Method of removing post-etch residues
A method of removing post-etch residues is provided. First, a substrate is provided. An isolation layer covers the substrate and a conductive layer is embedded in the isolation layer. A dielectric layer and a hard mask cover the isolation layer. Then, an etching process is performed, and a patterned hard mask is formed by etching the hard mask by ions or atoms. After that, a charge-removing process is performed by using a conductive solution to cleaning the patterned hard mask and the dielectric layer so as to remove the charges accumulated on the patterned hard mask and the dielectric layer during the etch process. Finally, the post-etch residues on the patterned hard mask and the dielectric layer is removed.
1. A method of removing post-etch residues, comprising:
providing a substrate covered by a isolation layer, a conductive layer embedded in the isolation layer and a dielectric layer and a hard mask positioned on the isolation layer and the conductive layer;
performing an plasma etching process to etch the hard mask with ions so as to form a patterned hard mask and exposes part of the dielectric layer;
rinsing the patterned hard mask and the dielectric layer with a solution containing conductive ions to remove charges accumulated on the patterned hard mask and the dielectric layer; and
performing a remove process to remove a post-etch residue on the patterned hard mask and the dielectric layer after removing the charges accumulated on the patterned hard mask and the dielectric layer, wherein the post-etch residue does not react with the conductive ions.
2. The method of removing post-etch residues of claim 1 , wherein the solution comprises deionized water.
3. The method of removing post-etch residues of claim 2 , wherein the conductive ions are selected from the group consisting of bicarbonate ions, (HCO3-), carbonate ions (CO 3 2− ) and ammonium ions (NH4+).
4. The method of removing post-etch residues of claim 2 , wherein the solution is a saturated solution of the conductive ions.
5. The method of removing post-etch residues of claim 1 , wherein the resistance of the solution is between 1 KΩ-cm to 3000 KΩ-cm.
6. The method of removing post-etch residues of claim 1 , wherein the pH value of the solution is substantially 3.
7. The method of removing post-etch residues of claim 1 , wherein the solution contains water more than 80%.
8. The method of removing post-etch residues of claim 1 , wherein the patterned hard mask comprises a via of a dual damascene structure.
9. The method of removing post-etch residues of claim 1 , wherein the patterned hard mask comprises a trench of a dual damascene structure.
10. The method of removing post-etch residues of claim 1 , wherein the conductive layer comprises copper.
11. A method of removing post-etch residues, comprising:
providing a substrate covered by a isolation layer, a conductive layer embedded in the isolation layer and a dielectric layer and a hard mask positioned on the isolation layer and the conductive layer, wherein the hard mask comprises TiN;
performing an plasma etching process to etch the hard mask with ions so as to form a patterned hard mask and exposes part of the dielectric layer;
rinsing the patterned hard mask and the dielectric layer with a solution containing conductive ions to remove charges accumulated on the patterned hard mask and the dielectric layer; and
performing a remove process to remove a post-etch residue on the patterned hard mask and the dielectric layer after removing the charges accumulated on the patterned hard mask and the dielectric layer, wherein the post-etch residue does not react with the conductive ions.