Characterization of Cleaved GaAs(110) with a Scanning Photoemission Microscope Capable of Submicron Resolution

1993 ◽  
Vol 307 ◽  
Author(s):  
A. K. Ray-Chaudhuri ◽  
W. Ng ◽  
S. Liang ◽  
S. Singh ◽  
H. Solak ◽  
...  
Keyword(s):  
Fermi Level ◽  
Spatial Resolution ◽  
Spatial Extent ◽  
Kelvin Probe ◽  
Fermi Level Pinning ◽  
Contrast Mechanism ◽  
Cleavage Step ◽  
Step Over ◽  
Monolayer Coverage

ABSTRACTWe have utilized a scanning photoemission spectromicroscope with sub-micron spatial resolution to observe microscopic Fermi level pinning on the cleaved GaAs(110) surface. We present micrographs which identify pinning that is highly localized to the vicinity of a single linear cleavage step. This extends previous work utilizing scanning Kelvin probe and imaging photoelectron microscopy conducted at lower spatial resolution. A sub-monolayer coverage of In uniformly pins the surface, thus allowing us to observe only the image contrast mechanism resulting from topography. From this one can determine the spatial extent of defects near a cleavage step. Initial observations indicate that Fermi level pinning can extend from a cleavage step over the range of 2 μm. This indicates the additional presence of defects at the adjacent surfaces of the step.

Contactless Electromodulation Characterization of Compound Semiconductor Surfaces and Device Structures

1993 ◽  
Vol 324 ◽  
Author(s):  
J.M. Woodall
Keyword(s):  
Fermi Level ◽  
Electric Fields ◽  
Growth Conditions ◽  
Compound Semiconductor ◽  
Conduction Band Edge ◽  
Semiconductor Surfaces ◽  
Air Exposure ◽  
Fermi Level Pinning ◽  
Characterization Of Properties

AbstractThis paper will review the use of contactless electromodulation methods, such as photoreflectance (PR) and contactless electroreflectance (CER), to characterize the electronic properties of compound semiconductor surfaces exposed to different growth and post-growth conditions. Also the characterization of properties critical to device performance can be evaluated. For example, using PR and CER it has been found that there is a lower density of surface hole traps than electron traps in certain as-grown MBE (001) GaAs samples and that this condition persists even after air exposure. This behaviour is in contrast to other samples, including both bulk and MBE grown (001) surfaces in which the Fermi level is pinned mid-gap for both n- and p-type structures. We also have observed that Ar+ bombardment under UHV conditions results in Fermi level pinning close to the conduction band edge and that thermal annealing restores mid-gap pinning. Finally, using PR we are able to characterize the electric fields and associated doping levels in the emitter and collector regions of heterojunction bipolar transistor structures (fabricated from III-V materials), thus demonstrating the ability to perform inprocess evaluation of important device parameters.

Characterization of SiGeC Using Pt(SiGeC) Silicide Schottky Contacts

1998 ◽  
Vol 533 ◽  
Author(s):  
Jeff J. Peterson ◽  
Charles E. Hunt ◽  
McDonald Robinson ◽  
Robin SCott
Keyword(s):  
Fermi Level ◽  
Conduction Band ◽  
Electrical Characterization ◽  
Schottky Contacts ◽  
Epitaxial Layers ◽  
Fermi Level Pinning ◽  
Barrier Heights ◽  
Xrd Studies ◽  
P Type

AbstractMaterial and electrical characterization of n-type and p-type Si1-x-yGex Cy epitaxial layers on Si(100) was performed using silicided platinum Schottky contacts. XRD studies show Pt silcidation of SiGeC proceeds from non-reacted Pt to Pt2(SiGeC) and completes with the Pt(SiGeC) phase similar to Pt/Si silicides, but Pt silicide reactions with SiGeC are shown to require higher temperatures than Pt reactions with Si. Electrical characterization of Pt(SiGeC) contacts to n-type Sil1-x-yGexCx/Si shows rectifying behavior with constant barrier heights of 0.67eV independent of composition, indicating Fermi level pinning relative to the SiGeC conduction band is occurring. Pt(SiGeC) contacts to p-type Si1-x-yGexCy/Si are also rectifying with barrier heights that track the variation of the SiGeC energy bandgap.

scholarly journals Probing electric properties of GaP nanowires with Kelvin probe force microscopy

2021 ◽  
Vol 2086 (1) ◽  
pp. 012207
Author(s):  
V A Sharov ◽  
P A Alekseev ◽  
V V Fedorov ◽  
I S Mukhin
Keyword(s):  
Fermi Level ◽  
Kelvin Probe Force Microscopy ◽  
Scanning Probe ◽  
Kelvin Probe ◽  
Free Standing ◽  
Force Microscopy ◽  
Fermi Level Pinning ◽  
Zinc Blende ◽  
Crystal Phases ◽  
The Difference

Abstract Surface electronic properties of GaP nanowires were investigated using scanning probe force microscopy. I-V curves of individual free-standing NWs with different doping types were obtained. Surface Fermi level positions in the nanowires of different crystal phases and doping types were extracted using phase-modulated Kelvin probe force microscopy. The results indicate on weak Fermi level pinning in GaP nanowires. The difference between wurtzite and zinc blende GaP work function is observed.

Spectro-mechanical Characterization of Aromaticity and Maturity of Kerogens in Oil Shale at 6 nm Spatial Resolution

2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu
Keyword(s):  
Spatial Resolution ◽  
Oil Shale ◽  
Infrared Imaging ◽  
Mechanical Characterization ◽  
Optical Diffraction ◽  
Chemical Compositions ◽  
Valuable Insight ◽  
Eagle Ford Shale

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>

Fermi level pinning and band bending in δ-doped BaSnO3

2021 ◽  
Vol 118 (5) ◽  
pp. 052101
Author(s):  
Youjung Kim ◽  
Hyeongmin Cho ◽  
Kookrin Char
Keyword(s):  
Fermi Level ◽  
Band Bending ◽  
Fermi Level Pinning

Fermi‐Level Pinning Free High‐Performance 2D CMOS Inverter Fabricated with Van Der Waals Bottom Contacts

2021 ◽  
pp. 2001212
Author(s):  
Tien Dat Ngo ◽  
Zheng Yang ◽  
Myeongjin Lee ◽  
Fida Ali ◽  
Inyong Moon ◽  
...  
Keyword(s):  
Fermi Level ◽  
High Performance ◽  
Van Der Waals ◽  
Cmos Inverter ◽  
Fermi Level Pinning

scholarly journals Defect Dominated Charge Transport and Fermi Level Pinning in MoS2/Metal Contacts

2017 ◽  
Vol 9 (22) ◽  
pp. 19278-19286 ◽  
Author(s):  
Pantelis Bampoulis ◽  
Rik van Bremen ◽  
Qirong Yao ◽  
Bene Poelsema ◽  
Harold J. W. Zandvliet ◽  
...  
Keyword(s):  
Fermi Level ◽  
Charge Transport ◽  
Metal Contacts ◽  
Fermi Level Pinning
Sign in / Sign up

Export Citation Format

Share Document