| 摘要 |
A method for manufacturing a semiconductor device is provided to enhance the read speed of the semiconductor device by reducing capacitance between bit lines according to the air filled between the bit lines. An amorphous carbon layer, a second metal interlayer dielectric, a second stop layer, a first metal interlayer dielectric, and a first stop layer which are formed on a semiconductor substrate(100) having an interlayer dielectric(102), are sequentially etched. The width of the amorphous carbon layer is reduced by side etching. The second metal interlayer dielectric and the interlayer dielectric are etched by using the amorphous carbon layer as a mask. A barrier metal layer(118) and a tungsten layer(120) are formed on the resultant structure and then the polishing is executed to form isolated bit lines. By removing sequentially the second metal interlayer dielectric, the second stop layer, the first metal interlayer dielectric, and the first stop layer, a gap is formed between the line lines. An insulating layer(122) is formed on the resultant structure so as to fill air(a) in the gap. By etching whole surface of the resultant structure, a part of the upper layer of the bit lines is removed.
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