Semiconductor testing at very low currents

Based in Warsaw, Poland, the Łukasiewicz - Institute of Microelectronics and Photonics conducts scientific research and development work in areas such as micro- and nanoelectronics, optoelectronics, materials engineering and power electronics. The institute works with the country’s entrepreneurs and seeks to help the Polish economy by implementing and distributing the results of these projects.

In a recent project, the Institute sought to develop a new generation of pioneering devices and materials based on wide-bandgap semiconductors such as GaN, SiC, Ga₂O₃ and others for power electronics, with particular applications in fast charging stations for electric cars.

PhD Eng. Andrzej Taube of the Łukasiewicz - Institute of Microelectronics and Photonics said: “We found the biggest challenge the project posed was meeting the stringent requirements for the functionality and flexibility of the system when measuring semiconductor devices, which were in the form of both on-wafer chips and in TO-220 and TO-247 packages. “The project also required a variety of measurement procedures with some current measurements in the femtoAmp range.”

In addition, dynamic characterisation of GaN power semiconductor devices presents specific challenges not encountered with other semiconductors. This involves a complex test setup to retrieve key figures such as dynamic RDS (on) or the capacitance value between the terminals. The customer also specified the need for automatic switching between high-voltage and high-current measurements without re-cabling which Tektronix equipment was able to provide.

The Łukasiewicz - IMiF chose devices from the 2600 Series of Source Meter Units (SMUs) to measure current-voltage characteristics in a wide range of voltages (up to 3kV) and current, extending from the femtoAmp range up to 50A. This series of SMUs are designed specifically to characterise and test high voltage/current electronics and power semiconductors, such as diodes, FETs, and IGBTs, high brightness LEDs and DC-DC converters.

Moreover, 2600 Series Source Measure Units, along with an ATV HV switch and Tektronix MDO3034 digital oscilloscopes, will be used to meet the need for dynamic RDS (on) measurements of GaN power transistors.

Tektronix not only supplied equipment to the Institute, but was also advised the researchers on effective measurement techniques. Dr inż. Taube said: “We received technical advice for measurements of very low current levels, below 10^-14 A with good resolution.”

PhD Eng. A.Taube added: “I can definitely recommend Tektronix and Keithley products due to the wide measurement ranges of various electrical quantities, a wide and unique range of measurement procedures offered and their ease of use and configuration. They also offer the flexibility to expand the system with new measurement possibilities in the future, as well as good price, quality and quick and trouble-free help and technical advice.”

Maria Heriz, Present EMEAI, Tektronix, commented: “At Tektronix, we are dedicated to supporting our customers throughout all their endeavors. We are delighted to have been able to provide the Lukasiewicz - Institute of Microelectronics and Photonics with not only high-quality equipment to match their requirements, but also high-level technical advice to benefit their project and ensure innovative work can continue.”

The purchase of the measurement system was financed under the project: 'Center for Nanoelectronics, Microsystems and Photonics' (contract number: RPMA.01.01.00-14-9873/17-00) co-financed by the European Regional Development Fund under: Priority Axis I.' The use of research and development activities in the economy' Measure 1.1 'Research and development activity of scientific units' of the Regional Operational Program for Mazowieckie Voivodeship 2014-2020.