Patent ID: 9252207
Filing Date: 2016-02-02
CPC Classification: H01L

Claim Text:
1. A composite substrate for epitaxial-layer growth, the composite substrate being of at least 50.8 mm diameter, and comprising: a first substrate composed of a nitride compound semiconductor and therein having a nitrogen-face side, said first substrate being implanted with ions at a predetermined angle such that implanted ions disposed along the substrate's c-axis are in proportion to implanted ions disposed along the substrate's a-axis in an axial ratio c/a of from 1.626 to 1.629; a first either oxide or nitride coating of between 50 nm and 1000 nm, inclusive, thickness, formed on the nitrogen-face side of said first substrate; a second substrate composed of a material that is either identical with or different from the material constituting the first substrate, said second substrate having a bonding side; and a second either oxide or nitride coating of between 50 nm and 1000 nm, inclusive, thickness, formed on the bonding side of said second substrate; wherein a join between the nitrogen-face side of said first substrate and the bonding side of said second substrate is constituted by said first and second coatings such as to occupy an at least 90% surface-area proportion between the nitrogen-face side of said first substrate and the bonding side of said second substrate.