THICK-FILM SOI TECHNOLOGY - CHARACTERISTICS OF DEVICES AND PERFORMANCE OF CIRCUITS FOR HIGH-ENERGY PHYSICS AT CRYOGENIC TEMPERATURES - EFFECTS OF IONIZING-RADIATION

We report here the characteristics of elementary devices and circuits when they are exposed at low temperature (approximate to 90 K) to ioni zing radiation. These devices and circuits are implemented in a radiat ion-hardened SOI monolithic technology. We have made irradiations both at high dose rates (approximate to 100 krads/h) and low dose rate (ap proximate to 0.02 krad/h), the low dose rate is of the order of magnit ude of the value which should be encountered in high-energy physics ca lorimeters during future experiments. A reduction of the dose rate, at identical total dose received, has a favourable effect on the thresho ld voltage shift of MOSFETs and, consequently, on the behaviour of cir cuits designed with these devices. For example, a preamplifer remained functional with no significant change in its characteristics (noise a nd rise time) after approximate to 100 krads irradiation during a long er than 6 months exposure al 90 K; (liquid-argon temperature). This is of key importance for the future development of silicon microelectron ics for Liquid-Argon Calorimetry.