Nitride lasers on SiC substrates

Laser diode (LD) structures were fabricated by metal-organic chemical vapor deposition (MOCVD) from the AlN-InN-GaN system on single crystal 6H-SiC substrates. A conducting buffer layer was developed for these devices which uses an AlGaN buffer layer and provides a conduction path between SiC substrate and the active device region. Violet and blue multiple quantum well (MQW) separate confinement heterojunction (SCH) LDs were fabricated having InGaN wells and GaN barriers. The lowest pulsed operation threshold current density obtained for lasing was 7.1 kA/cm/sup 2/ in a 4-well structure.