Method of forming opening on semiconductor substrate
The present invention provides a method of forming an opening on a semiconductor substrate. First, a substrate is provided. Then a dielectric layer and a cap layer are formed on the substrate. A ratio of a thickness of the dielectric layer and a thickness of the cap layer is substantially between 15 and 1.5. Next, a patterned boron nitride layer is formed on the cap layer. Lastly, an etching process is performed by using the patterned hard mask as a mask to etch the cap layer and the dielectric layer so as to form an opening in the cap layer and the dielectric layer.
1. A method of forming an opening on the semiconductor substrate, comprising:
providing a substrate;
forming a dielectric layer on the substrate;
forming a patterned hard mask composite layer on the dielectric layer, wherein the patterned hard mask composite layer comprises:
a metal nitride layer; and
a boron nitride layer, wherein the metal nitride layer is disposed directly on the boron nitride layer; and
performing an etching process by using the patterned hard mask composite layer as a mask to etch the dielectric layer so as to form an opening in the dielectric layer.
2. The method of claim 1 , further comprising forming a cap layer between the dielectric layer and the patterned hard mask composite layer, and forming the opening in the cap layer during the etching process.
3. The method of claim 1 , wherein in the boron nitride layer, the boron concentration with respect to whole atoms in the boron nitride layer is substantially between 50% and 80%.
4. The method of claim 1 , wherein in the boron nitride layer, the boron concentration with respect to whole atoms in the boron nitride layer is substantially between 60% and 70%.
5. The method of claim 1 , wherein the boron nitride layer comprises a stress substantially between −50 MPa and 400 MPa.
6. The method of claim 1 , wherein the boron nitride layer comprise a stress substantially between 10 MPa and 100 MPa.
7. The method of claim 1 , wherein the cap layer comprises SiN, SiO 2 , SiC, SiCN or SiON.