Scalable strained FET device and method of fabricating the same
View Patent ↗An integrated circuit including pairs of strained complementary CMOS field-effect devices consisting of n-FET and p-FET transistors on a substrate. The n-FET is provided with a compressive dielectric stressor, while the p-FET is provided with a tensile stressed dielectric. Each dielectric stressor includes a discrete horizontal segment on a surface overlying and contacting the gate of the respective FET. The stress enhancement is insensitive to PC pitch, and by reducing the height of the polysilicon stack, the scalability which is achieved contributes to a performance improvement. The n-FET leverages higher stress values that are obtainable in the compressive liners are greater than 3 GPa compared to less than 1.5 GPa for tensile liners.
1. A method for forming a semiconductor device on a substrate comprising:
forming at least one n-channel field effect transistor (n-FET) and at least one p-channel field effect transistor (p-FET) that are separated from each other by a common dielectric layer; and
forming a compressively stressed discrete dielectric liner segment overlaying and contacting a gate of said at least one n-FET and a discrete dielectric liner segment under tensile stress overlaying and contacting a gate of said at least one p-FET; wherein said tensile discrete dielectric liner segment overlaying and contacting said at least one p-FET gate is a compressive nitride cap.
2. The method of claim 1 , wherein said tensile discrete dielectric liner segment nitride cap overlays and contacts only one of said p-FET gates and said n-FET gates.
3. The method of claim 1 , wherein said tensile discrete dielectric liner segment overlaying and contacting said at least one p-FET gate is a compressive nitride cap in combination with a relaxation cap.
4. The method of claim 1 , wherein each of said compressive and tensile discrete dielectric liner segments have a thickness ranging from 40 nm to 100 nm.
5. The method of claim 1 , wherein said compressive discrete dielectric liner segment is made of a material selected from a group consisting of SiN, SiO 2 , SiCOH, HfO 2 , and ZrO 2 .