Segmented PECVD Chamber Lid for Uniform Large-Panel Deposition
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Solution Overview
Problem
Achieving uniform film thickness across large area substrates in plasma-enhanced chemical vapor deposition (PECVD) processes is challenging due to the structural limitations of dielectric materials in inductively coupled plasma systems.
Innovation Solution
A lid assembly for process chambers is designed with a plasma generation system and a gas distribution assembly. The plasma generation system includes cavities with recesses for dielectric plates, and coils positioned over these plates to create an inductively coupled plasma. The gas distribution assembly features a first and second diffuser with channels that intersect, allowing for independent control of plasma density and gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If inductively coupled plasma arrangements are used for large substrate deposition, then substrate area coverage is improved, but structural strength to withstand pressure differential deteriorates due to dielectric materials
Solution Approach 1:
The lid assembly is segmented into multiple components: a plate structure with cavities, multiple dielectric plates positioned within cavities, and coils wrapped around the dielectric plates. This segmentation allows the system to achieve large area coverage while distributing structural loads across multiple smaller elements rather than relying on a single large dielectric component.
Solution Approach 2:
The plate structure serves as an intermediary element that provides mechanical support and houses the dielectric plates and coils. The plate with its cavities allows the dielectric materials to be positioned in a configuration that maintains structural integrity while enabling large substrate area coverage, mediating between the structural requirements and the plasma generation needs.
2Strength
If conventional capacitively coupled electrode arrangement is used, then structural strength is maintained, but film thickness uniformity across large substrates deteriorates
Solution Approach 1:
The patent replaces the conventional capacitively coupled electrode arrangement with an inductively coupled plasma system. Instead of using a capacitively coupled mechanical electrode structure, the invention uses electromagnetic induction through coils wrapped around dielectric plates to generate plasma, thereby improving film thickness uniformity while maintaining structural strength through the plate and cavity design.
Solution Approach 2:
The invention changes the plasma generation mechanism from capacitive coupling to inductive coupling. This parameter change in the electromagnetic field generation method improves the uniformity of plasma distribution across large substrates, which directly enhances film thickness uniformity while the structural design maintains the required strength.
3Use of energy by moving object
If dielectric materials are used in inductively coupled plasma systems, then plasma generation is enabled, but pressure differential承受能力 deteriorates
Solution Approach 1:
The dielectric materials are segmented into multiple smaller dielectric plates positioned within cavities in the plate structure. This segmentation allows the system to generate plasma effectively across large areas while distributing the pressure differential loads across multiple smaller components supported by the plate structure, rather than using large continuous dielectric sheets.
Solution Approach 2:
The system uses a composite structure combining the plate material, dielectric plates, and coils. This composite arrangement enables plasma generation through the dielectric materials while the overall composite structure (plate + dielectric plates + coils) provides the necessary mechanical strength to withstand pressure differentials, overcoming the limitation of dielectric materials alone.
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 configuration enables independent control of plasma density and gas distribution, improving film thickness uniformity across large substrates by addressing the structural limitations of dielectric materials in conventional systems.
Implementation Method 1
One or more coils are positioned on or over the plurality of dielectric plates
Implementation Method 2
The precursor gas in the chamber may be energized (e.g., excited) into a plasma by applying a radio frequency (RF) power
Implementation Method 3
The gas distribution assembly includes a first diffuser. The first diffuser includes one or more first diffuser inlets disposed in the plate and a plurality of first channels in fluid communication with at least one of the first diffuser inlets
Data Source
AI summary
Embodiments described herein provide a lid assembly of a chamber for independent control of plasma density and gas distribution within the interior volume of the chamber. The lid assembly includes a plasma generation system and a gas distribution assembly. The plasma generation system includes a plurality of dielectric plates having a bottom surface oriented with respect to vacuum pressure and a top surface operable to be oriented with respect to atmospheric pressure. One or more coils are positioned on or over the plurality of dielectric plates. The gas distribution assembly includes a first diffuser and a second diffuser. The first diffuser includes a plurality of first channels intersecting a plurality of second channels of the second diffuser.