Tower Semiconductor Ltd.

Yossi Netzer

Ira Naot

Robert J Strain

Sharon Levin

Shye Shapira

Yakov Roizin

Ephie Koltin

Israel Rotstein

Myriam Buchbinder

Avi Ben-Guigui

A pre-metal dielectric structure of a single-poly EEPROM structure includes a UV light-absorbing film, which prevents the charge on a floating gate of the EEPROM structure from being changed in response to UV radiation. In one embodiment, the pre-metal dielectric structure includes a first pre-metal dielectric layer, an amorphous silicon layer located over the first pre-metal dielectric layer, and a second pre-metal dielectric layer located over the amorphous silicon layer.

Ultra-violet protected tamper resistant embedded EEPROM

A Schottky diode exhibiting low series resistance is efficiently fabricated using a substantially standard CMOS process flow by forming the Schottky diode using substantially the same structures and processes that are used to form a field effect transistor (FET) of a CMOS IC device. Polycrystalline silicon, which is used to form the gate structure of the FET, is utilized to form an isolation structure between the Schottky barrier and backside structure of the Schottky diode. Silicide (e.g., cobalt silicide (CoSi)) structures, which are utilized to form source and drain metal-to-silicon contacts in the FET, are used to form the Schottky barrier and backside Ohmic contact of the Schottky diode. Heavily doped drain (HDD) diffusions and lightly doped drain (LDD) diffusions, which are used to form source and drain diffusions of the FET, are utilized to form a suitable contact diffusion under the backside contact silicide.

Gate defined Schottky diode

A Schottky diode is formed on an isolated well (e.g., a P-well formed in a buried N-well), and utilizes cobalt silicide (CoSi) structures respectively formed on heavily doped and lightly doped regions of the isolated well to provide the Schottky barrier and backside (ohmic) contact structures of the Schottky diode. The surrounding buried N-well is coupled to a bias voltage. The Schottky barrier and backside contact structures are separated by isolation structures formed using polycrystalline silicon, which is used to form the gate structure of CMOS FETs, in order to minimize forward resistance. Heavily doped drain (HDD) diffusions and lightly doped drain (LDD) diffusions, which are used to form source and drain diffusions of the FET, are utilized to form a suitable contact diffusion under the backside contact silicide.

Cobalt silicide schottky diode on isolated well

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&deg; 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 &mgr;m. A mask is used during n&plus; doping of the light sensitive region to shield an inner edge of the surrounding field oxide and extends 0.5 &mgr;m 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 &mgr;m 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.

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Hadera, Israel

Yossi Netzer