Dual Damascene Interconnect Dummy Plug Formation
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Solution Overview
Problem
The miniaturization of semiconductor devices leads to increased interconnect resistance and parasitic capacitance, causing signal delays, and existing dual damascene interconnect processes face challenges in pattern dimension stability and resist pattern collapse during trench formation.
Innovation Solution
A method involving the formation of a via hole and trench in an interlayer insulating film, where a resin film is used to create a dummy plug, and then etched with an active hydrogen species to form a trench connected with the via hole, using a resist mask for precise etching to improve controllability and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional via first process is used to form trenches for dual damascene interconnects, then compatibility with single damascene process is improved and conversion is easier, but pattern dimension fluctuation occurs and pattern-collapse of patterned resist happens
Solution Approach 1:
The invention forms a dummy plug in the via hole before forming the trench opening. This preliminary action provides structural support that prevents pattern collapse during subsequent etching processes while maintaining the via first process advantages for compatibility with single damascene processes
Solution Approach 2:
The dummy plug acts as an intermediary structure between the via hole and the trench formation. It provides mechanical support to the patterned resist during etching, preventing collapse while allowing the via first process sequence to proceed with improved dimensional stability
2Productivity
If miniaturization is pursued to increase integration, then device functionality is improved, but interconnect resistance increases and parasitic capacitance increases causing signal delay
Solution Approach 1:
The invention changes the material parameter by using a resin film with specific etching characteristics for the dummy plug. This material selection enables precise control of the via hole dimensions and provides adequate structural support, allowing miniaturization while maintaining signal propagation performance through stable interconnect geometry
3Ease of manufacture
If etching is performed to form trenches and via holes, then interconnect structure is created, but leakage current between interconnects increases
Solution Approach 1:
The invention extracts and removes the dummy plug after the trench formation is complete. This removal eliminates the potential leakage path through the resin material while maintaining the structural benefits during the critical formation stages, thus preventing leakage current between interconnects
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the formation of dual damascene interconnects with improved controllability and quality, enhancing production yield and reducing leakage current, while maintaining a low dielectric constant and preventing pattern collapse.
Implementation Method 1
etching the resin film exposed outside the via hole off with an etching gas mainly containing an active hydrogen species to form a dummy plug composed of the resin film in the via hole
Data Source
AI summary
A method for manufacturing an electronic device, in which a via hole and a trench for an interconnect are integrally provided in an interlayer insulating film formed on a substrate, and the via hole and the trench for the interconnect are plugged with an electric conductor film is provided. The method includes: forming a via hole in the interlayer insulating film; forming a resin film plugging the via hole on the interlayer insulating film; etching the resin film exposed outside the via hole off with an etching gas mainly containing an active hydrogen species to form a dummy plug composed of the resin film in the via hole; forming a resist mask having an opening for an interconnect on the dummy plug and on the interlayer insulating film.