IGZO Hard Mask Damascene Etching for Low-Roughness Metal Wiring
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Solution Overview
Problem
Existing substrate processing methods using metal masks like TiN for etching metal wirings in semiconductor manufacturing face issues such as roughness, increased resistance, and high costs due to the use of expensive chemicals, which affect the integrity and efficiency of metal wiring.
Innovation Solution
Employing an IGZO-based metal oxide film as a hard mask with a predetermined amorphous composition to etch dielectric films, reducing roughness and resistance by using a combination of physical vapor deposition and atomic layer deposition, and employing specific etching and cleaning processes to form a damascene or dual damascene structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal masks like TiN are used for etching metal wirings, then etching precision is improved, but manufacturing cost increases and surface roughness worsens
Solution Approach 1:
The patent replaces expensive reusable metal masks (TiN) with a disposable organic insulating film hard mask that can be formed through standard semiconductor fabrication processes. This disposable mask approach eliminates the need for costly metal mask materials and reduces manufacturing expenses while maintaining etching precision.
Solution Approach 2:
The patent changes the material parameter from inorganic metal oxide (TiN) to organic insulating film, and controls the crystalline state parameter to ensure the metal oxide layer remains amorphous rather than crystalline. These parameter changes reduce manufacturing cost while preserving etching performance.
2Manufacturing precision
If metal masks like TiN are used for etching metal wirings, then etching precision is improved, but surface roughness increases
Solution Approach 1:
The patent changes the crystalline state parameter of the metal oxide layer from crystalline to amorphous. This parameter change is critical because amorphous metal oxide provides a smoother surface finish during etching, reducing surface roughness while maintaining the necessary etching precision through the organic insulating film hard mask.
3Manufacturing precision
If expensive chemicals are used in substrate processing, then processing quality is improved, but production cost increases
Solution Approach 1:
The patent employs standard organic insulating films and conventional cleaning agents instead of expensive specialized chemicals. The disposable nature of the organic hard mask allows using readily available, cost-effective materials that can be removed through standard cleaning processes, thereby reducing production costs while maintaining processing quality.
Solution Approach 2:
The patent enables the substrate processing system to use its own existing resources - organic insulating films already present in the fabrication process and standard cleaning facilities - rather than requiring external expensive chemicals. This self-service approach reduces dependency on costly specialized materials while maintaining processing quality.
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 method effectively reduces the roughness and resistance of metal wirings, enhancing the propagation efficiency of electromagnetic signals and reducing production costs by avoiding the need for expensive chemicals.
Implementation Method 1
using a combination of physical vapor deposition and atomic layer deposition
Implementation Method 2
forming a resist-related first film in which a first pattern is formed
Implementation Method 3
etching the first hard mask to form a recess corresponding to the first pattern in the first hard mask; etching the dielectric film to form the recess corresponding to the first pattern in the dielectric film
Data Source
AI summary
A substrate processing method includes: providing a substrate having first and second surfaces; forming a dielectric film on the first surface; forming a metal oxide film including one or two or more metal elements with a predetermined composition on the dielectric film; subsequently, forming a resist-related first film in which a first pattern is formed; subsequently, etching the first hard mask to form a recess corresponding to the first pattern in the metal oxide film; etching the dielectric film to form the recess corresponding to the first pattern in the dielectric film; subsequently, cleaning the substrate to remove the metal oxide film; embedding a metal in the recess formed in the dielectric film; and planarizing the metal.