Transistor structure and method of manufacturing the same
AssigneeInotera Memories, Inc.
InventorsTZUNG-HAN LEE, NENG-TAI SHIH, YAW-WEN HU
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Abstract
A method of manufacturing a transistor structure includes a step of implanting a light dosage into a substrate at a bit line junction and two cell side junctions, and a step of implanting a light dosage into the bit line junction an additional time. A uniform region having a substantially uniform dopant concentration is formed at the bit line junction. The dopant concentration of the uniform region is higher than that of the cell side junctions and higher than that of the region of the bit line junction under the uniform region.
Claims16
A transistor structure formed on a substrate and comprising:
- two trenches formed on the substrate, wherein a dielectric layer is disposed in each of the two trenches, and a gate is disposed on each of the dielectric layers in the trenches;
- a bit line junction defined between the two trenches, and including a uniform region formed by implanting dopant of light dosage into the substrate at least two times;
- and
- two cell side junctions defined respectively at sides of the trenches opposite the bit line junction, and each including a drain region formed by implanting dopant of light dosage into the substrate one time;
- wherein
- the uniform region of the bit line junction has a substantially uniform dopant concentration which is higher than the dopant concentration of the region of the bit line junction thereunder and higher than the dopant concentration of the cell side junctions, and the depth of the uniform region ranges from above the top of each of the gates to below the top of each of the gates.
A method of manufacturing a transistor structure, comprising:
- providing a substrate and forming two trenches thereon, wherein a bit line junction is defined between the two trenches, and two cell side junctions are defined respectively at the sides of the trenches opposite the bit line junction;
- disposing a dielectric layer in each of the two trenches;
- disposing conductive material on each of the dielectric layers to form a gate in each of the two trenches;
- implanting dopant of light dosage into the substrate at the bit line junction and the two cell side junctions, forming a drain region in each of the two cell side junctions;
- and
- implanting dopant of light dosage into the bit line junction an additional time, forming a uniform region having a substantially uniform dopant concentration within the bit line junction, wherein the depth of the uniform region ranges from above the top of each of the gates to below the top of each of the gates.
Dependencies are inferred from the claim text.