METHOD FOR REMOVING NITRIDE MATERIAL

摘要

A method for removing silicon nitride material includes following steps. A substrate having at least a gate structure formed thereon is provided, and at least a silicon nitride hard mask is formed on top of the gate structure. A first removal is performed to remove a portion of the silicon nitride hard mask with a first phosphoric acid (H3PO4) solution. A second removal is subsequently performed to remove remnant silicon nitride hard mask with a second phosphoric acid solution. The first removal and the second removal are performed in-situ. A temperature of the second phosphoric acid solution is lower than a temperature of the first phosphoric acid solution.

主权项

1. A method for removing silicon nitride material comprising:
providing a substrate having at least a silicon nitride layer formed thereon; performing a first removal to remove a portion of the silicon nitride layer with a first phosphoric acid (H3PO4) solution; and performing a second removal to remove remnant silicon nitride layer with a second H3PO4 solution, a temperature of the second H3PO4 solution is lower than a temperature of the first H3PO4 solution, a process duration of the second removal is longer than a process duration of the first removal, and a concentration of the first H3PO4 solution and a concentration of the second H3PO4 solution are identical.