パルススパッタ堆積法によるサファイア基板上N極性面InGaN LEDの作製

抄録

  We demonstrated the growth of device-quality N-polar GaN films on sapphire (0001) substrates. Specifically, we investigated the crystalline quality of N-polar GaN and basic electrical properties of Mg-doped N-polar GaN films. We found that the dislocation density of PSD-grown N-polar GaN could be reduced with increase in the film thickness. By Mg doping, p-type conductivity in N-polar GaN could be well controlled in the hole concentration range between 8 × 10¹⁶ and 2 × 10¹⁸ cm⁻³. With the use of these materials, we demonstrated the successful operation of N-polar InGaN LEDs with a long wavelength up ot 609 nm. The results presented in our manuscript indicate that the PSD growth technique is quite promising for fabricating N-polar devices such as high-efficiency InGaN-based long-wavelength LEDs or solar cells.