Micro-fabrication of a prototype hybrid GaAs/ceramics cantilever for SPM applications

As a first step to realize new type cantilevers to be used in the scanning probe microscopies (SPMs) more suitable to optical and magnetic nano-scale analyses, we have fabricated a prototype hybrid GaAs/ceramics cantilever composed of a tip, a beam, and a small seat made of GaAs, and a large seat made of ceramics. We have established the fabrication process for this hybrid GaAs/ceramics cantilever and succeeded in obtaining preliminary atomic force microscopy (AFM) and magnetic force microscopy (MFM) images. The GaAs components were made by wet etching with phosphoric acid for the tip and sulfuric acid for the beam and small seat, while the large ceramic pedestal was made with small-scale machine fabrication technologies. The tips, with ∼6 μm height, 30 nm top curvature, and a high aspect ratio, were fabricated reproducibly. Beam length and thickness of the fabricated cantilevers were within 168–479 and 7.5–20 μm, respectively. The measured resonance frequencies of 30–365 kHz agreed well with the calculation. Since GaAs has a smaller Young's modulus than Si and a variety of unique optic and magnetic properties which cannot be realized in Si, the fabrication technologies developed here could contribute to the production of a low-cost GaAs cantilever possibly used in new type scanning estimation measurements.