Damascene Wire Uniformity via Dummy Shape Exclusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chemical mechanical polishing processes for damascene wires in integrated circuit chips face challenges in achieving uniformity due to parasitic proximity effects caused by metal dummy shapes, which can degrade wire performance.
Innovation Solution
Simultaneously forming damascene wires and metal dummy shapes in a dielectric layer, with the latter being removed or modified within exclusion regions to maintain uniform pattern density and prevent parasitic effects, using a method that involves generating specific photomask data sets and reticles for photolithographic fabrication steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal dummy shapes are added to improve pattern density for CMP uniformity, then damascene wire uniformity is improved, but parasitic proximity effects occur that degrade wire performance
Solution Approach 1:
The patent extracts and removes metal dummy shapes from exclusion regions around damascene wires after they have been used to provide sufficient pattern density for CMP uniformity. This selective removal eliminates the parasitic proximity effects that would otherwise degrade wire performance while maintaining the uniformity benefits during the critical CMP process.
Solution Approach 2:
The patent applies different treatments to different regions: metal dummy shapes are retained in regions where they provide CMP uniformity benefits, but are removed from exclusion regions around wires where they would cause parasitic effects. This local differentiation optimizes both wire uniformity and performance.
2Object-affected harmful factors
If metal dummy shapes are removed from exclusion regions to eliminate parasitic effects, then wire performance is improved, but pattern density uniformity may be compromised
Solution Approach 1:
The patent segments the dummy shape population into two groups: those within exclusion regions (removed) and those outside exclusion regions (retained). This segmentation allows the pattern density to remain sufficient for CMP uniformity while eliminating parasitic effects from the wire-proximity regions.
Solution Approach 2:
Different regions are treated differently: exclusion regions have metal dummy shapes removed to eliminate parasitic effects, while non-exclusion regions retain metal dummy shapes to maintain overall pattern density uniformity for CMP process control.
Data Source
AI summary
A method of improving damascene wire uniformity without reducing performance. The method includes simultaneously forming a multiplicity of damascene wires and a multiplicity of metal dummy shapes in a dielectric layer of a wiring level of an integrated circuit chip, the metal dummy shapes being dispersed between damascene wires of the multiplicity of damascene wires; and removing or modifying those metal dummy shapes of the multiplicity of metal dummy shapes within exclusion regions around selected damascene wires of the multiplicity of damascene wires. Also a method of fabricating a photomask and a photomask for use in improving damascene wire uniformity without reducing performance.