W911NF24C0041

Small Technology Transfer Research Program (STTR) Phase II

Atomic fusion wafer bonding tool for ultra-high power switches

Ultra-Pure Atomic Wafer Fusion for Ultra-Wide Bandgap, Ultra-High Power, High Thermal Conductivity Power Switches

High power electronic systems with small Size, Weight and Power (SWaP) are required in many military and industrial applications. GaN and Ga2O3 are two ultra-wide band gap (UWBG) materials that are commonly used in power electronic applications, due to their high critical field and high electron mobility. The maximum output power in these materials is limited by near-junction Joule-heating, which in turn reduces device performance and reliability. The main approach to resolve heat dissipation problem is to use a high material with high thermal conductivity such as SiC as the substrate. Though, grown GaN on SiC shows higher thermal conductivity; however, the heat dissipation flow disrupts in the interface due to the defects in grown semiconductor material. The direct bonding of these semiconductors to SiC with an intermediate layer can increase the heat transfer in the junction and in turn helps to achieve higher performance and more reliable power electronic devices needed by Navy and DoD. Heterogeneous wafer bonding can be done using surface activation. Here, we will develop a bonding system that employs either surface activation or surface activated diffusion to achieve heterogenous bonding between semiconductor wafer and SiC wafer. In addition to power electronic systems, the developed surface activated bonding system can be used in developing heterogeneous wafer structures that are used in the integrated photonic applications. For example, transferring thin film lithium niobate (TFLN) to silicon wafer can provide the electro-optic and nonlinear properties required for amplification or high-fidelity modulation, where silicon photonic integrated circuits cannot achieve.

The goal of phase II is to continue the R&D efforts initiated in Phase I. Funding is based on the results achieved in Phase I and the scientific and technical merit and commercial potential of the project proposed in Phase II. STTRs are completed in conjunction with a research institution.

UCLA Samueli School of Engineering

OSD22B-004

O22B-004-0002

22.B

Lynn Petersen