GaN Island Lateral Power Layout for Higher Breakdown Voltage

The patent transitions from a planar lateral architecture to a three-dimensional architecture by forming GaN islands that protrude above the substrate surface. This vertical dimension allows the GaN layer to achieve greater effective thickness for voltage handling while maintaining lateral contact arrangements for simplified fabrication. The islands are formed by selective epitaxial growth on patterned substrate regions, creating raised structures that provide both mechanical strength and electrical performance.

The patent segments the continuous GaN layer into discrete islands separated by trenches or grooves. Each island is independently formed and can be optimized for specific voltage requirements. The segmentation allows different regions to have different GaN thicknesses or compositions, enabling tailored electrical characteristics while maintaining overall device integration.

Instead of removing substrate material to create air gaps for voltage isolation, the patent adds vertical dimension by growing GaN islands that protrude from the substrate. This positive architecture maintains full substrate support for mechanical strength while achieving voltage isolation through the raised island structures and surrounding trenches. The substrate remains intact and provides continuous mechanical support.

The patent introduces trenches or grooves as intermediary structures between GaN islands. These trenches filled with dielectric material or air gaps provide electrical isolation and voltage breakdown prevention without requiring substrate removal. The trenches act as mediators that separate high-voltage regions while maintaining substrate integrity and mechanical support.

The patent concentrates the increased GaN thickness in the vertical dimension rather than expanding laterally. The islands protrude upward from the substrate with controlled heights that provide the necessary breakdown voltage while occupying minimal lateral space. This vertical stacking approach maintains compact device footprint while achieving high voltage handling capability.

The patent uses thin film epitaxial growth techniques to create precisely controlled GaN island structures. The islands have controlled dimensions and heights that provide maximum voltage handling with minimum material usage. The thin film approach allows precise thickness control to achieve optimal balance between voltage rating and device compactness.

The patent converts the potential harm of exposed island edges into a benefit by deliberately forming trenches around the islands and filling them with dielectric material or conducting layers. The trench structures that could be sources of leakage are instead used to create field-plate effects or shielding that redirect electric fields and suppress leakage currents at the island perimeters.

The patent modifies the electrical parameters at the island edges by introducing additional layers or structures in the trenches. This changes the electric field distribution and potential profiles at the mesa edges, suppressing field enhancement effects that cause leakage. The parameter changes include adding dielectric constants, conductive layers, or geometric modifications to control field distribution.