| 摘要 |
A structure and method of forming the structure are disclosed. According to an embodiment, a structure includes three devices in respective three regions of a substrate. The first device comprises a first gate stack, and the first gate stack comprises a first dielectric layer. The second device comprises a second gate stack, and the second gate stack comprises a second dielectric layer. The third device comprises a third gate stack, and the third gate stack comprises a third dielectric layer. A thickness of the third dielectric layer is less than a thickness of the second dielectric layer, and the thickness of the second dielectric layer is less than a thickness of the first dielectric layer. A gate length of the third gate stack differs in amount from a gate length of the first gate stack and a gate length of the second gate stack. |
