Semiconductor apparatus and method for fabricating the same
AssigneeOki Electric Industry Co., Ltd.
InventorsShinzi Kawada, Hiroyuki Kawano
Life of this patent
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Abstract
First, a substrate, on which a plurality of semiconductor devices is formed, is provided. Next, a first etching treatment is carried out to the substrate with a first etching gas comprising CF4 to form a base trench having a rounded-off upper edge or tapered upper edge. A second etching treatment is carried out to the substrate to form a trench region at the base trench so that the trench region has a rounded-off upper edge. And then, an insulating layer is formed on the substrate to fill up the trench region therewith.
Claims10
A method for fabricating a semiconductor apparatus, comprising:
- providing a substrate having a principal surface;
- performing a first etching treatment on the substrate with a first etching gas comprising CF4 and HBr to form a base trench having a rounded-off upper edge or tapered upper edge, wherein a flow rate of CF4 is larger than a flow rate of HBr;
- performing a second etching treatment on the substrate to form a trench region at the base trench so that the trench region has a rounded-off upper edge;
- and
- forming an insulating layer on the substrate to fill up the trench region therewith.
A method for fabricating a semiconductor apparatus, comprising:
- providing a substrate on which a plurality of semiconductor devices are formed;
- performing a first etching treatment on the substrate with a first etching gas comprising HBr and CF4 to form a base trench having a rounded-off upper edge;
- performing a second etching treatment on the substrate using a second etching gas excluding CF4 to form a trench region at the base trench so that the trench region has a rounded-off upper edge;
- and
- forming an oxide layer on the substrate to fill up the trench region therewith, wherein
- a ratio of flow rate of HBr and CF4 in the first etching gas is between 1:2 and 1:5.
A method for fabricating a semiconductor apparatus, comprising:
- providing a substrate on which a plurality of semiconductor devices are formed;
- performing a first etching treatment on the substrate with a first etching gas comprising HBr, CF4 and CH2F2 to form a base trench having a tapered upper edge;
- performing a second etching treatment on the substrate using a second etching gas excluding CF4 and CH2F2 to form a trench region at the base trench;
- performing a thermal oxidation treatment on the substrate so that the trench region has a rounded-off upper edge;
- and
- forming an oxide layer on the substrate to fill up the trench region therewith, wherein
- a ratio of flow rate of CF4 and CH2F2 in the first etching gas is between 2:1 and 3:1.
Dependencies are inferred from the claim text.