iDEAL argues that, instead of using a bulk p-type pillar to occupy ~50% of the structure, you can use a nanometer-thin high-k dielectric film (like alumina and hafnia) via atomic layer deposition (ALD) inside a narrow trench that can theoretically occupy as little as 5% of the total device structure to do the same charge-balancing and multi-dimensional (vertical + lateral) depletion, reclaiming the other 95% for conduction. This effectively restores the HEXFET’s wide conductive area while maintaining the RESURF’s high-voltage blocking capability.
