Plasma etching of silicon carbide
AssigneeLam Research Corporation
InventorSi Yi Li
Life of this patent
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Abstract
A process for plasma etching silicon carbide with selectivity to an overlying and/or underlying dielectric layer of material. The dielectric material can comprise silicon dioxide, silicon oxynitride, silicon nitride or various low-k dielectric materials including organic low-k materials. The etching gas includes a chlorine containing gas such as Cl2, an oxygen containing gas such as O2, and a carrier gas such as Ar. In order to achieve a desired selectivity to such dielectric materials, the plasma etch gas chemistry is selected to achieve a desired etch rate of the silicon carbide while etching the dielectric material at a slower rate. The process can be used to selectively etch a hydrogenated silicon carbide etch stop layer or silicon carbide substrate.
Claims20
A method of plasma etching a layer of silicon carbide with selectivity to underlying and/or overlying dielectric material, the method comprising:
- positioning a semiconductor substrate in a reactor chamber, the substrate including a layer of silicon carbide and an underlying and/or overlying layer of dielectric material;
- supplying an etchant gas to the chamber, the etchant gas comprising a chlorine containing gas, an oxygen containing gas, and optional carrier gas;
- and
- energizing the etchant gas into a plasma state and etching openings in the silicon carbide layer, the silicon carbide layer being etched at a faster rate than the dielectric material.
Dependencies are inferred from the claim text.