Controlling the amount of material deposited by pulsed laser deposition (PLD) down to fractions of one atomic layer is crucial for nanoscale technologies based on thin-film heterostructures. Albeit unsurpassed for measuring growth rates with high accuracy, the quartz crystal microbalance (QCM) suffers from some limitations when applied to PLD. The strong directionality of the PLD plasma plume and its pronounced dependence on deposition parameters (e.g., background pressure and fluence) require that the QCM is placed at the same position as the substrate during growth. However, QCM sensors are commonly fixed off to one side of the substrate. This also entails fast degradation of the crystal, as it is constantly exposed to the ablated material. The design for a movable QCM holder discussed in this work overcomes these issues. The holder is compatible with standard transfer arms, enabling easy insertion and transfer between a PLD chamber and other adjoining vacuum chambers. The QCM can be placed at the same position as the substrate during PLD growth. Its resonance frequency is measured in vacuum at any location where it can be in contact with an electrical feedthrough, before and after deposition. We tested the design for the deposition of hematite (Fe2O3), comparing the rates derived from the QCM and from reflection high-energy electron diffraction oscillations during homoepitaxial growth.

中文翻译：

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用于石英晶体微量天平的可移动支架，可在脉冲激光沉积中获得精确的生长速率

将脉冲激光沉积 (PLD) 沉积的材料量控制在一个原子层的一小部分，对于基于薄膜异质结构的纳米级技术至关重要。尽管石英晶体微量天平 (QCM) 在高精度测量生长速率方面无与伦比，但在应用于 PLD 时会受到一些限制。PLD 等离子体羽流的强方向性及其对沉积参数（例如背景压力和注量）的显着依赖性要求 QCM 在生长过程中与基板放置在相同的位置。然而，QCM 传感器通常固定在基板的一侧。这也导致晶体的快速降解，因为它不断地暴露在烧蚀的材料中。本工作中讨论的可移动 QCM 支架的设计克服了这些问题。该支架与标准转移臂兼容，可以轻松插入和转移 PLD 室和其他相邻的真空室。在 PLD 生长过程中，QCM 可以放置在与衬底相同的位置。其谐振频率是在真空中在沉积之前和之后可以与电馈通接触的任何位置测量的。我们测试了赤铁矿 (Fe2O3) 沉积的设计，比较了 QCM 和同质外延生长过程中反射高能电子衍射振荡的速率。其谐振频率是在真空中在沉积之前和之后可以与电馈通接触的任何位置测量的。我们测试了赤铁矿 (Fe2O3) 沉积的设计，比较了 QCM 和同质外延生长过程中反射高能电子衍射振荡的速率。其谐振频率是在真空中在沉积之前和之后可以与电馈通接触的任何位置测量的。我们测试了赤铁矿 (Fe2O3) 沉积的设计，比较了 QCM 和同质外延生长过程中反射高能电子衍射振荡的速率。