Semiconductor device manufacturing method
In a semiconductor device manufacturing method according to this invention, an SiO 2 film used as a mask at the time of trench formation is removed by a wet process after hydrophilic treatment is performed on the interior of a hydrophobic trench.
1 . A semiconductor device manufacturing method comprising:
forming a mask layer on a silicon substrate;
forming a photo resist layer on the mask layer;
forming a pattern surrounding a predetermined region in the photo resist layer;
etching the mask layer using the pattern to form a mask;
forming a trench in the silicon substrate using the mask;
cleaning an interior of the trench with a cleaning solution containing hydrofluoric acid;
performing hydrophilic treatment on the interior of the trench; and
removing the mask by a wet process after the hydrophilic treatment step.
2 . The semiconductor device manufacturing method according to claim 1 , wherein the mask layer includes a silicon oxide film.
3 . The semiconductor device manufacturing method according to claim 1 , wherein the mask layer includes a silicon oxide film and a silicon nitride film.
4 . The semiconductor device manufacturing method according to claim 1 , wherein the wet process is performed using a solution containing hydrofluoric acid-ammonium fluoride mixture.
5 . The semiconductor device manufacturing method according to claim 1 , wherein the hydrophilic treatment is performed using APM and SPM.
6 . The semiconductor device manufacturing method according to claim 1 , wherein the hydrophilic treatment is performed by oxidation.
7 . The semiconductor device manufacturing method according to claim 1 , wherein formation of the trench is performed by dry etching.
8 . The semiconductor device manufacturing method according to claim 1 , wherein the photo resist layer is removed after etching the mask layer using the pattern and before forming the trench in the silicon substrate.