Aluminum Oxide Carbon Hybrid Hardmask for Precise Pattern Transfer
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Solution Overview
Problem
Existing carbon-based hardmasks in photolithography have limited etch selectivity and pattern transfer accuracy, leading to issues like line edge roughness and line width roughness, which can result in device failure and yield loss.
Innovation Solution
A method involving a sequential infiltration synthesis (SIS) process to convert a carbon hardmask into an aluminum oxide carbon hybrid hardmask, which is denser and provides improved etching selectivity and profile control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carbon-based hardmask is used, then the hardmask provides basic etching protection, but the etch selectivity between the PR layer and underlayer is limited and the hardmask becomes deteriorated during etching
Solution Approach 1:
The patent creates a composite hardmask structure by forming a first hardmask layer (carbon-based) and a second hardmask layer (aluminum oxide-based) on top of it. This composite structure combines the advantages of both materials: the carbon-based layer provides good pattern definition while the aluminum oxide layer provides superior etch resistance and selectivity, preventing deterioration during the etching process.
Solution Approach 2:
The patent changes the material composition parameter of the hardmask by introducing aluminum oxide as a second layer. This parameter change transforms the hardmask from a single carbon-based material to a composite structure with enhanced etch selectivity and stability, allowing it to maintain integrity during etching operations.
2Manufacturing precision
If existing carbon-based hardmasks are used, then the process is simple, but pattern transfer accuracy is poor with moderate line edge roughness and line width roughness
Solution Approach 1:
The patent employs a composite hardmask structure with a carbon-based first layer and an aluminum oxide-based second layer. This composite approach improves pattern transfer accuracy by reducing line edge roughness and line width roughness, as the aluminum oxide layer provides better etch resistance and profile control during the etching process.
Solution Approach 2:
The patent applies different materials to different layers of the hardmask structure: the carbon-based material in the first layer provides good pattern definition, while the aluminum oxide-based second layer provides enhanced etch resistance. This local differentiation of material properties optimizes both pattern transfer accuracy and etching performance.
3Reliability
If a denser hardmask structure is created, then etching selectivity improves, but the manufacturing process becomes more complex
Solution Approach 1:
The patent uses Sequential Infiltration Synthesis (SIS) to change the material composition parameter by infiltrating aluminum precursor into the carbon hardmask and converting it to aluminum oxide. This parameter change creates a denser, more etch-resistant hardmask structure with improved etching selectivity, despite the added process complexity.
Solution Approach 2:
The patent introduces an aluminum precursor as an intermediary material that infiltrates the carbon hardmask structure through the SIS process. This intermediary material serves as a precursor to aluminum oxide, enabling the transformation from a carbon-based to an aluminum oxide-based hardmask with enhanced properties.
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 aluminum oxide carbon hybrid hardmask enhances etching selectivity and profile control, reducing line edge roughness and line width roughness, thereby improving the accuracy and reliability of pattern transfer in photolithography.
Implementation Method 1
infiltrating the carbon hardmask layer with the aluminum precursor via pores contained in the carbon hardmask layer
Implementation Method 2
infiltrating the carbon hardmask layer with the oxidizing agent via the pores contained in the carbon hardmask layer to produce an aluminum oxide coating
Implementation Method 3
exposing the carbon hardmask layer to an oxidizing agent, infiltrating the carbon hardmask layer with the oxidizing agent via the pores contained in the carbon hardmask layer to produce an aluminum oxide coating
Implementation Method 4
treating the carbon hardmask layer by exposing the workpiece to a SIS process to produce an aluminum oxide carbon hybrid hardmask which is denser than the carbon hardmask layer
Data Source
AI summary
Embodiments of the present disclosure generally relate to methods for enhancing carbon hardmask to have improved etching selectivity and profile control. In some embodiments, a method of treating a carbon hardmask layer is provided and includes positioning a workpiece within a process region of a processing chamber, where the workpiece has a carbon hardmask layer disposed on or over an underlying layer, and treating the carbon hardmask layer by exposing the workpiece to a sequential infiltration synthesis (SIS) process to produce an aluminum oxide carbon hybrid hardmask which is denser than the carbon hardmask layer. The SIS process includes exposing and infiltrating the carbon hardmask layer with an aluminum precursor, purging to remove gaseous remnants, exposing and infiltrating the carbon hardmask layer to an oxidizing agent to produce an aluminum oxide coating disposed on inner surfaces of the carbon hardmask layer, and purging the process region to remove gaseous remnants.