Simultaneous Formation of Source/Drain Openings with Different Profiles

A method comprising:

• forming a first gate stack and a second gate stack over a first portion and a second portion, respectively, of a semiconductor substrate;
• implanting the second portion of the semiconductor substrate with an etch-tuning element to form an implanted region, wherein the first portion of the semiconductor substrate is covered during the implanting;
• simultaneously etching the first portion and the second portion of the semiconductor substrate to form a first opening and a second opening, respectively, in the semiconductor substrate, wherein substantially an entirety of the implanted region is removed by the etching, and a first gate proximity of the first opening is different from a second gate proximity of the second opening, with the first gate proximity being a lateral distance from the first opening to a closest edge of the first gate stack, and the second gate proximity being an additional lateral distance from the second opening to a closest edge of the second gate stack;
• and
• simultaneously growing a first source/drain region and a second source/drain region in the first opening and the second opening, respectively.

A method comprising:

• forming a first gate stack and a second gate stack over a first portion and a second portion, respectively, of a semiconductor substrate;
• implanting the second portion of the semiconductor substrate with an etch-tuning element to form an implanted region, wherein the first portion of the semiconductor substrate is covered during the implanting;
• simultaneously etching the first portion and the implanted region of the semiconductor substrate to form a first opening and a second opening, respectively, in the semiconductor substrate, wherein the implanted region has a lower lateral etching rate than the first portion of the semiconductor substrate, wherein after the etching, the etch-tuning element includes residue portions remaining in a layer of the semiconductor substrate, and the layer of the semiconductor substrate is overlapped by the second opening;
• and
• simultaneously growing a first source/drain region and a second source/drain region in the first opening and the second opening, respectively.