[X-ray dosimetry using SAMOS type read-only memory].

Abstract

An X-ray dosimeter has been investigated with the use of a PROM of a SAMOS (stacked gate avalanche injection type MOS) structure. The SAMOS is employed as a memory IC. The SAMOS is different from a FAMOS (floating gate avalanche injection type MOS) in the presence of a control gate, with the use of this electrode, the analog amount of electrical charge accumulated in the floating gate can be measured. The X-ray dose can be determined by decreasing the amount of electron injected into floating gate by avalanche effect through X-ray irradiation. This dosimeter shows good linearity and flat energy response. The dosimeter has no effect on fading.