Semiconductor device and manufacturing method thereof
A flip-chip mounting technique with high reliability is provided in flip-chip mounting using a Cu pillar. In a semiconductor device to be coupled to a mounting board via a Cu pillar, the Cu pillar is caused to have a laminated structure including a pillar layer, a barrier layer, and a bump in this order from below, and the bump is formed to be smaller than the barrier layer.
1. A manufacturing method of a semiconductor device, comprising the steps of:
(a) applying a resist film having an opening over a terminal pad formed over a semiconductor substrate;
(b) forming a pillar layer, a barrier layer, and a bump in the opening in this order from below;
(c) removing the resist film;
(d) etching outer peripheries of the bump; and
(e) reflowing the bump by a heat treatment such that a width of the bump is smaller than that of the barrier layer in a cross section of the semiconductor device.
2. The manufacturing method of a semiconductor device according to claim 1 ,
wherein, in the step (d), the etching is performed by using dilute hydrofluoric acid.
3. The manufacturing method of a semiconductor device according to claim 1 ,
wherein, in the step (b), the pillar layer, the barrier layer, and the bump are formed by electrolytic plating.
4. The manufacturing method of a semiconductor device according to claim 1 ,
wherein, in the step (c), the resist film is removed by ashing.
5. The manufacturing method of a semiconductor device according to claim 1 ,
wherein, in the step (d), the outer peripheries of the bump are wet etched.
6. The manufacturing method of a semiconductor device according to claim 1 ,
wherein the pillar layer is a Cu film,
wherein the barrier layer is an Ni film, and
wherein the bump is an SnAg film.
7. A manufacturing method of a semiconductor device, comprising the steps of:
(a) applying a first resist film over a terminal pad formed over a main surface of a semiconductor substrate;
(b) forming a first opening in the first resist film for exposing the terminal pad in the bottom thereof;
(c) forming a pillar layer and a barrier layer in this order from below;
(d) removing the first resist film;
(e) applying a second resist film over the terminal pad, the pillar layer, and the barrier layer;
(f) forming a second opening in the second resist film for exposing the barrier layer in the bottom thereof;
(g) forming a bump in the second opening; and
(h) removing the second resist film.
8. The manufacturing method of a semiconductor device according to claim 7 ,
wherein a diameter of the second opening is smaller than that of the first opening.
9. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (b), the first opening is formed by photolithography.
10. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (c), the pillar layer and the barrier layer are formed by electrolytic plating.
11. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (d), the first resist film is removed by ashing.
12. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (f), the second opening is formed by photolithography.
13. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (g), the bump is formed by electrolytic plating.
14. The manufacturing method of a semiconductor device according to claim 7 ,
wherein, in the step (h), the second resist film is removed by ashing.
15. The manufacturing method of a semiconductor device according to claim 7 ,
wherein the pillar layer is a Cu film,
wherein the barrier layer is an Ni film, and
wherein the bump is an SnAg film.