Method for fabricating semiconductor device
AssigneeDongbu Electronics Co., Ltd.
InventorSung Ho Kwak
Life of this patent
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Abstract
A method for fabricating a semiconductor device can prevent a leakage current and the decrease of threshold voltage by rounding corners of a trench. The method may include the steps of forming a pad insulating layer in a semiconductor substrate defined with an active region and a device isolation region, forming a first trench, forming polymer at inner sidewalls of the first trench, forming a second trench, removing the polymer, forming an oxide layer by thermally oxidizing the semiconductor substrate, and forming insulating layers for device isolation in the first and second trenches.
Claims3
A method for fabricating a semiconductor device comprising:
- forming a pad insulating layer on a semiconductor substrate defined with an active region and a device isolation region;
- forming a first trench by etching the pad insulating layer and the semiconductor substrate corresponding to the device isolation region to a predetermined depth;
- forming polymer on sidewalls of the first trench, wherein the polymer is formed by generating plasma with fluorine gas including carbon;
- forming a second trench by etching the semiconductor substrate to a predetermined depth using the polymer and the pad insulating layer as a mask;
- removing the polymer and the pad insulating layer;
- forming an oxide layer on an entire surface of the semiconductor substrate by thermal-oxidizing the semiconductor substrate;
- and
- forming an insulating layer for device isolation in the first and second trenches,
- wherein forming the insulating layer for device isolation includes steps of:
- removing the oxide layer
- forming an insulating layer on the entire surface of the semiconductor substrate to completely fill the first trench and the second trench;
- and
- etching the insulating layer by CMP such that the insulating layer remains only inside the first and second trenches.
Dependencies are inferred from the claim text.