Methods for Fabricating Semiconductor Devices Using Liner Layers to Avoid Damage to Underlying Patterns

A method for fabricating a semiconductor device, the method comprising:

• forming a lower interlayer insulating layer, an upper interlayer insulating layer and a hard mask pattern on a substrate including a lower pattern, the hard mask pattern including titanium nitride;
• forming a trench exposing the lower pattern in each of the upper interlayer insulating layer and the lower interlayer insulating layer using the hard mask pattern;
• conformally forming an aluminum compound layer along sidewalls and a bottom surface of the trench and on a top surface of the hard mask pattern;
• forming a sacrificial layer on the aluminum compound layer and in the trench;
• forming a sacrificial pattern exposing the aluminum compound layer on the top surface of the hard mask pattern by removing a portion of the sacrificial layer;
• removing the aluminum compound layer on the top surface of the hard mask pattern and the hard mask pattern together using the sacrificial pattern as a wet etch mask;
• exposing the aluminum compound layer in the trench by removing the sacrificial pattern;
• and
• exposing the lower pattern by removing the exposed aluminum compound layer in the trench using a first wet etching process.

A method of fabricating a semiconductor device, the method comprising:

• patterning an interlayer insulating layer including a hard mask pattern thereon to define a trench therein, wherein the trench in the interlayer insulating layer exposes a lower pattern on a layer therebelow;
• prior to removing the hard mask pattern, forming a liner layer extending along sidewalls and a bottom surface of the trench;
• performing a first etching process to remove the hard mask pattern without removing portions of the liner layer extending along the bottom surface of the trench;
• and
• after removing the hard mask pattern, performing a second etching process to remove the portions of the liner layer extending along the bottom surface of the trench.