Semiconductor Mask Pattern Formation via Silicon Oxide Sidewalls
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Solution Overview
Problem
The existing methods for forming mask patterns in semiconductor devices using the side wall patterning (SWP) technique face challenges such as increased process complexity and cost due to the need to etch the anti-reflective coating film, limited material options for this film, and potential pattern collapse issues when the anti-reflective coating film is not properly etched.
Innovation Solution
A method that omits the etching of the anti-reflective coating film by using a silicon oxide film to coat the resist pattern array, embedding gaps with a carbon film, and etching back the carbon film to form a mask pattern, allowing the anti-reflective coating film to function as a mask for etching the silicon oxide film, thereby preventing pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the anti-reflective coating film is etched to enable SWP method, then the mask pattern can be formed with smaller size, but the number of processes increases and production cost increases
Solution Approach 1:
The invention extracts and removes the anti-reflective coating film from the structure before forming the silicon oxide film. By removing this layer that would otherwise require etching, the process complexity is reduced while still enabling the formation of precise mask patterns through the silicon oxide film sidewalls.
Solution Approach 2:
The anti-reflective coating film is removed in advance before the silicon oxide film is deposited. This preliminary action eliminates the need for subsequent etching steps of the anti-reflective coating film, simplifying the overall process while maintaining the ability to form precise mask patterns.
2Manufacturing precision
If the anti-reflective coating film is etched to enable SWP method, then the mask pattern can be formed with smaller size, but the material selection for anti-reflective coating film is limited
Solution Approach 1:
By removing the anti-reflective coating film before silicon oxide deposition, the invention eliminates the constraint that limited material selection. The silicon oxide film can now be deposited directly on the resist pattern without being hindered by the anti-reflective coating film, allowing broader material choices for the anti-reflective coating layer.
3Device complexity
If the anti-reflective coating film is not etched, then the process is simplified, but the exposed anti-reflective coating film is eroded with ashing and pattern collapse occurs
Solution Approach 1:
The anti-reflective coating film is removed in advance before the silicon oxide film is deposited and before ashing is performed. This preliminary removal prevents the anti-reflective coating film from being exposed and eroded during subsequent ashing processes, eliminating the pattern collapse issue while maintaining process simplicity.
Solution Approach 2:
By removing the anti-reflective coating film beforehand, the invention prevents the potential harm of ashing erosion on this layer. The silicon oxide film then serves as the protective sidewall structure that prevents pattern collapse, cushioning against the harmful effects of subsequent processing steps.
4Manufacturing precision
If the thickness of anti-reflective coating film is increased to make it function as hard mask, then the etching effectiveness is improved, but the film thickness cannot be increased due to SWP method requirements
Solution Approach 1:
By removing the anti-reflective coating film before silicon oxide deposition, the invention eliminates the constraint on film thickness. The silicon oxide film can now be deposited to any required thickness to serve as an effective hard mask, without being limited by the thickness requirements of the anti-reflective coating film in traditional SWP methods.
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 reduces production costs, eliminates the need for etching the anti-reflective coating film, and prevents pattern collapse, enabling the formation of precise mask patterns with improved material selection and thickness options for the anti-reflective coating film.
Implementation Method 1
a silicon oxide film is formed to isotropically coat a surface of the resist pattern array
Implementation Method 2
the gap in the resist pattern array is embedded with a carbon film and an upper portion of the resist pattern array is coated with the carbon film
Implementation Method 3
the carbon film is removed from the upper portion of the resist pattern array and the carbon film is etched back to leave the carbon film within the gap
Implementation Method 4
a first mask pattern array made from the silicon oxide film is formed with a center portion and film sidewall portions sandwiching the predetermined width of the center portion by an ashing process
Data Source
AI summary
A disclosed mask pattern forming method includes isotropically coating a surface of a resist pattern array having a predetermined line width with a silicon oxide film, embedding a gap in the resist pattern array coated by the silicon oxide film with a carbon film, removing the carbon film from the upper portion and etching back the carbon film while leaving the carbon film within the gap in any order, removing the remaining carbon film and etching back the upper portion of the resist pattern array to have a predetermined film thickness in any order, and forming a first mask pattern array which has a center portion having a predetermined width and film sidewall portions sandwiching the predetermined width, and arranged interposing a space width substantially the same as the predetermined line width with an asking process provided to the resist pattern array exposed from the removed silicon oxide film.