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.

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.

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.

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.

Role of Surfaces and Interfaces for the Electronic Properties of Conducting Oxides

2001 ◽  
Vol 666 ◽  
Author(s):  
Andreas Klein
Keyword(s):  
Work Function ◽  
Electronic Properties ◽  
Photoelectron Spectroscopy ◽  
Band Alignment ◽  
Surface Band ◽  
Band Bending ◽  
Conducting Oxides ◽  
Degenerate Semiconductors ◽  
Surfaces And Interfaces

ABSTRACTTransparent conductive oxides (TCOs) are generally considered as degenerate semiconductors doped intrinsically by oxygen vacancies and by intentionally added dopants. For some applications a high work function is required in addition to high conductivity and it is desired to tune both properties independently. To increase the work function, the distance between the Fermi energy and the vacuum level must increase, which can be realized either by electronic surface dipoles or by space charge layers. Photoelectron spectroscopy data of in-situ prepared samples clearly show that highly doped TCOs can show surface band bending of the order of 1 eV. It is further shown that the band alignment at heterointerfaces between TCOs and other materials, which are crucial for many devices, are also affected by such band bending. The origin of the band bending, which seems to be general to all TCOs, depends on TCO thin film and surface processing conditions. The implication of surface band bending on the electronic properties of thin films and interfaces are discussed.

scholarly journals Surface band bending in semimetal Td-WTe2

2020 ◽  
Author(s):  
Aixi Chen ◽  
Huifang Li ◽  
Rong Huang ◽  
Yanfei Zhao ◽  
Tong Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electric Polarization ◽  
Property A ◽  
Surface Band ◽  
Band Bending ◽  
Xps Spectra ◽  
Surface Polarization ◽  
Out Of Plane ◽  
Microscopic Origin ◽  
Ferroelectric Switching

Abstract Recently, spontaneous out-of-plane electric polarization and ferroelectric switching were found in WTe2 devices. On single crystal with ferroelectric property, a built-in electric field and corresponding band bending would be expected at the surface. However, such band bending in WTe2 hasn’t directly been observed experimentally. Here, by fitting angle-dependent X-ray photoelectron spectroscopy (XPS) spectra on WTe2 surface, we clearly observed downward band bending after slightly exposure to air, verifying appearance of surface polarization. Such band bending can’t be observed on pristine WTe2 surface and will disappear on fully oxidized sample. It suggests strong correlation between surface band bending and oxidation. Ionized donors from oxide species pinned at surface may contribute to the formation of surface band bending and polarization. Our study here offers new insight to figure out the microscopic origin of ferroelectric in WTe2.

Effects of surface treatment using aqua regia solution on the change of surface band bending of p-type GaN

2001 ◽  
Vol 30 (3) ◽  
pp. 129-133 ◽  
Author(s):  
Jong Kyu Kim ◽  
Ki-Jeong Kim ◽  
Bongsoo Kim ◽  
Jae Nam Kim ◽  
Joon Seop Kwak ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Surface Band ◽  
Band Bending ◽  
Aqua Regia ◽  
P Type

Surface Electronic Structure of Nitric-oxide-treated Indium Tin Oxide

2003 ◽  
Vol 796 ◽  
Author(s):  
Hu Jianqiao ◽  
Pan Jisheng ◽  
Furong Zhu ◽  
Gong Hao
Keyword(s):  
Nitric Oxide ◽  
Binding Energy ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Surface Region ◽  
Valence Band Maximum ◽  
Surface Band ◽  
Band Bending ◽  
Surface Electronic Structure

ABSTRACTThe surface electronic properties of the nitric oxide (NO) treated indium tin oxide (ITO) are examined in-situ by a four-point probe and X-ray photoelectron spectroscopy (XPS). The XPS N1s peak emerged at a high binding energy of 404 eV indicating that NO is reactive with ITO. NO adsorption induces an increase of film sheet resistance, arising from an oxygen rich layer near the ITO surface region, with approximately 2.5 nm thick. This implies that the interaction of NO with ITO is occurred around surface region. Valence band maximum measured for NO-absorbed ITO was shifted to the low binding energy side. This is related to the upward surface band bending.

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