US 6,486,035 B1Granted

Semiconductor device and method for fabricating the same

AssigneeHyundai Electronics Industries Co., Ltd.

InventorSug Bo Chun

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Abstract

Semiconductor device and method for fabricating the same, the device including a semiconductor substrate, a recessed channel region recessed below a surface of the semiconductor substrate, and a gate oxide film formed on the recessed channel region, a first and a second lightly doped impurity regions in surfaces of the substrate adjacent to, and on both sides of the recessed channel region respectively, and a first and a second highly doped impurity regions adjacent to the first and second lightly doped impurity regions, respectively, inverted sidewalls on the first and second lightly doped impurity regions each having a round in a side of the recessed channel region, and a gate electrode both on the inverted sidewalls and the recessed channel region, whereby securing a fabrication allowance and improving a device packing density.

Claims6

Dependent claims

A method for fabricating a semiconductor device, comprising the steps of:

(1) forming an oxide film and a nitride film on a semiconductor substrate in succession and patterning selectively, and forming trenches using the patterned oxide film and the nitride film;
(2) stuffing an insulating material in the trenches, to form device isolating layers;
(3) removing a width of the nitride film on an active region defined by the device isolating layers, to form a channel defining trench;
(4) using the patterned nitride film as a mask in implanting impurities lightly, to form lightly doped impurity regions for forming LDDs;
(5) forming inverted sidewalls at sides of the channel defining trench, and oxidizing a bottom portion, to form the LDD regions;
(6) removing the oxide film on a bottom surface of the channel defining trench, to form a channel of semispherical recess with a depth;
(7) removing the nitride layer, forming a gate oxide film on a surface of a recessed channel region, and forming a gate electrode both on the inverted sidewalls and the gate oxide film;
and,
(8) using the gate electrode inclusive of the inverted sidewalls as a mask in implanting impurities, heavily.

6 more elements

Dependencies are inferred from the claim text.