Abstract: A GaN high electron mobility transistor (HEMT) device having a silicon carbide substrate including a top surface and a bottom surface, where the substrate further includes a via formed through the bottom surface and into the substrate. The device includes a plurality of epitaxial layers provided on the top surface of the substrate, a plurality of device layers provided on the epitaxial layers, and a diamond layer provided within the via.

Abstract: A GaN high electron mobility transistor (HEMT) device having a silicon carbide substrate including a top surface and a bottom surface, where the substrate further includes a via formed through the bottom surface and into the substrate. The device includes a plurality of epitaxial layers provided on the top surface of the substrate, a plurality of device layers provided on the epitaxial layers, and a diamond layer provided within the via.

Abstract: The disclosure relates to a method for forming an intermediate lattice transition buffer layer. The method includes: (a) depositing a first graded InAlAs layer on a substrate at a first constant temperature, the first graded InAlAs layer having an In/AI composition ratio which increases across the buffer layer from a first level to a second level; (b) annealing at least the first graded InAlAs layer; (c) depositing the second graded InAlAs layer on the first graded InAlAs layer at the first constant temperature, the second graded InAlAs layer having an In/Al composition ratio which increases across the buffer layer from the second level to a third level; and (d) annealing at least the second graded InAlAs layer; the buffer layer being formed under Groups III/V overpressure.

Abstract: A semiconductor surface processing method in one example comprises disposing a polishing pad in rotating engagement with a semiconductor wafer to be polished, dripping a first polishing solution onto the polishing pad at a first drip rate, and, concurrently, dripping a second polishing solution onto the polishing pad at a second drip rate.

Abstract: An improved HEMT formed from a GaN material system is disclosed which has reduced gate leakage current relative to known GaN based HEMTs and eliminates the problem of current constrictions resulting from deposition of the gate metal over the step discontinuities formed over the gate mesa. The HEMT device is formed from a GaN material system. One or more GaN based materials are layered and etched to form a gate mesa with step discontinuities defining source and drain regions. In order to reduce the leakage current, the step discontinuities are back-filled with an insulating material, such as silicon nitride (SiN), forming a flat surface relative to the source and drain regions, to enable to the gate metal to lay flat. By back-filling the source and drain regions with an insulating material, leakage currents between the gate and source and the gate and drain are greatly reduced. In addition, current constrictions resulting from the deposition of the gate metal over a step discontinuity are virtually eliminated.

Abstract: Die of high aspect ratio formed in a hard wafer substrate are sawed out without requiring tape, obtaining high die yields. Preliminary to sawing the semiconductor die (3) from a sapphire wafer (2), the wafer is joined (20) to a silicon carrier substrate (6) by a thermoplastic layer (4) forming a unitary sandwich-like assembly. Sawing the die from the wafer follows. The thermoplastic is removed, and the die may be removed individually (50) from the silicon carrier substrate. Thermoplastic produces a bond that holds the die in place against the shear force exerted by the saw and by the stream of coolant (30).