Elevated source/drain MOSFET with solid phase diffused source/drain extension

摘要

The MOSFET has a stacked gate structure which has a first silicon layer, a second silicon layer, and a spacer structure. The first silicon layer is formed over the semiconductor substrate. The second silicon layer contains second type dopants and is formed on the first silicon layer. The spacer structure containing first type dopants is formed on the sidewall of the first silicon layer and the second silicon layer. A gate insulator layer is formed between the first silicon layer and the semiconductor substrate. The second silicon layer is also formed on the semiconductor substrate at a region uncovered by the stacked gate structure. A junction region is formed in the semiconductor substrate under the second silicon layer but not under the stacked gate structure. An extended junction is formed in the semiconductor substrate under the spacer structure.