Secondary Electron Potential Contrast for Dopant Profiling of Silicon Carbide Devices

2006 ◽  
Author(s):  
Marco Buzzo ◽  
Mauro Ciappa ◽  
Wolfgang Fichtner
Keyword(s):  
Silicon Carbide ◽  
Wide Band ◽  
Wide Band Gap ◽  
Experimental Conditions ◽  
Dopant Profiling ◽  
Wide Band Gap Semiconductors ◽  
The Difference ◽  
Main Component ◽  
The Impact ◽  
Relevant Factors

Abstract Secondary electrons potential contrast (SEPC) by scanning electron microscopy has emerged as a powerful tool for two-dimensional quantitative dopant imaging. The main component of the SEPC signal arises from the difference in the built-in potential between differently doped regions; which is very high in wide-band-gap semiconductors and particularly intense in SiC. This paper, after discussing the physical principles leading to the dopant contrast and the proper experimental setup, investigates the impact of relevant factors such as experimental conditions, surface effects, and sample preparation on image quality. The quantitative capabilities of this technique are demonstrated by the analysis of different test structures and prototypes of power devices such as MOSFET and JFET. The application to completely process devices demonstrates that SEPC represents an unequalled characterization technique, which provides accurate imaging and dopant profiling capabilities for silicon carbide devices.

Spontaneous and Piezoelectric Polarization Effects on the Frequency Response of Wurtzite Aluminium Gallium Nitride / Silicon Carbide Heterojunction Bipolar Transistors

2008 ◽  
Vol 1069 ◽  
Author(s):  
Choudhury Praharaj
Keyword(s):  
Silicon Carbide ◽  
Frequency Response ◽  
Heterojunction Bipolar Transistors ◽  
Wide Band ◽  
Bipolar Transistors ◽  
Flat Band ◽  
Aluminium Gallium Nitride ◽  
Wide Band Gap ◽  
Base Resistance ◽  
Wide Band Gap Semiconductors

ABSTRACTWe present theoretical calculations for the effect of spontaneous and piezoelectric polarization on the base resistance and frequency response of wurtzite Aluminium Gallium Nitride / Silicon Carbide Heterojunction Bipolar Transistors. Heterojunction Bipolar Transistors ( HBTs ) built using wide band gap semiconductors with AlGaN emitter and SiC base/collector hold the promise of high-power and high-frequency operation due to lower impact ionization coefficients and higher breakdown voltages. Further, Silicon Carbide has an indirect bang gap, and a large lifetime of minority carriers compared to most other compound semiconductors, which tend to have direct band gaps. This reduces the base recombination factor when the base is made from SiC, and helps to achieve higher overall current gain. Spontaneous and piezoelectric polarizations of the order of 1013 electrons per cm2 exist in wurtzite wide band-gap semiconductors. This has a non-trivial effect on band profile, charge transport and overall device characteristics since the polarization-induced charges are of the same order of magnitude as the total dopant charge content of critical device layers, and can significantly affect the amount of mobile charge depletion or accumulation in these layers. We calculate the effect of this polarization for both very thin pseudomorphic emitters and for relaxed emitter structures. We present calculations for the cases of Si-face and C-face SiC, since the signs of polarization-induced charges are different for the two cases. The intrinsic base resistance near emitter flat-band conditions is changed by a factor of 10 depending on the alloy composition of the emitter and the polarity of growth. The maximum frequency of oscillation under emitter flat-band conditions can also be modulated by the polarization-induced charges by up to 60%. Our calculations show that the technologically less prevalent C-face SiC can give a higher advantage for frequency response, especially when the emitter thickness is larger than the critical thickness.

Wetting behavior of water on silicon carbide polar surfaces

2016 ◽  
Vol 18 (40) ◽  
pp. 28033-28039 ◽  
Author(s):  
W. W. Zhong ◽  
Y. F. Huang ◽  
D. Gan ◽  
J. Y. Xu ◽  
H. Li ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Wetting Behavior ◽  
Polar Surfaces ◽  
Wide Band Gap Semiconductors

Technically important wide band-gap semiconductors such as GaN, AlN, ZnO and SiC are crystallized in polar structures.

scholarly journals Ion Implantation Doping in Silicon Carbide and Gallium Nitride Electronic Devices

Micro ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 23-53
Author(s):  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Giuseppe Greco
Keyword(s):  
Silicon Carbide ◽  
Gallium Nitride ◽  
Ion Implantation ◽  
Band Gap ◽  
Electronic Devices ◽  
Wide Band ◽  
Decomposition Temperature ◽  
Wide Band Gap ◽  
Selective Doping ◽  
The Impact

Wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) are excellent materials for the next generation of high-power and high-frequency electronic devices. In fact, their wide band gap (>3 eV) and high critical electric field (>2 MV/cm) enable superior performances to be obtained with respect to the traditional silicon devices. Hence, today, a variety of diodes and transistors based on SiC and GaN are already available in the market. For the fabrication of these electronic devices, selective doping is required to create either n-type or p-type regions with different functionalities and at different doping levels (typically in the range 1016–1020 cm−3). In this context, due to the low diffusion coefficient of the typical dopant species in SiC, and to the relatively low decomposition temperature of GaN (about 900 °C), ion implantation is the only practical way to achieve selective doping in these materials. In this paper, the main issues related to ion implantation doping technology for SiC and GaN electronic devices are briefly reviewed. In particular, some specific literature case studies are illustrated to describe the impact of the ion implantation doping conditions (annealing temperature, electrical activation and doping profiles, surface morphology, creation of interface states, etc.) on the electrical parameters of power devices. Similarities and differences in the application of ion implantation doping technology in the two materials are highlighted in this paper.

Doped Amorphous and Microcrystalline Silicon Carbide as Wide Band-Gap Material

1992 ◽  
Vol 242 ◽  
Author(s):  
F. Demichelis ◽  
C.F. Pirri ◽  
E. Tresso ◽  
P. Rava
Keyword(s):  
Silicon Carbide ◽  
Band Gap ◽  
Energy Gap ◽  
Wide Band ◽  
Microcrystalline Silicon ◽  
Wide Band Gap ◽  
Wide Band Gap Semiconductors ◽  
Sic Films

Amorphous and microcrystalline silicon carbide, undoped and doped, are promising materials as wide band gap semiconductors (Eg > 2 eV). In the present work results on nydrogenated and fluorinated a-SiC and uc-SiC films intrinsic, B or P doped are reported. Energy gap higher than 2 eV are obtained together with electrical dark conductivities in the range 10-12 -10-2 Ω-1cm-1

A pathway to p-type wide-band-gap semiconductors

2009 ◽  
Vol 95 (17) ◽  
pp. 172109 ◽  
Author(s):  
Anderson Janotti ◽  
Eric Snow ◽  
Chris G. Van de Walle
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Wide Band Gap Semiconductors ◽  
P Type

SiC vs. Si - Evaluation of Potentials for Performance Improvement of Power Electronics Converter Systems by SiC Power Semiconductors

2010 ◽  
Vol 645-648 ◽  
pp. 1101-1106 ◽  
Author(s):  
Jürgen Biela ◽  
Mario Schweizer ◽  
Stefan Waffler ◽  
Benjamin Wrzecionko ◽  
Johann Walter Kolar
Keyword(s):  
Band Gap ◽  
Power Electronics ◽  
Power Density ◽  
Performance Improvement ◽  
Wide Band ◽  
System Level ◽  
Wide Band Gap ◽  
Power Semiconductors ◽  
Power Electronics Converter ◽  
The Impact

Switching devices based on wide band gap materials as SiC oer a signicant perfor- mance improvement on the switch level compared to Si devices. A well known example are SiC diodes employed e.g. in PFC converters. In this paper, the impact on the system level perfor- mance, i.e. eciency/power density, of a PFC and of a DC-DC converter resulting with the new SiC devices is evaluated based on analytical optimisation procedures and prototype systems. There, normally-on JFETs by SiCED and normally-off JFETs by SemiSouth are considered.

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