Karsten Mayr

Microfabrication of new sensors for scanning probe microscopy

The paper presents a new concept of a micromachined integrated sensor for combined atomic force/near-field optical microscopy. The sensor consists of a microfabricated cantilever with an integrated waveguide and a transparent near-field aperture tip. The fabrication process involves a novel method for the micromachining of optical near-field tips with an aperture diameter of 100 to 200 nm. A simple concept is introduced for the effective light coupling from the cantilever into the tip.

Micromachined aperture probe tip for multifunctional scanning probe microscopy

The paper presents a new concept of a micromachined integrated sensor for combined atomic force/near field optical microscopy. The sensor consists of a microfabricated cantilever with an integrated waveguide and a transparent near field aperture tip. The advantage compared to the fiber based near field tips is the high reproducibility of the aperture and the control of the tip-sample distance by the AFM-channel. The aperture tip is fabricated in a reliable batch process which has the potential for implementation in micromachining processes of scanning probe microscopy sensors and therefore leads to new types of multifunctional probes. For evaluation purposes, the tip was attached to an optical fiber by a microassembly setup and subsequently installed in a near-field scanning optical microscope. First measurements of topographical and optical near-field patterns demonstrate the proper performance of the hybrid probe.

Micromachined aperture probe for combined atomic force and near-field scanning optical microscopy (AFM/NSOM)

A novel concept for the realization of a multifunctional scanning probe designed for simultaneous atomic force microscopy and near-field scanning optical microscopy measurements is described. It is based on micromachining and thin film technology and includes the fabrication of a cantilever, an integrated optical waveguide, an aperture probe tip, and the integration of all components into the complete sensor. Key processes are the fabrication of the probe providing a sharp tip together with a small optical aperture and the coupling of light from the integrated optical waveguide into the probe tip. The aperture probe consists of a transparent silicon nitride cone covered with aluminum except for the sharp cone tip thus forming a circular aperture around the protruding tip apex. In order to couple light from the waveguide into the tip a simple structure has been developed and optimized using numerical simulation procedures for the electromagnetic field distribution in the coupling structure. The complete sensor is fabricated in a reliable batch process and experimental evidence for the validity of the coupling concept is given.