Abstract Amorphous lithium niobate (LiNbO3) films were deposited onto silicon substrates by the radio-frequency magnetron sputtering method in a pure Ar environment and an Ar + O2 gas mixture with various oxygen contents. The oxide charge existing in as-grown films has two components: the positive +Qox distributed in the bulk of a film and the negative −Qox located at the film/substrate interface with a maximum magnitude corresponding to an Ar (80%) + O2 (20%) gas mixture. The potential barrier height, φ, at the LiNbO3/Si interface correlates with Qox. The lowest φ value is attributed to the LiNbO3/Si heterostructures fabricated under an Ar/O2 = 60/40 gas ratio. The electron traps, affecting the charge transport are distributed exponentially in the bandgap of as-grown amorphous LN films with the “smoothest” distribution, corresponding to the films deposited in an Ar (60%) + O2 (40%) gas mixture. Thermal annealing (TA) leads to the crystallization of as-grown films, decreasing the −Qox value greatly in heterostructures fabricated in an Ar + O2 environment, and declining the φ value. The φ value is insensitive to the crystallization of LN films deposited in a pure Ar environment. The recrystallization process occurring under TA turns the trap distribution into uniform one. The dielectric constant of polycrystalline LiNbO3 films, fabricated in both (Ar (80%) + O2 (20%) and Ar (60%) + O2 (40%)) gas mixtures and annealed at 550 °C, is higher than that for the films deposited in a pure Ar atmosphere.

中文翻译：

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反应气体成分对射频磁控溅射法生长的Si/LiNbO3异质结性能的影响

摘要 在纯Ar环境和不同氧含量的Ar+O2混合气体中，采用射频磁控溅射法在硅衬底上沉积了无定形铌酸锂(LiNbO3)薄膜。生长薄膜中存在的氧化物电荷有两个组成部分：分布在薄膜主体中的正 +Qox 和位于薄膜/衬底界面的负 -Qox，其最大值对应于 Ar (80%) + O2 (20%) 气体混合物。LiNbO3/Si 界面处的势垒高度 φ 与 Qox 相关。最低的 φ 值归因于在 Ar/O2 = 60/40 气体比下制造的 LiNbO3/Si 异质结构。影响电荷传输的电子陷阱在生长的非晶LN薄膜的带隙中呈指数分布，具有“最平滑”的分布，对应于在 Ar (60%) + O2 (40%) 气体混合物中沉积的薄膜。热退火 (TA) 导致生长薄膜的结晶，大大降低了在 Ar + O2 环境中制造的异质结构中的 -Qox 值，并降低了 φ 值。φ 值对在纯 Ar 环境中沉积的 LN 薄膜的结晶不敏感。在 TA 下发生的再结晶过程使陷阱分布变得均匀。在 (Ar (80%) + O2 (20%) 和 Ar (60%) + O2 (40%)) 气体混合物中制造并在 550 °C 下退火的多晶 LiNbO3 薄膜的介电常数高于在纯 Ar 气氛中沉积的薄膜。在 Ar + O2 环境中制造的异质结构中大大降低了 -Qox 值，并降低了 φ 值。φ 值对在纯 Ar 环境中沉积的 LN 薄膜的结晶不敏感。在 TA 下发生的再结晶过程使陷阱分布变得均匀。在 (Ar (80%) + O2 (20%) 和 Ar (60%) + O2 (40%)) 气体混合物中制造并在 550 °C 下退火的多晶 LiNbO3 薄膜的介电常数高于在纯 Ar 气氛中沉积的薄膜。在 Ar + O2 环境中制造的异质结构中大大降低了 -Qox 值，并降低了 φ 值。φ 值对在纯 Ar 环境中沉积的 LN 薄膜的结晶不敏感。在 TA 下发生的再结晶过程使陷阱分布变得均匀。在 (Ar (80%) + O2 (20%) 和 Ar (60%) + O2 (40%)) 气体混合物中制造并在 550 °C 下退火的多晶 LiNbO3 薄膜的介电常数高于在纯 Ar 气氛中沉积的薄膜。