Vertical transfer gate structures and methods
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsFeng-Chien Hsieh, Wei-Li Hu, Chien Nan Tu
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Abstract
A semiconductor structure is provided that includes: a plurality of pixel sections arranged in a substrate, each pixel section having a plurality of sides; and first pixel section of the plurality of pixel sections including: a photo detector; and a vertical transfer gate (VTG) structure disposed above the photo detector, the VTG structure having a laterally extending body portion and a plurality of wall sections connected to end regions of the body portion that vertically extend into the substrate and laterally extend adjacent to a side of the pixel section.
Claims20
A semiconductor structure, comprising:
- a plurality of pixel sections arranged in a substrate, each pixel section having a plurality of sides;
- and
- a first pixel section of the plurality of pixel sections comprising:
- a photo detector;
- and
- a vertical transfer gate (VTG) structure disposed above the photo detector, the VTG structure having a laterally extending body portion and a plurality of wall sections connected at different end regions of the body portion that vertically extend into the substrate wherein at least a first wall section of the plurality of wall sections laterally extends a first distance adjacent to a first side of the first pixel section and a second wall section of the plurality of wall sections laterally extends a second distance adjacent to a second side of the first pixel section, wherein the first distance is greater than half the length of the first side and the second distance is greater than half the length of the second side.
A semiconductor structure, comprising:
- a pixel region in a substrate;
- a photo detector in the pixel region;
- and
- a vertical transfer gate (VTG) structure disposed above the photo detector, the VTG structure having a laterally extending body portion and a plurality of wall sections connected to end regions of the body portion that vertically extend a predetermined depth into the substrate;
- wherein the predetermined depth is configured based on a wavelength band of captured light the photo detector is configured to detect.
A method, comprising:
- providing a substrate;
- forming a vertical trench in a pixel sensor area of the substrate, wherein the trench laterally extends along a plurality of sides that bounds the pixel sensor area;
- forming a gate oxide layer in the vertical trench;
- and
- forming a gate poly region for a vertical transfer gate transistor over the gate oxide layer, wherein the gate poly region has a plurality of wall sections connected at different end regions of a body portion that vertically extend into the substrate wherein at least a first wall section of the plurality of wall sections laterally extends a first distance adjacent to a first side that bounds the pixel sensor area and a second wall section of the plurality of wall sections laterally extends a second distance adjacent to a second side that bounds the pixel sensor area, wherein the first distance is greater than half the length of the first side and the second distance is greater than half the length of the second side.
Dependencies are inferred from the claim text.