Substrate Oxide Layer Formation via Dual-Stage Plasma Gas Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in modifying substrate surfaces into oxide layers with desired thickness and properties at low temperature conditions, as conventional methods often require higher temperatures to achieve adequate oxidation rates and desired thickness, which can be detrimental to the thermal history of the device structure.
Innovation Solution
A method involving a substrate processing apparatus that modifies the surface of a substrate into a first oxide layer using a plasma-excited gas with a specific hydrogen-to-oxygen ratio, followed by a second modification step using a gas with a lower hydrogen ratio to form a second oxide layer, optimizing the oxidation rate and thickness while maintaining low processing temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional plasma oxidation methods are used at low temperature, then thermal impact on device structure is minimized, but oxidation rate and oxide layer thickness are insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the processing gas by controlling the hydrogen to oxygen ratio. By adjusting this ratio dynamically during different stages of the oxidation process, the patent achieves both low temperature processing and high oxidation rate. Specifically, a higher hydrogen ratio is used initially to enhance oxidation rate, then reduced to improve oxide quality, all while maintaining low processing temperature.
Solution Approach 2:
The patent employs periodic action by dividing the plasma oxidation process into multiple stages with different gas composition ratios. The first stage uses a higher hydrogen-to-oxygen ratio to rapidly form oxide layer, while the second stage uses a lower ratio to improve oxide quality. This periodic variation in gas composition allows the system to achieve both high oxidation rate and good oxide properties at low temperature.
2Productivity
If higher temperature is used to increase oxidation rate, then oxide layer thickness is improved, but thermal damage to device structure occurs
Solution Approach 1:
Instead of changing temperature to control oxidation rate, the patent changes the chemical composition of the processing gas. By controlling the hydrogen-to-oxygen ratio in the plasma gas, the patent achieves high oxidation rate without increasing temperature. This parameter substitution allows decoupling of oxidation rate from temperature, preventing thermal damage while maintaining productivity.
3Productivity
If hydrogen-rich plasma gas is used for oxidation, then oxidation rate increases, but hydrogen incorporation in oxide layer increases causing property degradation
Solution Approach 1:
The patent uses periodic action by implementing a two-stage oxidation process with different gas compositions. The first stage uses hydrogen-rich plasma gas to achieve high oxidation rate and form the oxide layer. The second stage switches to hydrogen-poor or hydrogen-free gas to remove excess hydrogen from the oxide layer and improve its electrical and structural properties. This temporal separation of functions resolves the contradiction between oxidation rate and oxide quality.
Solution Approach 2:
The patent segments the oxidation process into distinct stages with different gas composition requirements. The first stage focuses on rapid oxide formation using hydrogen-rich gas, while the second stage focuses on oxide quality improvement using hydrogen-poor gas. This segmentation allows each stage to optimize for its specific function without compromising the other.
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 allows for the formation of oxide layers with improved thickness and properties, such as increased oxidation rate and enhanced processing resistance, while minimizing thermal impact on the device structure, even at low temperatures.
Implementation Method 1
modifying a surface of the substrate into a first oxide layer by supplying, to the substrate, a reactive species generated by plasma-exciting a first processing gas
Implementation Method 2
modifying the first oxide layer into a second oxide layer by supplying, to the substrate, a reactive species generated by plasma-exciting a second processing gas
Implementation Method 3
modifying a surface of the substrate into a first oxide layer
Data Source
AI summary
A method of processing a substrate, includes: (a) modifying a surface of the substrate into a first oxide layer by supplying, to the substrate, a reactive species generated by plasma-exciting a first processing gas in which oxygen and hydrogen are contained and a ratio of hydrogen in the oxygen and hydrogen of the first processing gas is a first ratio; and (b) modifying the first oxide layer into a second oxide layer by supplying, to the substrate, a reactive species generated by plasma-exciting a second processing gas in which oxygen is contained and hydrogen is optionally contained and a ratio of hydrogen in the oxygen and hydrogen of the second processing gas is a second ratio smaller than the first ratio.