania Libertino ◽  
Francesco La Via ◽  
...  
Keyword(s):  
Low Temperature ◽  
Deep Level Transient Spectroscopy ◽  
Room Temperature ◽  
Deep Level ◽  
Room Temperature Photoluminescence ◽  
Temperature Range ◽  
Defect Annealing ◽  
Luminescence Peak ◽  
Transient Spectroscopy ◽  
Dlts Spectra

Deep-Level Transient Spectroscopy and room temperature photoluminescence were used to characterise a 6H-SiC epitaxial layer irradiated with 10 MeV C+ and to follow the defect annealing in the temperature range 300-1400 °C. The intensity of luminescence peak at 423 nm, related to band to band transitions, decreases after irradiation and it is slowly recovered after annealing in the temperature range 1000-1400 °C. The DLTS spectra of low temperature annealed samples show the presence of several overlapping traps, which anneal and evolve at high temperatures. After 1200 °C a main level at Ec-0.43 eV (E1/E2) is detected. The comparison between luminescence and DLTS results indicates that the defect associated with the E1/E2 level is mainly responsible for the luminescence quenching after irradiation.

Recent Nanofabrication of Silicon Dioxide on Silicon Wafer Using AFM Operated at Low Temperature

2011 ◽  
Vol 84-85 ◽  
pp. 317-320
Author(s):  
Agus Geter Edy Sutjipto ◽  
Afzeri ◽  
Amir Akramin Shafie
Keyword(s):  
Low Temperature ◽  
Silicon Dioxide ◽  
Silicon Wafer ◽  
Water Film ◽  
Water Layer ◽  
Sample Surface ◽  
Wafer Surface ◽  
Zero Bias ◽  
Atomic Force ◽  
Air Film

Field-induced oxidation has become a promising process that is capable of directly producing high-resolution surface oxide patterns on variety materials. This report initiated the idea of the possibility of a controlled nanofabrication of SiO2 on silicon wafer by utilizing a frozen humid air film. A low temperature (-70°C) operation of an atomic force microscope (AFM) was used to condense ambient humidity (40%) to perform a thin frozen water layer covering a silicon wafer surface. A scanning probe was contacted with the layer and a zero bias voltage was applied to the sample surface with the AFM probe tip connected to the reference -2.44V. The frozen water film acted both as an electrolyte to form silicon dioxide and as a resource of hydroxide. Using this technique (a) a consistency in height of 6 nm silicon dioxide patterns layer could be achieved showing that the effect of tip vibration could be reduced; (b) easy to remove frozen water by just operating the AFM to the ambient temperature; (c) it is possible to control thickness by making different humidity.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Hydrogen absorption in Ni-catalyzed Mg: A model for measurements in the low temperature range

2014 ◽  
Vol 39 (22) ◽  
pp. 11501-11508 ◽  
Author(s):  
Federico Cova ◽  
Fabiana Gennari ◽  
Pierre Arneodo Larochette
Keyword(s):  
Low Temperature ◽  
Hydrogen Absorption ◽  
Temperature Range

Evidence For Non-Correlation Between The 0.15 eV And 0.44 eV Cu-Related Acceptor Levels In GaAs

1996 ◽  
Vol 442 ◽  
Author(s):  
K. Leosson ◽  
H. P. Gislason
Keyword(s):  
Reverse Bias ◽  
Deep Level ◽  
Current Transient ◽  
Zero Bias ◽  
Lithium Diffusion ◽  
Transient Spectroscopy ◽  
Plasma Hydrogenation

AbstractWe present investigations on the two dominating acceptor levels observed in Cu-diffused GaAs which have frequently been attributed to the two ionization levels of a double CuGa acceptor. We employed plasma hydrogenation and lithium diffusion followed by reverse-bias and zero-bias annealing to passivate and subsequently reactivate the Cu-related acceptor levels. Deep-level current-transient spectroscopy measurements reveal that the two levels are independently reactivated, strongly indicating that they arise from different defects.

LOW TEMPERATURE MODELS OF METAL OXIDE SEMICONDUCTOR FIELD-EFFECT TRANSISTORS

1995 ◽  
Vol 06 (02) ◽  
pp. 317-373 ◽  
Author(s):  
G. GILDENBLAT ◽  
D. FOTY
Keyword(s):  
Low Temperature ◽  
Field Effect Transistors ◽  
Numerical Models ◽  
Three Dimensional ◽  
Oxide Semiconductor ◽  
Characteristic Time Scale ◽  
Mos Transistors ◽  
Short Channel ◽  
Temperature Range ◽  
Dimensional Models

We review the modeling of silicon MOS devices in the 10–300 K temperature range with an emphasis on the specifics of low-temperature operation. Recently developed one-dimensional models of long-channel transistors are discussed in connection with experimental determination and verification of the effective channel mobility in a wide temperature range. We also present analytical pseudo-two-dimensional models of short-channel devices which have been proposed for potential use in circuit simulators. Several one-, two-, and three-dimensional numerical models are discussed in order to gain insight into the more subtle details of the low-temperature device physics of MOS transistors and capacitors. Particular attention is paid to freezeout effects which, depending on the device design and the ambient temperature range, may or may not be important for actual device operation. The numerical models are applied to study the characteristic time scale of freezeout transients in the space-charge regions of silicon devices, to the analysis and suppression of delayed turn-off in MOS transistors with compensated channel, and to the temperature dependence of three-dimensional effects in short-channel, narrow-channel MOSFETs.

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