Method and apparatus for non-aggressive plasma-enhanced vapor deposition of dielectric films
View Patent ↗According to the invention, while performing plasma-enhanced chemical vapor deposition on a substrate by exposing the substrate in a vacuum to a flow of particles generated by a plasma, which particles react to form a passivation layer on the substrate, a grid is interposed between the plasma and the substrate, thereby reducing the flow of charged particles towards the substrate while conserving a flow of neutral particles. The grid is formed of metal wires that are crossed at a pitch that is less than two or three times the Debye length (λD) of the plasma used, at least at the beginning of deposition. The aging properties of semiconductor components made by such a method is thereby improved.
1. A method of depositing dielectric films by plasma-enhanced chemical vapor deposition, in which a substrate in a vacuum is exposed to a flow of particles generated by a plasma, which particles react to form a passivation layer on the substrate, a selective trap being interposed between the plasma and the substrate, thereby reducing the flow of charged particles towards the substrate while conserving a flow of neutral particles, the method being characterized in that it comprises two successive steps:
a) an initial step of non-aggressive deposition, during which the selective trap effectively reduces the flow of charge particles; and
b) a following step of deposition, during which the selective trapping effect is inhibited, so that deposition occurs more rapidly than in said initial deposition.
2. A method according to claim 1 , in which the selective trapping effect is inhibited by modifying the trap, e.g. by moving it, during said following deposition step.
3. A method according to claim 1 , in which the selective trapping effect is inhibited by modifying the properties of the plasma during said following deposition step.