W-SBD show exceptional reliability from 200 to 500K, however, its barrier analysis has never been performed thoroughly down 81K. This paper shows our study of Schottky barrier and Richardson coefficient was extracted for different temperature ranges. We observed fluctuation in function of the temperature. We analyse this phenomenon and compare it to literature for other barriers. Measurements of reverse characteristics up 1200V have been performed from 81 to 450K. It confirms that partial ionization influence on the drift doping impacts on the barrier height.