Semiconductor integrated circuit and method of fabricating same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsHideomi SUZAWA, Yasuhiko TAKEMURA
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Abstract
A semiconductor integrated circuit comprising thin-film transistors in each of which the second wiring is prevented from breaking at steps. A silicon nitride film is formed on gate electrodes and on gate wiring extending from the gate electrodes. Substantially triangular regions are formed out of an insulator over side surfaces of the gate electrodes and of the gate wiring. The presence of these substantially triangular side walls make milder the steps at which the second wiring goes over the gate wiring. This suppresses breakage of the second wiring.
Claims1
A SOI integrated circuit comprising:
- a first insulating film formed over a semiconductor substrate;
- an n-channel transistor formed over the first insulating film, the n-channel transistor comprising:
- a first semiconductor film including a first channel formation region, first source and drain regions, and first lightly doped regions between the first channel formation region and the first source and drain regions formed over the first insulating film;
- a first gate insulating film formed over the first semiconductor film;
- a first gate electrode formed over the first gate insulating film;
- first side walls formed adjacent to side surfaces of the first gate electrode;
- and
- a second insulating film interposed between the first side walls and the side surfaces of the first gate electrode, and extending below the first side walls;
- and
- a p-channel transistor formed over the first insulating film, the p-channel transistor and the second-type transistor comprising:
- a second semiconductor film including a second channel formation region, second source and drain regions, and second lightly doped regions between the second channel formation region and the second source and drain regions formed over the first insulating film;
- a second gate insulating film formed over the second semiconductor film;
- a second gate electrode formed over the second gate insulating film;
- and
- second side walls formed adjacent to side surfaces of the second gate electrode;
- and
- a third insulating film interposed between the second side walls and the side surfaces of the second gate electrode, and extending below the second side walls,
- wherein the first lightly doped regions of the n-channel transistor overlaps with the first side walls of n-channel transistor, and
- wherein the second lightly doped regions of the p-channel transistor overlaps with the second side walls of p-channel transistor.
Dependencies are inferred from the claim text.