This Small Business Innovation Research Phase I project will demonstrate the feasibility of manufacturing electrically shielded, conductive carbon nanotube (CNT) probes for use in scanning probe microscopes (SPMs). The Phase I work will demonstrate fabrication of electrically conductive scanning probe CNT tips with enhanced electrical characteristics, electrical shielding of scanning probe CNT tips, and performance of electrically conductive and shielded scanning probe CNT tips for key electrical probing applications. Success with the proposed research will enable production of CNT-based electrical probes that overcome long-standing problems with commercially available tips, which are not adequate for advanced electrical profiling applications. Since resolution and contrast of topographic and electrical properties are both dictated by tip geometry and composition, new higher resolution probe tips must be developed. Specifically, metal-coated silicon tips utilized for atomic force microscope (AFM)-based electrical measurements rapidly wear out during operation and their quality and performance cannot be assessed during the measurement. Additionally, commercially conductive AFM tips generally have larger tip diameters, which limit the resolution of the measurement to hundreds of nanometers. The targeted spatial resolution for these conductive CNT probes is in the 1-10 nanometer range required for advanced applications.
The broader impact/commercial potential of this project will be realized in the form of new commercial products already in demand for industrial and scientific applications, including applications in the semiconductor industry. Conductive shielded CNT probes enabled by the project will meet an urgent need within the semiconductor industry for ultra-high resolution electrical measurements. SEMATECH has underscored this need by supporting research and development of this technology, in anticipation of use by their member companies. Electrically shielded CNT probes will be an enabling technology for making electrical measurements needed in nanoscience and nanotechnology. Example research areas where these devices will find application include materials science (e.g. for electrochemical probing to measure energy storage and conversion at solid-liquid interfaces or for electromechanical energy conversion research for supercapacitor development), biology, medical research, and forensics. Electrically shielded CNT probes will also enable bioelectromechanical measurements at the molecular level (e.g. electromechanical imaging in a liquid environment for biological applications including protein unfolding spectroscopy and electromechanical cell imaging), providing a capability which is not provided by any other commercial SPM probe.