| 摘要 |
A method for forming a bitline contact hole in a semiconductor device is provided to decrease the number of process steps by using an NBC(nitride barrier contact etch) process while avoiding an open defect and an SAC(self-aligned contact) fail. A gate line is formed on a semiconductor substrate(21) in which a cell region and a peripheral region are defined, including a gate hard mask nitride layer. A landing plug contact is formed between the gate lines in the cell region. An interlayer dielectric is formed on the resultant structure. A mask is formed on the interlayer dielectric, simultaneously defining a bitline contact hole to be formed in the cell region and a bitline contact hole to be formed in the peripheral region. By performing a first etch process using the mask as an etch barrier, the bitline contact hole is partially opened by a first etch process using the mask as an etch barrier and the bitline contact hole is completely opened in the cell region. A second etch process is performed to completely open the bitline contact hole in the peripheral region. In the first etch process, etch gas having high etch selectivity with respect to a nitride layer can be used wherein plenty of polymer(31) is generated by the etch gas.
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