Semiconductor device and manufacturing method thereof
A semiconductor device includes an embedded wire in a first wire trench formed in a first interlayer dielectric film, the embedded wire having a barrier metal, a first seed film, a second seed film, and a copper film. The first seed film is formed by a copper film containing metal, and the second film is formed by a copper film. The second seed film suppresses that the metal contained in the first seed film diffuses into a wiring material film in a manufacturing process.
1 . A semiconductor device comprising:
a first interlayer dielectric film on a substrate, the first interlayer dielectric film having a trench,
a first wire in the trench of the first interlayer dielectric film,
a second interlayer dielectric film on the first wire and the first interlayer dielectric film, and
a plug and a second wire in the second interlayer dielectric film, the plug and the second wire being formed above the first wire,
wherein the first wire includes:
a first metal film covering the trench, the first metal film including copper and a metal which has binding energy with oxygen higher than that of the copper,
a second metal film provided on the first metal film to cover the trench, the second metal film including a metal which has binding energy with oxygen lower than that of the first metal film, and
a copper film provided on the second metal film to fill the trench, and
wherein the semiconductor device further includes a metal oxide film on upper end surfaces of the first metal film and second metal film and an upper surface of the copper film.
2 . A semiconductor device of claim 1 , wherein the second metal film is a copper film.
3 . A semiconductor device of claim 2 , wherein the second metal film further contains Ag or Au.
4 . A semiconductor device of claim 1 , wherein the metal having the binding energy with oxygen higher than that of the copper is any one of Al, Mg, Zn, Fe, Sn, and Ti.
5 . A semiconductor device of claim 1 , wherein the metal oxide film includes:
an oxide film of the metal which has the binding energy with oxygen higher than that of the copper, and
a copper oxide film.
6 . A semiconductor device of claim 1 , wherein the first wire further includes a barrier metal film provided between the first interlayer dielectric film and the first metal film to covering the trench.
7 . A semiconductor device of claim 1 , wherein a film thickness of the metal oxide film is thinner on the upper surfaces of the copper film and second metal film than on the upper end surface of the first metal film.
8 . A semiconductor device of claim 1 , further comprising:
a liner dielectric film between the first interlayer dielectric film and the second interlayer dielectric film, the liner dielectric film having an opening over the first wire,
wherein the plug is provided in the opening.
9 . A semiconductor device of claim 1 , in the first wire, a concentration of the metal having the binding energy with oxygen higher than that of the copper is lower in the second metal film than in the first metal film.
10 . A semiconductor device manufacturing method comprising the steps of:
(a) forming a first wire in a trench formed in a first interlayer dielectric film,
(b) forming a second interlayer dielectric film on the first wire and the first interlayer dielectric film, and
(c) forming a plug and a second wire in the second interlayer dielectric film on the first wire,
wherein step (a) includes:
(a1) forming a first metal film to cover the trench, the first metal film containing copper and a metal which has binding energy with oxygen higher than that of the copper,
(a2) forming a second metal film on the first metal film to cover the trench, the second metal film containing a metal which has binding energy with oxygen lower than that of the first metal film, and (a3) forming a copper film on the second metal film to fill the trench, wherein before step (c), a metal oxide film is formed on upper end surfaces of the first metal film and second metal film and on an upper surface of the copper film, and a film thickness of the metal oxide film is thinner on the upper surfaces of the copper film and second metal film than on the upper end surfaces of the first metal film.
11 . A semiconductor device manufacturing method of claim 10 , wherein the second metal film is a copper film.
12 . A semiconductor device manufacturing method of claim 11 , wherein the second metal film further contains Ag or Au.
13 . A semiconductor device manufacturing method of claim 10 , wherein the metal oxide film includes:
an oxide film of the metal which has the binding energy with oxygen higher than that of the copper, and
a copper oxide film.