Electrical measurements are essential for characterizing the materials, devices, and circuits developed at NaMLab. Alongside our in-house cleanroom, electrical characterization is one of our core competences. Four well-equipped labs cover a broad spectrum of measurement techniques and analysis methods. These include capacitance measurements such as C(V), C(T), and C(f), and current measurements with femtoampere resolution at temperatures between 5 K and 450 K and voltages up to 3000 V. Transistors can be characterized at radio frequencies up to 25 GHz to extract small-signal parameters for modeling purposes. Pulsed measurements combine source and pulse measurement units with dedicated digital control electronics, allowing memory and logic devices to be operated as they would in real circuits. Samples ranging from a few mm² up to 300 mm wafers are measured on semi- and fully automatic probe stations using single probes, probe cards, or RF probes. Package-level testing under controlled temperature and atmosphere enables long-term reliability characterization and the integration of our devices into test circuits.
Contact
Dr. Stefan Slesazeck
Senior Scientist
E-Mail: info[at]namlab.com
Wafer Contacting
For electrical connections between wafers and measurement instruments, we are equipped with a range of wafer probers, including manual, semi-automatic, and fully automatic systems. This allows us to contact wafers of various sizes, ranging from approximately 1 cm² up to full 300 mm wafers. We use single DC and coaxial probes, as well as 4.5-inch probe cards. These typically feature 25 probes in a single line, with pitches of 72, 80, or 100 µm. In addition, we also have a TPT wire-bonder wafer bonder at our disposal to contact sample for measurements in package.
Instruments
Our equipment portfolio includes a wide range of instruments for electrical characterization. These include multiple Keithley 4200A-SCS systems, an Agilent/Keysight B1505A analyzer, aixACCT TF3000 thin film analyzers, and various switch matrices for both low-leakage and high-speed applications. Furthermore, our equipment includes oscilloscopes, waveform generators, vector network analyzers, a load-pull system, lock-in amplifiers, and many more instruments to support a broad range of electrical characterization requirements.
Established Measurement Methods
- DC measurements with voltages up to 3 kV and currents down to the sub-femtoampere range.
- Transient measurements up to 1.5 GHz frequency bandwidth.
- IV pulse measurements with pulse widths as short as 10 ns.
- CV measurements and impedance spectroscopy with frequency range from 1 mHz to 10 MHz.
- RF measurements up to 24 GHz.
- Temperature ranges from 5 K to 450 K.
- Lock-In-Amplifier methods. Such as mobility extraction of transport in Hall-bars.
Although not all of these specifications can be combined in a single measurement setup, we are flexible and can develop customized measurement solutions for a wide range of applications. From simple test measurements to complex, fully automated measurement routines. From individual devices, such as capacitors, memristors, FTJs, and transistors to large-scale memory arrays.
Front End Reliability
Beyond their initial performance, new devices must also prove that they operate reliably over their entire lifetime. NaMLab therefore investigates the front-end-of-line reliability of transistors and gate dielectrics using established stress methods such as bias temperature instability (BTI), hot-carrier injection (HCI), and time-dependent dielectric breakdown (TDDB). For memory devices, endurance and retention measurements indicate how many switching cycles a device can withstand and how long it retains its stored information. In addition, NaMLab develops new methods that go beyond conventional DC stress tests, including RF-based degradation analysis and assessment of how device degradation affects circuit behavior. The results feed into reliability models that predict device lifetime and help optimize materials, processes, and operating conditions at an early stage of development.
