Duality MOS – PN Junction in the AL/Silicon Rich Oxide/Si Structure as a radiation Sensors

DUALITY MOS – PN JUNCTION IN THE Al/SILICON RICH OXIDE/Si STRUCTURE AS A RADIATION SENSORS

M. Aceves, J. Carrillo, J. Carranza, W. Calleja, C. Falcony¹

INAOE, Apdo, 51 Pue. Pue. 72000 México.

^{1CIEA-IPN (Física), A. P. 14-740, 07000, México D.F.

The Al/SRO/Si devices behaves similar to a MOS capacitor, but as the voltage increases, the depletion region associated to the surface inversion starts to increase similar to a P - N junction reverse biased. This duality of MOS capacitor and P – N junction can be used as radiation sensor. This will be a very simple, well controlled, reproducible, and MOS compatible radiation sensor. In this work, the induced P – N junction of an Al/SRO/Si structure was used as a visible light detector, and the initial results are presented. A silicon substrate of 10¹² cm^-3 bulk concentration and a LPCVD SRO film with Ro=30 and thickness of 100 nm were used. The current increases, at least, two orders of magnitude when the structure is illuminated with light of 543 Å @ 0 to 100 V.}