为获得高质量的β-Ga2O3薄膜，对传统的GaN薄膜高温氧化方法进行了优化。我们通过对GaN薄膜分别进行一步或两步高温氧化的方法制备了β-Ga2O3薄膜，并通过X射线衍射、场发射扫描电子显微镜、拉曼光谱等对制备的样品进行了测试、对比与分析。结果表明，950 ℃下GaN薄膜无法完全氧化，而直接1 150 ℃氧化得到的样品并没有明显的晶向。相比之下，通过两步氧化法，GaN薄膜被完全氧化，且得到的β-Ga2O3薄膜具有明显的沿<201>方向的晶向，样品表面显示出明显的纳米线结构。最佳的氧化时间为在950 ℃下氧化3 h之后在1 150 ℃下氧化1 h，此时得到样品的纳米线结构最明显，其纳米线的直径约为30~40 nm。拉曼光谱测试证实了该条件下获得的样品具有较高的晶体质量。通过分析不同样品结构以及形貌特性，我们发现不同温度下的不同氧化模式是导致该结果的主要原因。

To obtain β-Ga2O3 films with high quality, we optimized conventional GaN high temperature oxidation. The β-Ga2O3 thin films were prepared from GaN thin films by one-step and two-step high temperature oxidation, respectively. The prepared samples were characterized by X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM) and Raman spectroscopy. The results showed that the GaN films could not be completely oxidized at 950 ℃, and the sample obtained directly at 1 150 ℃ had no obvious crystal orientation. In contrast, the GaN films were completely oxidized by two-step oxidation method, and the obtained β-Ga2O3 films had obvious crystal orientation along the direction of <201>. The surfaces of the samples obtained by two-step oxidation showed nanowire structures. The optimized oxidation time was oxidation at 950 ℃ for 3 h followed by oxidation at 1 150 ℃ for 1 h, the obtained sample had most obvious nanowire structures, and the diameters of the nanowires were about 30-40 nm. Raman spectroscopy confirmed that the sample obtained under this condition had high crystalline quality. By analyzing the structure and morphology properties of different samples, we found that different oxidation modes at different temperatures were the main causes of these results.