Micromachined Probes for Measurement and Characterization of Terahertz Materials and Devices

The objective of this phase II STTR program is twofold: (1) to design, prototype, and commercialize differential on-wafer probes for characterizing devices in the 140220 GHz and 220320 GHz bands, and (2) to engineer the geometry and material of the micromachined probe tip to enable robust, consistent, and low-resistance electrical contact to devices with various contact pad metallizations, including gold and aluminum. Although the measurement capability described above currently does not exist above W-band (75110 GHz), it is widely recognized as a critical need for the future development of terahertz science and engineering. The primary technical aims of this phase II STTR program are: 1) to exploit the flexibility afforded by micromachining fabrication technology to design and fabricate robust probe architectures suitable for measuring broad classes of devices that have non-standard geometries ― with primary focus on two-terminal and differential-mode devices that are not readily amenable to coplanar waveguide media. The frequency bands for the differential probe development will be WR-5.1 (140220 GHz) and WR-3.4 (220320 GHz), corresponding to a region of the spectrum where there is intense current interest for engineering and scientific applications. 2) to apply lithographic processing and deposition techniques to realize engineered micromachined probe tips that retain their electrical and mechanical integrity over thousands of measurement cycles and consistently provide low-resistance (below 100 m) contacts to devices and test structures utilizing various metallizations, such as gold and aluminum. 3) to evaluate and assess the robustness, reliability, and ultimate performance of differential on- wafer micromachined probes utilizing engineered contact tips.