Dynamic testing for radiation induced failures in a standard CMOS submicron technology pixel front-end

A testing method for the detection of performance degradation induced by high-dose irradiation in high-energy experiments has been developed. The method used is based on a fault signature generation defined on the basis of the state-space analysis for linear circuits. By sampling the response of the circuit under test (CUT) to a single rectangular pulse, a set of parameters α are evaluated which are functions of the circuit singularities and constitute a signature for the CUT. Amplitude perturbations of these parameters engendered by element drift failure indicate a possible faulty condition. The effects of radiation induced faults in the analogue CMOS front-end of a silicon pixel detector employed in high energy physics experiments has been investigated. The results show that, even for the 800 krad dose, the test devised is able to detect the degradation of the amplifier performances. The results show also that hardened devices do not necessarily produce high circuit immunity to radiation and the proposed test method provides a mean to detect these performance deviations and to monitor them during the operating life of the chip. (A.C.)