| abstract |
A method of etching a pattern in a porous dielectric material layer (140), comprising: defining the pattern in a mask (120, 130) overlying the porous dielectric material layer (140), minus an etching of the porous dielectric material layer (140) through the mask (120, 130). The etching is performed in a plasma formed by a mixture comprising a silicon-based gas, in the presence of nitrogen (N 2) or oxygen (O 2) so as to grow a passivation layer throughout the etching ( 112), at least on the flanks of the porous dielectric material layer (140). The invention applies particularly advantageously to the formation of trenches to form electrical interconnection lines. |