Taiwan Semiconductor Manufacturing Comp. Ltd.

Hsien-Tsong Liu

Yeh-Jye Wann

Shang-Hsuan Liu

Hung-Jen Tsai

Kuang-Peng Lin

Kuen-Hsien Lin

Chih-Hsing Chen

Hung Jen Tsai

A method and system for preventing white pixel difficulties resulting from undesired current induced in an image sensor having a photodiode and a depletion region therein. The photodiode is isolated in a pixel layout for an image sensor. A depletion region is configured, such that the depletion region is maintained in a defect-free region associated with the pixel layout for the image sensor, thereby reducing white pixel difficulties caused by induced and undesired current. The image sensor is preferably a CMOS image sensor. A depletion region of the photodiode is constantly maintained in a defect-free region during operation of the CMOS image sensor.

Method to prevent white pixels in a CMOS image sensor

A method and an apparatus for preparing a backside-ground wafer for testing are described. The method includes the steps of first providing a calibration wafer that has a pattern formed on a top surface of an insulating material such as oxide or nitride. Three droplets of water are applied with each droplet sufficiently apart from the other droplets on the top surface of the calibration wafer. A backside-ground wafer that has a ground backside and a front side to be tested is then mated to the calibration wafer by mating the ground backside to the top surface of the calibration wafer with water droplets therein-between forming a bond by capillary reaction in-between the oxide pattern on the calibration wafer. The apparatus for mounting a backside-ground wafer to a calibration wafer consists of a slanted block having a top surface with a slant angle between about 10&deg; and about 30&deg;.

Apparatus and method for preparing backside-ground wafers for testing

A substrate is covered with a gate oxide layer between FOX regions with a blanket lower lamina for a gate on the surface. A Mask code mask has a window overlying the desired gate location. A doped code implant region is formed in the substrate by ion implanting code implant dopant through the mask. Following mask removal a blanket upper lamina of the gate covers the lower lamina. A gate mask covers the upper and lower laminae. The gate mask is patterned to protect the gate region over the device, leaving the remainder of the upper and lower lamina exposed. Exposed surfaces of the laminae are etched away leaving a laminated gate. Lightly doped regions are formed in the substrate between the FOX regions and the gate by ion implanting dopant through portions of the gate oxide layer unprotected by the gate; forming spacers next to the gate; and forming source and drain regions in the substrate between the FOX regions and the spacers adjacent to the gate.

Laminated gate mask ROM device

Method of making mask ROM with two layer gate electrode

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Hsinchu, Taiwan

Hsien-Tsong Liu