Method of manufacturing semiconductor device

摘要

A method of manufacturing a semiconductor device is disclosed, which can completely remove hard mask residues left along boundaries between a high-voltage device region and STI structures after a dry etch process, by partially reducing a thickness of each of the exposed portion of the respective STI structures adjacent to the high-voltage device region so as to sufficiently expose the residues. As a result, after a portion of an underlying pad oxide corresponding to the high-voltage device region is removed in a subsequent process, the exposed surface of the substrate is uniform with a smooth and clear border. Therefore, no sharp corners will emerge at a border of a gate oxide subsequently grown on the exposed surface of the substrate, and the gate oxide is thus morphologically improved, thereby resulting in an improvement of the reliability of the high-voltage semiconductor device being fabricated.

主权项

1. A method of manufacturing a semiconductor device, comprising the steps of:
1) providing a substrate and forming a pad oxide over the substrate; 2) etching the pad oxide and the substrate to form two shallow trenches and filling the two shallow trenches with an oxide to form two shallow trench isolation structures, a high-voltage device region being provided between the two shallow trench isolation structures; 3) forming a hard mask layer over the substrate; 4) performing a dry etching process to remove a portion of the hard mask layer in the high-voltage device region to expose both a portion of the pad oxide in the high-voltage device region and adjacent portions of the respective shallow trench isolation structures, wherein hard mask residues are left along boundaries between the high-voltage device region and the shallow trench isolation structures after the dry etching process; 5) reducing a thickness of each of the exposed portions of the respective shallow trench isolation structures using a first rinsing liquid to expose the hard mask residues; and 6) removing the hard mask residues using a second rinsing liquid.