Method of fabricating strain-silicon CMOS
First Claim
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1. A method of manufacturing a metal-oxide-semiconductor (“
- MOS”
) transistor comprising;
forming first sidewall spacers on the sides of a gate of the MOS transistor;
performing a first anisotropic silicon etch in source and drain regions of the MOS transistor so as to form first recesses;
depositing a second sidewall film on the MOS transistor;
forming second sidewall spacers;
performing a second anisotropic silicon etch in the source and drain regions of the MOS transistor so as to form second recesses, combined recesses being formed from at least the first recesses and the second recesses;
removing the second sidewall spacers; and
forming stressed material in the combined recesses.
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Abstract
Recesses are formed in the drain and source regions of an MOS transistor. The recesses are formed using two anisotropic etch processes and first and second sidewall spacers. The recesses are made up of first and second recesses, and the depths of the first and second recesses are independently controllable. The recesses are filled with a stressed material to induce strain in the channel, thereby improving carrier mobility. The widths and depths of the first and second recesses are selectable to optimize strain in the channel region.
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Citations
11 Claims
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1. A method of manufacturing a metal-oxide-semiconductor (“
- MOS”
) transistor comprising;forming first sidewall spacers on the sides of a gate of the MOS transistor; performing a first anisotropic silicon etch in source and drain regions of the MOS transistor so as to form first recesses; depositing a second sidewall film on the MOS transistor; forming second sidewall spacers; performing a second anisotropic silicon etch in the source and drain regions of the MOS transistor so as to form second recesses, combined recesses being formed from at least the first recesses and the second recesses; removing the second sidewall spacers; and forming stressed material in the combined recesses. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- MOS”
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8. A method of fabricating a metal-oxide-semiconductor (“
- MOS”
) transistor in a complementary MOS (“
CMOS”
) cell having a first-conductivity-type MOS portion and a second-conductivity-type MOS portion comprising;forming first sidewall spacers on sides of a first gate of the first-conductivity-type MOS portion and on sides of a second gate of the second-conductivity-type MOS portion; performing lightly-doped drain and halo implants on the first-conductivity-type MOS portion; patterning photoresist over the first-conductivity-type MOS portion; performing a first anisotropic selective etch in exposed source/drain areas of the second-conductivity-type MOS portion so as to form first recesses; depositing a second sidewall film over at least the first sidewall spacers on the sides of the second gate; forming second sidewall spacers on at least the second gate; depositing an epitaxial mask film over the CMOS cell; removing the epitaxial mask film from the second-conductivity-type MOS portion; performing a second anisotropic selective etch in source/drain regions to form second recesses, the second recesses and first recesses forming combined recesses; removing the second sidewall spacers from the second gate; and forming stressed material in the combined recesses. - View Dependent Claims (9, 10, 11)
- MOS”
Specification