Single-crystal gallium oxide (Ga2O3) has attracted increasing attention as a promising material for power device applications. It possesses excellent material properties and has the potential for mass productivity of low-cost and high-quality bulk crystals by using methods such as the edge-defined film-fed growth (EFG) method [1].

A new class of high-voltage semiconductor devices, known as a reverse conducting IGBT (RC-IGBT), has emerged in recent years from research efforts to diminish the usage of external anti-parallel free-wheeling diode chips for IGBT switching applications. The RC-IGBT device concept is based on the monolithic integration of a freewheeling diode into an IGBT chip. Hereby, an anti-parallel diode is formed through the embedment of an n+ region in an anode/collector region of the IGBT. Both the n+ region and the p+ anode are then shorted together by an anode/collector contact. Although the RC-IGBT has many advantages over the conventional IGBT, especially in terms of manufacturing cost, total chip size and reliability of power modules, it is detrimental to the snapback effect at forward conduction of IGBT mode.

Interdigitated back contact silicon heterojunction (IBC-SHJ) combines the advantages of interdigitated back contact (IBC) and silicon heterojunction (SHJ) solar cells. Having all the contacts at the back of the cell eliminates contact shading, leading to a higher short-circuit current (JSC). Being a heterojunction device, IBC-SHJ also has the potential of higher open circuit voltage (VOC) due to the better surface passivation of the deposited amorphous silicon (a-Si) layer. The low temperature deposition, instead of high temperature diffusion, decreases thermal stress, which is the trend of future silicon solar cells. Rear surface passivation by deposited intrinsic amorphous silicon (a-Si) buffer layer in IBC-SHJ solar cells significantly improves open circuit voltage (VOC) and short circuit current (JSC) but can lead to very low fill factor (FF) with an “S” shape J-V curve. In this paper, methods to optimize IBC-SHJ solar cell with improved FF are discussed and guided by two-dimensional numerical simulation. The modeling of the IBC-SHJ solar cell requires device simulation software operating in two dimensions and incorporating amorphous silicon. To study this innovative structure, we use ATLAS two-dimensional (2-D) device simulation software that provides accurate bulk and interface defects needed to model amorphous silicon. We first present the geometrical structure of the solar cell, then review the general framework of the simulation by specifying the different physical models, and finally examine the simulation results in order to determine the important parameters to achieve high efficiency.

Monte Carlo module of Athena allows accurate simulation of ion implantation in 4H-SiC and 6H-SiC [1]. It is known that channeling effects are very pronounced in SiC since its lattice has several wide open channels ( e.g. 〈0001〉, 〈1120〉, and 〈1123〉 for 4H-SiC) and therefore implant profiles strongly depend on wafer orientation and ion beam direction. Another important aspect of ion implantation simulation in SiC is the fact that most of commercially available standard 〈0001〉 wafers are offered with miscut of 3.5° – 8.5° usually toward 〈1120〉 direction. The miscut is introduced primarily to facilitate epitaxial growth. In the same time the miscut alters ion implantation, because implanting normal to the wafer surface is equivalent to a tilt of the beam in the (1120) plane.