Electron Irradiation Induced Crystallization of Amorphous Al₂O₃ Films on Silicon Substrates

Abstract

An in situ study of electron beam irradiation induced amorphous–to–crystalline transformation of Al2O3 films on silicon substrates has been carried out using transmission electron microscopy. Trigonal α–Al2O3 crystallites can be observed for electron beam dose rates larger than 10 mA/cm2. It is found that the nucleation and growth processes dominate near the Al2O3–Si interface. The possible effect of the silicon substrate on the growth of Al2O3 crystallites is considered.

CVD‐Fabricated Aluminum Oxide Coatings from Aluminum tri‐iso‐propoxide: Correlation Between Processing Conditions and Composition

“…Similar behavior is observed for samples processed on silicon at 2 kPa (15 Torr). Liu et al [42] have described such an electron irradiation-induced crystallization of amorphous alumina films on silicon substrates. The authors calculated that the amorphous-to-crystalline transformation resulted from e-beam induced defects rather than from a local temperature increase.…”

Irradiation-Induced Amorphous-to-Crystalline Phase Transformations in Ceramic Materials

“…The a-to-c transformations can be broadly categorized into three types: (1) athermal, resulting exclusively from either electron or ion irradiation of amorphous material, (2) resulting from the combined effects of heating and either ion or electron irradiation, or (3) epitaxial growth or recrystallization of an amorphous oxide due to ion or electron irradiation. The a-to-c transformations are usually observed in target materials that are amorphous as-prepared [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. Less commonly, crystalline or single crystal materials are first amorphized by one type of irradiation, and then the a-to-c transformation is accomplished by irradiating the material in a subsequent experiment [ 48 , 49 , 50 , 51 ].…”

“…Liu et al investigated the effects of electron irradiation of amorphous Al 2 O 3 that led to an a-to-c transformation [ 45 , 46 ]. The as-prepared samples were 300 nm thick layers of amorphous Al 2 O 3 on dislocation-free B-doped Si wafers.…”

“…The authors initially thought that thermal activation from the electron beam due to local heating was the main cause of the a-to-c transformation [ 45 ]. However, in a follow-up publication, the estimated temperature contribution was found to not be significant enough to be a factor in the mechanism for the observed a-to-c transformation [ 46 ]. The authors subsequently proposed that electron irradiation-induced defects were a more likely cause for the a-to-c transformation [ 46 ].…”

Synthesis of Microcrystalline Silicon Films by Low Energy Electron-Beam-Induced Deposition at Cryogenic Temperature

“…In these processes, secondary electrons generated by high-energy electron irradiation on substrates which adsorbed metalorganic compounds play a key role of metal deposition. In this article, electron irradiation was thought to have effect of heating as well as defect formation which enhances the amorphous -to-crystalline transformation [4]. In this article, electron irradiation was thought to have effect of heating as well as defect formation which enhances the amorphous -to-crystalline transformation [4].…”