Influence of growth conditions on the V-defects in InGaN/GaN MQWs

The influence of the growth temperature,TMIn/TEGa andⅤ/Ⅲratio on the V-defects of InGaN/GaN multi-quantum wells（MQWs） has been investigated and discussed.When the TMIn flow increases from 180 to 200 sccm,the density of V-defects increases from 2.72×10;to 5.24×10;cm;,and the V-defect width and depth increase too.The density also increases with the growth temperature.The densities are 2.05×10;,2.72×10;and 4.23×10;cm;,corresponding to a growth temperature of 748,753 and 758℃respectively.When the NH;flows are 5000,6600 and 8000 sccm,the densities of the V-defects of these samples are 6.34×10;,2.72×10;and 4.13×10;cm;,respectively.A properⅤ/Ⅲratio is needed to achieve step flow growth mode.We get the best quality of InGaN/GaN MQWs at a growth temperature of 753℃TMIn flow at 180 sccm,NH;flow at 6600 sccm,a flatter surface and less V-defects density.The depths of these V-defects are from 10 to 30 nm,and the widths are from 100 to 200 nm.In order to suppress the influence of V-defects on reverse current and electro-static discharge of LEDs,it is essential to grow thicker p-GaN to fill the V-defects.