Mask Layer Plasma Pre-treatment for Etch Line Edge Roughness
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Solution Overview
Problem
The existing dry plasma etch process in semiconductor processing often results in line edge roughness (LER) and pattern abnormalities due to the use of ballistic electron beams, which can lead to reduced manufacturing yields and poor device performance.
Innovation Solution
Treating the mask layer with an oxygen-containing, halogen-containing, or noble gas plasma before etching, without forming a ballistic electron beam, to create a resilient sub-layer or passivate the surface, thereby reducing LER during the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a ballistic electron beam is used during plasma etching, then etching speed and efficiency are improved, but line edge roughness and pattern abnormalities increase
Solution Approach 1:
The patent applies preliminary action by treating the mask layer with plasma before the actual etching process. This pre-treatment modifies the mask layer surface to create a more resilient structure that can withstand the subsequent ballistic electron beam exposure during etching, thereby preventing line edge roughness while maintaining etching efficiency
Solution Approach 2:
The patent applies preliminary anti-action by exposing the mask layer to plasma treatment that creates a protective effect against the harmful effects of ballistic electrons. This pre-established resistance counteracts the damage that would otherwise occur during the etching process, reducing pattern abnormalities and line edge roughness
2Productivity
If a ballistic electron beam is used during plasma etching, then etching efficiency is improved, but manufacturing yield decreases due to pattern abnormalities
Solution Approach 1:
The plasma treatment of the mask layer before etching creates a resilient sub-layer that protects against electron beam damage, ensuring consistent pattern transfer and reducing defects that would lead to manufacturing failures, thereby improving yield while maintaining efficiency
Solution Approach 2:
The patent converts the potentially harmful effect of ballistic electrons into a beneficial process by using controlled plasma exposure that modifies the mask layer properties. This treatment makes the mask layer more resistant to electron beam damage, transforming what would be a source of defects into a mechanism for improving pattern fidelity and manufacturing yield
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 pre-treatment of the mask layer significantly reduces line edge roughness and pattern abnormalities, enhancing etch selectivity and manufacturing yields by creating a more resistant mask layer that minimizes damage from energetic electrons.
Implementation Method 1
forming plasma in a plasma processing system from a process gas
Implementation Method 2
treating the mask layer by exposing the mask layer to an oxygen-containing plasma or a halogen-containing plasma or a noble gas plasma
Implementation Method 3
coupling direct current (DC) power to an electrode in the plasma processing system to form an electron beam within the plasma processing system
Implementation Method 4
etching the thin film in order to transfer a pattern of the mask layer to the thin film
Implementation Method 5
exposing the substrate to the plasma and the electron beam
Data Source
AI summary
A method of pre-treating a mask layer prior to etching an underlying thin film is described. A thin film, such as a dielectric film, is etched using plasma that is enhanced with a ballistic electron beam. In order to reduce the loss of pattern definition, such as line edge roughness effects, the mask layer is treated with an oxygen-containing plasma or halogen-containing plasma or a noble gas plasma or a combination of two or more thereof prior to proceeding with the etching process.