scholarly journals Influences of ALD Al2O3 on the surface band-bending of c-plane, Ga-face GaN

2021 ◽  
Author(s):  
Jiarui Gong ◽  
Kuangye Lu ◽  
Jisoo Kim ◽  
Tien Khee Ng ◽  
Donghyeok Kim ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Band ◽  
Band Bending ◽  
X Ray ◽  
The Poor ◽  
P Type

Abstract The recently demonstrated approach of grafting n-type GaN with p-type Si or GaAs, by employing ultrathin Al2O3 at the interface, has shown the feasibility to overcome the poor p-type doping challenge of GaN. However, the surface band-bending of GaN that could be influenced by the Al2O3 has been unknown. In this work, the band-bending of c-plane, Ga-face GaN with ultrathin Al2O3 deposition at the surface of GaN was studied using X-ray photoelectron spectroscopy (XPS). The study shows that the Al2O3 can help suppress the upward band-bending of the c-plane, Ga-face GaN with a monotonic reduction trend from 0.48 eV down to 0.12 eV as the number of Al2O3 deposition cycles increases from 0 to 20. The study further shows that the band-bending can be mostly recovered after removing the Al2O3 layer, concurring that the introduction of ultrathin Al2O3 is the main reason for the surface band-bending modulation.

scholarly journals H-Terminated Diamond Surface Band Bending Characterization by Angle-Resolved XPS

Surfaces ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Gonzalo Alba ◽  
David Eon ◽  
M. Pilar Villar ◽  
Rodrigo Alcántara ◽  
Gauthier Chicot ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapour ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Surface Band ◽  
Band Bending ◽  
New Approach ◽  
Shallow Acceptors ◽  
New Interpretation ◽  
P Type

Concerning diamond-based electronic devices, the H-terminated diamond surface is one of the most used terminations as it can be obtained directly by using H2 plasma, which also is a key step for diamond growth by chemical vapour deposition (CVD). The resultant surfaces present a p-type surface conductive layer with interest in power electronic applications. However, the mechanism for this behavior is still under discussion. Upward band bending due to surface transfer doping is the most accepted model, but has not been experimentally probed as of yet. Recently, a downward band bending very near the surface due to shallow acceptors has been proposed to coexist with surface transfer doping, explaining most of the observed phenomena. In this work, a new approach to the measurement of band bending by angle-resolved X-ray photoelectron spectroscopy (ARXPS) is proposed. Based on this new interpretation, a downward band bending of 0.67 eV extended over 0.5 nm was evidenced on a (100) H-terminated diamond surface.

Interface Analysis of P-Type 4H-SiC/Al2O3 Using Synchrotron-Based XPS

2016 ◽  
Vol 858 ◽  
pp. 693-696 ◽  
Author(s):  
Sethu Saveda Suvanam ◽  
Milad Ghadami Yazdi ◽  
Muhammad Usman ◽  
Mats Götelid ◽  
Anders Hallén
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Cleaning ◽  
Surface Band ◽  
Band Bending ◽  
Oxide Charge ◽  
Semiconductor Test ◽  
No Formation ◽  
A Value ◽  
P Type ◽  
Post Deposition

In this paper, the interface between Al2O3 and p-type 4H-SiC is evaluated using x-ray photoelectron spectroscopy (XPS) measurements. These studies are made on dielectric-semiconductor test structures with Al2O3 as dielectric with different pre-and post-deposition treatments. XPS measurements on the as-deposited samples with two different pre-surface cleaning have shown no formation of a SiO2 interlayer. However, after the post deposition rapid thermal annealing (RTA) at 1100 °C in N2O for 60s, a SiO2 interlayer is formed. The surface band bending was determined from Si 2p core level peak shifts measured using XPS. These results suggest that Al2O3 deposited on the p-type 4H-SiC have a net positive oxide charge which is complementary to that of n-type 4H-SiC. From these shifts it was found that the as-deposited RCA cleaned sample had an oxide charge of 5.6×1013 q/cm-2, as compared to standard cleaned samples, having 4.6×1013 q/cm-2. A further reduction in oxide charge was observed after annealing at 1100 °C in N2O, down to a value of 4×1013 q/cm-2.

The effect of covalently bonded aryl layers on the band bending and electron density of SnO2 surfaces probed by synchrotron X-ray photoelectron spectroscopy

2019 ◽  
Vol 21 (32) ◽  
pp. 17913-17922 ◽  
Author(s):  
Joel C. Schuurman ◽  
Alexandra R. McNeill ◽  
Rodrigo F. Martinez-Gazoni ◽  
Jonty I. Scott ◽  
Roger J. Reeves ◽  
...  
Keyword(s):  
Electron Density ◽  
Photoelectron Spectroscopy ◽  
Surface Band ◽  
Band Bending ◽  
X Ray ◽  
Covalently Bonded

A downward to upward surface band bending change can be induced by grafted 4-(trifluoromethyl)phenyl groups on SnO2.

An angular dependent X-ray photoemission study of Indium-tin-oxide surfaces

2002 ◽  
Vol 747 ◽  
Author(s):  
H. H. Fong ◽  
W. J. Song ◽  
S. K. So
Keyword(s):  
Work Function ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Surface Band ◽  
Band Bending ◽  
X Ray ◽  
Plasma Treatments ◽  
Photoemission Study ◽  
Uv Ozone

ABSTRACTThe surface properties of indium-tin-oxide (ITO) thin films treated by UV ozone or plasma were analyzed by angular dependent X-ray photoelectron spectroscopy (ADXPS) and by ultraviolet photoemission (UPS). The chemical composition, chemical states and the work function of the ITO surfaces were deduced. Our analysis indicate that ITO surface is Sn-rich. Both UV ozone and O-plasma treatments are most effective in removing surface hydrocarbon. Among all treatments, O-plasma treated surface achieved the highest work function of 4.4eV, whereas argon ion sputtered surface had the lowest work function of 3.9eV. Both O-plasma and UV ozone treatments increase the surface oxygen concentration. It is proposed that O2-ions diffuse into ITO. The diffusion length is about 50Å as deduced from ADXPS. The stoichiometry of the surface is the major factor in controlling the surface work function of ITO. A surface band bending model is proposed to account for the change of work function due to “oxidized” ITO surface after UV-ozone or oxygen plasma treatments.

scholarly journals Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-Ray photoemission spectroscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yanfei Zhao ◽  
Hongwei Gao ◽  
Rong Huang ◽  
Zengli Huang ◽  
Fangsen Li ◽  
...  
Keyword(s):  
Electrostatic Potential ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Core Level ◽  
Level Energy ◽  
Linear Potential ◽  
Surface Band ◽  
Band Bending ◽  
X Ray ◽  
Bending Effect

AbstractWe present a systematic study of surface band bending in Ga-polar n-GaN with different Si doping concentrations by angular dependent X-ray photoelectron spectroscopy (ADXPS). The binding energies of Ga 3d and N 1 s core levels in n-GaN films increase with increasing the emission angle, i. e., the probing depth, suggesting an upward surface band bending. By fitting the Ga 3d core level spectra at different emission angles and considering the integrated effect of electrostatic potential, the core level energy at the topmost surface layer is well corrected, therefore, the surface band bending is precisely evaluated. For moderately doped GaN, the electrostatic potential can be reflected by the simply linear potential approximation. However, for highly doped GaN samples, in which the photoelectron depth is comparable to the width of the space charge region, quadratic depletion approximation was used for the electrostatic potential to better understand the surface band bending effect. Our work improves the knowledge of surface band bending determination by ADXPS and also paves the way for studying the band bending effect in the interface of GaN based heterostructures.

Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

1998 ◽  
Vol 76 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
I Coulthard ◽  
S Degen ◽  
Y -J Zhu ◽  
T K Sham
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gold Nanoclusters ◽  
Gold Complex ◽  
X Ray Diffraction ◽  
Complex Ions ◽  
X Ray ◽  
Preparation Conditions ◽  
P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

Passivation of Gaas by Novel P2S5/(NH4)2Sx Sulfurization Techniques

1992 ◽  
Vol 281 ◽  
Author(s):  
J. T. Hsieh ◽  
C. Y. Sun ◽  
H. L. Hwang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Passivation ◽  
Schottky Diodes ◽  
Lower Surface ◽  
State Density ◽  
Surface Band ◽  
Band Bending ◽  
Barrier Heights ◽  
Effective Barrier ◽  
Metal Work

ABSTRACTA new surface passivation technique using P2S5/(NH4)2S on GaAs was investigated, and the results are compared with those of the (NH4)2Sx treatment. With this new surface treatment, the effective barrier heights for both Al- and Au—GaAs Schottky diodes were found to vary with the metal work functions, which is a clear evidence of the lower surface state density. Results of I—V measurements show that P2S5/(NH4)2S—passivated diodes have lower reverse leakage current and higher effective barrier height than those of the (NH4)2Sx -treated ones. Auger Electron Spectroscopy, X—ray photoelectron spectroscopy and Raman scattering measurements were done to characterize the surfaces including their compositions and surface band bending. In this paper, interpretations on this novel passivation effect is also provided.

Surface Band Structure Studies of Si Rich Reconstructions on 4H-SiC(1-100)

2005 ◽  
Vol 483-485 ◽  
pp. 547-550 ◽  
Author(s):  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley ◽  
A. Tadich ◽  
L. Broekman ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Surface Band ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Different Temperatures ◽  
Low Energy Electron

We have investigated Si-rich reconstructions of 4H-SiC( 00 1 1 ) surfaces by means of low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and angleresolved ultraviolet photoelectron spectroscopy (ARUPS). The reconstructions of 4H-SiC( 00 1 1 ) were prepared by annealing the sample at different temperatures in a flux of Si. Depending on the temperature different reconstructions were observed: c(2×2) at T=800°C, c(2×4) at T=840°C. Both reconstructions show strong similarities in the electronic structure.

p-Type dopant incorporation and surface charge properties of catalyst-free GaN nanowires revealed by micro-Raman scattering and X-ray photoelectron spectroscopy

Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 9970-9976 ◽  
Author(s):  
Q. Wang ◽  
X. Liu ◽  
M. G. Kibria ◽  
S. Zhao ◽  
H. P. T. Nguyen ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Surface Charge ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Gan Nanowires ◽  
Catalyst Free ◽  
Dopant Incorporation ◽  
P Type

p-Type dopant (magnesium) incorporation and surface charge properties of catalyst-free GaN nanowires are revealed by micro-Raman scattering and X-ray photoelectron spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document