Patent attributes
A MOS device having corner spacers and a method for forming the same are provided. The method includes forming a gate structure overlying a substrate, forming a first dielectric layer over the gate structure and the substrate, forming a second dielectric layer on the first dielectric layer, forming a third dielectric layer on the second dielectric layer, and etching the first, the second and the third dielectric layers using the third dielectric layer as a mask. The remaining first and second dielectric layers have an L-shape. The method further includes implanting source/drain regions, removing remaining portions of the third dielectric layer, blanket forming a fourth dielectric layer, etching the fourth dielectric layer, siliciding exposed source/drain regions, and forming a contact etch stop layer. The remaining portion of the fourth dielectric layer forms corner spacers.