Dipole layers can be formed at epitaxial interfaces of perovskite oxides by intentionally inserting charged atomic layers. Perovskite oxides such as SrTiO₃ (STO) can provide dielectrics with very high dielectric constants, but their bandgaps are so small that the suppression of leakage current is one of the critical issues when they are applied for DRAM capacitors. However, their conduction band offset will be manipulated if we can control the dipole layer formation. In this study, we investigated the opportunities of band alignment manipulation using the interface dipole effect especially focusing on the number of charge-introducing atomic layers. STO/LaAlO₃ (LAO)/SrRuO₃(SRO) stacks were fabricated by pulsed laser deposition method, to demonstrate the modulation of the band alignment at STO/SRO interface as large as ±0.5 eV, when we change the number of inserted atomic layers of LAO.

通过有意插入带电原子层，可以在钙钛矿氧化物的外延界面处形成偶极层。钙钛矿氧化物如 SrTiO ₃ (STO) 可以提供具有非常高介电常数的电介质，但它们的带隙非常小，以至于当它们应用于 DRAM 电容器时，抑制漏电流是关键问题之一。然而，如果我们可以控制偶极层的形成，它们的导带偏移将被操纵。在这项研究中，我们研究了使用界面偶极子效应进行能带对准操作的机会，特别是关注引入电荷的原子层的数量。STO/LaAlO ₃ (LAO)/SrRuO ₃(SRO) 堆栈是通过脉冲激光沉积方法制造的，以证明当我们改变 LAO 插入原子层的数量时，STO/SRO 界面处的能带对准调制高达 ±0.5 eV。