Method for making field oxide of semiconductor device
AssigneeHyundai Electronics Industries Co., Ltd.
InventorSe Aug Jang
Life of this patent
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Abstract
There is disclosed a method for making a field oxide, by which wafer warpage is minimized when a local oxidation of silicon process is applied for a large wafer. A material layer having a compressive stress and a nitride are laminated over the back side of a wafer, so that the compressive stress of the material layer complementarily interacts with the tensile stress of the nitride.
Claims6
A method for making a field oxide of a semiconductor device, comprising the steps of:
- depositing an oxide layer and a material layer having compressive stress over the front side and the back side of a wafer;
- removing only the material layer and the oxide layer over the front side;
- laminating a pad oxide and a nitride over the front side and the back side of the wafer;
- etching the nitride and pad oxide selectively at a predetermined field region over the front side of the wafer;
- and
- oxidizing the wafer at the field region, to grow a field oxide, whereby wafer warpage is minimized by laminating the material layer and the nitride over the back side of a wafer in such a way that the compressive stress of the material layer relieves the tensile stress of the nitride.
A method for making a field oxide of a semiconductor device, comprising the steps of:
- depositing an oxide layer and a material layer having compressive stress over the front side and the back side of a wafer;
- removing only the material layer and the oxide layer over the front side;
- laminating a pad oxide and a nitride over the front side and the back side of the wafer;
- etching the nitride and pad oxide selectively at a predetermined field region over the front side of the wafer;
- forming a spacer at the side wall of the nitride and etching the wafer at the exposed field region to form a groove;
- and
- oxidizing the wafer at the field region, to grow a field oxide, whereby wafer warpage is minimized by laminating the material layer and the nitride over the back side of a wafer in such a way that the compressive stress of the material layer relieves the tensile stress of the nitride.
A method for making a field oxide of a semiconductor device comprising the steps of:
- depositing an oxide layer and a polysilicon over the front side and the back side of the wafer;
- removing only the polysilicon layer and the oxide layer over the front side;
- laminating a pad oxide and a nitride over the front side and the back side of the wafer;
- etching the nitride and pad oxide selectively at a predetermined field region over the front side of the wafer;
- and
- oxidizing the wafer at the field region to grow a field oxide, whereby wafer warpage is minimized by laminating the polysilicon layer and a nitride over the back side of a wafer in such a way that the compressive stress of the polysilicon layer relieves the tensile stress of the nitride .
Dependencies are inferred from the claim text.