A new 4H-SiC hydrogen sensor with oxide ramp termination. (February 2016)

• Record Type: Journal Article
• Authors: Pascu, Razvan; Kusko, Mihaela; Craciunoiu, Florea; Pristavu, Gheorghe; Brezeanu, Gheorghe; Badila, Marian; Avramescu, Viorel
• Is Part Of: Materials science in semiconductor processing. Volume 42:Part 2(2016:Feb.)
• Page Start: 268
• Page End: 272
• Publication Date: 2016-02
• Subjects: Hydrogen sensor -- SiC-MOS capacitor -- Flat-band voltage -- Sensor response; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2015.08.019
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: A Pd/SiO2 /4H-SiC MOS capacitor with oxide ramp termination has been fabricated and its utilization for hydrogen (H2 ) sensing is reported. The grown oxide and oxide-semiconductor interface properties investigation by electrical measurements on test capacitors gave an electron tunneling barrier ( Φ b =2.62 eV) very close to the theoretical one ( Φ b =2.7 eV). This large electron tunneling barrier shows good oxide insulating properties. The density of interface states ( D it ) has a relatively low value for a 31 nm thick oxide, with no post-oxidation annealing. The gas sensing capabilities of the SiC-MOS capacitor were tested at elevated temperatures, for different H2 concentrations. The sensor response increased with temperature, the maximum sensitivity (80%) being reached at 450 K. The flat band voltage ( V FB ) is left shifted up to 1.51 V at 20 ppm H2 concentration, showing sensitivity at low gas concentrations. The response/recovery times of about 5 to 6 s, respectively, were measured at 10, 000 ppm hydrogen in nitrogen. These results recommend this capacitor structure for H2 detection.