Characterizing sensitive CMOS radiation detector

Semiconductor sensors cover a wide range of the electromagnetic spectrum for detecting nuclear-particle radiation. The most important properties of these detectors are their sensitivity i.e. their ability to low level radiation, charge transport, efficiency (electron-hole pair creation), and their response time. This article addresses the sensitivity of these devices. The following methods can increase the sensitivity of any electronic sensors: 1. Proper selection of the material with respect to the desired radiation detection, i.e matching the energy gap of the device, E/sub g/, to the energy of incoming radiation. 2. Application of proper process technology, such as CMOS, BiCMOS, etc. 3. Fabrication technology i.e. using proper doping, substrate, etc. 4. Finally the design of the external circuitry. This paper reports the investigation of the circuitry of a newly developed CMOS a particle radiation detector and characterization of its sensitivity. We also discuss the the effect of external power supply connection on the sensitivity, the derivation of the analytical expression for the sensitivity and we compare the theoretical prediction with the experimental values. In addition, the effect of radiation on the threshold voltage is discussed as well as an increase in sensitivity due to radiation. Finally, a method is suggested to obtain an optimum performance.