Semiconductor Pedestal Annular Member for Etch Uniformity
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Solution Overview
Problem
Maintaining uniformity of etching processes across semiconductor substrates is challenging due to variations in precursor delivery and plasma exposure, leading to inconsistent edge and central etch rates, which affects the usable area and efficiency of substrate processing.
Innovation Solution
The implementation of a semiconductor processing chamber with a remote plasma region and a processing region fluidly coupled, featuring a support pedestal with an annular member made of a second material that has a higher affinity for fluorine than the pedestal material, along with a sidewall heating element, to maintain the annular member at a higher temperature than the pedestal, promoting recombination of fluorine radicals and reducing edge etch rates while preserving central etch rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If process conditions are adjusted to improve etch rate uniformity, then manufacturing precision is improved, but device complexity increases due to additional system components
Solution Approach 1:
The patent applies local quality by creating a non-uniform temperature distribution across the substrate surface. A heating element is positioned to heat the central region of the substrate to a higher temperature than the edge regions. This localized temperature variation compensates for the non-uniform precursor delivery, ensuring that fluorine radical recombination occurs at comparable rates across the entire substrate surface, thereby achieving uniform etch rates without requiring complex process condition adjustments.
2Manufacturing precision
If the annular member temperature is increased to maintain etch rate uniformity, then manufacturing precision is improved, but energy consumption increases
Solution Approach 1:
The patent employs parameter changes by optimizing the temperature parameters of the heating system. The heating element is designed to maintain the central substrate region at a specific elevated temperature that promotes appropriate fluorine radical recombination. By carefully controlling this temperature parameter, the system achieves uniform etch rates across the substrate while minimizing excess energy consumption that would occur with higher temperature settings.
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 ensures that the edge etch rate is maintained within 5% of the central etch rate, enhancing process uniformity and increasing the usable substrate area by reducing edge etch rate variations without compromising overall etch rate efficiency.
Implementation Method 1
fluorine may have a higher affinity to the second material than the first material, and the second material may include nickel or platinum
Implementation Method 2
a sidewall heating element may be embedded in the sidewall proximate the showerhead
Implementation Method 3
a remote plasma region, and a processing region fluidly coupled with the remote plasma region
Data Source
AI summary
A semiconductor processing chamber may include a remote plasma region, and a processing region fluidly coupled with the remote plasma region. The processing region may be configured to house a substrate on a support pedestal. The support pedestal may include a first material at an interior region of the pedestal. The support pedestal may also include an annular member coupled with a distal portion of the pedestal or at an exterior region of the pedestal. The annular member may include a second material different from the first material.