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US 5,705,029 AGranted
Dry etching method
AssigneeHitachi, Ltd.
InventorsSadayuki Okudaira, Kazunori Tsujimoto, Shinichi Tachi
Life of this patent
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Abstract
Etching of an article is carried out by maintaining the article at a temperature at which the vapor pressure of etching gas molecules becomes equal to or higher than the pressure of etching gas and the vapor pressure of neutral radicals contained in a plasma becomes equal to or lower than the pressure of an etching gas. An etching pattern with a substantially vertical side profile and extremely small in dimensional shift from the mask can be formed at high precision.
Claims8
A dry etching method, comprising the steps of;
- providing an article to be etched, including a silicon region having a mask pattern thereon, on a support stage located in a reaction chamber;
- producing a plasma of Cl.sub.2 gas in said reaction chamber;
- lowering the temperature of the article to be etched to a temperature in a range of -60.degree. C. to -120.degree. C., so as to provide the article to have a lowered temperature during the dry etching, including supplying a cooling gas to a back side of said article;
- and
- etching an exposed surface of the article, exposed through the mask pattern, using the plasma,
- wherein the step of lowering the temperature includes (1) selectively choosing the temperature at which dry etching is to be performed so as to be a predetermined temperature, said predetermined temperature being determined based upon the material being etched and the etching gas, being within a range which is different for different materials being etched and different etching gases, and being a temperature such that a dimensional shift of the article etched, as compared to a size of the mask pattern, is less than 0.2 .mu.m, and (2) decreasing the temperature of the article to said predetermined temperature.
3 more elements
A dry etching method, comprising:
- providing an article on a support stage in a reaction chamber, said article having a front side and a back side, said front side including a region comprising poly Si or Si and a mask pattern provided over said region;
- cooling said support stage to a temperature below 0.degree. C.;
- supplying a cooling gas to said back side of said article;
- producing a plasma of chlorine gas in said reaction chamber;
- and
- etching said region of said article through said patterned mask using said plasma of said chlorine gas, wherein said article is maintained at a temperature in a range of -120.degree. C. to -60.degree. C. during said etching.
3 more elements
Dependencies are inferred from the claim text.