Method of wet etching a silicon and nitrogen containing material
View Patent ↗The invention relates to a method of manufacturing a semiconductor device comprising the step of removing a silicon and nitrogen containing material by means of wet etching with an aqueous solution comprising hydrofluoric acid in a low concentration, the aqueous solution being applied under elevated pressure to reach a temperature above 100° C.
1. A method of manufacturing a semiconductor device comprising the step of removing a silicon and nitrogen containing material by means of wet etching with an aqueous solution comprising hydrofluoric acid in a low concentration, the aqueous solution being applied under elevated pressure to reach a temperature above 100° C.
2. A method as claimed in claim 1 , wherein the silicon and nitrogen containing material is silicon nitride or silicon oxynitride.
3. A method as claimed in claim 1 , wherein the silicon and nitrogen containing material is silicon-rich silicon nitride or silicon-rich silicon oxynitride.
4. A method as claimed in claim 1 , wherein the silicon and nitrogen containing material is etched by means of a single-wafer process.
5. A method as claimed in claim 1 , wherein the aqueous solution is applied at a temperature in the range from 100° C. to about 130° C.
6. A method as claimed claim 1 , wherein the aqueous solution is treated so as to keep the layer of silicon in an non-oxidized state during etching the inorganic anti-reflective layer.
7. A method as claimed in claim 6 , wherein dissolved oxygen is removed from the aqueous solution by evacuating the aqueous solution.
8. A method as claimed in claim 6 , wherein dissolved oxygen is removed from the aqueous solution by exchanging it for an inert gas.
9. A method as claimed in claim 6 , wherein a reducing agent is added to the aqueous solution.
10. A method as claimed in claim 1 , wherein the hydrofluoric acid is applied in an concentration in the range of about 0.001 to 0.1 M.