Copper Wiring Surface Protective Liquid for Semiconductor Manufacturing
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Solution Overview
Problem
Copper wiring materials used in semiconductor circuit devices are prone to corrosion, oxidation, and contamination during production processes, leading to increased electric resistance and defective products, especially when exposed before being covered with a diffusion preventing film.
Innovation Solution
A copper wiring surface protective liquid containing an oxyalkylene adduct of acetylenediol is applied to the exposed copper surfaces, which effectively prevents corrosion, oxidation, and contamination by adsorbing onto the surface and being easily removed before the formation of a diffusion preventing film, ensuring a clean surface for the subsequent processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If copper wiring material is exposed before covering with diffusion preventing film, then the copper surface can be processed and prepared, but the copper surface is oxidized and contaminated by oxygen and production environment
Solution Approach 1:
The patent applies preliminary action by forming a protective film on the copper surface before the copper is exposed to oxygen and contamination. The protective film is formed during the copper plating process itself, so when the copper wiring material is subsequently exposed during manufacturing steps, the surface is already protected from oxidation and contamination.
Solution Approach 2:
The patent uses an intermediary substance - a protective film formed by a specific additive during copper plating - that acts as a mediator between the copper surface and the harmful environment. This intermediary layer prevents direct contact between oxygen/contaminants and the copper surface while allowing the copper to be processed.
2Reliability
If waiting time until forming diffusion preventing film is limited to avoid oxidation, then copper surface remains clean, but productivity decreases due to complicated procedures
Solution Approach 1:
The protective film is formed in advance during the copper plating process, eliminating the need for time-critical scheduling between copper exposure and diffusion preventing film formation. This preliminary protection allows flexible scheduling without compromising surface cleanliness.
Solution Approach 2:
The copper plating process itself provides the protective function through the additive that forms the protective film during plating. The system serves its own protection need without requiring separate protective measures or tight process scheduling.
3Reliability
If copper wiring material is used instead of aluminum alloy, then electric resistance decreases and migration characteristics improve, but copper is difficult to etch by dry etching method and diffuses into insulating material
Solution Approach 1:
The patent introduces a protective film as an intermediary layer between the copper wiring material and the etching environment. This film allows the copper to be manufactured using standard processes while preventing copper diffusion into insulating materials during subsequent processing steps.
Solution Approach 2:
The patent changes the chemical composition parameters of the copper plating process by adding specific compounds (carboxylic acid derivatives, heterocyclic compounds, or their combinations) to the plating solution. This parameter change transforms the copper surface properties to provide inherent protection without affecting the bulk electrical properties of the copper.
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
The protective liquid maintains a clean copper surface throughout the production process, reducing the occurrence of defects and ensuring high-quality semiconductor devices by preventing oxidation and corrosion, and allowing for efficient removal of the adsorbed component before forming the diffusion preventing film.
Implementation Method 1
containing an oxyalkylene adduct of an acetylenediol which has an oxyalkylene having from 2 or 3 carbon atoms added thereto
Data Source
AI summary
A copper wiring material surface protective liquid for production of a semiconductor device is provided, containing an oxyalkylene adduct of an acetylenediol containing an acetylenediol having an oxyalkylene having 2 or 3 carbon atoms added thereto. A method for producing a semiconductor circuit device is provided, containing: forming an insulating film and/or a diffusion preventing film on a silicon substrate; then forming a copper film by a sputtering method; then forming a copper wiring containing 80% by mass or more of copper thereon by a plating method; and flattening the wiring by a chemical mechanical polishing (CMP) method, thereby providing a semiconductor substrate containing a copper wiring, the semiconductor substrate having an exposed surface of a copper wiring material being treated by making in contact with the copper wiring material surface protective liquid.