Semiconductor device including air gap between semiconductor substrate and L-shaped spacer and method of fabricating the same

A method of fabricating a semiconductor device, comprising:

• forming a gate pattern on a semiconductor substrate, wherein the gate pattern has opposite side walls;
• forming a support layer, a spacer insulating layer and a sacrificial layer sequentially on the semiconductor substrate including over the gate pattern;
• anisotropically etching the sacrificial layer, the spacer insulating layer, and the support layer so as to form L-shaped support patterns covering the side walls of the gate pattern and respective portions of the semiconductor substrate adjacent to the gate pattern, L-shaped spacers covering the L-shaped support patterns, and sacrificial patterns covering the L-shaped spacers, wherein the L-shaped spacers each include a vertical portion normal to the semiconductor substrate and a lateral portion extending laterally from the bottom of the vertical portion;
• isotropically etching the L-shaped support patterns from between at least the lateral portions of the L-shaped spacers and the semiconductor substrate so as to form an air gap between the lateral portions of the L-shaped spacers and the semiconductor substrate;
• and
• implanting ions into the semiconductor substrate, including using the gate pattern and the L-shaped spacers as an ion implantation mask, so as to form source/drain regions in the semiconductor substrate adjacent the gate pattern.

A method of fabricating a semiconductor device, comprising:

• forming a gate pattern on a semiconductor substrate, wherein the gate pattern has opposite side walls;
• forming a buffer insulating layer on the semiconductor substrate including over the gate pattern, the buffer insulating layer being of a material having an etch selectivity with respect to the gate pattern;
• forming a support layer, a spacer insulating layer and a sacrificial layer sequentially on the semiconductor substrate including over the gate pattern, wherein the support layer and the sacrificial layer are of the same material and have an etch selectivity with respect to the spacer insulating layer;
• anisotropically etching the sacrificial layer, the spacer insulating layer, and the support layer so as to form L-shaped support patterns covering the side walls of the gate pattern and respective portions of the semiconductor substrate adjacent to the gate pattern, L-shaped spacers covering the L-shaped support patterns, and sacrificial patterns covering the L-shaped spacers, wherein the L-shaped spacers each include a vertical portion normal to the semiconductor substrate and a lateral portion extending laterally from the bottom of the vertical portion;
• removing the sacrificial patterns, and isotropically etching the L-shaped support patterns so as to provide an air gap between at least the lateral portion of each of the L-shaped spacers and the semiconductor substrate;
• and
• implanting ions into the semiconductor substrate, including using the gate pattern and the L-shaped spacers as an ion implantation mask, so as to form source/drain regions in the semiconductor substrate adjacent the gate pattern.