Application on nano/micro electromechanical systems using plasma treatment technology

• Main Authors: Wang Shen Su, 蘇旺申
• Other Authors: Weileun Fang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/51533916128880325200

博士 === 國立清華大學 === 微機電工程研究所 === 95 === The traditional nano/micro systems devices were fabricated using standard semiconductor processes as well as micro fabrication processes. Thus the design and applications of the nano/micro devices are frequently limited to these processes. In this study, the integration of various plasma treatment technologies with the micro fabrication processes has successfully been established. The applications of the plasma treatments on various nano/micro devices are also demonstrated. This study is organized and presented as the following four parts: Firstly, the tuning of thin film properties by means of plasma surface modification was discussed. To demonstrate the feasibility of this approach, various plasma treatments, including O2, H2 and NH3 atmospheres, on silicon oxide and ploy silicon films were investigated. Other parameters including, treatment conditions and annealing process, were also used to tune the thin film characteristics (e.g. surface roughness, surface chemical bonding, hardness, Young’s modulus and residual stress). In the second part, the NH3 plasma was employed to modify the surface characteristic of thin film. Thus, the shape of suspended micromachined structures made of the treated film can be tuned. Moreover, the combination of various plasma treatment positions and areas could further control the deflection profile of three dimension of micro suspension structure, such as shape, curvature and buckling direction. To show the feasibility of this approach, the shape-control of bending cantilevers and buckling bridges (clamped-clamped beam) were demonstrated. In the third part, the lithography and deposition on a complicated three dimension substrate surface were demonstrated under the assistant of plasma treatment. The selective film deposition on three dimension surface and even underneath the suspended microstructures is realized using the contact displacement electroless plating. In applications, the Cu film was conformally plated and patterned on a Si substrate with 50µm~200µm deep cavities and 54.7�a~90�asidewalls. Moreover, the Cu electrode underneath suspended microbeams was also plated. Finally, this study has established a plasma-assisted particle assembly template to fabricate nano/micro patterns through self-assembly on hydrophilic regions. The plasma surface modification is employed to tune the contact angle of droplet, so as to further tune the shape and thickness of self-assembled particles. In applications, the micro/nano patterns formed by commercial polystyrene (PS) and colloidal silica slurry (Bayer-50CK) particles after O2 and H2 plasma treatments were successfully demonstrated.