Method of plasma etching dielectric materials
AssigneeLam Research Corporation
InventorsHelen Zhu, Roger F. Lindquist
Life of this patent
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Abstract
A semiconductor manufacturing process wherein deep and narrow 0.3 micron and smaller openings are plasma etched in a dielectric layer such as doped and undoped silicon oxide. The etching gas includes at least one fluorocarbon reactant and carbon monoxide and optionally a carrier gas such as Ar. The etching process is carried out in a high density plasma reactor and is effective to etch the dielectric layer with high selectivity to the masking layer and/or a stop layer. The process is useful for etching 0.25 micron and smaller contact or via openings in forming structures such as damascene structures.
Claims27
A process for etching a dielectric layer, comprising the steps of:
- introducing a semiconductor substrate into a high density plasma etching reactor, the semiconductor substrate having a masking layer over a dielectric layer and an electrically conductive or semiconductive layer underlying the dielectric layer;
- supplying etching gas to the plasma etching reactor and energizing the etching gas into a high density plasma state, the etching gas consisting essentially of a fluorocarbon reactant of C4F8 and CH2F2 and carbon monoxide;
- and
- exposing the masking layer and exposed portions of the dielectric layer to the high density plasma so as to etch openings in the dielectric layer with the high density plasma, the etching rate of the dielectric layer to the etching rate of the masking layer being at least about 5.
The process of clam 1, wherein the high density plasma reactor is formed by inductively coupling RF energy into the plasma reactor and the fluorocarbon reactant is supplied to the plasma reactor at a flow rate of 5 to 100 sccm.
Dependencies are inferred from the claim text.