Abstract

The purpose of this research is to examine the effect of iron catalyst thickness on the straightness of growth of carbon nanotube microelectromechanical systems (CNT-MEMS). One of the key benefits of CNT-MEMS is that they can potentially have very high aspect ratios. One of the challenges in attaining these high aspect ratios is maintaining device straightness; as these devices get taller, the edges tend to curve rather than grow straight vertically. Scanning electron mi- croscope images of samples grown using various iron catalyst thicknesses show that both straight growth and relatively good edge definition can be achieved using iron thicknesses between 7 and 8 nm. Below this thickness, individual CNT are well-aligned, but CNT forests are not necessarily straight. Above this thickness, the CNT forests are relatively straight, but individual CNT are not well-aligned and edge definition is very poor. Iron availability for CNT growth is also affected by a device's or feature's proximity to other regions of iron. By using an iron catalyst thickness ap- propriate for straight growth, and by adding borders of iron around features or devices, a designer can greatly improve straightness of growth for CNT-MEMS.

Degree

College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering

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