Systematic oxygen impurity reduction in smooth N-polar GaN by chemical potential control
Systematic oxygen impurity reduction in smooth N-polar GaN by chemical potential control
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DOI：
10.1088/1361-6641/ac3638
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发表时间：
2022-01-01
影响因子：
1.9
通讯作者：
Collazo，Ramon
中科院分区：
文献类型：
--
作者：
Szymanski，Dennis;Wang，Ke;Collazo，Ramon
通过控制工艺化学势和减少位错来控制通过金属有机化学气相沉积（MOCVD）在蓝宝石衬底上生长的N极性GaN层中的氧浓度。随着工艺过饱和度从10030改变到3400，氧点缺陷的形成能增加，这导致氧掺入减少25倍。将位错减少约4倍（减少到1017 cm− 3），可以进一步将氧的掺入减少到低-1017 cm− 3范围。通过两步工艺实现了具有低氧含量的平滑N极性GaN层，首先生长具有高氧浓度的1 μm厚的平滑N极性层，然后在高过饱和度下生长低氧浓度层。
Process chemical potential control and dislocation reduction were implemented to control oxygen concentration in N-polar GaN layers grown on sapphire substrates via metal organic chemical vapor deposition (MOCVD). As process supersaturation was changed from∼ 30 to 3400, the formation energy of the oxygen point defect increased, which resulted in a 25-fold decrease in oxygen incorporation. Reducing dislocations by approximately a factor of 4 (to∼ 10 9 cm− 3) allowed for further reduction of oxygen incorporation to the low-10 17 cm− 3 range. Smooth N-polar GaN layers with low oxygen content were achieved by a two-step process, whereas first a 1 µm thick smooth N-polar layer with high oxygen concentration was grown, followed by low oxygen concentration layer grown at high supersaturation.