Fermi-level pinning and intrinsic surface states of Al1−xInxN(101¯0) surfaces

2017 ◽  
Vol 110 (2) ◽  
pp. 022104 ◽  
Author(s):  
V. Portz ◽  
M. Schnedler ◽  
L. Lymperakis ◽  
J. Neugebauer ◽  
H. Eisele ◽  
...  
2000 ◽  
Vol 07 (05n06) ◽  
pp. 583-588 ◽  
Author(s):  
HIDEKI HASEGAWA

Microscopic properties of free surfaces and metal–semiconductor interfaces related to successful realization of mesoscopic devices are discussed for III–V compound semiconductors, with a particular emphasis on Fermi level pinning. Surface states causing pinning are present even on freshly MBE-grown clean (001) and (110) surfaces with well-defined surface structures. Scanning tunneling spectroscopy (STS) measurement gives anomalous spectra with large conductance gaps, and this can be explained by tip-induced local charging of surface states. Pinning on free surfaces can be considerably suppressed by a surface passivation using an ultrathin MBE-grown silicon interface control layer (Si ICL). In mesoscopic scale metal–semiconductor contacts, Fermi level pinning underneath the metal contact itself is remarkably reduced with the use of the optimum in situ electrochemical metal deposition. However, Fermi level pinning on the surrounding free surfaces has large effects on current transport and capacitance properties in such contacts.


2020 ◽  
Vol 10 (8) ◽  
pp. 2754
Author(s):  
Yu Zhang ◽  
Xiong Chen ◽  
Hao Zhang ◽  
Xicheng Wei ◽  
Xiangfeng Guan ◽  
...  

Molybdenum disulfide (MoS2) field-effect transistors (FETs) with four different metallic electrodes (Au,Ag,Al,Cu) of drain-source were fabricated by mechanical exfoliation and vacuum evaporation methods. The mobilities of the devices were (Au) 21.01, (Ag) 23.15, (Al) 5.35 and (Cu) 40.52 cm2/Vs, respectively. Unpredictably, the on-state currents of four devices were of the same order of magnitude with no obvious difference. For clarifying this phenomenon, we calculated the Schottky barrier height (SBH) of the four metal–semiconductor contacts by thermionic emission theory and confirmed the existence of Fermi-level pinning (FLP). We suppose the FLP may be caused by surface states of the semiconductor produced from crystal defects.


1990 ◽  
Vol 238 (1-3) ◽  
pp. 271-279 ◽  
Author(s):  
J.M Palau ◽  
M Dumas

1997 ◽  
Vol 484 ◽  
Author(s):  
Jingxi Sun ◽  
Dong Ju Seo ◽  
W. L. O'Brien ◽  
F. J. Himpsel ◽  
T. F. Kuech

AbstractSelenium disulfide has been demonstrated to be an effective passivant for GaAs (001) surfaces. This chemical treatment can be more robust and effective in reducing surface-states-based Fermi level pinning than other analogous chemical treatments. We have studied SeS2-passivated surfaces, formed by treatment of GaAs in SeS2:CS2 solution, with synchrotron radiation photoemission spectroscopy. The SeS2-treated surface consists of a chemically stratified structure of several atomic layers thickness. The As-based sulfides and selenides appear to reside on the outermost surface with the Ga-based compounds adjacent to the bulk GaAs substrate. The motion of the Fermi level within the band gap was monitored during controlled annealing conditions allowing for the specific chemical moieties responsible for the reduction in surface charge to be identified. As-based species are removed at low annealing conditions with little motion of the Fermi level. GaSe-based species, formed on the surface, are clearly shown to be associated with the unpinning of the Fermi level.


2008 ◽  
Vol 93 (19) ◽  
pp. 192110 ◽  
Author(s):  
L. Ivanova ◽  
S. Borisova ◽  
H. Eisele ◽  
M. Dähne ◽  
A. Laubsch ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document