Abstract Na-flux method is the most promising approach to grow GaN thick film substrate for GaN homoepitaxy. Here, the influence of solution stirring on grown GaN crystal morphology, crystal quality, dislocation density and impurity concentration was assessed for GaN crystal growth by Na-flux method. It is proved that the crystallinity, surface roughness and dominated orientation of the GaN thick layers are greatly influenced by stirring process, revealing a direct and correlated growth mechanism for the growth of GaN using Na-flux method. Notably, the surface roughness was reduced by three orders of magnitude under stirring (compared to un-stirred sample). This stirring-assisted GaN thick film was then used as seed layer to grow high resistance Fe-doped GaN epitaxial layer by applying HVPE method. On which Ohmic contact was successfully fabricated and an UV-detector with a high detectivity of ∼1013 Jones, which was among the highest values, and fast response (rise time of 100 ms, decay time of 160 ms) was obtained.

中文翻译：

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搅拌辅助 Na-flux 工艺 GaN 厚膜上生长的 Fe 掺杂 GaN 及其在欧姆接触紫外检测器上的应用

摘要 Na-flux法是生长GaN厚膜衬底用于GaN同质外延的最有前景的方法。在这里，溶液搅拌对生长的 GaN 晶体形态、晶体质量、位错密度和杂质浓度的影响通过 Na-flux 法评估了 GaN 晶体生长。证明搅拌过程对GaN厚层的结晶度、表面粗糙度和主导取向有很大影响，揭示了使用Na-flux法生长GaN的直接和相关的生长机制。值得注意的是，在搅拌下（与未搅拌样品相比），表面粗糙度降低了三个数量级。然后将该搅拌辅助的 GaN 厚膜用作种子层，通过应用 HVPE 方法生长高电阻 Fe 掺杂的 GaN 外延层。