60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of V<sub>F</sub> with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The...

Full description

Bibliographic Details
Main Authors: Razvan Pascu, Gheorghe Pristavu, Gheorghe Brezeanu, Florin Draghici, Philippe Godignon, Cosmin Romanitan, Matei Serbanescu, Adrian Tulbure
Format: Article
Language:English
Published: MDPI AG 2021-01-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/21/3/942
Description
Summary:A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of V<sub>F</sub> 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 Ni<sub>2</sub>Si 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 (<i>p-diode</i>) 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 (R<sup>2</sup> 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.
ISSN:1424-8220