Fabrication of a ZnO piezoelectric micro cantilever with a high-aspect-ratio nano tip

Abstract

This paper reports on a ZnO piezoelectric micro cantilever with a high-aspect-ratio (HAR) nano tip, which is proposed for a ferroelectric material based nano storage system. The system uses the interaction between the nano tip and a storage medium, and the HAR nano tip is needed to suppress undesirable effects caused by the small gap between the cantilever and the storage medium. The fabrication process for the cantilever with the HAR nano tip consists of three parts: the HAR nano tip formation, the cantilever fabrication, and the bonding/releasing process. The HAR nano tip is formed by the Si deep reactive ion etching for a long shaft and the anisotropic wet etching for a nano tip end. The cantilever is made up of 1 lm-thick LPCVD poly-Si layer and 0.2 lm-thick Si nitride layer, and has 0.5 lm-thick ZnO actuation layer. A final releasing process is followed by an anodic bonding process. The fabricated HAR nano tip has 6 lm side length, over 18 lm height, and less than 15 nm tip radius, which is built on the 85 lm-wide, 300 lm-long, and 1.2 lm-thick cantilever. The experimental results show a linear behavior with respect to input voltage of 1 to 5 V and the first resonance frequency at 17.9 kHz.

Nanosphericals and nanobundles of ZnO: Synthesis and characterization

“…This metal oxide has a variety of applications, including chemical sensors [2], catalysts [3], UV light-emitters [4], photovoltaics [5] cantilevers [6] and other optoelectronic devices [7]. In addition, ZnO is nontoxic, at least in the bulk form, relatively cheap and stable in air [8].…”

Fabrication and Characterization of Zinc Oxide-Based Electrospun Nanofibers for Mechanical Energy Harvesting

“…Piezoelectric material-based NGs may play an important role because they can scavenge mechanical energy and transform it into a more flexible form, such as electrical energy. To date, piezoelectric materials based on PZT (lead zirconate titanate) [1][2][3], BaTiO 3 [4,5], polyvinylidene difluoride (PVDF) [6,7], BNT (bismuth sodium titanate) [8], and zinc oxide (ZnO) [9][10][11][12][13][14][15][16][17][18][19][20] have been the most widely investigated ones for use in transducers, actuators, transformers, photonics, optoelectronics, and sensors. However, fiber-based piezoelectric NGs [21][22][23] have not been extensively developed for keyboards because they must be resistant to large mechanical loads.…”

Fabrication and characterization of 3-Dimensional MOS transistor tip integrated micro cantilever

“…In addition to the well-known isotropic dry etching method (Suh et al 2003;Vettiger et al 2000;Lutwyche et al 1999) and bulk etching/deposition method (Mamin et al 1994), special methods such as a rocket tip method (Rasmussen et al 2001), an INCISIVE tip method (Ried et al 1997) and a deep trench refilling method (Lee et al 2005) have been proposed and researched. The reason to require the tip is to place it properly on the desired small area, and to make the better sensitivity about the external signal.…”

“…In those cases, the properties of the etched surface are important since they can affect the fluidic phenomenon, but the low tip height makes difficult in detecting the deep trenches. Moreover, low tip height can affect the measurement of surface electric properties (Lee et al 2005;Hong et al 2001). The cantilever of the probe as well as the tip can be affected by the surface electric properties if the probe has low tip height like Fig.…”