Gas Distribution Showerhead with Dual Zone Flow Control
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Solution Overview
Problem
As substrate sizes increase in semiconductor processing, achieving uniform deposition of films on large substrates becomes challenging due to non-uniform gas distribution in processing chambers, necessitating an improved gas distribution assembly for enhanced uniformity.
Innovation Solution
A gas distribution assembly comprising a gas distribution plate, a blocker plate, and a dual zone showerhead with independent center to edge flow zonality, two precursor delivery, and mixing via a mixing manifold, along with recursive mass flow distribution, which includes patterned gas holes and trenches to prevent co-axial flow and ensure uniform gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If substrate size is increased to meet demand for larger electronic devices, then productivity and device capability are improved, but deposition uniformity deteriorates due to non-uniform gas distribution
Solution Approach 1:
The showerhead is divided into multiple independent flow zones (e.g., inner zone and outer zone) with separate gas distribution channels and holes. Each zone can independently control gas flow to different regions of the substrate, allowing optimized deposition uniformity across the entire large substrate area while maintaining the ability to process large substrates
Solution Approach 2:
Different regions of the showerhead are designed with different gas hole distributions, channel configurations, and flow characteristics tailored to local requirements. The inner zone and outer zone have distinct gas distribution patterns that address the specific uniformity challenges of their respective regions, enabling improved deposition uniformity across the large substrate
2Device complexity
If a simple gas distribution system is used, then device complexity is reduced, but gas distribution uniformity deteriorates
Solution Approach 1:
The gas distribution system is segmented into multiple functional components including a dual-zone showerhead with separate inner and outer zones, each with independent gas channels and hole patterns. This segmentation allows complex gas distribution control to be achieved through modular, manageable sections rather than a single monolithic structure
Solution Approach 2:
The gas distribution system incorporates vertical layering with a blocker plate positioned beneath the showerhead, creating multiple levels of gas flow control. This three-dimensional arrangement allows gas to be distributed through multiple pathways and zones, achieving superior uniformity without requiring an overly complex planar structure
3Device complexity
If co-axial flow is allowed in gas holes, then device structure is simplified, but deposition uniformity deteriorates due to non-uniform gas distribution
Solution Approach 1:
The gas holes in the showerhead are deliberately patterned with asymmetric orientations and non-co-axial arrangements. Instead of simple aligned circular holes, the design incorporates elliptical or angled holes with specific orientation patterns that create symmetric gas flow distribution across the substrate, preventing the non-uniformity that would result from co-axial flow
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 provides improved uniformity of gas distribution across large substrates, enabling better deposition uniformity and allowing for independent control of flow rates between inner and outer zones, enhancing processing chamber performance.
Implementation Method 1
a plurality of channels forming a path splitting manifold operatively connected to the gas supply inlet, and a first plurality of gas holes disposed within the plurality of channels and through the gas distribution plate
Implementation Method 2
a mixing manifold operatively coupled to the gas distribution plate. The mixing manifold includes a plurality of mixing channels. The mixing channels each include a first portion and a second portion. A diameter of a choke channel disposed between the first portion and the second portion is less than any diameter of the first portion or the second portion
Implementation Method 3
a first barrier wall separating the inner zone from the outer zone. The dual zone showerhead includes an inner zone comprising a fourth plurality of gas holes, an outer zone comprising a fifth plurality of gas holes, and a trench disposed between the inner zone and the outer zone. The trench is configured to accept the first barrier wall such that the inner zone of the dual zone showerhead is physically separated from the outer zone of the dual zone showerhead
Data Source
AI summary
Embodiments disclosed herein generally relate to a gas distribution assembly for providing improved uniform distribution of processing gases into a semiconductor processing chamber. The gas distribution assembly includes a gas distribution plate, a blocker plate, and a dual zone showerhead. The gas distribution assembly provides for independent center to edge flow zonality, independent two precursor delivery, two precursor mixing via a mixing manifold, and recursive mass flow distribution in the gas distribution plate.