It is known that light sensitivity in ion sensitive field effect transistors (ISFETs) during illumination is due to carrier generation in the silicon substrate. In order to improve this drawback, multi-structure ISFETs: tin oxide/Al/insulator/Si ISFET devices are investigated in this study. In this structure, aluminum is used as a light shield, and the tin oxide is used as a pH sensitive layer. We have developed SnO 2 /Si 3 N 4 /SiO 2 /Si ISFETs and SnO 2 /Al/Si 3 N 4 /SiO 2 /Si ISFETs, respectively. The pH sensitivity of these devices was measured and the data shows that the SnO 2 /Al/Si 3 N 4 /SiO 2 /Si ISFET sensors have a linear pH response of about 56-58 mV/pH in a concentration range between pH2 and pH10 under room light conditions. Subsequently, the light sensitivity of the ISFETs with/without aluminum as a light shield were investigated under 2000 lx white light exposure. The data show that ISFETs with aluminum as a light shield have low light sensitivity compared with ISFETs without aluminum as a light shield.