Laser Stealth Slicing (LSS) process allows to separate thin GaN films containing device structure from bulk GaN substrates.
Main advantages of the LSS process:
- The cut can be made at any depth in the range from 5um to 500um.
- No sacrificial layers between film and substrate are required
- The device structure is not damaged during the LSS process
Two implementations of the LSS process were developed and patented by TRINITRI:
- “Method of Laser Separation of the Epitaxial Film or of the Epitaxial Film Layer from the Growth Substrate of the Epitaxial Semiconductor Structure (Variations)” United States Patent Application US20140206178A1
- “Method of Separating Surface Layer of Semiconductor Crystal Using a Laser Beam Perpendicular to the Separating Plane,” United States Patent Application US20130248500A1
LED structure, grown on a bulk GaN substrate, after the LSS and transfer to copper heat sink: