The MOCVD growth of InGaN:Si base layers on a semi-relaxed InGaN substrate, where growth is generally difficult due to the presence of V-pits, is examined. These V-pits can propagate through the crystal, causing severe morphological degradation and significantly reducing material quality for device use. Such V-pits may also be a source of leakage current if they extend from the substrate through p-n junction. A wide range of InGaN growth conditions and their impact on V-pit formation and density are investigated. The use of thin GaN interlayers, carrier gas selection, and V/III ratio are found play a critical role in managing V-pit quantity and size. Finally, high temperature GaN interlayers are implemented, fully eliminating V-pit formation in 1200 nm thick InGaN base layers grown coherently on semi-relaxed InGaN substrates.

研究了半松弛InGaN衬底上InGaN：Si基层的MOCVD生长，该衬底由于存在V坑而通常难以生长。这些V形凹坑会在晶体中传播，从而导致严重的形态退化，并大大降低器件使用的材料质量。如果此类V凹坑从衬底延伸穿过pn结，则也可能是泄漏电流的来源。研究了各种InGaN生长条件及其对V形坑形成和密度的影响。发现使用薄的GaN中间层，选择载气和V / III比在管理V坑数量和尺寸方面起着关键作用。最后，实现了高温GaN中间层，从而完全消除了在半松弛InGaN衬底上连贯生长的1200 nm厚InGaN基层中的V坑形成。