柔性衬底上使用等离子增强原子层沉积制备的氮化镓薄膜物性分析

Physical Analysis of Polycrystalline GaN Thin Films on Flexible Substrate by Plasma-Enhanced Atomic Layer Deposition

摘要:

采用等离子增强原子层沉积技术（PE-ALD）在350℃温度下,在KAPTON柔性衬底上直接生长出多晶GaN薄膜。利用低角度掠入射X射线衍射仪、AFM、SEM、TEM、XPS对薄膜的晶体结构、表面形貌及薄膜成分进行了表征和分析。结果表明,薄膜呈多晶态,且具有良好的均匀性;薄膜中的N元素全部以N-Ga键形式存在;大部分Ga元素以Ga-N键形式构成GaN;少量的Ga元素分别以Ga-Ga键和Ga-O键形式构成金属镓以及Ga2O3。研究发现,虽然KAPTON具有较好的耐高温性,但GaN会反向扩散进入KAPTON衬底,形成具有一定厚度的GaN扩散层。

Abstract:

Polycrystalline GaN thin films were successfully fabricated on KAPTON flexible substrates at 350℃ by plasma-enhanced atomic layer deposition (PE-ALD). The crystal structure, surface morphology and composition of GaN thin films were characterized by grazing incident X-ray diffraction (GIXRD), atomic force microscope (AFM), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectrometer (XPS). The results show that the thin films are polycrystalline and have a good uniformity, and all the N elements of the as-deposited thin films are in the form of N-Ga bond, indicating that all the N elements are formed into GaN thin films. A little amount of Ga elements exist in the form of Ga-O and Ga-Ga bond to form Ga and Ga2O3. It is indicated that, although KAPTON has good resistance of high temperature, GaN will diffuse back into the KAPTON substrate with a certain distance to form a GaN diffusion layer.