Semiconductor device and method for fabricating the same

摘要

A semiconductor device includes: a first well and a second well formed in a substrate and having a different impurity doping concentration; a first isolation layer and a second isolation layer formed in the first well and the second well, respectively, and having a different depth; and a third isolation layer formed in a boundary region in which the first well and the second well are in contact with each other, and having a combination type of the first isolation layer and the second isolation layer.

主权项

1. A method for fabricating a semiconductor device, comprising:
forming a first well and a second well having a different impurity doping concentration on a substrate; etching the substrate to form a trench in a boundary region in which the first well and the second well are in contact with each other such that a first side of the trench is disposed in the first well and a second side of the trench is disposed in the second well; forming a sacrificial pattern to cover the first side of the trench without covering the second side of the trench; etching an exposed bottom surface of the second side of the trench by using the sacrificial pattern as an etch barrier; removing the sacrificial pattern; and filling the trench with an insulation material to form an isolation layer having two different depths with respect to a top surface of the substrate.