MIM Fuse Wiring Structure to Prevent Step Disconnection
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Solution Overview
Problem
In semiconductor devices with a Metal Insulator Metal (MIM) structure, issues of insufficient coverage and step disconnection occur due to film thinning and side etching of polyimide films during etching and high-temperature treatment, leading to metal delamination.
Innovation Solution
A semiconductor device design where a groove portion on the substrate includes fuse wirings covered by a polymeric insulating film, with specific metal and insulating layers formed to prevent film thinning and delamination, involving a manufacturing method that includes forming a semiconductor substrate with groove portions, metal layers, and insulating films to ensure adequate coverage and exposure of metal portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyimide film is formed between metal layers in a MIM structure, then the insulating properties are improved, but film thinning and side etching occur during etching and high-temperature treatment, leading to insufficient coverage and step disconnection
Solution Approach 1:
The patent changes the material parameter from polyimide film to spin-on-glass (SOG) film, which has different thermal and chemical stability characteristics. The SOG film maintains its physical dimensions better during high-temperature treatment and etching processes, preventing film thinning and side etching while providing sufficient coverage for subsequent metal layers.
Solution Approach 2:
The patent addresses thermal effects by selecting SOG film which has better thermal stability and lower outgassing behavior during high-temperature processing. This prevents the thermal expansion and gas generation issues that cause delamination in polyimide films, thereby maintaining coverage uniformity throughout the manufacturing process.
2Reliability
If high-temperature treatment is performed to form SiO2 film, then the insulating layer quality is improved, but degassed gas generation causes delamination of the metal layer
Solution Approach 1:
The patent changes the insulating film material parameter from polyimide to spin-on-glass (SOG) film. SOG film exhibits significantly lower outgassing behavior during high-temperature treatment compared to polyimide, preventing gas bubble formation and subsequent metal layer delamination while still providing high-quality insulating properties.
Solution Approach 2:
The patent uses SOG film as a temporary insulating layer that can withstand high-temperature processing without degrading. The SOG film serves its insulating function during manufacturing and can be removed or integrated into the final structure without causing adhesion issues, effectively acting as a process-enabling material.
3Ease of manufacture
If etching is performed on the second metal layer in wiring portions, then the wiring pattern is formed, but film thinning occurs on the polyimide film leading to insufficient coverage
Solution Approach 1:
The patent changes the film material parameter from polyimide to spin-on-glass (SOG) film, which has superior etch resistance and dimensional stability. During the etching process to form wiring patterns, the SOG film maintains its thickness and coverage uniformity, preventing the film thinning and side etching problems that occur with polyimide films.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate having one principal surface on which a groove portion is formed, a plurality of fuse wirings formed in the groove portion, a metal wiring disposed at a position separated from the groove portion and exposed on the one principal surface, a first insulating film covering the one principal surface and having a first opening that exposes the plurality of fuse wirings and a second opening that exposes the metal wiring, a polymeric insulating film in the first opening burying the plurality of fuse wirings in the groove portion, a first metal portion covering the polymeric insulating film, a second metal portion extending so as to cover a surface of the metal wiring exposed in the second opening and a surface of the first insulating film at a peripheral edge of the second opening, a second insulating film burying the first metal portion on an upper surface of the polymeric insulating film and covering the second metal portion so as to partially expose an upper surface thereof, and a third metal portion ranging from an upper surface of the second metal portion exposed from the second insulating film to an upper surface of the second insulating film.