Plasma Etching of Carbon Films Using Subzero H2O Condensation
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Solution Overview
Problem
Existing plasma etching methods face challenges in efficiently supplying etchants to the bottom of high aspect ratio structures, leading to reduced etching rates in carbon-containing films.
Innovation Solution
The method involves etching a carbon-containing film using plasma generated from a gas containing H and O, with the substrate support temperature adjusted to 0° C. or less, forming a condensed or solidified layer of H2O at the etching shape bottom, and applying bias power to attract ions for enhanced etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If plasma etching is performed on carbon-containing film in high aspect ratio structures, then etching depth increases, but etching rate decreases due to insufficient etchant supply to the bottom
Solution Approach 1:
The substrate support temperature is changed from conventional room temperature or higher to 0°C or lower. This temperature parameter change causes water vapor in the plasma to condense or solidify at the bottom of the etching shape, forming a reservoir that continuously supplies etchant species to the bottom surface, thereby maintaining high etching rates even at great depths
Solution Approach 2:
The invention utilizes the phase transition of water vapor from gas phase to liquid or solid phase at the substrate bottom. By controlling the substrate support temperature to 0°C or lower, water vapor in the plasma undergoes condensation or solidification at the bottom of the etching shape, creating a physical reservoir that enhances etchant supply to the bottom surface
2Productivity
If substrate support temperature is lowered to 0°C or less, then etchant supply to bottom improves, but additional temperature control complexity is introduced
Solution Approach 1:
The invention changes the temperature parameter from conventional values to 0°C or lower, which fundamentally alters the physical state of water vapor in the plasma. This single parameter change triggers phase transition effects that automatically enhance etchant supply, reducing the need for complex additional control systems
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 efficiently supplies etchants to the bottom of the etching shape, increasing the etching rate and maintaining or improving etching efficiency even in high aspect ratio structures.
Implementation Method 1
etching the substrate with a plasma to form an etching shape in the carbon-containing film
Implementation Method 2
the temperature of the substrate support is adjusted to 0° C. or less
Implementation Method 3
forming a condensed or solidified layer of H2O at the etching shape bottom
Implementation Method 4
applying bias power to attract ions for enhanced etching
Data Source
AI summary
An etching method includes (a) providing a substrate including a carbon-containing film, the substrate being situated on a substrate support and (b) etching the substrate with a plasma to form an etching shape in the carbon-containing film, the plasma being configured to be formed from a gas containing H and O, the etching shape including a bottom. In (b), a temperature of the substrate support is adjusted to 0° C. or less.