Damascene process using cleaning solution
A cleaning solution is provided. The cleaning solution includes a fluorine containing compound, an inorganic acid, a chelating agent containing a carboxylic group and water for balance. The content of the fluorine containing compound is 0.01-0.5 wt % of. The content of the inorganic acid is 1-5 wt %.
1. A damascene process, comprising:
providing a substrate having a conductive layer thereon;
sequentially forming a dielectric layer and a metal hard mask layer on the substrate;
sequentially etching the metal hard mask layer and the dielectric layer, so as to form an opening exposing the conductive layer; and
performing a post-etch cleaning process with a cleaning solution, wherein the cleaning solution comprises:
(a) 0.01-0.5 wt % of a fluorine containing compound;
(b) 1-5 wt % of an inorganic acid;
(c) a chelating agent containing a carboxylic group;
(d) water for balance; and
(e) ethylenediaminetetraacetic acid (EDTA).
2. The damascene process of claim 1 , wherein the inorganic acid comprises sulfuric acid (H 2 SO 4 ) or hydrochloric acid (HCI).
3. The damascene process of claim 1 , wherein the chelating agent comprises oxalic acid.
4. The damascene process of claim 1 , wherein the opening comprises a dual damascene opening, a via opening or a contact opening.
5. The damascene process of claim 1 , wherein the metal hard mask layer comprises titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, or a combination thereof.
6. The damascene process of claim 1 , further comprising forming a buffer layer after the steps of forming the dielectric layer and before the step of forming the metal hard mask layer and forming a cap layer after the step of forming the metal hard mask layer, wherein the cap layer comprises silicon carbide, silicon nitride or silicon oxynitride.
7. The damascene process of claim 6 , wherein the buffer layer comprises silicon oxide or silicon oxynitride.
8. The damascene process of claim 1 , wherein the fluorine containing compound comprises hydrofluoric acid (HF) and ammonium fluoride (NH 4 F).
9. The damascene process of claim 8 , wherein the hydrofluoric acid (HF) is 0.01-0.1 wt %.
10. The damascene process of claim 8 , wherein the ammonium fluoride (NH 4 F) is 0.05-0.5 wt %.
11. The damascene process of claim 1 , wherein the cleaning solution further comprises (f) triethanolamine (TEA).