Electron transparent TEM lamella with unaltered microstructure and chemistry is the prerequisite for successful TEM explorations. Currently, TEM specimen preparation of quantum nanostructures, such as quantum dots (QDs), remains a challenge. In this work, we optimize the sample-preparation routine for achieving high-quality TEM specimens consisting of SrRuO₃ (SRO) QDs grown on SrTiO₃ (STO) substrates. We demonstrate that a combination of ion-beam-milling techniques can produce higher-quality specimens of quantum nanostructures compared to TEM specimens prepared by a combination of tripod polishing followed by Ar⁺ ion milling. In the proposed method, simultaneous imaging in a focused ion-beam device enables accurate positioning of the QD regions and assures the presence of dots in the thin lamella by cutting the sample inclined by 5° relative to the dots array. Furthermore, the preparation of TEM lamellae with several large electron-transparent regions that are separated by thicker walls effectively reduces the bending of the specimen and offers broad thin areas. The final use of a NanoMill efficiently removes the amorphous layer without introducing any additional damage.

具有透明的微观结构和化学性质的电子透明TEM薄片是成功进行TEM探索的前提。当前，诸如量子点（QDs）之类的量子纳米结构的TEM样品制备仍然是一个挑战。在这项工作中，我们优化了样品制备程序，以实现由在SrTiO ₃（STO）衬底上生长的SrRuO ₃（SRO）QD组成的高质量TEM样品。我们证明，与通过三脚架抛光再结合Ar ⁺制备的TEM标本相比，结合离子束铣削技术可以生产出更高质量的量子纳米结构标本离子铣削。在提出的方法中，聚焦离子束设备中的同时成像可以精确定位QD区域，并通过切割相对于点阵列倾斜5°的样品来确保薄薄片中存在点。此外，制备具有几个较大的电子透明区域（由较厚的壁隔开）的TEM薄片可有效减少样品的弯曲并提供较宽的薄区域。NanoMill的最终使用可有效去除非晶层，而不会造成任何其他损害。