Method of forming metal line in semiconductor device including forming first and second zirconium films
View Patent ↗Provided is a method of forming a metal line in a semiconductor device. According to the present invention, a barrier metal layer, a Zr film, and a Cu thin film is sequentially formed in insides of a dual damascene pattern comprising via holes and trenches. Then, a Zr film is formed on the Cu thin film, and Zr is allowed to be diffused into crystal particles of Cu and interfaces between the crystal particles by carrying out a heat treatment process thereto, so that uniform Cu (Zr) bonds are formed regardless of a depth. As a result, an EM resistance characteristic of the Cu thin film even in narrower and deeper via holes can be improved, and thus reliability of process and an electrical characteristic of a device can be also improved.
1. A method of forming a metal line in a semiconductor device, comprising the steps of:
forming an interlayer insulating film on a semiconductor substrate in which various elements for forming a semiconductor device are formed;
forming a dual damascene pattern in the interlayer insulating film;
forming an barrier metal layer over the entire structure including the dual damascene pattern;
forming a first Zr film on the barrier metal layer;
filling the dual damascene pattern with a conductive layer;
forming a second Zr film over the entire structure including the conductive layer;
forming a Zr compound metal layer by allowing the conductive layer to react with Zr components of the first and the second Zr films by means of a heat treatment process; and
removing the Zr compound metal layer and the barrier metal layer on the interlayer insulating film to form a metal line.
2. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the barrier metal layer is formed to have a laminated structure of TaN/Ta.
3. The method of forming a metal line in a semiconductor device according to claim 2 , wherein the TaN film is formed to have a thickness of 50 Å to 150 Å, and the Ta film is formed to have a thickness of 100 Å to 300 Å.
4. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the first Zr film or the second Zr film is formed using a CVD method or a PECVD method.
5. The method of forming a metal line in a semiconductor device according to claim 4 , wherein, when the first Zr film and the second Zr film are formed, Zr (N(C 2 H 5 ) 2 ) 4 or Zr (N(CH 3 ) 2 ) 4 is supplied as precursor, an inert gas such as Ar or He is supplied as a carrier gas, and H 2 gas is supplied as a reaction gas.
6. The method of forming a metal line in a semiconductor device according to claim 5 , wherein a supply amount of the precursor is set to be in the range of 30 sccm to 1000 sccm, and a supply amount of the reaction gas is set to be in the range of 100 sccm to 3000 sccm.
7. The method of forming a metal line in a semiconductor device according to claim 6 , wherein the first Zr film or the second Zr film is formed at a temperature in the range of 300° C. to 400° C., with a power of 200 W to 5000 W applied.
8. The method of forming a metal line in a semiconductor device according to claim 5 , wherein the first Zr film or the second Zr film is formed at a temperature in the range of 300° C. to 400° C., with a power of 200 W to 5000 W applied.
9. The method of forming a metal line in a semiconductor device according to claim 4 , wherein the first Zr film or the second Zr film is formed at a temperature in the range of 300° C. to 400° C., with a power of 200 W to 5000 W applied.
10. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the first Zr film is formed to have a thickness in the range of 50 Å to 1000 Å.
11. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the conductive layer is formed by forming a metal seed layer and then performing an electroplating method using the metal seed layer.
12. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the conductive layer is formed of copper.
13. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the conductive layer is formed of copper.
14. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the second Zr film is formed using a physical vapor deposition method or chemical vapor deposition method.
15. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the heat treatment process is carried out in an N 2 /H 2 atmosphere by using an annealing method such as a furnace annealing or an RTP.
16. The method of forming a metal line in a semiconductor device according to claim 15 , wherein a mixture ratio of the N 2 and H 2 is in the range of 5:1 to 15:1.
17. The method of forming a metal line in a semiconductor device according to claim 15 , wherein the heat treatment process is carried out at a temperature in the range of 100° C. to 300° C. for 1 to 40 minutes.
18. The method of forming a metal line in a semiconductor device according to claim 1 , wherein the heat treatment process is carried out at a temperature in the range of 100° C. to 300° C. for 1 to 40 minutes.
19. The method of forming a metal line in a semiconductor device according to claim 1 , further comprising a step of forming a capping layer over the entire structure including the metal line, after forming the metal line.
20. The method of forming a metal line in a semiconductor device according to claim 19 , wherein the capping layer is formed of SiN.
21. The method of forming a metal line in a semiconductor device according to claim 20 , wherein the SiN is formed at a temperature of 200° C. to 400° C. by using SiH 4 gas, N 2 gas, and NH 3 gas to have a thickness of 100 Å to 500 Å.