Ultra-High Voltage Insulated Gate Bipolar Transistor on Silicon Carbide

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Microelectronics The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Develop an ultra-high voltage (UHV) insulated gate bipolar transistor (IGBT) on silicon carbide (SiC) technology with high reliability and yield so that these devices may be produced in a high volume manufacturing setting. DESCRIPTION: Despite nearly three decades of research and development (R&D) efforts into SiC power devices, commercial SiC power transistors with voltage ratings greater than 1.7kV are not widely available. Despite significant R&D investments, a fully-qualified, commercially-available, greater than 6.5kV rated SiC power transistor has remained elusive [1-7]. On the other hand, there is an increased demand for UHV SiC power transistors, especially SiC IGBTs, for mission critical applications in both defense and commercial sectors. Other semiconductor materials (e.g., GaN) have been studied for their applicability in the UHV market, yet SiC has emerged as the material of choice for its UHV capabilities and enhanced thermal conductivity [2, 3, 5]. At present, there are very few manufacturing sources within the U.S. that can produce UHV SiC technologies [2, 5]. In addition, the manufacturing challenges associated with UHV SiC devices has hindered its adoption and advancement in the semiconductor industry. For example, in order to achieve ultra-high blocking voltages (e.g., >15kV), manufacturers must produce or procure SiC substrates with ultra-thick (>100um) SiC epilayers [3 7]. Ultra-thick SiC epilayers suffer from high basal plane defect (BPD) levels, especially if appropriately thick (>3um) buffer layers are not employed in the epi structure [5]. It is extremely important to tightly control the density of BPDs in the epilayers procured for device fabrication. It is imperative that an UHV SiC power transistor be developed to meet the UHV and switching speed requirements in mission critical systems. A SiC IGBT is an ideal candidate to meet this demand signal. The proposed SiC IGBT must be produced on 150mm SiC substrates to facilitate high volume manufacturing, demonstrate a blocking voltage greater than 20kV, possess a current rating of at least 15A, threshold voltage Vth ~3.0V, and