Epitaxial lateral overgrowth of GaN on sapphire substrates using in-situ carbonized photoresist mask

Study of a-Plane GaN Epitaxial Lateral Overgrowth Using Carbonized Photoresist Mask on r-Plane Sapphire

“…This new approach to ELOG offers several advantages: (1) wafer scale patterning is achieved in one lithography step; (2) no energetic plasma is used at any point; (3) a carbonized mask should exhibit selectivity, so that GaN preferentially grows on the opening region, not the carbonized PR mask. 14,15) We show that growth of a-plane GaN film, the stripe morphology and their growth mechanism by the growth conditions of the first overgrowth step. We obtained reduced dislocation density from the ELO GaN layer.…”

Photoreflectance study of GaN grown on SiN treated sapphire substrate by MOVPE

“…Further improvements in high performance devices call for the reduction of dislocation densities which are known to affect optical and electrical properties of GaN-based devices by trapping point defects or forming complexes with them [6][7][8]. In this regard, various strategies were employed and many methods have been developed to reduce the dislocation density such as epitaxial lateral overgrowth (ELOG) [9][10][11][12], pendeo-epitaxy (PENDO) [13,14], facet controlled epitaxial lateral overgrowth (FACELO) [15,16], and SiN treatment [17][18][19][20][21][22]. In contrast to the overgrowth techniques which have shown a high degree of complication, the SiN treatment procedure is simpler and has been proven to significantly reduce threading dislocation density in GaN.…”

Low Dislocation Densities of Nitride-Based Light-Emitting Diodes with a Preflow of NH3Source before Growth of AlN Buffer Layer

“…Although nitride-based LEDs prepared on sapphire (Al 2 O 3 ) substrates are already commercially available, GaN grown on sapphire substrates always contains a high density of threading dislocations owing to the large lattice mismatch between GaN and sapphire substrates. 1,2) Thus, it is extremely important to reduce the density of threading dislocations. Many techniques, such as those involving an interlayer, 3) an epitaxial lateral over growth (ELOG), 4) and a patterned sapphire substrate (PSS), 5) were developed to reduce the threading dislocation density.…”