Carbon Hard Mask Structure With SP3 Bond Conversion for Etch Stability
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Solution Overview
Problem
The existing carbon film layers used in semiconductor manufacturing have low hardness, leading to deformation during the etching process, resulting in low product yield and increased manufacturing costs due to the need for thicker film layers and poor etching selectivity.
Innovation Solution
A method is developed to form a target carbon film layer by converting SP2 hybrid bonds in an initial carbon film layer to SP3 hybrid bonds through ion implantation, increasing the film's hardness and etching selectivity by forming a diamond-like regular tetrahedral structure, which enhances the carbon film's durability and reduces material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carbon film layer is used as a hard mask in the patterning process, then the etching selectivity is improved, but the hardness of the film layer is low causing deformation during etching
Solution Approach 1:
The patent applies parameter changes by controlling the plasma processing conditions (power, frequency, pressure, temperature) to adjust the hybridization state of carbon bonds in the film. By optimizing these parameters, the carbon film transitions from having predominantly SP2 bonds (softer) to having predominantly SP3 bonds (harder), thereby increasing hardness while maintaining etching selectivity
Solution Approach 2:
The patent creates a composite carbon film structure by combining different carbon hybridization states (SP2 and SP3 bonds) within the same film layer. This composite structure allows the film to simultaneously exhibit etching selectivity (from the carbon material property) and increased hardness (from the SP3 bond network), resolving the contradiction between these two properties
2Stability of the object's composition
If the carbon film layer thickness is increased to prevent deformation, then the structural integrity is improved, but the manufacturing cost increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the carbon film (specifically the SP3 bond content through plasma processing) to achieve higher hardness. This allows the film to maintain structural integrity at reduced thickness, thereby lowering material usage and manufacturing costs while preventing deformation during etching
3Shape
If a thicker carbon film layer is used to maintain etching shape, then the etching shape integrity is improved, but the material consumption increases
Solution Approach 1:
The patent modifies the carbon film's internal structure by increasing SP3 bond content through controlled plasma processing. This structural change enhances the film's resistance to deformation during etching, allowing thinner films to maintain etching shape integrity and thereby reducing carbon material consumption
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 increased hardness of the target carbon film layer improves etching selectivity and product yield, allowing for thinner film layers and reduced manufacturing costs while maintaining etching shape integrity.
Implementation Method 1
implanting modifying ions into the initial carbon film layer to convert the SP2 hybrid bonds into SP3 hybrid bonds
Implementation Method 2
plasma-bombarding the carbon-containing gas at a first preset temperature, a first preset power, a first preset frequency, and a first preset pressure to form an initial carbon film attached to the surface of the substrate
Data Source
AI summary
The disclosure relates to a semiconductor structure and a method for forming it. The method includes: providing a substrate; forming an initial carbon film layer on the surface of the substrate, the initial carbon film layer includes at least SP2 hybrid bonds; implanting modifying ions into the initial carbon film layer to convert the SP2 hybrid bonds into SP3 hybrid bonds to obtain the target carbon film layer. Applying the method can increase the hardness of the carbon film layer. In addition the etching selectivity ratio increases during the etch process using the carbon film as a hard mask, because the carbon film layer is not easily deformed in etch, which can ensure the patterned shape with improved etch window so to increase the product yield. Meanwhile, higher carbon hardness of the film layer can properly reduce the carbon film thickness during etch, saving carbon materials and reducing manufacturing costs.