Method for forming a tapered dual damascene via portion with improved performance
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChih-Fu Chang, Yu-Chun Huang
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Abstract
A method for selectively anisotropically a semiconductor feature to form a tapered sidewall profile including providing a semiconductor wafer including an anisotropically etched feature formed in at least one dielectric insulating layer including a relatively larger width dimension portion overlying and encompassing at least one relatively smaller diameter dimension portion the smaller diameter dimension portion further including a bottom portion including an overlying liner; and, selectively anisotropically etching the anisotropically etched feature according to a reactive ion etching (RIE) process to form a tapered sidewall portion of the at least one relatively smaller diameter portion.
Claims20
A method for selectively anisotropically etching a semiconductor feature to form a tapered sidewall profile comprising the steps of:
- providing a semiconductor wafer comprising an anisotropically etched feature formed in at least one dielectric insulating layer comprising a relatively larger width dimension portion overlying and encompassing at least one relatively smaller diameter dimension portion the smaller diameter dimension portion further comprising a bottom portion including an overlying liner;
- and,
- selectively anisotropically etching the anisotropically etched feature according to a reactive ion etching (RIE) process to form a tapered sidewall portion of the at least one relatively smaller diameter portion.
A method for selectively anisotropically etching a dual damascene opening to form a tapered via portion sidewall having an improved electrical performance comprising the steps of:
- providing a semiconductor wafer comprising a via opening portion and a trench line portion to form a dual damascene opening extending through at least one silicon dioxide containing dielectric insulating layer the via opening portion comprising a metal nitride liner covering a bottom portion of the via opening;
- and,
- selectively anisotropically etching the dual damascene opening according to a reactive ion etching (RIE) process comprising removing the metal nitride liner to form a tapered sidewall portion within the via opening portion the tapered sidewall portion comprising an upper portion adjacent the trench line portion relatively larger in diameter compared to the bottom portion diameter.
Dependencies are inferred from the claim text.