Study of integrated circuits in natural space environment

In this thesis we study one of the critical phenomena induced by the radiation of integrated circuits in the natural space environment: the so-called upset phenomenon. This phenomenon, caused by a heavy-ion strike on circuit sensitive areas, result in the modification of the information stored in a memory element. Upsets may then perturb the functioning of satellite-borne complex processors with serious consequences on the control of equipments operating in space. As commonly used processes or design hardening techniques cannot guarantee a total immunity against upsets, provisional methods are generally adopted to select the less sensitive circuits among components to be used in a space application. These methods consist in the simulation of the irradiated environment by means of particle accelerators, to get experimental figures about the upset sensitivity of the considered circuit, and the use of these measures to estimate the in orbit circuit vulnerability. To implement such experiments on different processor types, we have designed and developed a dedicated test system, the FUTE 16 tester. This tester has been used in several test experiments where irradiated environment was simulated by means of particle accelerators. The activity of the target circuit during the irradiation could have a great influence on the measured upset sensitivity. Generally used test sequences so-called ''register test'', consist on the initialization of accessible registers with known data, and the observation of their content after a given delay to detect errors due to upsets. The main goal of this thesis is to compare in orbit error rate estimations obtained with register tests, to those obtained with ''application like'' test sequences. Both kinds of test sequences have been used during heavy-ion test experiments performed on commercially available CISC and RISC processors. The results obtained clearly show that using ''register tests'' may lead to wrong decisions in the selections of parts intended for space applications. (author). 71 figs., 27 tabs., 132 refs., 7 appendix