Adjustable Geometry Trim Coil for Plasma Uniformity Control
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Solution Overview
Problem
Controlling plasma uniformity and etch rate in semiconductor manufacturing is challenging due to residual magnetic fields within CCP-based vacuum chambers, which vary significantly between chambers and locations, affecting plasma density and ion tilt.
Innovation Solution
An adjustable geometry trim coil (AGTC) is used to generate supplemental magnetic fields that counteract residual magnetic fields, detected by sensors, to achieve predetermined uniformity and etch rates by adjusting parameters such as geometry and current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional techniques (changing ground electrode dimension, gas flow, RF frequency) are used to control plasma uniformity, then plasma density uniformity can be adjusted, but the control is insufficient due to varying residual magnetic fields between chambers and locations
Solution Approach 1:
The patent applies parameter changes by adjusting the geometry parameters of the trim coil (such as coil radius, turn density, and positioning) to generate compensating magnetic fields that counteract residual magnetic fields. This allows dynamic adjustment of magnetic field parameters to achieve consistent plasma uniformity across different chambers and locations, directly addressing the adaptability issue.
2Ease of manufacture
If residual magnetic fields are present in the vacuum chamber, then chamber components can be magnetized, but plasma density uniformity and etch rate consistency deteriorate
Solution Approach 1:
The patent implements preliminary anti-action by using trim coils to generate compensating magnetic fields that counteract the harmful residual magnetic fields before they can significantly affect plasma uniformity and etch rate consistency. This proactive approach prevents the deterioration of manufacturing precision while allowing chamber components to maintain their magnetized state for ease of manufacture.
3Manufacturing precision
If trim coils are added to compensate for residual magnetic fields, then plasma uniformity improves, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the trim coil system to perform multiple functions: compensating for residual magnetic fields, adjusting plasma uniformity, and potentially optimizing etch rate consistency. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting the increase in device complexity while achieving improved plasma 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
This approach effectively reduces residual magnetic fields to improve plasma uniformity and etch rate consistency across different chambers and locations, enhancing the precision and reliability of semiconductor manufacturing processes.
Implementation Method 1
The AGTC is configured to generate a supplemental magnetic field through the processing zone of the vacuum chamber
Implementation Method 2
The magnetic field sensor is configured to detect a residual magnetic field within the vacuum chamber
Implementation Method 3
the supplemental magnetic field reducing the residual magnetic field to a pre-determined value
Data Source
AI summary
Methods, systems, apparatuses, and computer programs are presented for controlling etch rate and plasma uniformity using magnetic fields. A substrate processing apparatus includes a vacuum chamber including a processing zone for processing a substrate. The apparatus further includes a magnetic field sensor configured to detect a signal representing a residual magnetic field associated with the vacuum chamber. At least one magnetic field source is configured to generate one or more supplemental magnetic fields through the processing zone of the vacuum chamber. A magnetic field controller is coupled to the magnetic field sensor and the at least one magnetic field source. The magnetic field controller is configured to adjust at least one characteristic of the one or more supplemental magnetic fields, causing the one or more supplemental magnetic fields to reduce the residual magnetic field to a pre-determined value.