Gallium nitride (GaN) that is additively manufactured from a liquid gallium precursor allows for the possibility of manufacturing high-performance semiconducting materials with complex device geometries. However, mitigation of impurities such as carbon and oxygen in the final GaN film is crucial to manufacturing functional films with these methods. In this work, two methods of mitigating native gallium oxide in the liquid gallium precursor were employed and evaluated: (1) “wet” etching of the precursor in solution before GaN growth and (2) “dry” etching of the precursor during the growth using a reducing carrier gas. The carbon impurity content of films grown by using this method was also studied. Data obtained via scanning electron microscopy, time-of-flight secondary ion mass spectrometry, and hot probe electrical characterization indicated that both etch methods were linked to a significant reduction in oxygen content in the resulting GaN film. Photoluminescence data further indicated that the gas-phase reactive additive manufacturing process is linked to a reduction in luminescent defects in the resulting film as compared to commercial GaN grown via chemical vapor deposition.

中文翻译：

---

增材制造外延氮化镓中杂质的评估和减少

由液态镓前驱体增材制造的氮化镓 (GaN) 使得制造具有复杂器件几何形状的高性能半导体材料成为可能。然而，减少最终 GaN 薄膜中碳和氧等杂质对于用这些方法制造功能薄膜至关重要。在这项工作中，采用并评估了两种减少液态镓前驱物中天然氧化镓的方法：(1) 在 GaN 生长之前在溶液中对前驱物进行“湿式”蚀刻；(2) 在生长过程中对前驱物进行“干式”蚀刻使用还原性载气。还研究了使用该方法生长的薄膜的碳杂质含量。通过扫描电子显微镜、飞行时间二次离子质谱和热探针电表征获得的数据表明，两种蚀刻方法都与所得 GaN 薄膜中氧含量的显着降低有关。光致发光数据进一步表明，与通过化学气相沉积生长的商用 GaN 相比，气相反应增材制造工艺与所得薄膜中发光缺陷的减少有关。