Dual Gas Feed Plasma CVD for Uniform Wafer Edge Film Thickness
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Solution Overview
Problem
Existing semiconductor manufacturing methods face challenges in accurately adjusting film thickness and improving in-plane evenness of film thickness, particularly at the outer peripheral parts of semiconductor substrates during plasma CVD processing.
Innovation Solution
A semiconductor manufacturing apparatus with dual gas feeders, where one feeder supplies a gas that is easier to ionize and generates plasma, and another feeder supplies a gas more difficult to ionize, which is used to control the plasma distribution and density, allowing for precise adjustment of film thickness by confining plasma to the center part of the substrate and maintaining it at the periphery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single gas feeder is used for plasma CVD processing, then the device complexity is reduced, but the manufacturing precision of film thickness and in-plane evenness deteriorates
Solution Approach 1:
The gas feeder is divided into multiple independent gas feeders, each capable of supplying different gases to different regions of the substrate. This segmentation allows independent control of plasma generation and plasma distribution, enabling precise control of film thickness uniformity without requiring complex integrated systems
Solution Approach 2:
Different regions of the substrate receive different gases with different ionization characteristics. The first gas feeder supplies easily ionizable gas to the center region for plasma generation, while the second gas feeder supplies difficult-to-ionize gas to the peripheral regions for plasma distribution control. This local differentiation achieves uniform film thickness through region-specific plasma control
2Manufacturing precision
If plasma is confined to the center part of the substrate, then the in-plane evenness of film thickness is improved, but the film deposition coverage at the periphery may be reduced
Solution Approach 1:
The system changes the chemical composition parameter of the gas supplied to different regions. By supplying easily ionizable gas to the center and difficult-to-ionize gas to the periphery, the plasma density and distribution are controlled through gas composition changes, achieving both uniform thickness and adequate coverage
Solution Approach 2:
The system uses composite gas supply where different types of gases (with different ionization energies) are supplied to different regions simultaneously. This composite approach combines the plasma-generating capability of easily ionizable gases with the plasma-distributing capability of difficult-to-ionize gases, achieving both uniformity and coverage
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 enables improved in-plane evenness and easier control of film thickness at the outer peripheral parts of the substrate, reducing the risk of abnormal discharge and allowing for flexible film deposition conditions without the need for multiple stages or expensive equipment changes.
Implementation Method 1
The first gas processor supplies high frequency power to the stage and renders the first gas fed from the first gas feeder into plasma
Data Source
AI summary
A semiconductor manufacturing apparatus according to the present embodiment includes a first gas feeder, a first gas processor and a second gas feeder. The first gas feeder is provided above a stage on which a substrate is to be placed and feeds a first gas to the substrate. The first gas processor supplies high frequency power to the stage and renders the first gas fed from the first gas feeder into plasma. The second gas feeder is provided above the stage and feeds a second gas more difficult to render into plasma than the first gas to an outer periphery of the first gas having been rendered into plasma.