SiC etch development has been performed in a Lam TCP 9400SE II system (a system meant for polysilicon etching and modified for SiC etching). SiC etching has never been reported in this particular system. Various parameters (carrier material, pressure, gas additives, gas flow, and electrode power) were examined and their effects determined on etch rate and resulting surface morphology. An efficient carrier material (graphite), operating pressure (25 mTorr), and gas flow rate (30 sccm) for obtaining peak etch rates were determined for this system. Peak etch rates of 1254 Å/min. in CHF3:O2, 4314 Å/min. in SF6:O2, and 1255 Å/min. in NF3:O2 plasmas were obtained at 25 mTorr with 60%, 20%, and 30% O2 concentrations, respectively, and 1978 Å/min. in a NF3:Ar plasma with 10% Ar concentration. Gas additives were determined to have little or no effect in enhancing the etch rate at low pressures (2 mTorr). The addition of H2 in CHF3 plasmas resulted in severe polymerization when the concentration of H2 was 60% or greater. Increased bottom electrode power resulted in higher etch rates and more anisotropic etch profiles.

This thesis presents the development of compact model of novel silicon carbide (SiC) Vertical Junction Field Effect Transistor (VJFET) for high-power circuit simulation. An empirical Angelov model is developed for SiC VJFET in PSpice. The model is capable of accurately replicating the device behavior for the DC and Transient conditions. The model was validated against measured data obtained from devices developed by Mississippi Center for Advanced Semiconductor Prototyping at MSU and SemiSouth Laboratories. The modeling approach is based on extracting Angelov Equations Coefficients from experimental device characteristics using non linear fitting. The coefficients are extracted for different parameters (temperature, width, etc). Multi-Dimensional Interpolation Technique is used to incorporate the effect of more than one parameter. The models developed in this research are expected to be valuable tools for electronic designers in the future. The developed model was applied for investigating the characteristics of a few standard analog circuit blocks using SiC VJFET and Si JFET in order to demonstrate the capabilities of the model to reveal the relative advantages of one over the other. The selected circuits of interest were Voltage Follower, Common Source Amplifier, Current Source and Differential Amplifier. Simulations of analog circuit building blocks incorporating SiC VJFET showed better circuit functionality compared to their Si counterparts.

Dans le domaine de l’électronique de puissance, les dispositifs en carbure de silicium (SiC) sont bien adaptés pour fonctionner dans des environnements à haute température, haute puissance, haute tension et haute radiation. Le carbure de silicium (SiC) est un matériau semi-conducteur à large bande d’énergie interdite. Ce matériau possède des caractéristiques en température et une tenue aux champs électriques bien supérieure à celles de silicium. Ces caractéristiques permettent des améliorations significatives dans une grande variété d’applications et de systèmes. Parmi les interrupteurs existants, le JFET en SiC est l’interrupteur le plus avancé dans son développement technologique, et il est au stade de la pré-commercialisation. Le travail réalisé au cours de cette thèse consiste à caractériser électriquement des JFET- SiC de SiCED en fonction de la température (25°C-300°C). Des mesures ont été réalisé en statique (courant-tension), en dynamique (capacité-tension) et en commutation sur charge R-L (résistive-inductives) et dans un bras d’onduleur. Un modèle multi-physique du transistor VJFET de SiCED à un canal latéral a été présenté. Le modèle a été développé en langage MAST et validé aussi bien en mode de fonctionnement statique que dynamique en utilisant le simulateur SABER. Ce modèle inclut une représentation asymétrique du canal latéral et les capacités de jonction de la structure. La validation du modèle montre une bonne concordance entre les mesures et la simulation. / In the field of power of electronics, silicon carbide (SiC) devices are well suited to operate in environments at high temperature, high power, high voltage and high radiation. The silicon carbide belongs to the class of wide band gap semiconductor material. Indeed, this material has higher values than the silicon ones for the temperature breakdown and a high electric field breakdown. These characteristics enable significant improvements in wide varieties of applications and systems. Among the existing switches, SiC JFET is the most advanced one in its technological development because it is at the stage of pre-marketing. The study realized during this thesis was to electrically characterize SiC JFETs from SiCED versus the temperature (25°C-300°C). The characteristic are based on static measurements (currentvoltage), capacitive measurements (capacitive-voltage) and switching measurements in an R-L (resistor-inductor) load circuit and an inverter leg. A multi-physical model of the VJFET with a lateral channel is presented. The model was developed and validated in MAST language both in static and dynamic modes using the SABER simulator. The model includes an asymmetric representation of the lateral channel and the junction capacitances of the structure. The validation of the model shows a good agreement between measurements and simulation.