Maskless Formation of Tungsten Films by Ion Beam Assisted Deposition Technique

1989 ◽  
Vol 158 ◽  
Author(s):  
Zheng Xu ◽  
Toshihiko Kosugi ◽  
Kenji Gamo ◽  
Susumu Namba

ABSTRACTW films were deposited on n-GaAs by ion beam assisted deposition technique using low energy H2+ and Ar+, and film properties and residual damage in the substrate were investigated by measuring X-ray photoemission, current-voltage characteristics and deep level transient spectroscopy. Films with a resistivity of 1O−5 ohm·cm were formed. It was observed that damage can be reduced using the low energy beams and that Schottky contacts with n-factor of almost 1 and barrier height of 0.88 eV were formed.

1996 ◽  
Vol 283 (1-2) ◽  
pp. 182-187
Author(s):  
S Mohajerzadeh ◽  
C.R Selvakumar ◽  
D.E Brodie ◽  
M.D Robertson ◽  
J.M Corbett

2006 ◽  
Vol 957 ◽  
Author(s):  
Yahya Alivov ◽  
Xiao Bo ◽  
Fan Qian ◽  
Daniel Johnstone ◽  
Cole Litton ◽  
...  

ABSTRACTThe conduction band offset of n-ZnO/n-6H-SiC heterostructures fabricated by rf-sputtered ZnO on commercial n-type 6H-SiC substrates has been measured. Temperature dependent current-voltage characteristics, photocapacitance, and deep level transient spectroscopy measurements showed the conduction band offsets to be 1.25 eV, 1.1 eV, and 1.22 eV, respectively.


2006 ◽  
Vol 527-529 ◽  
pp. 1167-1170 ◽  
Author(s):  
Vito Raineri ◽  
Fabrizio Roccaforte ◽  
Sebania Libertino ◽  
Alfonso Ruggiero ◽  
V. Massimino ◽  
...  

The defects formation in ion-irradiated 4H-SiC was investigated and correlated with the electrical properties of Schottky diodes. The diodes were irradiated with 1 MeV Si+-ions, at fluences ranging between 1×109cm-2 and 1.8×1013cm-2. After irradiation, the current-voltage characteristics of the diodes showed an increase of the leakage current with increasing ion fluence. The reverse I-V characteristics of the irradiated diodes monitored as a function of the temperature showed an Arrhenius dependence of the leakage, with an activation energy of 0.64 eV. Deep level transient spectroscopy (DLTS) allowed to demonstrate that the Z1/Z2 center of 4H-SiC is the dominant defect in the increase of the leakage current in the irradiated material.


1993 ◽  
Vol 325 ◽  
Author(s):  
Z.C. Huang ◽  
C.R. Wie

AbstractDeep levels have been measured in molecular beam epitaxy grown Ga0.51In0.49P/GaAs heterostructure by double correlation deep level transient spectroscopy. Gold(Au) and Aluminum (Al) metals were used for Schottky contact. A contact-related hole trap with an activation energy of 0.50-0.75eV was observed at the A1/GaInP interface, but not at the Au/GaInP interface. To our knowledge, this contact-related trap has not been reported before. We attribute this trap to the oxygen contamination, or a vacancy-related defect, VIn or VGa. A new electron trap at 0.28eV was also observed in both Au- and Al-Schottky diodes. Its depth profile showed that it is a bulk trap in GaInP epilayer. The temperature dependent current-voltage characteristics (I-V-T) show a large interface recombination current at the GaInP surface due to the Al-contact. Concentration of the interface trap and the magnitude of recombination current are both reduced by a rapid thermal annealing at/or above 450°C after the aluminum deposition.


2009 ◽  
Vol 156-158 ◽  
pp. 541-546
Author(s):  
I.V. Antonova ◽  
E.P. Neustroev ◽  
S.A. Smagulova ◽  
M.S. Kagan ◽  
P.S. Alekseev ◽  
...  

The set of quantum confinement levels in SiGe quantum wells (QW) was observed in the temperature range from 80 to 300 K by means of charge deep-level transient spectroscopy (Q-DLTS) and transport measurements. These observations proved possible due to a passivation of structure surface with organic monolayer deposition. Si/SiGe/Si structures with different Ge contents in SiGe layer were studied. The confined levels in passivated structures became apparent through DLTS measurements as various activation energies in temperature dependence of the rate of carrier emission from QW. It was found that the recharging of SiGe QWs and carrier emission accomplish due to thermo-stimulated tunneling. The steps in the current-voltage characteristics originated from direct tunneling via the confined states were found to determine the current flow at high fields.


2005 ◽  
Vol 483-485 ◽  
pp. 359-364 ◽  
Author(s):  
Antonio Castaldini ◽  
Anna Cavallini ◽  
L. Rigutti ◽  
Filippo Nava

The effects of irradiation with protons and electrons on 4H-silicon carbide epilayers were investigated. The particle energy was 6.5 and 8.2 MeV. The electronic levels associated with the irradiation-induced defects were analyzed by current-voltage characteristics and deep level transient spectroscopy measurements up to 700 K. In the same temperature range the apparent free carrier concentration was measured by capacitance-voltage characteristics to monitor possible compensation effects due to the deep level associated to the induced defects. Introduction rate, enthalpy and capture cross-section of such deep levels were compared and some conclusions about the nature of the defects were drawn.


2001 ◽  
Vol 693 ◽  
Author(s):  
Z-Q. Fang ◽  
D.C. Look ◽  
P. Visconti ◽  
C. Lu ◽  
D. Wang ◽  
...  

AbstractDeep traps in a 300-m m-thick freestanding GaN sample were characterized by deep level transient spectroscopy (DLTS), using Schottky barrier diodes (SBDs) fabricated on the Ga polarity surface. Most of the SBDs show nearly ideal current-voltage characteristics, with both forward and reverse currents controlled by the thermionic emission mechanism. Five common traps, which include A1 (1.0 eV), A (0.66 eV), B (0.59 eV), C (0.35 eV), and D (0.25 eV), can be consistently observed in all SBDs. Two of them, A1 and C, are related to surface damage. Surprisingly, some new traps can be found in the DLTS spectra of some SBDs if higher reverse biases are used in the measurements. However, they cannot be fitted by DLTS simulations, and are likely associated with parasitic capacitance somewhere in the cryostat.


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