Perforated Microwave Coupler in RF Plasma Chambers for Uniformity
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Solution Overview
Problem
Current plasma processing technologies face challenges in achieving spatial uniformity and precise control of electromagnetic power distribution for semiconductor wafer processing, particularly at atomic scale dimensions, which is crucial for high-volume IC manufacturing.
Innovation Solution
A plasma processing system that combines radio frequency (RF) and microwave power, utilizing a conductive spatial uniformity component with adjustable through openings to control the spatial distribution of electromagnetic power, allowing for precise adjustment of the unfilled depth to optimize the coupling of microwave power and improve spatial uniformity metrics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma processing technology is used, then plasma processing can be performed, but spatial uniformity of electromagnetic power distribution is insufficient
Solution Approach 1:
The patent combines RF and microwave power sources into a single plasma processing system, merging two different electromagnetic power delivery mechanisms to achieve superior spatial uniformity that neither source could achieve alone. The RF source electrode and microwave source work together through the conductive spatial uniformity component to provide complementary power distribution patterns.
Solution Approach 2:
The conductive spatial uniformity component is segmented into multiple regions with different electromagnetic properties, including through openings that create localized field variations. This segmentation allows different portions of the plasma to receive optimized power distribution for their specific processing requirements, improving overall spatial uniformity.
2Manufacturing precision
If spatial uniformity is improved using complex power distribution systems, then plasma uniformity increases, but control precision of electromagnetic power decreases
Solution Approach 1:
The system incorporates control circuits that monitor and adjust the RF and microwave power levels in real-time, using feedback from plasma parameters to maintain optimal spatial uniformity. The conductive spatial uniformity component works with the power sources to provide controlled power distribution that responds to plasma conditions.
Solution Approach 2:
The patent utilizes changes in electromagnetic parameters (frequency, power level, phase) between RF and microwave sources to achieve spatial uniformity. By adjusting these parameters independently and in combination, the system maintains precise control over plasma characteristics while achieving improved uniformity.
3Manufacturing precision
If RF power alone is used to ignite plasma, then plasma can be sustained, but spatial distribution uniformity is insufficient
Solution Approach 1:
The patent merges RF and microwave power delivery systems to achieve complementary spatial distribution patterns. The RF source provides one distribution pattern while the microwave source provides another, and their combination through the conductive spatial uniformity component creates a more uniform overall plasma distribution.
Solution Approach 2:
The conductive spatial uniformity component acts as a composite electromagnetic structure that integrates properties of both RF and microwave interactions. This composite approach allows the system to leverage the strengths of both frequency ranges to achieve superior power distribution uniformity.
4Manufacturing precision
If microwave power is coupled through simple structures, then power coupling is achieved, but spatial uniformity metric is insufficient
Solution Approach 1:
The conductive spatial uniformity component is divided into multiple segments with different geometries and electromagnetic properties, including through openings that create localized field effects. This segmentation enables precise control over microwave power coupling to different plasma regions, improving spatial uniformity metric.
Solution Approach 2:
Different portions of the conductive spatial uniformity component have locally optimized properties tailored to their specific function in the plasma. The through openings and conductive regions are positioned and dimensioned to create specific electromagnetic field patterns where needed, achieving superior spatial uniformity through local optimization.
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 results in more uniform plasma distribution and improved process characteristics for semiconductor wafers, enhancing the precision and repeatability required for advanced semiconductor fabrication.
Implementation Method 1
igniting plasma by coupling RF power from the RF source electrode to gas in the plasma processing chamber
Implementation Method 2
coupling microwave power from the microwave power system to a plasma ignited in the plasma processing chamber by coupling the microwave oscillator to the microwave source
Data Source
AI summary
In one example, a plasma processing system includes a vacuum system, a plasma processing chamber including a chamber cavity coupled to the vacuum system, a substrate holder including a surface disposed inside the chamber cavity, a radio frequency (RF) source electrode coupled to an RF power source, the RF source electrode configured to ignite plasma in the chamber cavity. The system includes a microwave source coupled to a microwave oscillator, and a conductive spatial uniformity component including a plurality of through openings, where the conductive spatial uniformity component includes a major surface electromagnetically coupled to the microwave source, the major surface configured to couple microwave power to the plasma in the chamber cavity.