| 摘要 |
This invention relates to a method for decreasing the resistivity of the gate and leaky junction of the source/drain, more particularly, to the method for forming a metal silicide layer at the gate region and the source/drain region by using two times in depositing metal layer. This condition will form a thicker metal silicide layer at the gate region to decrease the resistivity of the gate and will form a thinner metal silicide layer at the source/drain region to decrease defects in leaky junction at the source/drain region. At first, a semiconductor substrate is provided and a MOS is formed on the substrate and a shallow trench isolation is formed in the substrate. The MOS comprises a gate region, a source region, a drain region, and a spacer which is formed on the sidewall of the gate. The first metal layer is formed over the MOS and a oxide layer is formed over the first metal layer. Partial oxide layer is etched to show the first metal layer which is formed on the gate. The first metal layer which is on the gate is removed. The remained oxide is removed. The second metal layer is formed on the first metal layer. Then two times rapid thermal process are passed through and the salicide process is finished.
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