SMF C3NiT: Coalesced GaN on Silicon Semi-vertical Schottky Diodes

Purpose and goal:

The overall objective of the project was to demonstrate Hexagem´s coalescence technology on silicon substrates and to manufacture semi-vertical components in the form of Schottky diodes.

The purpose of the project was to accelerate the development of coalescence technology on Si in order to more quickly reach out to industrial players in the power electronics market and create interest in collaborative projects for upscaling and verification of Hexagems materials technology on a commercial scale.

Expected results and effects:

The project has led to the development of crack-free GaN layers on 50mm silicon substrates with up to 4 micrometer thick GaN layers. The quality of these layers reaches a very high standard, comparable to results from industrial research. Furthermore, component structures have been manufactured for Schottky diodes which have shown very good forward voltage characteristics but with increased leakage current in the reverse direction.

The results have raised interest from industry and discussions on collaborations for upscaling to 150mm substrate are ongoing. Approach and implementation:

The project has been carried out with three project partners, Hexagem, Chalmers and LiU. The material development has taken place by Hexagem with characterization help from LiU and component design, processing and electrical characterization by Chalmers. The workflows between partners have worked excellently with good discussions about results and planning of subsequent measures.

The biggest obstacle, which also caused delays, has been on the logistics side with delays in substrates and process deliveries outside the consortium as a result of worldwide logistics problems.