Structure and method of applying stresses to PFET and NFET transistor channels for improved performance
View Patent ↗A semiconductor device structure is provided which includes a first semiconductor device; a second semiconductor device; and a unitary stressed film disposed over both the first and second semiconductor devices. The stressed film has a first portion overlying the first semiconductor device, the first portion imparting a first magnitude compressive stress to a conduction channel of the first semiconductor device, the stressed film further having a second portion overlying the second semiconductor device, the second portion not imparting the first magnitude compressive stress to a conduction channel of the second semiconductor device, the second portion including an ion concentration not present in the second portion such that the second portion imparts one of a compressive stress having a magnitude much lower than the first magnitude, zero stress, and a tensile stress to the conduction channel of the second semiconductor device.
1. A semiconductor device structure, comprising:
a p-type channel field effect transistor (“PFET”);
an n-type channel field effect transistor (“NFET”);
a first stressed film disposed over both said PFET and said NFET, said first stressed film having a first portion imparting a first magnitude compressive stress to a conduction channel of said PFET, said first stressed film further having a second portion overlying said NFET, said second portion not imparting said first magnitude compressive stress to a conduction channel of said NFET, said second portion including an ion concentration not present in said first portion such that said second portion imparts one of a compressive stress having a magnitude much lower than said first magnitude, zero stress, or a tensile stress to said conduction channel of said NFET;
a second stressed film overlying said PFET and said NFET, said second stressed film imparting a tensile stress to said conduction channel of said NFET; and an intermediate layer overlying said PFET between said first and said second stressed films, said intermediate layer not overlying said NFET.
2. The semiconductor device structure as claimed in claim 1 , wherein said second stressed film consists essentially of a nitride.
3. The semiconductor device structure as claimed in claim 1 , wherein said second stressed film consists essentially of silicon nitride.
4. The semiconductor device structure as claimed in claim 1 , wherein said intermediate layer includes conformal dielectric material.
5. The semiconductor device structure as claimed in claim 1 , wherein said intermediate layer consists essentially of an oxide.
6. The semiconductor device structure as claimed in claim 5 , wherein said intermediate layer consists essentially of silicon dioxide.
7. The semiconductor device structure as claimed in claim 5 , wherein a thickness of said intermediate layer is between 100 angstroms (Å) and 150 angstroms (Å).
8. A semiconductor device structure, comprising:
n-type channel field effect transistor (“NFET”);
a p-type channel field effect transistor (“PFET”);
a first stressed film disposed over both said NFET and said PFET, said first stressed film having a first portion imparting a tensile stress having a first magnitude to a conduction channel of said NFET, said first stressed film further having a second portion overlying said PFET, said second portion not imparting said first magnitude tensile stress to a conduction channel of said PFET, said second portion including an ion concentration not present in said first portion such that said second portion imparts one of a tensile stress having a magnitude much lower than said first magnitude, zero stress, or a compressive stress to said conduction channel of said PFET;
a second stressed film overlying said PFET and said NFET, said second stressed film imparting a compressive stress to said conduction channel of said PFET; and
an intermediate layer overlying said NFET between said first and said second stressed films, said intermediate layer not overlying said PFET.
9. The semiconductor device structure as claimed in claim 1 , wherein said unitary stressed film includes silicon nitride and said ion concentration includes a concentration of implanted germanium (Ge) ions.