Abstract: A method includes: forming a first contact hole by etching a first inter-layer dielectric layer; forming a preliminary first conductive plug that fills the first contact hole; forming a bit line structure over the preliminary first conductive plug; forming a first conductive plug by etching the preliminary first conductive plug so that a gap is formed between a sidewall of the first contact hole and the first conductive plug; forming an insulating plug in the gap; forming a multi-layer spacer including a sacrificial spacer; forming a second conductive plug neighboring the bit line structures and the first conductive plugs with the multi-layer spacer and the insulating plug therebetween; and forming a line-type air gap within the multi-layer spacer by removing the sacrificial spacer.

Abstract: A method for fabricating a semiconductor device includes preparing a substrate which includes a memory cell region and a peripheral circuit region; forming a buried word line in the substrate in the memory cell region; forming a planar gate structure over the substrate in the peripheral circuit region; forming a bit line structure over the substrate in the memory cell region; forming a first air spacers over a sidewalls of the planar gate structure; and forming a second air spacers over a sidewalls of the bit line structure.

Abstract: A method for fabricating a semiconductor device includes preparing a substrate which includes a memory cell region and a peripheral circuit region; forming a buried word line in the substrate in the memory cell region; forming a planar gate structure over the substrate in the peripheral circuit region; forming a bit line structure over the substrate in the memory cell region; forming a first air spacers over a sidewalls of the planar gate structure; and forming a second air spacers over a sidewalls of the bit line structure.

Abstract: A method includes: forming a first contact hole by etching a first inter-layer dielectric layer; forming a preliminary first conductive plug that fills the first contact hole; forming a bit line structure over the preliminary first conductive plug; forming a first conductive plug by etching the preliminary first conductive plug so that a gap is formed between a sidewall of the first contact hole and the first conductive plug; forming an insulating plug in the gap; forming a multi-layer spacer including a sacrificial spacer; forming a second conductive plug neighboring the bit line structures and the first conductive plugs with the multi-layer spacer and the insulating plug therebetween; and forming a line-type air gap within the multi-layer spacer by removing the sacrificial spacer.

Abstract: A method for fabricating a semiconductor device includes preparing a substrate which includes a memory cell region and a peripheral circuit region; forming a buried word line in the substrate in the memory cell region; forming a planar gate structure over the substrate in the peripheral circuit region; forming a bit line structure over the substrate in the memory cell region; forming a first air spacers over a sidewalls of the planar gate structure; and forming a second air spacers over a sidewalls of the bit line structure.

Abstract: A method for fabricating a semiconductor device includes preparing a substrate which includes a memory cell region and a peripheral circuit region; forming a buried word line in the substrate in the memory cell region; forming a planar gate structure over the substrate in the peripheral circuit region; forming a bit line structure over the substrate in the memory cell region; forming a first air spacers over a sidewalls of the planar gate structure; and forming a second air spacers over a sidewalls of the bit line structure.

Abstract: A method includes: forming a first contact hole by etching a first inter-layer dielectric layer; forming a preliminary first conductive plug that fills the first contact hole; forming a bit line structure over the preliminary first conductive plug; forming a first conductive plug by etching the preliminary first conductive plug so that a gap is formed between a sidewall of the first contact hole and the first conductive plug; forming an insulating plug in the gap; forming a multi-layer spacer including a sacrificial spacer; forming a second conductive plug neighboring the bit line structures and the first conductive plugs with the multi-layer spacer and the insulating plug therebetween; and forming a line-type air gap within the multi-layer spacer by removing the sacrificial spacer.

Abstract: A method includes: forming a first contact hole by etching a first inter-layer dielectric layer; forming a preliminary first conductive plug that fills the first contact hole; forming a bit line structure over the preliminary first conductive plug; forming a first conductive plug by etching the preliminary first conductive plug so that a gap is formed between a sidewall of the first contact hole and the first conductive plug; forming an insulating plug in the gap; forming a multi-layer spacer including a sacrificial spacer; forming a second conductive plug neighboring the bit line structures and the first conductive plugs with the multi-layer spacer and the insulating plug therebetween; and forming a line-type air gap within the multi-layer spacer by removing the sacrificial spacer.