Semiconductor device and semiconductor device manufacturing method
According to one embodiment, a semiconductor device includes an interconnect provided on a first interlayer insulating film covering a semiconductor substrate in which an element is formed, a cap layer provided on the upper surface of the interconnect, and a barrier film provided between the interconnect and a second interlayer insulating film covering the interconnect. The interconnect includes a high-melting-point conductive layer, and the width of the interconnect is smaller than the width of the cap layer. The barrier film includes a compound of a contained element in the high-melting-point conductive layer.
1. A semiconductor device manufacturing method comprising:
forming a first interlayer insulating film on a semiconductor substrate; forming a high-melting-point conductive layer on the first interlayer insulating film; fabricating the high-melting-point conductive layer to have an interconnect pattern; after fabricating the high-melting-point conductive layer to have the interconnect pattern, subjecting exposed side surfaces of the fabricated high-melting-point conductive layer having the interconnect pattern to a first heat treatment in a reduction atmosphere to remove a native oxide film on the exposed side surfaces of the fabricated high-melting-point conductive layer by a reduction treatment; subjecting the fabricated high-melting-point conductive layer to a second heat treatment in a reactive gas atmosphere to form a barrier film on the exposed side surfaces of the high-melting-point conductive layer, the barrier film including a compound of a contained element in the high-melting-point conductive layer; and forming a second interlayer insulating film covering the high-melting-point conductive layer,
wherein a first metal element as the contained element in the high-melting-point conductive layer is at least one element selected from the group including Mo, W, Ru, Ta, Co, and Ni.
2. The semiconductor device manufacturing method according to claim 1 , wherein
the barrier film inhibits the diffusion of an impurity originating from the second interlayer insulating film into the high-melting-point conductive layer when the second interlayer insulating film is deposited.
3. The semiconductor device manufacturing method according to claim 1 , wherein
the high-melting-point conductive layer is a material having a recrystallization temperature of 1000° C. or less.
4. The semiconductor device manufacturing method according to claim 1 , wherein
the high-melting-point conductive layer includes Mo, and the barrier film includes MoO 2 .
5. The semiconductor device manufacturing method according to claim 1 , wherein
the high-melting-point conductive layer which includes a first metal element and a second metal element as the contained element in the high-melting-point conductive layer is subjected to the second heat treatment, the second metal element being lower in compound formation energy than the first metal element, and
the barrier film which includes a compound of the second metal element is formed by the self-passivation of the second metal element.
6. The semiconductor device manufacturing method according to claim 5 , wherein
the second metal element is at least one element selected from the group including Al, Zr, Ti, and V.
7. The semiconductor device manufacturing method according to claim 1 , wherein
the high-melting-point conductive layer selectively remains on a side surface of a trench formed in the first interlayer insulating film, and the high-melting-point conductive layer fabricated into the interconnect pattern is formed.
8. The semiconductor device manufacturing method according to claim 1 , wherein
the second heat treatment is conducted under conditions in which the vaporization velocity of the high-melting-point conductive layer is less than the velocity of a chemical reaction of the high-melting-point conductive layer.
9. The semiconductor device manufacturing method according to claim 1 , wherein
the high-melting-point conductive layer is crystallized in at least one of the first and second heat treatments.