摘要 |
A gate insulator layer is formed over the semiconductor substrate and a first silicon layer is then formed over the gate insulator layer. An anti-reflection layer is formed over the first silicon layer. A gate region is defined by removing a portion of the gate insulator layer of the first silicon layer and of the anti-reflection layer. A portion of the gate insulator layer is removed to have undercut spaces under the first silicon layer. A dielectric layer is then formed on the semiconductor substrate, on the sidewalls of the gate region, and within the undercut spaces. A spacer structure containing first type dopants is then formed on the sidewalls of the gate region. Following the removal of the anti-reflection layer, a second silicon layer containing second type dopants is formed over the semiconductor substrate and the first silicon layer. Finally, a thermal process is performed to the semiconductor substrate for diffusing the first type dopants and the second type dopants into the semiconductor substrate.
|