For the work on integrated circuits as well as microwave and mm-wave components a dedicated clean room (ISO 7 / class 10.000; 30 m2) and a lab (not classified, streamed by filtered air; 50 m2) is available. The cleanroom is temperature and humidity controlled (±0.5°C and 40-60% humidity over 24 hours).
Located in this cleanroom we have a 300mm (12'') semi-automated wafer prober SUSS PA300IS equipped with a temperature chuck (-40°C to 160°C). The prober allows the generation of wafer maps. In this way a series of measurements in conjunction with a pass/fail analysis of multiple devices on a wafer are supported. For contacting integrated circuits or PCBs different types of probes are available covering a frequency range up to 110GHz. In general RF and DC Probes can be mounted at all four directions.
Our on-wafer measurement setup is equipped with a dual wavelength laser cutter. The 532 nm (green) wavelength is recommended for removing gold, copper, poly-silicon and aluminum. The 355 nm (ultraviolet) wavelength should be used to modify polyimide, Kapton, silicon-nitride and silicon-dioxide layers.
We have been using the system to analyze stability problems of integrated circuits like mm-wave power amplifiers. By cutting specific lines the stability of the circuits was evaluated and a stable operation established. Another recent activity was the tuning of a 5bit phase shifter at E-Band. The MMIC design had deliberately designed lines that could be tuned to obtain a 1 degree accuracy of the phase shifter.
Our Rohde & Schwarz ZVA 110 supports S-parameter measurements between 10 MHz and 110 GHz and is fully integrated into the wafer prober. Broadband diplexers with 1 mm connectors combine test signals up to 70 GHz provided directly from the ZVA with the signals generated by the frequency multipliers. In this way the full frequency range is accessible in a single continuous sweep. Several cal-kits (coaxial and waveguide) are available to calibrate the setup up to 110 GHz.
Using this VNA we are able to accomplish linear (single-tone) and nonlinear measurements (two-tone) measurements. The characterizing of nonlinear S-parameters (S-functions, load-line of amplifiers, etc.) is possible up to 24 GHz. Also differential devices and / or mixer can be measured.
Institute of Microwave and Photonic Engineering
Inffeldgasse 12/I 8010 Graz Tel.: +43 (0)316 873-3301 Fax: +43 (0)316 873-3302 E-Mail: ihfnoSpam@tugraz.at Web: www.ihf.tugraz.at