Electron irradiation was observed to induce crystallization of amorphous Al₂O₃ films grown by atomic layer deposition on β-Ga₂O₃ substrates. Growth of large, strongly oriented crystalline γ-Al₂O₃ regions was induced using conventional-mode transmission electron microscopy (TEM) and observed to propagate outward from the interface as well as from the previously crystallized Al₂O₃. A few nm of epitaxial Al₂O₃ was already visible at the beginning of the crystallization front propagation. The phenomenon is not explained by electron beam-induced heating, which amounted to less than 1 K at all times. Direct measurement of the beam current permitted quantitative correlation between electron dose rates and crystallization rates. Enlarging the electron beam to reduce current density was found to slow the propagation of the crystallization front. Furthermore, a factor of 4 smaller electron dose was required for a given rate using 100 keV electrons as compared to 200 keV, indicating that crystallization is driven by ionization-induced atomic rearrangement within the gate layer. Lattice spacing between the oxygen sub-lattices of β-Ga₂O₃ and γ-Al₂O₃ are favorable for the nucleation of crystallites at the interface. Multivariate statistical analysis of electron energy loss spectroscopy (EELS) data also showed evidence of diffusion between Al and Ga in the substrates and gate oxides, respectively. These structural transformations at the semiconductor–insulator interface are expected to influence the device electrical behavior and are relevant to the continued refinement of β-Ga₂O₃ device technology.

观察到电子辐射诱导了通过原子层沉积在β- Ga ₂ O ₃衬底上而生长的非晶Al ₂ O ₃膜的结晶。使用常规模式透射电子显微镜（TEM）诱导了大的，强取向的结晶γ- Al ₂ O ₃区域的生长，并观察到其从界面以及先前结晶的Al ₂ O ₃向外传播。几nm的外延Al ₂ O ₃在结晶前沿传播开始时就已经可见。这种现象不能用电子束感应加热来解释，该加热始终小于1K。直接测量束流可以实现电子剂量率和结晶率之间的定量相关。发现扩大电子束以减小电流密度会减慢结晶前沿的传播。此外，对于给定速率，使用100 keV电子要比使用200 keV小4倍的电子剂量，这表明结晶是由栅极层内电离引起的原子重排驱动的。β - Ga ₂ O ₃和γ- Al的氧亚晶格之间的晶格间距₂ O ₃对于界面处的微晶核化是有利的。电子能量损失谱（EELS）数据的多变量统计分析还显示出分别在衬底和栅极氧化物中Al和Ga之间扩散的证据。预计在半导体-绝缘体界面处的这些结构转变会影响器件的电性能，并且与β- Ga ₂ O ₃器件技术的不断完善有关。