Harnessing the recently discovered ferroelectricity in scandium aluminum nitride (Sc_xAl_1−xN) for the realization of integrated electronic and electromechanical devices requires a low‐temperature growth process that enables versatile control over film thickness, stoichiometric composition, and stress. Herein, a reactive magnetron sputtering process that enables extreme scaling of film thickness and tuning of composition and residual stress is reported on. Highly crystalline Sc_xAl_1−xN films with thicknesses of over 25–250 nm with scandium concentrations of over 22–30 at% are sputtered using a segmented target created from scandium and aluminum tiles. The residual stress in the films is widely tuned from highly compressive to tensile using a pressure‐ and gas‐flow‐independent approach based on adjusting the electrical termination of the targets. The crystallinity, texture, and ferroelectric characteristics are measured for Sc_xAl_1−xN films with different thicknesses, compositions, and residual stresses. The results highlight the consistent crystallinity and ferroelectric properties despite extreme thickness miniaturization to sub‐50 nm, and the large dependence of the coercive field on the residual stress and Sc concentration.

中文翻译：

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分段靶溅射工艺用于亚50纳米铁电Scan-铝-氮化物膜的生长及其组成和应力调整

利用最近发现的氮化铝aluminum（Sc _x Al _{1- x} N）中的铁电来实现集成的电子和机电设备需要低温生长过程，该过程能够对膜厚，化学计量组成和应力进行全面控制。在本文中，报道了一种反应性磁控溅射工艺，该工艺能够实现极高的膜厚缩放以及成分和残余应力的调整。高度结晶的Sc _x Al _{1- x}使用由scan和铝砖创建的分段靶溅射厚度超过25–250 nm的scan膜，concentrations浓度超过22–30 at％。薄膜的残余应力可以通过调整靶材的电端接，采用独立于压力和气流的方法，从高压缩应力调整为拉伸应力。测量具有不同厚度，成分和残余应力的Sc _x Al _{1- x} N薄膜的结晶度，织构和铁电特性。结果表明，尽管厚度极小化至50 nm以下，但结晶度和铁电性能仍保持一致，并且矫顽场对残余应力和Sc浓度的依赖性很大。