Abstract: Methods and systems for dry etching are disclosed. The methods and systems use a showerhead with a perforated plate. The perforated plate includes a primary solid zone having no holes; a first annular zone comprising a first plurality of holes with a first total hole area; a secondary solid zone having no holes; a second annular zone comprising a second plurality of holes with a second total hole area; a third annular zone comprising a third plurality of holes with a third total hole area; and a fourth annular zone comprising a fourth plurality of holes with a fourth total hole area. The third total hole area is greater than the first total hole area and less than the second total hole area, and the fourth total hole area is greater than the second total hole area. Dry etched wafers using these systems have improved edge uniformity and improved yield.

Abstract: Provided is a semiconductor device including a gate electrode, source and drain regions, and a spacer. The gate electrode is located over a substrate, and an angle of a base corner of the gate electrode is greater than 90 degrees. The source and drain regions are located in the substrate at sides of the gate electrode. The spacer is located at a sidewall of the gate electrode.

Abstract: Provided is a semiconductor device including a gate electrode, source and drain regions, and a spacer. The gate electrode is located over a substrate, and an angle of a base corner of the gate electrode is greater than 90 degrees. The source and drain regions are located in the substrate at sides of the gate electrode. The spacer is located at a sidewall of the gate electrode.