Damiano Crescini, Daniele Marioli, Andrea Taroni, Emilio Sardini, Marco Romani
NEW TEST STRUCTURE FOR INVESTIGATION OF THE PIEZORESISTIVE EFFECT IN HIGH TEMPERATURE
In different industrial applications, such as injection molding and/or hot rolling, it is necessary to measure pressure in critical environmental conditions where the temperature can reach values in the range of 350-380°C. In these cases, a fluid with low thermal conductivity is now typically used in order to transfer the pressure to the sensitive element, while preserving it from overheats. A preferred solution would be that of obtaining new sensing elements with an intrinsic capability of operation over an extended temperature range. Silicon piezoresistors are unsuitable for use in high-temperature applications due to the significant decrease of the piezoresistive effect in this material with rising temperature. On the other hand, piezoresistive films in SiC has been recently investigated as a material exhibiting a piezoresistive effect, which appears to be exploitable at high temperature. The purpose of this work is, therefore, to investigate the possibility of developing a testing structure to evaluate the longitudinal and transverse guage factors (GFL and GFT) in piezoresistive films in SiC, to evaluate the TCR and finally to define the temperature effect up to 400°C.