Method for forming barrier metal of semiconductor device
A method for forming a barrier metal of a semiconductor device wherein a TiSiN layer having an atomic layer thickness is deposited by performing deposition of an Si layer inside a contact hole of a semiconductor device using an atomic layer deposition process and by performing deposition of a precursor layer on the Si layer. By repetition of this ALD process, the TiSiN layer is thickly formed at a desired thickness. Then, the TiSiN layer is plasma processed under the atmosphere of a nitrogen gas and a hydrogen gas, or an ammonia gas, and thus impurities are removed from the TiSiN layer. Therefore, it is easy to thickly form the TiSiN layer for the barrier metal. It is possible to reduce resistivity of the TiSiN layer to a relatively low level. Thereby, it is possible to decrease a contact resistance of the TiSiN layer and, further, to enhance an electrical characteristic of the semiconductor device.
1. A method for forming a barrier metal of a semiconductor device, comprising:
forming an insulating layer on a semiconductor substrate and forming an opening in the insulating layer;
forming a TiSiN layer having a desired thickness by repeatedly performing a process of forming a TiSiN layer having an atomic layer thickness in a reaction chamber, wherein the process of forming a TiSiN layer having an atomic layer thickness comprises performing deposition of a Si layer inside the opening and on the insulating layer using an atomic layer deposition process, discharging a gas remaining in the reaction chamber by using an inert gas, performing deposition of a certain precursor layer on the Si layer, and discharging a gas of precursor material remaining in the reaction chamber by using an inert gas; and
performing plasma processing for the TiSiN layer so as to remove impurities contained in the TiSiN layer, wherein a pressure of the reaction chamber is between 90 and 300 Torr.
2. The method of claim 1 , wherein the Si layer is deposited using an SiH 4 gas.
3. The method of claim 1 , wherein the precursor layer is formed by any one of a Tetrakis DiMethyl Amido Titanium (TDMAT) layer, a Tetrakis DiEthyl Amido Titanium (TDEAT) layer and a TiCl 4 layer.
4. The method of claim 2 , wherein the precursor layer is formed by any one of a Tetrakis DiMethyl Amido Titanium (TDMAT) layer, a Tetrakis DiEthyl Amido Titanium (TDEAT) layer and a TiCl 4 layer.
5. The method of claim 3 , wherein the TiSiN layer having the atomic layer thickness is formed by reacting the precursor layer by thermal decomposition at a temperature ranging from 350 to 450° C.
6. The method of claim 4 , wherein the TiSiN layer having the atomic layer thickness is formed by reacting the precursor layer by thermal decomposition at a temperature ranging from 350 to 450° C.
7. The method of claim 1 , wherein the TiSiN layer is plasma processed so as to remove CH based impurities contained in the TiSiN layer.
8. The method of claim 7 , wherein the TiSiN layer is plasma processed under any one atmosphere of a nitrogen gas and a hydrogen gas, or an ammonia gas.
9. The method of claim 1 , wherein the opening is formed into any one of a contact hole and a via hole.
10. The method of claim 1 , wherein the inert gas is a nitrogen or argon gas.