The effect of selective area growth (SAG) on wafer bowing of GaN-based light-emitting diodes (LEDs) is investigated. The SAG of LED structures was carried out on a silicon dioxide (SiO2) mask pattern with periodic 1000×1000 μm openings, along the sapphire 〈1−1 0 0〉 and 〈−1−1 2 0〉 directions. The morphology of a selectively-grown n-GaN epilayer was examined in relation to various growth parameters such as temperature, pressure, and V/III ratio. Under optimized growth conditions, formation of a ridge-shaped epilayer with a v-pit free smooth surface was realized. Furthermore, the ridge-shaped vertical LED structure, after the removal of the sapphire substrate by laser lift-off (LLO) showed less wafer bowing compared with conventional vertical LED structures. This is attributed to the suppression of lateral strain and dislocations during the site-selective growth process, due to a reduction in the lateral dimensions.
Keywords
- A3. Selective epitaxy;
- A3. Metal-organic chemical vapor deposition;
- B1. Nitrides;
- B2. Semiconducting III–V materials;
- B3. Light-emitting diodes
- Source；Sciencedirect
- If you find them interesting, please visit us: www.qualitymaterial.net or contact with us: gan@powerwaywafer.com.
No comments:
Post a Comment