Structural and electrical characterizations of n-type implanted layers and ohmic contacts on 3C-SiC

In this work, non-intentionally doped cubic silicon carbide (3C-SiC) epilayers grown on (1 0 0) silicon substrates were implanted using nitrogen (N), phosphorus (P) implantations or their co-implantation (N&P). After annealing from 1150 to 1400 °C, Secondary Ion Mass Spectroscopy (SIMS), Atomic Force Microscopy (AFM), Fourier Transformed InfraRed spectroscopy (FTIR), Scanning Spreading Resistance Microscopy (SSRM) and Scanning Transmission Electron Microscopy (STEM) analysis were performed. Specific contact resistances (ρ_c) of Ti/Ni ohmic contacts were determined using Circular Transfer Length Method (c-TLM) patterns. Our work shows that co-implantation, experimentally investigated for the first time in 3C-SiC, is not beneficial for the doping efficiency.According to the silicon substrate, the post-implantation annealing is limited to 1400 °C. Consecutively to this limit, the total recovering of the lattice does not seem to be possible, whatever are the implanted species. Moreover, as the crystal damages increase when increasing the atomic mass of the implanted species, a comparative study using SSRM measurements proved that, for the same post-implantation annealing treatment, the resistivity of implanted layers depend on the doping species. As a consequence, the lowest ρ_c value (2.8 × 10⁻⁶ Ω cm²) has been obtained (using Ti/Ni 25/100 nm pattern) for a 1400 °C-30 min annealing consecutively to the nitrogen implantation. This value is among the best values obtained on implanted 3C-SiC layers in the literature. Furthermore, for this annealing temperature, a doping activation close to 100% has been evaluated by quantitative SSRM technique which evidences that an efficient dopant activation could be done. The high activation rate obtained on n-type implanted 3C-SiC and the low specific contact resistance achieved with Ti/Ni are very promising for electronic device fabrication.     

A privacy-preserving code-based authentication protocol for Internet of Things

The Journal of Supercomputing - The Internet of Things (IoT) is an upcoming technology that permits to interconnect different devices and machines using heterogeneous networks. One of the most...     

Light room anodic etching of highly doped n-type 4H SiC in high concentration HF electrolytes: difference between C and Si crystalline faces

In this paper, we study the electrochemical anodization of n-type heavily doped 4 H-SiC wafers in a HF-based electrolyte without any UV light assistance. We present, in particular, the differences observed between the etching of Si and C faces. In the case of the Si face, the resulting material is mesoporous (diameters in the range of 5 to 50 nm) with an increase of the ‘chevron shaped’ pore density with depth. In the case of the C face, a columnar morphology is observed, and the etch rate is twice greater than for the one for the Si face. We''ve also observed the evolution of the potential for a fixed applied current density. Finally, some wafer defects induced by polishing are clearly revealed at the sample surfaces even for very short etching times.     

RFID Authentication Protocols Based on Error-Correcting Codes: A Survey

Code-based cryptography is a very promising research area. It allows the construction of different cryptographic mechanisms (e.g. identification protocol, public-key cryptosystem, etc.). McEliece cryptosystem is the first code-based public-key cryptosystem; several variants of this cryptosystem were proposed to design various security protocols in different systems. In this paper, we present a survey on various and recent authentication protocols in radio frequency identification systems which use diverse variants of the McEliece cryptosystem. Moreover, we discuss the security and the performance of each presented protocol.

     

Controlled growth of 1D and 2D ZnO nanostructures on 4H-SiC using Au catalyst

A perfect control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic device/systems. In this article, we demonstrate the growth of various ZnO-derived nanostructures, including well-ordered arrays of high aspect ratio single crystalline nanowires with preferred growth direction along the [0001] axis, nanowalls, and hybrid nanowire-nanowall structures. The growths of the various ZnO nanostructures have been carried out on SiC substrates in a horizontal furnace, using Au thin film as catalyst. From experimental observations, we have ascribed the growth mechanisms of the different ZnO nanostructures to be a combination of catalytic-assisted and non-catalytic-assisted vapor–liquid-solid (VLS) processes. We have also found that the different ZnO nanoarchitectures'' material evolution is governed by a Zn cluster drift effects on the SiC surface mainly driven by growth temperature. Au thin film thickness, growth time, and temperature are the parameters to optimize in order to obtain the different ZnO nanoarchitectures.