Integrated Method for Low-Cost Wide Band Gap Semiconductor Device Manufacturing

A method for manufacturing a wide band gap semiconductor device using a GaN substrate on a SiC wafer comprising the steps of:

• coating the substrate with a hard mask material of silicon nitride;
• performing lithography to define patterned openings in the hard mask material of the substrate;
• etching the substrate to form patterned trenches from the defined patterned openings;
• depositing a conformal layer over the substrate and sidewalls of the patterned trenches;
• removing the conformal layer from top surfaces of the substrate leaving spacers of the conformal layer over sidewalls of the patterned trenches;
• etching the patterned trenches not covered by the spacers of the conformal layer to form globe shaped openings below the spacers;
• removing the hard mask and the spacers from the substrate;
• performing epitaxy on the substrate to deposit GaN to the substrate including the patterned trenches to form an array of voids;
• performing at least another epitaxy on the substrate to deposit at least one device epitaxial layer;
• forming GaN semiconductor devices in the at least one device epitaxy layer;
• and
• severing the array of voids to extract the GaN semiconductor devices from the GaN substrate of the SiC wafer.