Strain scaling for CMOS

This article describes various techniques for applying strain to current and future complementary metal–oxide–semiconductor (CMOS) channels to boost CMOS performance. A brief history of both biaxial and uniaxial strain engineering in planar CMOS technology is discussed. Scalability challenges associated with process-induced uniaxial strain in sub-22 nm CMOS is highlighted in view of shrinking device dimensions and 3D device architecture (such as fin field-effect transistors [FinFETs]). Non-uniform strain relaxation in patterned geometries in tight pitch two- and three-dimensional devices is addressed. A case is made that the future scalable strain platform will require a combination of biaxial strain at wafer level in conjunction with local uniaxial strain. Finally, potential application of strain engineering to advanced III–V metal oxide semiconductor FET channels will be examined.