类金字塔状GaN微米结构的生长及其形貌表征

采用金属有机化学气相沉积(MOCVD)技术,在非掺杂GaN层上原位生长SiNx掩模层,制备了形貌可控的类金字塔状GaN微米结构,并系统研究了生长温度、生长时间、反应压力和Ⅴ/Ⅲ比等不同生长参数对其形貌的影响。研究结果表明,在生长温度为1 075℃时,所生长的GaN呈现出类金字塔状微米锥结构;当生长时间由3 min延长至20 min时,微米锥的底面直径由3.6μm增大到19.8μm,密度由3.8×10~3cm~(-2)降低至0.8×10~3cm~(-2);压力及Ⅴ/Ⅲ比共同决定该结构顶部的微观形貌(锥状或截顶锥状)。本工作的研究结果为GaN微钠米结构的原位可控生长奠定了一定基础,并有助于三维GaN基LED器件的进一步发展。

The Growth and Morphology Characterization of GaN Micro-pyramid Structure

The GaN micro-pyramid was grown on unintentional doped GaN epitaxial layers with in-situ pre-deposited SiNx mask via metal organic chemical vapor deposition (MOCVD) .The effects of growth temperature ,growth time ,reaction pressure andⅤ/Ⅲ ratio on morphology of the GaN micro-pyramids were studied systematically .The results showed that the GaN micro-pyramid structures were formed at 1075 ℃ .As the growth time was prolonged from 3 min to 20 min ,the basal diameter of the GaN micro-pyramids increased from 3 .6μm to 19 .8μm ,while the density decreased from 3 .8 × 103 cm -2 to 0 .8 × 103 cm-2 .The final complete pyramid-like or truncated pyramid-like GaN micro-structures was mainly determined by reaction pressure and Ⅴ/Ⅲ ratio .These results pave the way for the controllable in-situ grow th of GaN micro/nano structures and may facilitate the further development of three-dimensional GaN-based LED devices .