60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes
Razvan Pascu,
Gheorghe Pristavu,
Gheorghe Brezeanu,
Florin Draghici,
Philippe Godignon,
Cosmin Romanitan,
Matei Serbanescu,
Adrian Tulbure
Affiliations
Razvan Pascu
National Institute for Research and Development in Microtechnologies—IMT Bucharest, 126A, Erou Iancu Nicolae Street, 077190 Bucharest, Romania
Gheorghe Pristavu
Faculty of Electronics, Telecommunications and Information Technology, University “Politehnica” of Bucharest, 060042 Bucharest, Romania
Gheorghe Brezeanu
Faculty of Electronics, Telecommunications and Information Technology, University “Politehnica” of Bucharest, 060042 Bucharest, Romania
Florin Draghici
Faculty of Electronics, Telecommunications and Information Technology, University “Politehnica” of Bucharest, 060042 Bucharest, Romania
Philippe Godignon
Centre Nacional de Microelectrònica, CNM-CSIC, 08193 Barcelona, Spain
Cosmin Romanitan
National Institute for Research and Development in Microtechnologies—IMT Bucharest, 126A, Erou Iancu Nicolae Street, 077190 Bucharest, Romania
Matei Serbanescu
Faculty of Electronics, Telecommunications and Information Technology, University “Politehnica” of Bucharest, 060042 Bucharest, Romania
Adrian Tulbure
Department of Informatics, Mathematics and Electronics, Faculty of Exact Sciences and Engineering, University “1 Decembrie 1918” of Alba Iulia, No. 5, Gabriel Bethlen Street, 510009 Alba Iulia, Romania
A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.
