CMOS IMAGER HAVING A NITRIDE DIELECTRIC
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Accused Products
Abstract
An imaging device formed as a CMOS semiconductor integrated circuit includes a nitrogen containing insulating material beneath a photogate. The nitrogen containing insulating material, preferably be one of a silicon nitride layer, an ONO layer, a nitrode/oxide layer and an oxide/nitrode layer. The nitrogen containing insulating layer provides an increased capacitance in the photogate region, higher breakdown voltage, a wider dynamic range and an improved signal to noise ratio. The invention also provides a method for fabricating a CMOS imager containing the nitrogen containing insulating layer.
16 Citations
114 Claims
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1-70. -70. (canceled)
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71. A method for fabricating a sensor cell of a CMOS imager, comprising the steps of:
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forming a doped photo-collection region in a semiconductor substrate; forming a first insulating layer over said substrate; forming a first conductive layer over said first insulating layer; removing at least a portion of said first conductive layer to form at least one transistor gate over said substrate; forming a nitrogen containing second insulating layer distinct from said first insulating layer and in contact with said semiconductor substrate, such that none of said nitrogen containing second insulating layer is located beneath said transistor gate; forming a second conductive layer atop said nitrogen containing second insulating layer; and removing any portion of the nitrogen containing second insulating layer not located beneath the second conductive layer. - View Dependent Claims (72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89)
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90. A method for fabricating a sensor cell of a CMOS imager, comprising the steps of:
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forming a doped photo-collection region in a semiconductor substrate; forming a first insulating layer over said substrate; forming a first conductive layer over said first insulating layer; removing at least a portion of said first conductive layer adjacent said doped photo-collection region; forming a nitrogen containing second insulating layer distinct from said first insulating layer and in contact with said semiconductor substrate; forming a second conductive layer atop said nitrogen containing second insulating layer; and removing any portion of the nitrogen containing second insulating layer not located beneath the second conductive layer. - View Dependent Claims (91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102)
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103. A method for fabricating a sensor cell of a CMOS imager, comprising the steps of:
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forming a doped photo-collection region in a semiconductor substrate; forming a nitrogen containing insulating layer over said doped photo-collection region and in contact with said semiconductor substrate; forming a photogate atop said nitrogen containing insulating layer, and removing any portion of the nitrogen containing second insulating layer not located beneath the photogate. - View Dependent Claims (104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114)
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Specification