Selective etching process of a mask disposed on a silicon substrate
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorNicolas Posseme
Life of this patent
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Abstract
The method includes the steps of: a) providing a silicon substrate including a first portion covered by the mask made from a carbonaceous material and a second doped portion, the mask including, at the surface, a surface layer including implanted ionic species and an underlying layer free of implanted ionic species, b) exposing the surface layer and the second portion to a SiCl4 and Cl2 plasma so as to deposit a silicon chloride SiClx layer on the second portion and etch the surface layer, c) etching the underlying layer so as to expose the first portion, and d) etching the silicon chloride SiClx layer so as to expose the second portion.
Claims12
A selective etching process of a carbon material mask disposed on a silicon substrate. comprises the steps of:
- a) providing a silicon substrate including a first portion covered by the carbon material mask and a second doped portion, the mask including at its surface a surface layer comprising implanted ionic species and an underlying layer free of implanted ionic species
- b) exposing the surface layer and the second portion to a SiCl4 and Cl2 plasma so as to deposit a silicon chloride SiClx layer on the second portion and to etch the surface layer,
- c) etch the underlying layer so as to expose the first portion, and
- d) etch the silicon chloride SiClx layer so as to expose the second portion.
Dependencies are inferred from the claim text.