Method for etching PT film
AssigneeSharp Kabushiki Kaisha
InventorsSeiichi Yokoyama, Yasuyuki Ito, Shigeo Onishi, Jun Kudo, Keizo Sakiyama
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Abstract
A method for etching a Pt film of the present invention includes the steps of: forming an etching resistant film on a Pt film, followed by patterning; etching the Pt film by using as an etching mask the etching resistant film and by using, as an etching gas, a mixed gas containing oxygen gas and chlorine gas or chloride gas, during which layers made of PtCl.sub.x O.sub.y or a mixture containing PtCl.sub.x and PtO.sub.y are formed on side walls of the etching resistant film and the Pt film; and removing the layers made of PtCl.sub.x O.sub.y or the mixture containing PtCl.sub.x and PtO.sub.y with an acid by wet etching after the etching step.
Claims4
A method for etching a Pt film comprising the steps of:
- forming an etching resistant film on a Pt film, followed by patterning;
- etching the Pt film by using as an etching mask the etching resistant film and by using, as an etching gas, a mixed gas containing oxygen gas and chlorine gas or chloride gas, during which layers made of PtCl.sub.x O.sub.y or a mixture containing PtCl.sub.x and PtO.sub.y are formed on side walls of the etching resistant film and the Pt film;
- and
- removing the layers made of PtCl.sub.x O.sub.y or the mixture containing PtCl.sub.x and PtO.sub.y with an acid by wet etching after the etching step.
A method for etching a Pt film comprising the steps of:
- forming an insulating film, a Ti film, a TiN film, a Ti film, a Pt film, and a ferroelectric film on a substrate in a successive manner;
- forming an etching resistant film on the ferroelectric film, followed by patterning;
- etching the ferroelectric film by using the patterned etching resistant film as an etching mask;
- etching the Pt film by using, as an etching gas, a mixed gas containing oxygen gas and chlorine gas or chloride gas under the conditions that a temperature of the substrate is in the range of 100.degree. C. to 400.degree. C. and a ratio of a flow rate of the oxygen gas with respect to a total flow rate of the mixed gas is 1% or more and less than 50%, during which layers made of PtCl.sub.x O.sub.y or a mixture containing PtCl.sub.x and PtO.sub.y on side walls of the etching resistant film, the ferroelectric film, and the Pt film;
- and
- removing the layers made of PtCl.sub.x O.sub.y or a mixture containing PtCl.sub.x and PtO.sub.y with an acid by wet etching after the etching step.
Dependencies are inferred from the claim text.