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

• 作 者: 纪攀峰 刘乃鑫 魏学成 刘喆 路红喜 王军喜 李晋闽
• 机 构: Semiconductor Lighting R&D Center,Institute of Semiconductors,Chinese Academy of Sciences,
• 出 处: 半导体学报
• 发表日期: 2011年10期
• 关键词: defects suppress depths hexagonal ultraviolet annealed indium segregation pyrami

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~(18) to 5.24×10~(18) cm~(-2),and the V-defect width and depth increase too.The density also increases with the growth temperature.The densities are 2.05×10~8,2.72×10~(18) and 4.23×10~8 cm~(-2),corresponding to a growth temperature of 748,753 and 758℃respectively.When the NH_3 flows are 5000,6600 and 8000 sccm,the densities of the V-defects of these samples are 6.34×10~(18),2.72×10~(18) and 4.13×10~(18) cm~(-2),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_3 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.

The influence of the growth temperature, TMIn / TEGa and V / III ratio 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 -defections increases from 2.72 × 10-18 to 5.24 × 10-18 cm -2, and the V-defect width and depth increase too.The density also increases with the growth temperature.The densities are 2.05 × 10 ~ 8, 2.72 × 10 ~ (18) and 4.23 × 10 ~ 8 cm ~ (-2) respectively, corresponding to a growth temperature of 748,753 and 758 ℃ .When the NH_3 flows are 5000, 6600 and 8000 sccm, the densities of the V-defects of these samples are 6.34 × 10 ~ (18), 2.72 × 10 ~ (18) and 4.13 × 10 ~ (18) cm ~ 2, respectively.A proper Ⅴ / Ⅲratio is needed to achieve step flow growth mode. We get the best quality of InGaN / GaN MQWs at a growth temperature of 753 ° C. TM In flow at 180 sccm, NH 3 flow at 6600 sccm, a flatter surface and less V-defects density. These depths of these V- defects are from 10 to 30 nm, and the widths are from 100 to 200 nm. 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.