Bachelor Thesis · WS 2025/26 – SS 2026 · TU Graz
RTN / TDDS Measurement Setup
Single-transistor defect characterisation under X-ray Total Ionising Dose
For my bachelor thesis, I built a system to control the instruments and record measurements from a single transistor over several days. The bench tools available could not provide the bandwidth, resolution and uninterrupted recording the experiment needed together.
The device under test is a single 40/120 nm MOSFET on a SIRENS chip. I measure its source current through a Femto DLPCA transimpedance amplifier (106 V/A, 105 Hz bandwidth) mounted right on the DUT breakout path. Two RTO2044 oscilloscopes run in a ping-pong configuration — one captures while the other uploads — so there is no acquisition dead time across runs of up to two days.
The same setup runs X-ray Total Ionising Dose experiments at 40 kV / 37 mA, aiming for up to 100 MRad in 42 hours, plus in-situ annealing up to 150 °C through a resistive heating cartridge I control over an ESP8266 thermocouple interface.
1100 pA
Noise floor @ 100 kHz
100 pA
Noise floor @ 10 Hz
2 days
Max run duration
150 °C
Max anneal temp
Software stack
I wrote nine Python microservices to control the instruments over VISA/HiSLIP/LXI/RS232, with HMAC-SHA256 authentication on each call. I use a React/Vite dashboard to operate the setup and a Dash/Flask viewer to inspect the waveforms. The viewer uses Zarr pyramid caching to keep load times under 5 ms at any zoom level, including captures with millions of samples.
scope_serviceRTO2044 oscilloscope pair — HiSLIPbias_serviceKeysight B2962A SMU — LAN/LXIadc_serviceADC6242 SMU — USBsupervisor_servicePID closed-loop controlannealing_serviceESP8266 heater — up to 150 °Cxray_serviceGE ISO-DEBYEFLEX X-ray tube — RS232Cpingpong_serviceDual-scope zero-dead-time coordinatoranalysis_serviceOn-the-spot waveform analysisexport_serviceCSV / MAT export pipelineSupervisor: Alicja Michalowska-Forsyth
Contributions: Semih Ramazanoglu, Tommaso Vincenzi
Institute: Institute of Electronics (IFE), TU Graz
Published & presented
This work became two conference contributions in 2026: the radiation results for RADECS, which I attended in Prague, and the data-analysis tool for MESS.
Total Ionizing Dose Influence on Trapping Activities in Nanoscale CMOS
Y. Chubenko, S. Ramazanoglu, A. Michałowska-Forsyth
We measured a single 40 nm transistor continuously during X-ray irradiation. The recordings show individual charge-trapping events and a rise in low-frequency noise that before-and-after measurements miss.
Participated in RADECS 2026 · Prague
Web-based Interactive Tool for Real-Time Analysis of Multi-day Nanoscale CMOS Defect Spectroscopy: Handling Terabyte-Scale Measurement Data
Y. Chubenko, S. Ramazanoglu, A. Michałowska-Forsyth
I built a browser-based viewer for five-day experiments producing terabytes of data. It can show the whole run or zoom in to a single trapping step of about 25 nA without pre-filtering or loading the full dataset into memory.
Microelectronic Systems Symposium (OVE) · Vienna