Atomic Layer Etch and Selective Carbon Deposition for EUV Edge Roughness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current EUV lithography methods result in poor edge roughness and weak patterns due to insufficient source power, leading to loss of pattern fidelity and increased costs in semiconductor processing.
Innovation Solution
A method involving atomic layer etching (ALE) and selective carbon deposition is used to process semiconductor substrates, where a carbon-containing material is modified with an oxidant and plasma to create a smooth surface, and then selectively deposited with a carbon-containing material to fill crevices, improving edge roughness and critical dimension uniformity without high source power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If EUV lithography is used to pattern small critical dimension features, then lithographic capability is extended beyond optical limits, but edge roughness deteriorates and pattern fidelity is lost
Solution Approach 1:
The patent applies preliminary action by performing atomic layer etching (ALE) and selective carbon deposition on the photoresist pattern before subsequent processing steps. The ALE process modifies the photoresist surface in advance to reduce edge roughness, and the selective carbon deposition fills crevices and smooths features beforehand, ensuring improved pattern fidelity carries through the remaining manufacturing process
Solution Approach 2:
The patent employs parameter changes by carefully controlling the bias power (5V-100V) and plasma power (15W-500W) during ALE, and self-bias power (5V-15V) during carbon deposition. These parameter optimizations enable precise material removal and selective deposition that smooth edges while maintaining critical dimensions, directly resolving the edge roughness problem
2Manufacturing precision
If high source power is used in EUV lithography, then pattern fidelity is maintained, but processing cost increases
Solution Approach 1:
The patent extracts the pattern fidelity enhancement function from the EUV lithography source itself and relocates it to post-exposure processing steps. By performing ALE and selective carbon deposition after EUV exposure, the method separates the patterning function (performed at lower power) from the pattern refinement function (performed through controlled etching and deposition), thereby reducing the energy requirement while maintaining pattern fidelity
Solution Approach 2:
The patent introduces an intermediary processing step using ALE and selective carbon deposition between EUV exposure and final pattern transfer. This intermediary process acts as a mediator that refines the exposed pattern, smoothing edges and filling crevices without requiring high EUV source power, thus decoupling pattern fidelity from high energy 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 method enhances edge roughness and critical dimension uniformity, reducing the need for high source power in EUV applications, thereby improving EUV scanner productivity and substrate quality.
Implementation Method 1
exposing a substrate including a first carbon-containing material to an oxidant and igniting a first plasma with a first bias power to modify a surface of the first carbon-containing material
Implementation Method 2
exposing the modified layer to a second plasma at a second bias power and for a duration sufficient to remove the modified surface without sputtering
Implementation Method 3
selectively depositing a second carbon-containing material on the substrate to fill crevices on the first carbon-containing material
Implementation Method 4
selectively depositing a second carbon-containing material on the substrate includes applying a self-bias at a power between about 5V and about 15V and igniting a plasma using a plasma power between about 30 W and about 500 W
Data Source
AI summary
Methods of and apparatuses for processing substrates having carbon-containing material using atomic layer etch and selective deposition are provided. Methods involve exposing a carbon-containing material on a substrate to an oxidant and igniting a first plasma to modify a surface of the substrate and exposing the modified surface to a second plasma at a bias power to remove the modified surface. Methods also involve selectively depositing a second carbon-containing material onto the substrate using a precursor having a chemical formula of CxHy, where x and y are integers greater than or equal to 1. ALE and selective deposition may be performed without breaking vacuum.