| abstract |
The integrated circuit structure includes a semiconductor substrate, a gate stack over the semiconductor substrate, and an opening extending into the semiconductor substrate, the opening adjacent the gate stack. The silicon germanium region is disposed within the opening and the silicon germanium region has a first p-type impurity concentration. A substantially germanium-free silicon cap is placed over the silicon germanium region. The silicon cap has a second p-type impurity concentration higher than the first p-type impurity concentration. |