| 摘要 |
<p>A method of forming the semiconductor device is provided to increase the thickness of the lower part of spacer by using the undercut structure and to increase the CD of pattern. The first material layer and the second material layer are successively formed at the upper part of the etch target layer(22). The first material layer and the second material layer have the different etch rate. The second material layer and the first material layer are successively etched to form the first pattern. The selective etching process is performed on the first material layer part of the first pattern to form the second pattern(25). The second pattern has the under cut structure. The spacer(30) is formed in the side wall of the second pattern. The second pattern is removed. By using spacer, the etch target layer is etched to form the third pattern.</p> |
