Recessed Structure Oxidation via Nitride Thickness Profiling
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in achieving a desired thickness distribution of oxide layers within recessed structures on substrates, as current methods lack precision in controlling the thickness and uniformity of these layers.
Innovation Solution
A method involving nitriding the inner surface of recessed structures on substrates to form a nitride layer, followed by oxidizing the nitride layer to create an oxide layer, where the thickness distribution of the nitride layer is set to achieve a desired oxide layer distribution, utilizing a substrate processing apparatus with plasma generation and controlled gas supply systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional oxidation methods are used to form oxide layers in recessed structures, then the oxidation process can be completed, but the thickness distribution of the oxide layer cannot achieve the desired uniformity and precision
Solution Approach 1:
The patent applies preliminary action by forming a nitride layer on the inner surface of the recessed structure before oxidation. This pre-treatment modifies the surface properties and creates a controlled interface that enables subsequent oxidation to proceed with precise thickness control. The nitride layer acts as a preparation step that ensures the final oxide layer achieves the desired thickness distribution and uniformity.
Solution Approach 2:
The patent utilizes parameter changes by controlling the thickness distribution of the nitride layer formed in the first step. By adjusting the nitride layer thickness to have a specific distribution pattern (thinner at the opening, thicker at the bottom), the oxidation process produces an oxide layer with the target thickness distribution. This parameter control transforms the oxidation outcome to meet precision requirements.
2Reliability
If the nitride layer thickness is increased to ensure complete coverage, then coverage is improved, but the resulting oxide layer thickness distribution deviates from the desired specification
Solution Approach 1:
The patent applies local quality by creating a non-uniform nitride layer thickness distribution tailored to specific locations within the recessed structure. The nitride layer is made thinner at the opening portion and thicker at the bottom portion, with each location having an optimized thickness that accounts for the local geometry and oxidation behavior. This local optimization ensures both complete coverage and precise final oxide layer thickness distribution.
Solution Approach 2:
The patent utilizes parameter changes by deliberately setting the nitride layer thickness parameter to vary across different locations. The thickness distribution parameter of the nitride layer is controlled to compensate for variations in oxidation rates, ensuring that the final oxide layer achieves the desired uniform thickness distribution despite geometric variations in the recessed structure.
3Device complexity
If oxidation is performed directly on the substrate without nitride layer formation, then the process is simpler, but the oxide layer thickness distribution cannot be precisely controlled
Solution Approach 1:
The patent applies preliminary action by introducing a nitride layer formation step before oxidation. Although this adds a process step, it creates a controlled intermediate state that enables precise oxidation. The nitride layer serves as a preparatory layer that defines the oxidation kinetics and final thickness distribution, making the overall process more controllable and precise despite the additional step.
Solution Approach 2:
The patent uses the nitride layer as an intermediary between the substrate and the final oxide layer. This intermediate layer mediates the oxidation process by providing a controlled interface that regulates oxygen diffusion and reaction rates. The nitride layer acts as a buffer that enables precise control over the final oxide layer thickness distribution, transforming a complex precision requirement into a manageable multi-step process.
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 precise control over the thickness distribution of the oxide layer, ensuring it meets desired specifications, enhancing the manufacturing process's accuracy and efficiency while minimizing thermal history and preventing nitrogen residue in the oxide layer.
Implementation Method 1
utilizing a substrate processing apparatus with plasma generation and controlled gas supply systems
Implementation Method 2
nitriding an inner surface of a recessed structure formed on a substrate to modify at least a portion of the inner surface into a nitride layer
Implementation Method 3
oxidizing the inner surface including the nitride layer to modify the inner surface into an oxide layer
Data Source
AI summary
There is provided a technique that includes: (a) nitriding an inner surface of a recessed structure formed on a substrate to modify at least a portion of the inner surface into a nitride layer; and (b) oxidizing the inner surface including the nitride layer to modify the inner surface into an oxide layer. (a) includes setting a thickness distribution of the nitride layer in the inner surface such that, in (b), a thickness distribution of the oxide layer in the inner surface becomes a desired distribution.