Method and structure for minimizing white spots in CMOS image sensors

A method for forming a CMOS image sensor cell such that stress is minimized in regions surrounding the light sensitive (e.g., photodiode) portion of the cell, thereby reducing leakage current and minimizing white spots in CMOS image sensors. The field oxide surrounding the light sensitive region is formed with interior angles greater than 90° and/or is continuously curved. The reset gate is offset from the light sensitive regions of active pixel cells by a distance greater than 0.25 mum. A mask is used during n+ doping of the light sensitive region to shield an inner edge of the surrounding field oxide and extends 0.5 mum or more over the light sensitive region. A mask is provided over the interface between the field oxide and the light sensitive region during sidewall spacer formation. A metal structure contacting the light sensitive region is spaced 0.4 mum or greater from the surrounding field oxide. Metal lines passing between the light sensitive regions are provided with stress-relieving slits. Metal lines of a guard ring surrounding the pixel array are non-continuous to also provide stress relief.