LED Grade 2 inch Fe-doped Semi-Insulating Gallium Nitride Single Crystal C plane (0001)
- Dimension: 2" diameter
- Thickness: 350 +/- 25 um
- Usable area: >70%
- Orientation:C-plane (0001) off angle toward M-axis <1-100> 0.35 deg +/- 0.15 deg
- Total Thickness Variation: <15 um
- Bow: <20 um
- Resistivity (300K): >106 Ohm-cm
- Dislocation Density: <3 x 106 cm-2
- Polishing: Front surface: Ra <0.5 nm, epi-ready polished. back surface fine ground.
- Package: packaged in a class 100 clean room environment, in single wafer container, under nitrogen atmosphere.
1. Study of GaN light-emitting diodes fabricated by laser lift-off technique
The fabrication process and performance characteristics of the laser lift-off (LLO) GaN light-emitting diodes (LEDs) were investigated. The LLO-GaN LEDs were fabricated by lifting off the Gallium Nitride LED wafer structure grown on the original sapphire substrate by a KrF excimer laser at 248 nm wavelength with the laser fluence of 0.6 J/cm2 and transferring it onto a Cu substrate. The LLO-GaN LEDs on Cu show a nearly four-fold increase in the light output power over the regular LLO-LEDs on the sapphire substrate. High operation current up to 400 mA for the LLO-LEDs on Cu was also demonstrated. Based on the emission wavelength shift with the operating current data, the LLO-LEDs on Cu show an estimated improvement of heat dissipation capacities by nearly four times over the light-emitting devices on sapphire substrate. The LLO process should be applicable to other GaN-based LEDs in particular for those high light output power and high operation current devices.