Laser Slicing Technique Revolutionizes GaN Substrate Recycling, Paving the Way for Cost-Effective Vertical Power MOSFETs

A study led by Takashi Ishida and colleagues explored a recycling process for gallium nitride (GaN) substrates using a laser slicing technique, aiming to reduce the cost of GaN vertical power MOSFETs. GaN is noted for its potential in high-power applications due to its superior electrical properties compared to silicon. The cost of GaN devices, while expected to be lower than silicon carbide (SiC) devices, is significantly impacted by the expensive GaN substrates. The proposed recycling process involves the use of laser slicing to separate used GaN substrates into thin device chips and a remaining substrate portion, which can then be smoothed, polished, and reused for further device fabrication.

The research demonstrated that the electrical properties of devices fabricated on recycled GaN substrates, specifically lateral MOSFETs and vertical PN diodes, showed no degradation compared to those on new substrates. This indicates that the recycling process does not adversely affect the substrate's quality or the performance of subsequent devices. The study's findings suggest that this recycling method could be a viable strategy to lower the production costs of GaN-based power devices, potentially facilitating their broader adoption in high-power applications.

Source: Demonstration of recycling process for GaN substrates using laser slicing technique towards cost reduction of GaN vertical power MOSFETs - IOPscience