Hydrocarbon Support Material for High Aspect Ratio Capacitor Etching
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Solution Overview
Problem
The use of silicon dioxide as a support material for microelectronic structures leads to tapered etch profiles and feature charging issues, resulting in aspect ratio dependent etch and feature twisting, which complicates the formation of high aspect ratio features in microelectronic devices.
Innovation Solution
A hydrocarbon-containing support material with at least 20 atomic % carbon, which can be electrically conductive or insulative, is used to reduce feature charging and improve etching profiles, allowing for higher aspect ratios and more stable processing by incorporating titanium and silicon for increased rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon dioxide is used as support material, then the material provides structural support, but it causes tapered etch profiles and feature charging issues
Solution Approach 1:
The patent changes the material parameter from silicon dioxide to hydrocarbon-containing material with at least 20 atomic % carbon. This parameter change fundamentally alters the etching behavior, eliminating the tapered profile issue while maintaining structural support capability.
Solution Approach 2:
The patent uses composite materials containing hydrocarbon with at least 20 atomic % carbon, optionally incorporating titanium and silicon. This composite approach provides both structural support and improved etching characteristics, resolving the contradiction between support reliability and etch profile precision.
2Reliability
If silicon dioxide is used as support material, then the material provides electrical insulation, but it creates vertical and lateral potential gradients causing feature twisting
Solution Approach 1:
The patent changes the electrical property parameter by selecting hydrocarbon-containing materials with specific carbon content (at least 20 atomic %). This parameter change reduces feature charging and eliminates potential gradients, preventing feature twisting while maintaining necessary electrical properties.
Solution Approach 2:
The patent applies local quality by incorporating titanium and silicon into the hydrocarbon matrix at specific locations and concentrations. This creates localized regions with enhanced rigidity and controlled electrical properties, addressing both insulation requirements and shape stability.
3Ease of manufacture
If traditional support materials are used, then the processing is simpler, but the aspect ratio of features is limited
Solution Approach 1:
The patent changes the material composition parameter to hydrocarbon-containing materials with at least 20 atomic % carbon, which enables superior etching performance. This parameter change allows formation of high aspect ratio features while maintaining processing simplicity through straightforward deposition and etching steps.
Data Source
AI summary
A capacitor forming method includes forming an electrically conductive support material over a substrate, forming an opening through at least the support material to the substrate, and, after forming the opening, forming a capacitor structure contacting the substrate and the support material in the opening. The support material contains at least 25 at % carbon. Another capacitor forming method includes forming a support material over a substrate, forming an opening through at least the support material to the substrate, and, after forming the opening, forming a capacitor structure contacting the substrate and the support material in the opening. The support material contains at least 20 at % carbon. The support material has a thickness and the opening has an aspect ratio 20:1 or greater within the thickness of the support material.