USA As Represented by Secretary of the Navy

Robert E Stahlbush

Marko J Tadjer

Charles R Eddy, Jr

David Kurt Gaskill

Rachael L Myers-Ward

Nadeemullah A Mahadik

Eugene A Imhoff

Karl D Hobart

Boris N Feigelson

Virginia D Wheeler

Nadeemmullah A Mahadik

Brenda L VanMil

Jordan D Greenlee

Francis J Kub

Joshua D Caldwell

Orest J Glembocki

Kok-Keong Lew

A method of cleaving includes providing a substrate. Optionally, the substrate includes &#x3b2;-gallium oxide, hexagonal zinc sulfide, or magnesium selenide. The substrate includes at least one natural cleave plane and a crystallinity. The substrate is cleaved along a first natural cleave plane of the at least one natural cleave plane. The cleaving the substrate along the first natural cleave plane includes the following. A micro-crack is generated in the substrate while maintaining the crystallinity adjacent to the micro-crack by generating a plurality of phonons in the substrate, the micro-crack comprising a micro-crack direction along the first natural cleave plane. The micro-crack is propagated along the first natural cleave plane while maintaining the crystallinity adjacent to the micro-crack. Optionally, generating a micro-crack in the substrate by generating a plurality of phonons in the substrate includes generating the plurality of phonons by electron-hole recombination. Optionally, the electron-hole recombination includes non-radiative electron-hole recombination.

UV laser slicing of &#x3b2;-GaOby micro-crack generation and propagation

A method for removing existing basal plane dislocations (BPDs) from silicon carbide epilayers by using a pulsed rapid thermal annealing process where the BPDs in the epilayers were eliminated while preserving the epitaxial surface. This high temperature, high pressure method uses silicon carbide epitaxial layers with a carbon cap to protect the surface. These capped epilayers are subjected to a plurality of rapid heating and cooling cycles.

Basal plane dislocation elimination in 4H&#x2014;SiC by pulsed rapid thermal annealing

A method of: providing an off-axis silicon carbide substrate, and etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.

Reduction of basal plane dislocations in epitaxial SiC using an in-situ etch process

A method of: providing an off-axis 4H&#x2014;SiC substrate, and etching the surface of the substrate with hydrogen or an inert gas.

A method and device including adding a protective layer on the surface of a substrate, annealing the substrate at a temperature approximately greater or equal to 1850&#xb0; C., removing the protective layer from the surface of the substrate after the annealing, and growing a first epilayer on the substrate after the removing of the protective layer, wherein the first epilayer is grown without attempting to prevent the basal plane dislocations to propagate in the first epilayer when growing the first epilayer, and wherein the first epilayer is free of the basal plane dislocations.

Removal of basal plane dislocations from silicon carbide substrate surface by high temperature annealing and preserving surface morphology

A method for reducing/eliminating basal plane dislocations from SiC epilayers is disclosed. An article having: an off-axis SiC substrate having an off-axis angle of no more than 6&#xb0;; and a SiC epitaxial layer grown on the substrate. The epitaxial layer has no more than 2 basal plane dislocations per cmat the surface of the epitaxial layer. A method of growing an epitaxial SiC layer on an off-axis SiC substrate by: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxially grow SiC on the substrate in the growth chamber. The substrate has an off-axis angle of no more than 6&#xb0;. The growth conditions include: a growth temperature of 1530-1650&#xb0; C.; a pressure of 50-125 mbar; a C/H gas flow ratio of 9.38&#xd7;10-1.5&#xd7;10; a C/Si ratio of 0.5-3; a carbon source gas flow rate during ramp to growth temperature from 0 to 15 sccm; and an electron or hole concentration of 10-10/cm.

Reduction of basal plane dislocations in epitaxial SiC

A method to remove basal plane dislocations in post growth silicon carbide epitaxial layers by capping post growth silicon carbide epilayers with a graphite cap and annealing the capped silicon carbon epilayers at a temperature of 1750&#xb0; C. or greater with a nitrogen overpressure of 60-110 psi, wherein basal plane dislocations in the epilayers are removed while surface morphology is preserved. Also disclosed is the related silicon carbide substrate material made by this method.

Elimination of basal plane dislocations in post growth silicon carbide epitaxial layers by high temperature annealing while preserving surface morphology

A method of: flowing a silicon source gas, a carbon source gas, and a carrier gas into a growth chamber under growth conditions to epitaxial grow silicon carbide on a wafer in the growth chamber; stopping or reducing the flow of the silicon source gas to interrupt the silicon carbide growth and maintaining the flow of the carrier gas while maintaining an elevated temperature in the growth chamber for a period of time; and resuming the flow of the silicon source gas to reinitiate silicon carbide growth. The wafer remains in the growth chamber throughout the method.

Method of producing epitaxial layers with low basal plane dislocation concentrations

A method of reversing Shockley stacking fault expansion includes providing a bipolar or a unipolar SiC device exhibiting forward voltage drift caused by Shockley stacking fault nucleation and expansion. The SiC device is heated to a temperature above 150&#xb0; C. A current is passed via forward bias operation through the SiC device sufficient to induce at least a partial recovery of the forward bias drift.

Growing community of inventors

Silver Spring, MD, United States of America

Robert E Stahlbush