Non-Plasma Dry Etching of High-Bond Metal Oxides at Low Temperature
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Solution Overview
Problem
Existing dry etching methods struggle to efficiently etch etch-resistant metal oxide films, such as those containing hafnium, at low temperatures (400° C. or lower) without causing damage to semiconductor devices.
Innovation Solution
A non-plasma dry etching method using a gas composition of β-diketones and nitrogen dioxide, which enables etching of metal oxide films with M-O bond energies of 5 eV or higher at temperatures as low as 300° C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional dry etching methods are used on metal oxide films with high M-O bond energy, then etching can proceed, but the process requires high temperatures (above 400°C) that cause damage to semiconductor devices
Solution Approach 1:
The patent changes the chemical parameters of the etching gas by introducing NO2 as a reactive component. This chemical parameter change enables the etching reaction to proceed at lower temperatures (300-400°C) by providing an alternative reaction pathway that is more effective for breaking strong M-O bonds, thereby resolving the contradiction between achieving good etching quality and avoiding thermal damage to devices
Solution Approach 2:
The patent uses a composite gas composition combining β-diketone and NO2. This composite approach creates synergistic effects where NO2 enhances the reactivity toward metal oxide films with high M-O bond energy, enabling effective etching at lower temperatures and thus preventing damage to semiconductor devices while maintaining etching quality
2Temperature
If plasma etching is used to achieve low etching temperature, then etching can proceed at lower temperatures, but expensive plasma equipment and RF power sources are required
Solution Approach 1:
The patent substitutes the plasma physical field with a chemical reaction field. By using a carefully designed gas composition (β-diketone + NO2), the etching process achieves low-temperature operation through enhanced chemical reactivity rather than through plasma activation, thereby eliminating the need for expensive plasma equipment and RF power sources while maintaining low etching temperatures
Solution Approach 2:
The patent changes the chemical composition parameters of the etching gas to achieve low-temperature etching without plasma. The specific ratio and selection of β-diketone and NO2 create optimal reaction conditions that lower the activation energy required for etching, allowing the process to proceed at lower temperatures using simple heating equipment instead of complex plasma generation 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
The method effectively etches etch-resistant metal oxide films at low temperatures, reducing damage to semiconductor devices and eliminating the need for expensive plasma equipment.
Implementation Method 1
reacting an etching target film formed on a surface of a workpiece with a β-diketone and nitrogen dioxide to etch the etching target film
Data Source
AI summary
A dry etching method according to an embodiment of the present disclosure includes reacting an etching target film formed on a surface of a workpiece with a β-diketone and nitrogen dioxide to etch the etching target film in a non-plasma state, the etching target film containing a metal having an M-O bond energy of 5 eV or higher or an oxide of the metal.