| 摘要 |
PURPOSE: A method for forming a copper metallization layer of a semiconductor device is provided to prevent an increase of contact resistance between lower and upper copper layers due to a high-resistance diffusion barrier interposed between the copper layers and thereby to improve related electrical characteristics. CONSTITUTION: After the lower copper layer(2) is formed on a semiconductor substrate(1), the diffusion barrier(3) and an interlayer dielectric layer(30) are sequentially formed thereon. The interlayer dielectric layer(30) has first and second insulating layers(4,6), an etch stop layer(5) and a hard mask layer(7). A dual damascene pattern is formed in the interlayer dielectric layer(30) to expose a portion of the lower copper layer(2). Then another diffusion barrier(8) is wholly formed and selectively removed on the interlayer dielectric layer(30) and on the exposed lower copper layer(2). After a seed copper layer is formed by CVD, the upper copper layer(9) is in-situ formed inside the dual damascene pattern and planarized. Therefore, a direct connection is made between the lower and upper copper layers(2,9).
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