Smart nano-machining and measurement system with semiconductive diamond AFM probe

我们开发了一种高性能的金刚石AFM探针系统，具有(1)纳米级超精密加工和(2)加工前后的原位形貌检测功能。器件实现微加工技术的发展利用新开发的选择性沉积技术和模具技术，开发了一种新型的CVD工艺，用于制造5 μm厚度的金刚石悬臂梁。实验证明，所制备的金刚石AFM材料具有AFM测量功能，具有较高的耐磨性能。在室温下溅射锆钛酸铅（PZT）薄膜，然后在氮气环境中以大于10℃/s的温度斜坡速率和大于500℃的温度快速退火。在金刚石薄膜衬底上制备的PZT薄膜具有钙钛矿结构，经极化处理后其压电常数约为65 pC/N。在SF_6等离子体中反应离子刻蚀PZT薄膜，在金刚石层上无损伤。为了计算金刚石AFM探针的位移和驱动力，提出了一种基于压电层悬臂梁自由振动的理论仿真方法。通过一系列的加工工艺，实现了一个金刚石原子力显微镜探针，其尺寸由计算结果确定。该探针的传感分辨率为0.2 nm，驱动力为80 μN。

We developed a high performance diamond AFM probe system with functions of (l) nano scale ultraprecision machining and (2) in situ topography inspection before and after machining.1. Development of microfabrication technology for device realizationA novel CVD process for fabrication of a diamond cantilever of 5 μm thickness was developed using a newly developed selective deposition technique together with a mold technique for fabrication of a pyramidal tip on the end of the cantilever. The fabricated diamond AFM prove was proved to have an AFM measurement function with high wear resistant properties. Lead zirconate titanate (PZT) thin film was sputtered at a room temperature, followed by rapid thermal annealing at a temperature ramp rate of more than 10℃/s and at temperatures of more than 500℃ in a nitrogen ambient. The PZT thin film fabricated on diamond thin film substrates had perovskite structure and its piezoelectric constant was about 65 pC/N after a poling treatment. The PZT thin film was successfully patterned by reactive ion etching in SF_6 plasma without any damage on a diamond layer.2. Development of diamond AFM probe with piezoelectric sensor and actuatorIn order to calculate displacement and actuation force, we developed a theoretical simulation method based on free vibration of a cantilever with a piezoelectric layer. A diamond AFM probe, whose dimensions were determined by calculated results, was realized under a sequence of fabrication processes. Properties of the probe were estimated to have a sensing resolution of 0.2 nm and an actuation force of 80 μN.