Plasma Oxide Layer Formation to Suppress Dopant Desorption
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Solution Overview
Problem
The existing semiconductor manufacturing processes face challenges in forming high-quality oxide layers without compromising productivity or causing unintended changes in substrate surface characteristics, particularly due to dopant desorption during high-temperature oxidation, which can lead to contamination and reduced film quality.
Innovation Solution
A method involving a two-step plasma oxidation process, where a first oxide layer is formed at a lower temperature to suppress dopant desorption, followed by a second oxidation step at a higher temperature to enhance film quality and thickness, using a substrate processing apparatus with controlled plasma generation and temperature management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature oxidation is performed to form a thick oxide layer, then the film thickness and quality are improved, but dopant desorption occurs causing surface characteristic changes and contamination
Solution Approach 1:
The oxidation process is divided into multiple stages with different temperatures. The first stage uses a lower temperature to form an initial oxide layer that prevents dopant desorption, while the second stage uses a higher temperature to achieve the desired final thickness and quality. This segmentation resolves the contradiction by separating the protective function from the thickness-building function.
Solution Approach 2:
A preliminary low-temperature oxidation step is performed before the main high-temperature oxidation. This preliminary action forms a protective oxide layer that prevents dopant desorption during the subsequent high-temperature process, thereby maintaining surface characteristics while enabling high-quality thick oxide formation.
2Object-generated harmful factors
If low-temperature oxidation is performed to suppress dopant desorption, then surface characteristics are maintained, but the oxidation rate and throughput decrease
Solution Approach 1:
The oxidation process is divided into two sequential stages: a first low-temperature stage that suppresses dopant desorption and maintains surface characteristics, followed by a second high-temperature stage that achieves rapid oxidation for desired thickness. This segmentation allows each stage to optimize for its specific function, resolving the contradiction between dopant suppression and oxidation rate.
Solution Approach 2:
The oxidation temperature parameter is dynamically changed between two distinct values during the process. The first stage operates at a lower temperature to suppress dopant desorption, then the temperature is increased for the second stage to achieve high oxidation rate. This parameter change enables both dopant suppression and high productivity.
3Manufacturing precision
If high-temperature oxidation is performed to achieve sufficient film thickness, then the oxide layer quality is improved, but the substrate temperature increases causing dopant desorption and contamination
Solution Approach 1:
The oxidation process is segmented into two temperature zones: a first lower temperature zone for initial oxide formation that prevents dopant desorption, and a second higher temperature zone for achieving the desired final thickness. This segmentation allows the substrate to experience high temperature only after the protective oxide layer is formed, resolving the contradiction between thickness achievement and temperature control.
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 effectively suppresses dopant desorption, maintains substrate surface characteristics, and improves oxidation rate and throughput, enabling the formation of desired oxide layers with enhanced quality and thickness.
Implementation Method 1
forming a first oxide layer by modifying a surface of a substrate at a first temperature with a plasma of a first oxygen-containing gas
Implementation Method 2
heating the substrate to a second temperature higher than the first temperature and modifying the surface of the substrate with a plasma of a second oxygen-containing gas
Data Source
AI summary
According to one aspect of the technique, there is provided a method of manufacturing a semiconductor device, including: (a) forming a first oxide layer by modifying a surface of a substrate at a first temperature with a plasma of a first oxygen-containing gas; and (b) forming a second oxide layer thicker than the first oxide layer by heating the substrate to a second temperature higher than the first temperature and modifying the surface of the substrate, on which the first oxide layer is formed, with a plasma of a second oxygen-containing gas.