Semiconductor device with a line and method of fabrication thereof
View Patent ↗A semiconductor device includes an interlayer insulation film, an underlying line provided in the interlayer insulation film, a liner film overlying the interlayer insulation film, an interlayer insulation film overlying the liner film. The underlying line has a lower hole and the liner film and the interlayer insulation film have an upper hole communicating with the lower hole, and the lower hole is larger in diameter than the upper hole. The semiconductor device further includes a conductive film provided at an internal wall surface of the lower hole, a barrier metal provided along an internal wall surface of the upper hole, and a Cu film filling the upper and lower holes. The conductive film contains a substance identical to a substance of the barrier metal. A highly reliable semiconductor device can thus be obtained.
1. A method of fabricating a semiconductor device, comprising the steps of:
depositing on a first insulation film having a line formed therein a second insulation film and a third insulation film deposited in layers;
providing said second and third insulation films with an upper hole reaching said line or said line and said first insulation film;
wet-etching an interior of said upper hole to form in said line a lower hole larger in diameter than said upper hole;
depositing an upper conductive film covering an inner wall surface of said upper hole and only a bottom of said lower hole;
physically etching said upper conductive film present at said bottom of said lower hole to provide a lower conductive film on an inner wall surface of said lower hole; and
depositing a conductive film containing copper and filling said upper and lower holes,
wherein the step of physically etching includes physically etching said upper conductive film and said line present at said bottom of said lower hole.
2. The method according to claim 1 , wherein the step of physically etching includes physical etching until said line is penetrated.
3. The method according to claim 1 , wherein the step of providing said upper hole includes providing said upper hole reaching said line and said first insulation film.