THE CURRENT–VOLTAGE CHARACTERISTICS OVER THE MEASUREMENT TEMPERATURE OF 60–400 K IN THE Au/Ti/n-GaAs CONTACTS WITH HIGH DIELECTRIC HfO2 INTERFACIAL LAYER

2019 ◽  
Vol 26 (08) ◽  
pp. 1950045 ◽  
Author(s):  
ABDULKERIM KARABULUT ◽  
IKRAM ORAK ◽  
MUJDAT CAGLAR ◽  
ABDULMECIT TURUT
Keyword(s):  
Photoelectron Spectroscopy ◽  
Interfacial Layer ◽  
Atomic Layer ◽  
Gate Insulator ◽  
Temperature Dependent ◽  
Mos Capacitor ◽  
Gaas Wafer ◽  
Layer Deposition ◽  
Current Voltage ◽  
High Dielectric

The Au/Ti/HfO2/[Formula: see text]-GaAs metal/insulating layer/semiconductor structures have been fabricated using standard thermal atomic layer deposition. We experimentally showed whether or not the HfO2 interfacial layer grown on the [Formula: see text]-GaAs wafer modifies the barrier height (BH) of the device at the room temperature. Besides, we investigated the measurement based on temperature dependence of the device parameters from the current–voltage ([Formula: see text]–[Formula: see text]) characteristics of the diode in 60–400[Formula: see text]K range with steps of 10[Formula: see text]K. The X-ray photoelectron spectroscopy (XPS) have been carried out to characterize the surfaces of both [Formula: see text]-GaAs wafer and HfO2 thin films. The series resistance value from the temperature-dependent [Formula: see text]–[Formula: see text] characteristics decreased with decreasing temperature, which is a desired positive result for the devices developed from the MOS capacitor. The BH value of 0.94[Formula: see text]eV (300[Formula: see text]K) has been obtained for the device with the HfO2 layer which is a higher value than the value of 0.77[Formula: see text]eV (300[Formula: see text]K) of the device without HfO2 layer. Therefore, we can say that the HfO2 thin layer at the metal/GaAs interface can also be used for the BH modification as a gate insulator for GaAs MOS capacitor and MOSFETs. When the temperature-dependent [Formula: see text]–[Formula: see text] characteristics at low temperatures have been considered, it has been observed that the current prefers to flow through the lowest BHs due to the BH inhomogeneities.

Electrical Characteristics of Stacked Titanium Oxide/Aluminum Oxide by Atomic Layer Deposition on (NH4)2 S-Treated Gaas

2012 ◽  
Vol 516-517 ◽  
pp. 1945-1948
Author(s):  
Ming Kwei Lee ◽  
Chih Feng Yen ◽  
Sheng Hsiung Yang ◽  
Jung Chan Lee ◽  
Chi Hsuan Cheng ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Electrical Characteristics ◽  
Leakage Currents ◽  
Mos Capacitor ◽  
Native Oxides ◽  
Layer Deposition ◽  
High Dielectric ◽  
P Type

The (NH4)2 S treatment was used for the reduction of native oxides and passivation on GaAs. Atomic layer deposited Al2O3 can further remove the residue native oxides and lower the leakage current on (NH4)2S treated GaAs from self-cleaning and high bandgap. For further stacked with high dielectric constant TiO2 also prepared by atomic layer deposition on Al2O3/(NH4)2S treated p-type GaAs MOS capacitor, the leakage currents can reach 1.9 × 10-8 and 3.1 × 10-6 A/cm2 at ± 2 MV/cm. The dielectric constant is 25.

scholarly journals Crystalline AlN Interfacial Layer on GaN Using Plasma-Enhanced Atomic Layer Deposition

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 405
Author(s):  
Il-Hwan Hwang ◽  
Myoung-Jin Kang ◽  
Ho-Young Cha ◽  
Kwang-Seok Seo
Keyword(s):  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Interfacial Layer ◽  
Mass Density ◽  
Atomic Layer ◽  
Electrical Characteristics ◽  
Low Carbon ◽  
Carbon Impurity ◽  
X Ray ◽  
Layer Deposition

In this study, we report on the deposition of a highly crystalline AlN interfacial layer on GaN at 330 °C via plasma-enhanced atomic layer deposition (PEALD). Trimethylaluminum (TMA) and NH3 plasma were used as the Al and N precursors, respectively. The crystallinity and mass density of AlN were examined using X-ray diffraction (XRD) and X-ray reflectivity (XRR) measurements, respectively, and the chemical bonding states and atomic concentrations of the AlN were determined by X-ray photoelectron spectroscopy (XPS). The AlN/n-GaN interface characteristics were analyzed using TOF-SIMS and STEM, and the electrical characteristics of the AlN were evaluated using metal-insulator-semiconductor (MIS) capacitors. The PEALD process exhibited high linearity between the AlN thickness and the number of cycles without any incubation period, as well as a low carbon impurity of less than 1% and high crystal quality even at a low deposition temperature of 330 °C. Moreover, the GaN surface oxidation was successfully suppressed by the AlN interfacial layer. Furthermore, enhanced electrical characteristics were achieved by the MIS capacitor with AlN compared to those achieved without AlN.

scholarly journals Structural and Optical Properties of Luminescent Copper(I) Chloride Thin Films Deposited by Sequentially Pulsed Chemical Vapour Deposition

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Richard Krumpolec ◽  
Tomáš Homola ◽  
David Cameron ◽  
Josef Humlíček ◽  
Ondřej Caha ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Chemical Vapour Deposition ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Atomic Layer ◽  
Nanocrystalline Films ◽  
Zinc Blende ◽  
Layer Deposition

Sequentially pulsed chemical vapour deposition was used to successfully deposit thin nanocrystalline films of copper(I) chloride using an atomic layer deposition system in order to investigate their application to UV optoelectronics. The films were deposited at 125 °C using [Bis(trimethylsilyl)acetylene](hexafluoroacetylacetonato)copper(I) as a Cu precursor and pyridine hydrochloride as a new Cl precursor. The films were analysed by XRD, X-ray photoelectron spectroscopy (XPS), SEM, photoluminescence, and spectroscopic reflectance. Capping layers of aluminium oxide were deposited in situ by ALD (atomic layer deposition) to avoid environmental degradation. The film adopted a polycrystalline zinc blende-structure. The main contaminants were found to be organic materials from the precursor. Photoluminescence showed the characteristic free and bound exciton emissions from CuCl and the characteristic exciton absorption peaks could also be detected by reflectance measurements.

scholarly journals Growth without Postannealing of Monoclinic VO2 Thin Film by Atomic Layer Deposition Using VCl4 as Precursor

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 431 ◽  
Author(s):  
Wen-Jen Lee ◽  
Yong-Han Chang
Keyword(s):  
Vanadium Dioxide ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Temperature Dependent ◽  
Vanadium Compounds ◽  
Multifunctional Material ◽  
Layer Deposition ◽  
Vanadium Tetrachloride ◽  
First Time ◽  
Deposited Films

Vanadium dioxide (VO2) is a multifunctional material with semiconductor-to-metal transition (SMT) property. Organic vanadium compounds are usually employed as ALD precursors to grow VO2 films. However, the as-deposited films are reported to have amorphous structure with no significant SMT property, therefore a postannealing process is necessary for converting the amorphous VO2 to crystalline VO2. In this study, an inorganic vanadium tetrachloride (VCl4) is used as an ALD precursor for the first time to grow VO2 films. The VO2 film is directly crystallized and grown on the substrate without any postannealing process. The VO2 film displays significant SMT behavior, which is verified by temperature-dependent Raman spectrometer and four-point-probing system. The results demonstrate that the VCl4 is suitably employed as a new ALD precursor to grow crystallized VO2 films. It can be reasonably imagined that the VCl4 can also be used to grow various directly crystallized vanadium oxides by controlling the ALD-process parameters.

Analysis of 3-Dimensional 4H-SiC MOS Capacitors Grown by Atomic Layer Deposition of Al2O3

2018 ◽  
Vol 924 ◽  
pp. 490-493 ◽  
Author(s):  
Muhammad I. Idris ◽  
Nick G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
Atomic Layer Deposition ◽  
Gate Dielectric ◽  
Atomic Layer ◽  
Oxide Semiconductor ◽  
Mos Capacitors ◽  
Mos Capacitor ◽  
3 Dimensional ◽  
Layer Deposition ◽  
Show Evidence ◽  
Flatband Voltage

3-Dimensional 4H-SiC metal-oxide-semiconductor capacitors have been fabricated to determine the effect of the sidewall on the characteristics of 3-Dimentional gate structures. Al2O3 deposited by Atomic Layer Deposition (ALD) was used as the gate dielectric layer on the trench structure. The 3-D MOS capacitors exhibit increasing accumulation capacitance with excellent linearity as the sidewall area increases, indicating that ALD results in a highly conformal dielectric film. The capacitance – voltage characteristics also show evidence of a second flatband voltage, located at a higher bias than that seen for purely planar devices on the same sample. We also observe that the oxide capacitance of planar and 3-D MOS capacitors increases with temperature. Finally, we have found that the 3-D MOS capacitor has a weaker temperature dependence of flatband voltage in comparison to the conventional planar MOS capacitor due to the incorporation of the (1120) plane in the sidewall.

scholarly journals Nucleation Studies of HfO2 Thin Films Produced by Atomic Layer Deposition

2007 ◽  
Vol 996 ◽  
Author(s):  
Justin C. Hackley ◽  
J. Derek Demaree ◽  
Theodosia Gougousi
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Flow Reactor ◽  
Atomic Layer ◽  
Sample Surface ◽  
Interfacial Region ◽  
Initial Growth ◽  
Layer Deposition ◽  
Similar Growth

AbstractA hot wall Atomic Layer Deposition (ALD) flow reactor equipped with a Quartz Crystal Microbalance (QCM) has been used for the deposition of HfO2 thin films with tetrakis (dimethylamino) hafnium (TDMAH) and H2O as precursors. HfO2 films were deposited on H-terminated Si and SC1 chemical oxide starting surfaces. Spectroscopic ellipsometry (SE) and QCM measurements confirm linear growth of the films at a substrate temperature of 275°C. FTIR spectra indicate the films are amorphous as-deposited. Two distinct growth regimes are observed: from 1-50 cycles, both surfaces display similar growth rates of about 1.0Å/cycle; from 50-200 cycles, HfO2 growth is decreased by about 15% to ~0.87Å/cycle on both surfaces. Nucleation and initial growth behavior of the films on Si-H were examined using X-ray photoelectron spectroscopy (XPS). Angle-resolved XPS, at take-off angles of θ=0, 15, 30, 45 and 60° measured from the normal to the sample surface, is used to probe the interfacial region of thin films (4, 7, 10, 15 and 25 cycles) on H-terminated samples. Initially, an interfacial layer comprised of a SiOx/HfSiOx mixture is grown between 1-10 ALD cycles. We observe that the Si/HfO2 interface is unstable, and oxidation continues up to the 25th ALD cycle, reaching a thickness of ~18Å.

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