Semiconductor device and manufacturing method thereof

A method, comprising:

• depositing a gate material layer over a substrate;
• etching the gate material layer to form a first gate over the substrate;
• depositing a spacer layer over the first gate;
• etching the spacer layer to form a first spacer over a sidewall of the first gate;
• performing an implantation process on the first spacer to form a first implantation region in the first spacer, wherein the implantation process is performed such that a topmost position of the first implantation region is higher than a topmost position of the first gate;
• and
• etching the first implantation region to thin the first spacer.

A method, comprising:

• depositing a gate material layer over a substrate;
• depositing a first mask layer over the gate material layer;
• etching the first mask layer and the gate material layer to form first, second, third, and fourth gates over the substrate and first, second, third, and fourth patterned masks respectively in contact with top surfaces of the first, second, third, and fourth gates, wherein a first distance between the first gate and the second gate is less than a second distance between the third gate and the fourth gate;
• forming a second mask layer over the first and second patterned masks, wherein the third and fourth patterned masks are exposed from the second mask layer;
• and
• etching the exposed third and fourth patterned masks to remove upper portions of the third and fourth patterned masks, while leaving lower portions of the third and fourth patterned masks in contact with the top surfaces of the third and fourth gates.