CAJ | 학술논문

目前商用原子力显微镜（ AFM）大多使用的微悬臂式探针，力灵敏度可达到pN级别。然而受到工艺水平及检测方法限制，微悬臂谐振频率难以超过3?5 MHz，且Q值较低，制约了AFM的成像速度以及在液体中的成像效果。另外，光杠杆的检测方法无法与探针本身进行片上集成，较小的悬臂也给激光束的聚焦带来困难。基于以上考虑，本文提出两种基于MEMS谐振器的探针，振频率可达11 MHz，Q值为4000，并集成了执行与传感功能以及批量加工纳米针尖的工艺。目前两种探针都已经实现对树脂图案的成像功能，力灵敏度最高可达5pN/√Hz。
목전상용원자력현미경（ AFM）대다사용적미현비식탐침，력령민도가체도pN급별。연이수도공예수평급검측방법한제，미현비해진빈솔난이초과3?5 MHz，차Q치교저，제약료AFM적성상속도이급재액체중적성상효과。령외，광강간적검측방법무법여탐침본신진행편상집성，교소적현비야급격광속적취초대래곤난。기우이상고필，본문제출량충기우MEMS해진기적탐침，진빈솔가체11 MHz，Q치위4000，병집성료집행여전감공능이급비량가공납미침첨적공예。목전량충탐침도이경실현대수지도안적성상공능，력령민도최고가체5pN/√Hz。
Most of the commercial Atomic Force Microscope ( AFM) oscillating probes are based on micro-scale cantilevers enabling measurement with pico-Newton force resolution in vacuum. However, the cantilever probes suffer from a degradation of both resonance frequency and quality factor when operating in liquids. Moreover, the laser-based vibration sensing unit also limits the integration and miniaturization as the cantilever width has to stay above 2 μm to control the diffraction effect. In such a context, two new concepts of MEMS-based atomic force microscope ( AFM) oscillating probes using ring-shaped resonator and I2 shaped resonator are presented. These probes are designed to feature MHz resonance frequencies and high quality factor of several thousands. Thanks to the integrated transduction methods including electrostatic driving/sensing, thermal driving and piezoresistive sensing, the optical detection unit is no longer needed. The probes are fabricated using standard silicon micromachining and the measured resonance frequency can reach up to 11 MHz with a quality factor of 1 500. Both probes are then mounted onto a commercial AFM set-up through a dedicated probe-holder and circuit board. Topographic images of patterned resist sample are obtained. The minimum force resolution deduced from the measurement is about 5pN/√Hz. The upcoming works consist of improving de detection scheme of the MEMS-based probes and realize high speed/quality AFM images in liquid.