Multi-Zone Gas Distribution for Uniform Semiconductor Plasma
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Solution Overview
Problem
Plasma uniformity issues in semiconductor manufacturing, particularly with fluorine-containing plasmas, lead to inconsistent etch or deposition rates across substrate surfaces, causing device failures due to irregularities in plasma distribution and electronegative species instability.
Innovation Solution
A zonal distribution manifold system with separate channels for reactants allows for independent control of gas delivery to different regions of the plasma, ensuring uniform etch or deposition profiles by maintaining separate flows until they enter the plasma region, using a zonal distribution plate and blocker plate configuration to prevent mixing until entry, and applying RF power to form stable plasmas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional gas distribution assemblies are used to deliver reactants to the plasma region, then the system structure is simple, but plasma uniformity deteriorates due to inability to control reactant distribution in different regions
Solution Approach 1:
The gas distribution system is segmented into multiple independent channels (first channel for first reactant, second channel for second reactant) that can deliver different reactants or reactant ratios to different regions of the plasma. This segmentation enables regional control of plasma composition to achieve uniform plasma distribution across the substrate surface.
Solution Approach 2:
Different reactants or reactant mixtures are delivered to specific regions of the plasma (center vs. outer portions) based on local plasma uniformity requirements. This local quality approach allows optimization of plasma composition in each region to maintain overall plasma uniformity and prevent plasma collapse.
2Productivity
If fluorine-containing precursors are used to achieve high etch rates, then productivity is improved, but plasma stability deteriorates due to electronegative species causing plasma collapse
Solution Approach 1:
A first reactant (such as hydrogen or a carrier gas) is introduced as an intermediary through the first channel to stabilize the plasma before or alongside the introduction of fluorine-containing precursors through the second channel. This intermediary reactant helps maintain plasma stability by providing electrons and preventing plasma collapse caused by highly electronegative fluorine species.
Solution Approach 2:
The system changes the composition and ratio of reactants delivered to different plasma regions. By controlling the ratio of fluorine-containing precursor to stabilizing reactant in different regions, the system maintains high etch rates where needed while preventing plasma instability and collapse in other regions.
3Manufacturing precision
If reactants are mixed before delivery to the plasma region, then the gas distribution system is simple, but process uniformity deteriorates due to inability to control regional reactant distribution
Solution Approach 1:
The gas distribution system uses separate channels (first channel and second channel) that remain distinct until they deliver reactants to the plasma region. This segmentation prevents premature mixing of reactants and enables independent control of reactant flow rates, compositions, and delivery timing to different plasma regions, achieving superior process uniformity.
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 achieves more uniform plasma distribution and process uniformity across substrate surfaces, preventing plasma collapse and enhancing the stability and intensity of fluorine plasmas, thereby improving semiconductor processing outcomes.
Implementation Method 1
A zonal distribution manifold system with separate channels for reactants allows for independent control of gas delivery to different regions of the plasma
Implementation Method 2
applying RF power to form stable plasmas
Data Source
AI summary
The present technology includes improved gas distribution designs for forming uniform plasmas during semiconductor processing operations or for treating the interior of semiconductor processing chambers. While conventional gas distribution assemblies may receive a specific reactant or reactant ratio which is then distributed into the plasma region, the presently described technology allows for improved control of the reactant input distribution. The technology allows for separate flows of reactants to different regions of the plasma to offset any irregularities observed in process uniformity. A first precursor may be delivered to the center of the plasma above the center of the substrate/pedestal while a second precursor may be delivered to an outer portion of the plasma above an outer portion of the substrate/pedestal. In so doing, a substrate residing on the pedestal may experience a more uniform etch or deposition profile across the entire surface.