Evaluation of On-State Resistance and Boron-Related Levels in n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 425-428 ◽  
Author(s):  
R.R Ciechonski ◽  
Samuele Porro ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova

Specific on-resistance Ron estimated from current density-voltage characteristics of Schottky diodes on thick layers exhibits variations from tens of mW.cm2 to tens of W.cm2 for different doping levels. In order to understand the occurrence of high on-state resistance, Schottky barrier heights were first estimated for both forward and reverse bias with the application of thermionic emission theory and were in agreement with a literature reported values. Decrease in mobility with the temperature was observed and its dependencies of T–1.3 and T–2.0 for moderately doped and low doped samples respectively were estimated. From deep level measurements by Minority Carrier Transient Spectroscopy, an influence of shallow boron related levels and D-center on dependence of on-state resistance was observed, being more pronounced in low doped samples. Similar tendency was observed in depth profiling of Ron. This suggests a major role of boron in a compensation mechanism thus resulting in high Ron.

2000 ◽  
Vol 5 (S1) ◽  
pp. 922-928
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  

The deep level spectra in both p+-n homojunction and n-type Schottky GaN diodes are studied by deep level transient spectroscopy (DLTS) in order to compare the role of the junction configuration on the defects found within the n-GaN layer. Both majority and minority carrier DLTS measurements are performed on the diodes allowing the observation of both electron and hole traps in n-GaN. An electron level at Ec−Et=0.58 and 0.62 V is observed in the p+-n and Schottky diodes, respectively, with a concentration of ∼3−4×1014 cm−3 and a capture cross section of ∼1−5×10−15 cm2. The similar Arrhenius behavior indicates that both emissions are related to the same defect. The shift in activation energy is correlated to the electric field enhanced-emission in the p+-n diode, where the junction barrier is much larger. The p+-n diode configuration allows the observation of a hole trap at Et−Ev=0.87 eV in the n-GaN which is very likely related to the yellow luminescence band.


1999 ◽  
Vol 595 ◽  
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  

AbstractThe deep level spectra in both p+-n homojunction and n-type Schottky GaN diodes are studied by deep level transient spectroscopy (DLTS) in order to compare the role of the junction configuration on the defects found within the n-GaN layer. Both majority and minority carrier DLTS measurements are performed on the diodes allowing the observation of both electron and hole traps in n-GaN. An electron level at Ec-Et=0.58 and 0.62 V is observed in the p+-n and Schottky diodes, respectively, with a concentration of ∼3-4×1014cm−3 and a capture cross section of ∼1-5×10−15cm2. The similar Arrhenius behavior indicates that both emissions are related to the same defect. The shift in activation energy is correlated to the electric field enhanced-emission in the p+-n diode, where the junction barrier is much larger. The p+-n diode configuration allows the observation of a hole trap at Et-Ev=0.87 eV in the n-GaN which is very likely related to the yellow luminescence band.


2012 ◽  
Vol 510-511 ◽  
pp. 265-270 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan

In this study, the effect of polar face on Schottky barrier diodes has been investigated. Two samples of ZnO were grown hydrothermally under similar growth conditions. The Palladium (Pd) metal contacts of area 0.78 mm2were fabricated on both faces and were studied comprehensively using DLS-83 Deep Level Spectrometer over temperature range of 160K330K. The current-voltage (IV) measurements revealed that the ideality factor n and barrier height ϕBwere strongly temperature dependent for both faces (Zn and O-face) of ZnO, indicating that the thermionic emission is not the dominant process, which showed the inhomogenity in the barrier heights of grown samples. This barrier height inhomogenity was explained by applying Gaussian distribution model. The extrapolation of the linear ϕapverses n plot to n = 1 has given a homogeneous barrier height of approximately 0.88±0.01 eV and 0.76±0.01 eV for Zn and O-faces respectively. ϕapversus 1/T plot was drawn to obtain the values of mean barrier height for Zn and O-face (0.88±0.01 eV, 0.76±0.01 eV) and standard deviation (δs) (0.015±0.001 V, 0.014±0.001 V) at zero bais respectively. The value of δsfor the Zn-face is larger than O-face, showing that inhomogenity in the barrier heights is more in the sample grown along Zn-face as compared to the sample grown along O-face.


2005 ◽  
Vol 865 ◽  
Author(s):  
Steven W. Johnston ◽  
Jehad A. M. AbuShama ◽  
Rommel Noufi

AbstractMeasurements of p-type Cu(InGa)Se2 (CIGS) using deep-level transient spectroscopy (DLTS) show peaks associated with minority-carrier traps, even though data were collected using reverse bias conditions not favorable to injecting minority-carrier electrons. These DLTS peaks occur in the temperature range of 50 to 150 K for the rate windows used and correspond to electron traps having activation energies usually in the range of 0.1 to 0.2 eV for alloys of CIS, CGS, and CIGS. The peak values also depend on the number of traps filled. For short filling times of 10 μs to 100 μs, a small peak appears. As the DLTS filling pulse width increases, the peak increases in response to more traps being filled, but it also broadens and shifts to lower temperature suggesting that a possible series of trap levels, perhaps forming a defect band, are present. The peaks usually saturate in a timeframe of seconds. These filling times are sufficient for electrons to fill traps near the interface from the n-type side of the device due to a thermionic emission current. Admittance spectroscopy data for the same samples are shown for comparison.


2013 ◽  
Vol 740-742 ◽  
pp. 661-664 ◽  
Author(s):  
Pavel Hazdra ◽  
Vít Záhlava ◽  
Jan Vobecký ◽  
Maxime Berthou ◽  
Andrei Mihaila

Electronic properties of radiation damage produced in 4H-SiC epilayer by proton and alpha particle irradiation were investigated and compared. 4H-SiC epilayers, which formed the low doped n-base of Schottky barrier power diodes, were irradiated to identical depth with 550 keV protons and 1.9 MeV alphas. Radiation defects were then characterized by capacitance deep-level transient spectroscopy and C-V measurements. Results show that both projectiles produce identical, strongly localized damage peaking at ion’s projected range. Radiation defects have a negligible effect on dynamic characteristic of irradiated 4H-SiC Schottky diodes, however acceptor character of introduced deep levels and their high introduction rates deteriorate diode’s ON-state resistance already at very low irradiation fluences.


1999 ◽  
Vol 572 ◽  
Author(s):  
A P Knights ◽  
D J Morrison ◽  
N G Wright ◽  
C M Johnson ◽  
A G O'Neill ◽  
...  

ABSTRACTThe edge termination of SiC by the implantation of an inert ion species is used widely to increase the breakdown voltage of high power devices. We report results of the edge termination of Schottky barrier diodes using 30keV Ar+ ions with particular emphasis on the role of postimplant, relatively low temperature, annealing. The device leakage current measured at 100V is increased from 2.5nA to 7μA by the implantation of 30keV Ar+ ions at a dose of 1×1015 cm−2. This is reduced by two orders of magnitude following annealing at 600°C for 60 seconds, while a breakdown voltage in excess of 750V is maintained. The thermal evolution of the defects introduced by the implantation was monitored using positron annihilation spectroscopy (PAS) and deep-level-transient spectroscopy (DLTS). While a concentration of open-volume defects in excess of 1×1019cm−3 is measured using PAS in all samples, electrically active trapping sites are observed at concentrations ∼1×1015cm−3 using DLTS. The trap level is well-defined at Ec−Et = 0.9eV.


Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 297
Author(s):  
Moonsang Lee ◽  
Chang Wan Ahn ◽  
Thi Kim Oanh Vu ◽  
Hyun Uk Lee ◽  
Yesul Jeong ◽  
...  

In this study, the charge transport mechanism of Pd/Si-based FS-GaN Schottky diodes was investigated. A temperature-dependent current–voltage analysis revealed that the I-V characteristics of the diodes show a good rectifying behavior with a large ratio of 103–105 at the forward to reverse current at ±1 V. The interface states and non-interacting point defect complex between the Pd metal and FS-GaN crystals induced the inhomogeneity of the barrier height and large ideality factors. Furthermore, we revealed that the electronic conduction of the devices prefers the thermionic field emission (TFE) transport, not the thermionic emission (TE) model, over the entire measurement conditions. The investigation on deep level transient spectroscopy (DLTS) suggests that non-interacting point-defect-driven tunneling influences the charge transport. This investigation about charge transport paves the way to achieving next-generation optoelectronic applications using Si-based FS-GaN Schottky diodes.


1990 ◽  
Vol 209 ◽  
Author(s):  
W.R. Buchwald ◽  
J.H. Zhao ◽  
F.C. Rong

ABSTRACTDeep level transient spectroscopy (DLTS) measurements have been performed on Schottky diodes fabricated on MBE grown InGaAs/GaAs heterostructures. The dominant electron trap in this material is found at a depth of 0.30eV below the GaAs conduction band and is believed to be the previously observed M3 defect. Two other defects, at depths of 0.50eV and 0.58eV below the GaAs conduction band, were also observed. Defect depth profiling shows the 0.50eV defect to be spatially locatednear the heterointerface. The 0.58eV defect is not observed near the heterointerface but is observed in large concentrations deep in the GaAs epilayer. Optical DLTS measurements reveal deep defects at 0.54eV and 0.31eV above the InGaAs valence band as well as a large, broad peak, most likely consisting of several energy levels with varying capture cross sections,located at the heterointerface. Two carrier accumulation peaks were also seen in the CV carrier profiling measurements and are suggested to be due to two heterointerface defects located at 0.68eV and 0.87eV below the GaAs conduction band.Thermally stimulated capacitance measurements also indicate minority hole emission in this n-InGaAs/N-GaAs heterostructure.


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