Semiconductor device and method of manufacturing the same
View Patent ↗A method of manufacturing a semiconductor device, includes the steps of forming an insulating film on a semiconductor substrate having a silicide layer, forming a hole in the insulating film on the silicide layer, cleaning an inside of the hole and a surface of the silicide layer, forming a titanium layer on a bottom surface and an inner peripheral surface of the hole by a CVD method, forming a copper diffusion preventing barrier metal layer on the titanium layer in the hole, and burying a copper layer in the hole.
1. A method of manufacturing a semiconductor device, comprising: forming a silicide layer over a semiconductor substrate; forming an insulating film over the silicide layer; forming a hole reaching the silicide layer in the insulating film; forming a titanium layer over a bottom surface and an inner wall surface of the hole, wherein the titanium layer is formed by a chemical vapor deposition, wherein the titanium layer has a thickness of 2 nm to 8 nm over a side wall of the hole; cleaning the surface of the formed titanium layer by annealing the semiconductor substrate in a hydrogen atmosphere after forming the titanium layer without exposing the titanium layer to an atmosphere during a first process for the forming the titanium layer to a second process for the annealing in the hydrogen atmosphere; forming a barrier layer having a thickness of 1 nm to 20 nm by sputtering for preventing copper diffusion over the titanium layer in the hole, wherein the barrier layer is directly formed on the titanium layer after the cleaning; and burying a copper layer in the hole.
2. The method of claim 1 , wherein the titanium layer is formed by a CVD method.
3. The method of claim 2 , wherein a source gas contains at least one of TiCl 4 and TiBr 4 in the CVD method.
4. The method of claim 3 , wherein the CVD method is executed to contain further an inert gas.
5. The method of claim 2 , wherein the titanium layer is grown while heating the semiconductor substrate at a temperature in a range of 400° C. to 600° C.
6. The method of claim 1 , further comprising:
cleaning an inside of the hole and a surface of the silicide layer before forming the titanium layer.
7. The method of claim 6 , wherein cleaning the inside of the hole and the surface of the silicide layer is executed by either of a sputter cleaning with an argon ion and a cleaning with a fluorine compound gas.
8. The method of claim 1 , wherein the barrier layer is a film that is at least one selected from of Ta, TiN, TaN, Ru, WN, W—N—C, Ti—Si—N, Ta—Si—N, and W—Si—N.
9. The method of claim 1 , wherein burying the copper layer in the hole includes forming a seed layer over the barrier layer in the hole.
10. The method of claim 9 , wherein the seed layer is formed of any one of Cu, Ru, and Cu alloy.
11. The method of claim 1 , wherein the copper layer, the barrier layer, and the titanium layer over the insulating film are removed by a chemical mechanical polishing.
12. The method of claim 1 , wherein the silicide layer includes any one of nickel silicide, cobalt silicide, and nickel alloy.
13. The method of claim 12 , wherein the nickel alloy is an alloy of nickel and platinum.
14. The method of claim 1 , wherein the silicide layer is formed over surfaces of source/drain regions, the source/drain region contacts an element isolation structure constructed by burying an insulating material in the semiconductor substrate, and a bottom portion of the hole is formed over the silicide layer and the element isolation structure that is adjacent to the silicide layer.
15. The method of claim 1 , further comprising:
forming a silicon germanium layer over the surfaces of the source/drain regions of a PMOS transistor formed in the semiconductor substrate; and
forming the silicide layer by a reaction of the silicon germanium layer and a metal.