Method of fabricating a complementary metal oxide semiconductor (cmos) image sensor
AssigneeCrosstek Capital, LLC
InventorsWon-Joon Ho, Kyung-Lak Lee
Life of this patent
Estimating the term…
Abstract
There are provided a CMOS image sensor and a method for fabrication thereof. The CMOS image sensor having a reset transistor, a select transistor, a drive transistor and a photodiode, includes an active region in shape of a line, a gate electrode of the drive transistor, which is intersected with the active region, a blocking layer interposed between the active region and the gate electrode in which the blocking layer is formed on an intersection region of the active region and the gate electrode, and a metal contact electrically connected to the gate electrode, wherein the metal contact is not electrically connected to the active region by the blocking layer.
Claims15
A method of fabricating a complementary metal oxide semiconductor (CMOS) image sensor including a reset transistor, a select transistor, a drive transistor and a photodiode, the method comprising:
- forming a field oxide layer in a shape of a trench to define an active region;
- forming a blocking layer on the active region;
- forming a trench with a predetermined depth by removing a portion of the field oxide layer adjacent to the active region;
- forming a gate oxide layer on sidewalls of the active region exposed by the trench;
- forming a gate electrode over the trench and the blocking layer;
- and
- forming a metal contact electrically connected to the gate electrode, wherein the metal contact is not electrically connected to the active region under the blocking layer.
A method of forming a complementary metal-oxide semiconductor (CMOS) image sensor, comprising:
- forming an active region of a drive transistor in the shape of a line;
- covering a vertical portion of a side of the active region with a single gate insulation layer;
- intersecting the active region with a gate electrode of the drive transistor;
- interposing a blocking layer between the active region and the gate electrode, wherein the blocking layer includes a stacked layer of oxide and nitride formed on a horizontal portion above the active region, wherein the single gate insulation layer is separate and distinct from the oxide in the blocking layer, wherein the single gate insulation layer covers a side of the oxide of the blocking layer, and wherein the single gate insulation layer covers only a portion of a side of the nitride of the blocking layer;
- and
- electrically connecting a metal contact to the gate electrode, wherein the metal contact is formed above an intersection region of the active region and the gate electrode.
A method of forming a complementary metal-oxide semiconductor (CMOS) image sensor, comprising:
- defining an active region with a field oxide layer including first trenches formed in a substrate;
- removing a portion of the field oxide layer adjacent to the active region to form second trenches with a predetermined depth;
- covering a vertical portion of a side of the active region exposed by the second trenches with a single gate oxide insulation layer;
- and
- forming a blocking layer on a horizontal portion above the active region, wherein the blocking layer includes a stacked layer of oxide and nitride, wherein the single gate oxide insulation layer is separate and distinct from the oxide in the blocking layer, wherein the single gate oxide insulation layer covers a side of the oxide of the blocking layer, and wherein the single gate oxide insulation layer covers only a portion of a side of the nitride of the blocking layer.
Dependencies are inferred from the claim text.