CHANGE OF THE DYNAMIC PROPERTIES DUE TO IRRADIATION WITH 65 MeV PROTONS OF CMOS SMALL SCALE INTEGRATION LOGIC DEVICES USED FOR A QUANTUM YIELD MONITORING SYSTEM

For the realization of an in-situ quantum efficiency measurement system, a compact interface electronics has been developed, that converts very low current signals into a proportional frequency]. In this way important information regarding the degradation of solar cells due to high energy particle irradiation, which is for example relevant for space applications, could be obtained in a noisy environment with an excellent signal-to-noise ratio. The developed interface electronics had been placed very close to the proton beam and it has therefore to be checked, if it can tolerate this high energy particle irradiation. Besides linear circuitry also simple CMOS ICs as NOR gates and counters have been used for the control electronics of the interface electronics. Most studies regarding the radiation hardness of CMOS circuits report only on changes in the static characteristics. In the present work the impact of the irradiation on the dynamic properties of this CMOS devices has been investigated. In particular changes of the signal rise- and fall-times of the CMOS octal counter and the delay time of the CMOS NOR gates have been measured before and after irradiation with 65 MeV protons with fluence values up to 10e13 p+/cm^2.