Selective Etching of Silicon Oxide and Nitride via Dynamic Temperature Control
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Solution Overview
Problem
Existing plasma etching methods struggle to selectively etch silicon oxide and silicon nitride films with high efficiency, as they often require precise temperature control and specific processing conditions to differentiate between these materials effectively.
Innovation Solution
A method involving a plasma processing apparatus that sets the temperature of a processing target object to specific levels to generate plasma for etching silicon oxide and silicon nitride films separately, utilizing a chiller unit for cooling and a gas exhaust device for heating to control temperature rapidly, allowing for efficient etching of silicon oxide at lower temperatures and silicon nitride at higher temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma etching is performed at a single fixed temperature, then the etching process is simple to control, but it cannot selectively etch both silicon oxide and silicon nitride films with high efficiency
Solution Approach 1:
The patent applies dynamic temperature control by switching between a first temperature (for etching silicon oxide) and a second temperature (for etching silicon nitride). The temperature is not fixed but dynamically adjusted according to the etching stage, enabling selective etching of different materials while maintaining process simplicity through automated control.
Solution Approach 2:
The patent changes the temperature parameter between two distinct values: a first temperature optimized for silicon oxide etching and a second temperature optimized for silicon nitride etching. This parameter switching enables selective etching by matching temperature conditions to the specific material being etched at each stage.
2Manufacturing precision
If temperature control is implemented to achieve selective etching, then etching selectivity improves, but processing time increases due to temperature switching
Solution Approach 1:
The patent performs preliminary temperature setting before each etching step. The temperature is pre-adjusted to the appropriate value (first or second temperature) before initiating the plasma etching process for each material type, ensuring optimal conditions are already in place when etching begins, thus minimizing actual processing time.
Solution Approach 2:
The patent employs periodic temperature switching between the first temperature and second temperature according to the etching sequence. This periodic action allows the system to efficiently alternate between different temperature conditions matched to the current etching target, optimizing both selectivity and time management through rhythmic control cycles.
3Productivity
If rapid temperature switching is implemented, then processing efficiency improves, but temperature control precision becomes more difficult to maintain
Solution Approach 1:
The patent implements feedback control in the temperature management system. The temperature control apparatus monitors the actual temperature and adjusts it to maintain the desired first or second temperature values during switching. This feedback mechanism ensures precise temperature control even during rapid switching between different temperature states for selective etching.
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
Enables selective and high-efficiency etching of silicon oxide and silicon nitride films by controlling the temperature of the processing target object, improving etching uniformity and reducing processing time.
Implementation Method 1
utilizing a chiller unit for cooling
Implementation Method 2
gas exhaust device for heating
Implementation Method 3
plasma of a processing gas is generated within a chamber main body of the plasma processing apparatus. An etching target region of a processing target object is etched by ions and/or radicals in the generated plasma.
Data Source
AI summary
First and second silicon containing films can be etched selectively against each other with high efficiency. A method includes preparing a processing target object within a chamber; etching the first silicon containing film of the processing target object by generating plasma of a processing gas within the chamber in a state that a temperature of the processing target object is set to a first temperature; and etching the second silicon containing film of the processing target object by generating the plasma of the processing gas within the chamber in a state that the temperature of the processing target object is set to a second temperature higher than the first temperature.