Novel Poly-Si/GaN Vertical Heterojunction Diode

2015 ◽  
Vol 821-823 ◽  
pp. 1015-1018
Author(s):  
Kenta Emori ◽  
Toshiharu Marui ◽  
Yuji Saito ◽  
Wei Ni ◽  
Yasushi Nakajima ◽  
...  

We previously reported a unipolar mode p+-polycrystalline silicon (poly-Si)/4H-SiC heterojunction diode (SiC-HJD) [1-3]. In this work, we demonstrate a poly-Si/GaN vertical unipolar heterojunction diode (GaN-HJD) based on numerical simulation and experimental results. The GaN-HJD is expected to control the electrical characteristics of both Schottky action with a p-type poly-Si and ohmic action with an n-type poly-Si. We investigated the detailed physics of the GaN-HJD between p+Si and n+Si by numerical simulation. The GaN-HJD was also fabricated with p+-type polycrystalline silicon on an n--type epitaxial layer on bulk GaN substrates. The measured barrier height of the GaN-HJD was 0.79 eV and the ideality factor was 1.10.

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 636
Author(s):  
Mehadi Hasan Ziko ◽  
Ants Koel ◽  
Toomas Rang ◽  
Muhammad Haroon Rashid

The diffusion welding (DW) is a comprehensive mechanism that can be extensively used to develop silicon carbide (SiC) Schottky rectifiers as a cheaper alternative to existing mainstream contact forming technologies. In this work, the Schottky barrier diode (SBD) fabricated by depositing Al-Foil on the p-type 4H-SiC substrate with a novel technology; DW. The electrical properties of physically fabricated Al-Foil/4H-SiC SBD have been investigated. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics based on the thermionic emission model in the temperature range (300 K–450 K) are investigated. It has been found that the ideality factor and barrier heights of identically manufactured Al-Foil/p-type-4H-SiC SBDs showing distinct deviation in their electrical characteristics. An improvement in the ideality factor of Al-Foil/p-type-4H-SiC SBD has been noticed with an increase in temperature. An increase in barrier height in fabricated SBD is also observed with an increase in temperature. We also found that these increases in barrier height, improve ideality factors and abnormalities in their electrical characteristics are due to structural defects initiation, discrete energy level formation, interfacial native oxide layer formation, inhomogenous doping profile distribution and tunneling current formation at the SiC sufaces.


2012 ◽  
Vol 717-720 ◽  
pp. 1005-1008 ◽  
Author(s):  
Shigeharu Yamagami ◽  
Tetsuya Hayashi ◽  
Masakatsu Hoshi

We experimentally investigated a method of controlling the energy barrier height (ΦB) of polycrystalline silicon (poly-Si)/4H-SiC heterojunction diodes (HJDs) and conducted a numerical simulation of a novel low Von and low reverse recovery current diode using ΦB control. The ΦB of the HJD with arsenic-doped n+-poly-Si was 0.79 eV and that of the HJD with boron-doped p+-poly-Si was 1.59 eV. The ΦB can be controlled over a wide range by varying the dopant and ion implantation dose of poly-Si. A novel merged HJD (M-HJD) with two different ΦB values obtained by using ΦB control is also presented. The numerical simulation results show that the M-HJD reduces Von without increasing reverse leakage current at high reverse voltage.


2014 ◽  
Vol 28 (13) ◽  
pp. 1450100
Author(s):  
Dil Nawaz Khan ◽  
Muhammad Hassan Sayyad ◽  
Fazal Wahab ◽  
Muhammad Tahir ◽  
Muhammad Yaseen ◽  
...  

This paper reports the temperature dependent electrical characterization of formyl- TIPPCu (II)/p- Si heterojunction diode which was fabricated by growing thin films of formyl- TIPPCu (II) on the p-type silicon substrate by thermal sublimation technique. The variation in electrical characteristics of the fabricated devices has been systematically investigated as the function of temperature by using current–voltage (I–V) measurements in the temperature range 299–339 K. The diode parameters like ideality factor, zero bias barrier height and parasitic series resistance have been found to be strongly temperature dependant. The zero bias barrier height increases while ideality factor and series resistance decreases with increasing temperature.


2008 ◽  
Vol 22 (14) ◽  
pp. 2309-2319 ◽  
Author(s):  
K. ERTURK ◽  
M. C. HACIISMAILOGLU ◽  
Y. BEKTORE ◽  
M. AHMETOGLU

The electrical characteristics of Cr / p – Si (100) Schottky barrier diodes have been measured in the temperature range of 100–300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41×10-3 Acm-2 K -2 is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm-2 K -2 for p-type Si . It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p – Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.


1995 ◽  
Vol 377 ◽  
Author(s):  
X. Xu ◽  
A. Banerjee ◽  
J. Yang ◽  
S. Guha ◽  
K. Vasanth ◽  
...  

ABSTRACTThe electrical bandgap of microcrystalline silicon (μc-Si:H) p type layers used in a-Si:H alloy solar cells and the band edge discontinuities between μc-Si:H and a-Si:H alloys have been determined by internal photoemission measurements. The bandgap of μc-Si:H is found to be in the range of 1.50 to 1.57 eV, and the discontinuities at the conduction and the valence band edges are 0 to 0.07 and 0.26 to 0.35 eV, respectively. Use of these parameters in the numerical simulation of single-junction a-Si:H and a-SiGe:H alloy solar cells is found to predict experimental results of solar cell performance.


2003 ◽  
Vol 798 ◽  
Author(s):  
Jay M. Shah ◽  
Yunli Li ◽  
Thomas Gessmann ◽  
E. Fred Schubert

ABSTRACTDiode ideality factors of 2.0–8.0 have been reported in GaN-based p-n junctions. These values are much higher than the expected values of 1.0–2.0 as per the Sah-Noyce-Shockley theory. We propose a fundamentally new model for the high ideality factors obtained in GaN-based diodes. This model is based on the effect of moderately doped unipolar heterojunctions as well as metal–semiconductor junctions in series with the p-n junction. A relation for the effective ideality factor of a system of junctions is developed. A detailed experimental study is performed on diodes fabricated from two different structures, a bulk GaN p-n junction structure and a p-n junction structure incorporating a p-type AlGaN/GaN superlattice. Bulk GaN p-n junction diode displays an ideality factor of 6.9, whereas the one with the superlattice structure displays an ideality factor of 4.0. In addition, device simulation results further strengthen the model by showing that moderately doped unipolar heterojunctions are rectifying and increase the effective ideality factor of a p-n junction structure.


2010 ◽  
Vol 645-648 ◽  
pp. 1131-1134 ◽  
Author(s):  
Viorel Banu ◽  
Pierre Brosselard ◽  
Xavier Jordá ◽  
Phillippe Godignon ◽  
José Millan

This work demonstrates that a stable voltage reference with temperature, in the 25°C-300°C range is possible with SiC. This paper reports the simulated and experimental results as well and a practical and simplified vision on the principles of thermally compensated voltage reference circuits, usually named bandgap references. For our demonstration, we have used SiC Schottky diodes. The influence of the barrier height and the ideality factor on the voltage reference and a comparison between simulated and experimental results are also presented.


2014 ◽  
Vol 1693 ◽  
Author(s):  
Masturina Kracica ◽  
Jim G. Partridge ◽  
Dougal G. McCulloch ◽  
Patrick W. Leech ◽  
Anthony S. Holland ◽  
...  

ABSTRACTEnergetically-deposited carbon contacts to n-type 6H-SiC have exhibited either insulating, rectifying or ohmic electrical characteristics depending on the average energy of the depositing flux and the substrate temperature. Deposition at room temperature and at a low-medium average energy (<500 eV) has resulted in carbon with a low graphitic content and insulating electrical contacts. With higher average energy and at a moderately elevated temperature (∼100 °C), the higher graphitic content contacts were rectifying with an ideality factor, η, of ∼1.8 and barrier height of ∼0.88 eV. Oriented graphitic carbon deposited at 200 °C with biases exceeding 300 V formed ohmic contacts.


2013 ◽  
Vol 699 ◽  
pp. 590-595
Author(s):  
Sung Kwen Oh ◽  
Meng Li ◽  
Hong Sik Shin ◽  
Hi Deok Lee

In this paper, the electricalcharacteristics of Ergermanideschottkyjunction werestudied for source / drain of n-typeschottky barrier Ge MOSFET.Ergermanideshowed the lowest ideality factor at RTP temperature of 600°C among the applied temperature range. When RTP temperature was increased, barrier height and work function of Ergermanidebecame similar to those of Er2Ge3. From the analysis of the leakage current, it is shown that the Poole-Frenkel barrier lowering was dominant at RTP 600°C and the influence of the Schottky barrier lowering was decreased as RTP temperature increased. The electrical characteristics of Ergermanideare very sensitive to the RTP temperature andclosely related tothe trapsites which are generated by germanidation.


2013 ◽  
Vol 446-447 ◽  
pp. 88-92
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Ryūhei Iwasaki ◽  
Tsuyoshi Yoshitake

n-Type nanocrystalline FeSi2/intrinsic Si/p-type Si heterojunctions were prepared by FTDCS. In order to estimate their diode parameters such as ideality factor, barrier height and series resistance, their current-voltage characteristics were measured in the temperature range from 300 to 77 K and analyzed on the basis of thermionic emission theory and Cheungs method. Based on thermionic emission theory, the ideality factor was calculated from the slope of the linear part from the forward lnJ-V characteristics. The barrier height was calculated once the saturation current density was derived from the straight line intercept of lnJ-V plot at a zero voltage. The obtained results exhibit an increase of ideality factor and a decrease of barrier height at low temperatures, which might be owing to inhomogeneity of material and non-uniformity of charge at the interface. Based on Cheungs method, the ideality factor and barrier height were estimated from y-axis intercept of dV/d (lnJ)J plot and y-axis intercept of H(J)J plot, respectively. The series resistance was analyzed from the slopes of dV/d (lnJ)J and H(J)J plots. The values of ideality factor and barrier height obtained from this method are in agreement with those obtained from the thermionic emission theory. The obtained series resistances from dV/d (lnJ)J and H(J)J plots, which were approximately equal to each others, were increased as the temperature decreased. This result should be owing to the increased ideality factor and remarkably reduced carrier concentrations at low temperatures.


Sign in / Sign up

Export Citation Format

Share Document