Work

Bonded GaN-Si pn Heterojunctions Fabricated Using Transferred GaN Membranes

Year: 2025

Type: article

Abstract: The ability to transfer and bond GaN membranes can enable new devices and new ways to optimize performance. Here, we demonstrate fabrication of GaN-Si pn diodes using van der Waals (vdW) lift-off and bonding of GaN membranes and assess the critical processing and interface challenges with this approach. Freestanding n-GaN layers were produced by epitaxial lift-off from sp2-bonded boron nitride-sapphire templates followed by direct bonding to p+-Si substrates. Fabricated diodes exhibited high on/off current ratios up to 8 × 107, ideality factors of 1.8, and low series resistance. Annealing bonded heterojunctions at 400°C improved the ideality factor compared to as-bonded devices. Transmission electron microscope imaging revealed a well-bonded interface with only a 2-nm-thick oxide interlayer. Current-voltage analysis and device simulations indicated that the observed transport mechanism is due to recombination at defects in the GaN near the bonded interface. These results pave the way for a better understanding of bonded GaN junctions and how to improve their quality.

Source: Journal of Electronic Materials

DOI: 10.1007/s11664-025-11854-2

Authors: Eric W. Blanton, Stefan Nikodemski, Matt Grupen, Nicholas R. Glavin, Michael Snure

Institutions: KBR (United States), United States Air Force Research Laboratory, Wright-Patterson Air Force Base, U.S. Air Force Research Laboratory Materials and Manufacturing Directorate

Language: English

Topic: GaN-based semiconductor devices and materials

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,390

Funder: Air Force Office of Scientific Research