OPTICAL GATED MOSFET MODELING B. K. Mishra G.Phade & J.Lochan S.C.Patil Thakur Engineering College. SNDT University SVKM’s NMIMS Mumbai University. Santacruz (West) Vile Parle (West) Mumbai, India Mumbai-400 049 Mumbai-400 056 drbk.mishra@thakureducation.org lochan.jolly@thakureducation.org sanjay.c.patil @gmail.com ABSTRACT In the recent decades, interest has been shown by the researcher towards the modeling of the optical effects on MOSFET with submicron channel length. It is mainly because device is expected to emerge as potential device to be integrated as MMIC, OEIC and ASIC for optical based system particularly optical communication. Present paper makes an attempt to investigate dependence of I-V characteristics and transconductance on optical illumination. Optical effects are mainly due to the lowering of surface potential barrier in presence of illumination called photon induced barrier lowering (PIBL).Investigation shows that drain current and the trans-conductance increases significantly in the presence of optical illumination. The device is expected to emerge for high speed application in optical system viz. photo- detector, optical switch, and imaging. Categories and subject Descriptors G.4 Matlab General Terms Algorithms, Performance, design and verification Keywords Optoelectronics, photo detector, photo voltage, n- MOSFET 1. INTRODUCTION Silicon–on-chip (SOI) MOFET is very attractive candidate for higher performance of integrated circuit for digital as well as mixed signal circuit. It is mainly because of some of the interesting features, such as reduction of junction capacitance, increase of packing density (compared to bulk devices), suppression of latch up, reduction of short channel effect and radiation hardness [1] and the maturity of the silicon technology. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made for distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise , or republish , to post on servers or to redistribute to lists, requires prior specific permission and /or a fee. ICWET’10,Februrary 26-27,2010,Mumbai,India. Copyright 2010 ACM 978-1-60558-812-4…$5.00. Recent investigation has shown the photosensitivity of metal- insulator- semiconductor (MIS) structure. Therefore, the possibility has opened up of its use as infrared photo detector, optically variable reactors and optical CCD’s for solid state imaging. The basic device can be modified to optically gated MISFET (OG-MISFET). One of the key device structure is Si-SiO2, the device is called OG-MOSFET .The device exhibits the strong dependence of the device I-V characteristics and its various parameters on optical illumination. Present paper deals with the rigorous modeling of the same under dark as well as illuminated condition. Content organization in the paper is as given below. Section-2 presents the relevant theory related to the simulation optically gated n-MOSFET, section-3 covers the results and discussions arises out of the simulation, section-4 deals with the major conclusion drawn fro the investigation and finally the references. Device is expected to emerge as the potential device for the above mentioned application with better control particularly for mixed signal application at higher frequencies. It can be integrated as optically controlled MMIC., OEICs, ASIC design etc. 2. THEORY The schematic structure of an illuminated n-MOSFET is shown in Figure1. Optical radiation is made to fall in the gate region and is perpendicular to the surface. Channel is uniformly doped. Gate current is assumed to be zero. Metallic gate is assumed to be opque. Optical radiation is assumed to be incident in the non-metallic gate region which will be absorbed in the depletion region. Figure1 Schematic of MOSFET under illumination Illumination intensity is assumed uniform along the direction parallel to the surface. The excess carriers generated also vary along X direction and uniform in Y