Semiconductor device having a low divot of alignment between a substrate and an isolation thereof and method of forming the same
First Claim
1. A method of forming vertical structures, comprising:
- providing a substrate;
forming a first oxide layer over the substrate;
forming a shallow trench isolation to divide the substrate into a first region and a second region;
forming a first dummy layer over the first oxide layer and the shallow trench isolation;
etching the first oxide layer and the first dummy layer to form a first recess in the first region and a second recess in the second region;
forming a second dummy layer in the first recess and the second recess;
removing the first dummy layer;
removing the first oxide layer;
etching a portion of the shallow trench isolation; and
etching the substrate to make the substrate aligned with a top of the shallow trench isolation and to form a first vertical structure in the first region and a second vertical structure in the second region.
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Accused Products
Abstract
According to an exemplary embodiment, a method of forming vertical structures is provided. The method includes the following operations: providing a substrate; forming a first oxide layer over the substrate; forming a first dummy layer over the first oxide layer; etching the first oxide layer and the first dummy layer to form a recess; forming a second dummy layer in the recess (and further performing CMP on the second dummy layer and stop on the first dummy layer); removing the first dummy layer; removing the first oxide layer; and etching the substrate to form the vertical structure. According to an exemplary embodiment, a semiconductor device is provided. The semiconductor device includes: a substrate; an STI embedded in the substrate; and a vertical transistor having a source substantially aligned with the STI.
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Citations
17 Claims
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1. A method of forming vertical structures, comprising:
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providing a substrate; forming a first oxide layer over the substrate; forming a shallow trench isolation to divide the substrate into a first region and a second region; forming a first dummy layer over the first oxide layer and the shallow trench isolation; etching the first oxide layer and the first dummy layer to form a first recess in the first region and a second recess in the second region; forming a second dummy layer in the first recess and the second recess; removing the first dummy layer; removing the first oxide layer; etching a portion of the shallow trench isolation; and etching the substrate to make the substrate aligned with a top of the shallow trench isolation and to form a first vertical structure in the first region and a second vertical structure in the second region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of forming a vertical structure, comprising:
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providing a substrate; forming a first oxide layer over the substrate; forming a first dummy layer over the first oxide layer; etching the first oxide layer and the first dummy layer to form a recess; forming a second dummy layer in the recess; removing the first dummy layer; removing the first oxide layer; and etching the substrate to form the vertical structure. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification