Multi-Layer Gas Supply Module for Epitaxial Growth
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Solution Overview
Problem
Conventional epitaxial growth apparatuses face challenges in achieving uniform gas distribution across large-area substrates, leading to poor epitaxial layer thickness uniformity, especially between the center and edge regions.
Innovation Solution
A multi-layer gas supply module with an injector having ports for different gases, a flow distribution unit for independent gas distribution, and a baffle with varying through hole shapes to optimize gas flow to the center, edge, and middle regions of the substrate, ensuring uniform gas distribution and epitaxial layer growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple gases are injected into the chamber through a single-layer inlet, then the gas supply system is simple in structure, but uniform gas distribution cannot be achieved across the substrate
Solution Approach 1:
The gas supply system is segmented into multiple layers (first layer, second layer, third layer) with each layer having dedicated ports for different gases. This segmentation allows independent control of gas flow to different regions, resolving the contradiction by transforming a simple single-layer structure into a multi-layer segmented structure that achieves uniform distribution.
Solution Approach 2:
Different regions of the substrate receive different gas compositions and flow rates through locally optimized port arrangements. The first layer ports discharge raw gas, the second layer ports discharge blocking gas, and the third layer ports discharge purifying gas, with each layer's ports positioned to address specific regional requirements of the substrate.
2Ease of manufacture
If a single-layer inlet is used for gas injection, then the system is easy to manufacture, but poor gas distribution uniformity occurs between center and edge regions
Solution Approach 1:
The gas supply system transitions from a single-layer (2D) inlet to a multi-layer (3D) structure with ports distributed vertically across three layers. This dimensional expansion enables gas to be supplied from multiple heights and positions, achieving uniform distribution across the substrate area while maintaining manufacturability through standardized port configurations.
Solution Approach 2:
The multi-layer gas supply module employs a nested structure where the first layer, second layer, and third layer ports are vertically stacked and spatially arranged to correspond to different regions of the substrate. This nested arrangement allows compact integration of multiple gas supply functions within a confined space.
3Device complexity
If multiple gases are supplied through a single inlet, then the device structure remains simple, but the epitaxial layer thickness uniformity deteriorates to 5% or more
Solution Approach 1:
The inlet configuration is segmented into three distinct layers with multiple ports each, allowing separate control of raw gas, blocking gas, and purifying gas flow. This segmentation transforms the simple single-inlet structure into a complex multi-layer system that achieves thickness uniformity of 1% or less.
Solution Approach 2:
The system changes multiple parameters simultaneously: the number of layers (from 1 to 3), the number of ports per layer, the vertical positions of ports, and the gas flow rates through mass flow controllers. These parameter changes enable precise control of gas distribution to achieve uniform epitaxial layer thickness.
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
The solution enables uniform epitaxial layer growth across large-area substrates with improved thickness uniformity, achieving less than 1% variation by independently controlling gas flow to different regions of the substrate.
Implementation Method 1
a mass flow controller connected to each of the ports
Implementation Method 2
a flow distribution unit configured to independently distribute the gas to the ports by including a single inflow line receiving the gas from a source module, a plurality of branch lines branched off from the single inflow line and directly connected to the respective ports
Implementation Method 3
a baffle including through holes which are positioned in front of the injector, and through which the gas discharged from the ports passes
Implementation Method 4
an injector including ports of a plurality of layers, each of which discharges a different gas for each layer
Implementation Method 5
ports of a first layer discharging a raw gas forming the epitaxial layer
Implementation Method 6
ports of a second layer positioned above the ports of the first layer and discharging a blocking gas blocking the raw gas from diffusing upward
Implementation Method 7
ports of the third layer disposed below the ports of the first layer and discharging a purifying gas purifying a by-product occurring during a growth of the epitaxial layer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided are an epitaxial growth apparatus and a multi-layer gas supply module used therefor, the epitaxial growth apparatus including: a reaction chamber; a susceptor positioned in the reaction chamber and configured to seat a wafer thereon; and a multi-layer gas supply module configured to supply a gas to the reaction chamber to form an epitaxial layer on the wafer, wherein the multi-layer gas supply module includes an injector including ports of a plurality of layers, each of which discharges a different gas for each layer, among the ports of the plurality of layers, the ports of each layer including a center port corresponding to a central region of the wafer, and a pair of edge ports corresponding to both edge regions of the wafer, and a flow distribution unit configured to distribute gas flows input to the center port and the edge port among the ports of each layer independently from each other.