Electromagnetic Coil Cathode Assembly for Real-Time Plasma Profile Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hardware solutions for plasma control in PVD processes rely on solid state magnets, which require extensive hardware work and chamber downtime for tuning or modification, and fail to provide precise control over plasma profiles.
Innovation Solution
The use of a plasma cathode assembly comprising a plurality of electromagnetic (EM) coils positioned within each other, allowing for software-controlled modulation of the magnetic field, including control over the spacing, current flow, and position of the EM coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If solid state magnets are used for plasma control, then magnetic field generation is achieved, but hardware modification requires extensive work and chamber downtime
Solution Approach 1:
The patent replaces solid state magnets with electromagnetic coils that generate magnetic fields through controlled current flow. This substitution allows magnetic field configuration to be changed via software control of coil currents rather than requiring physical hardware modification, thereby eliminating chamber downtime for tuning and accelerating process development
Solution Approach 2:
The electromagnetic coil system enables dynamic adjustment of magnetic field strength and configuration by varying current parameters in real-time. This dynamic control allows rapid optimization of plasma profiles without mechanical intervention, directly addressing the productivity-time contradiction
2Adaptability or versatility
If solid state magnets are used for plasma control, then magnetic field is generated, but tuning and modification require extensive hardware work
Solution Approach 1:
By replacing solid state magnets with electromagnetic coils, the system transitions from mechanical hardware modification to software-based control. The coils can be programmed to generate various magnetic field configurations, providing plasma profile control flexibility without complex hardware work
Solution Approach 2:
The electromagnetic coil system allows adjustment of plasma profiles by changing electrical parameters (current magnitude, direction, and timing) rather than modifying hardware geometry. This parameter-based control enhances adaptability while simplifying the ease of manufacture
3Productivity
If high DC power is used in sputtering, then sputtering rate increases, but target surface temperature rises significantly
Solution Approach 1:
The electromagnetic coil system enables pulsed or modulated power delivery to the target by controlling current flow through the coils. This periodic action allows high power density sputtering intervals followed by cooling intervals, maintaining high average sputtering rates while preventing excessive target temperature accumulation
Solution Approach 2:
The system dynamically adjusts power delivery timing and magnitude through electromagnetic coil control, optimizing the balance between sputtering rate and target temperature management by responding to real-time process conditions
4Manufacturing precision
If magnet configuration is modified for plasma control, then plasma profile control is achieved, but chamber downtime increases
Solution Approach 1:
The electromagnetic coil system replaces mechanical magnet configuration changes with software-controlled electrical parameter adjustments. This substitution achieves precise plasma profile control through programmable current patterns while eliminating the need for physical magnet repositioning, thereby reducing chamber downtime
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 solution enables rapid, real-time tuning of plasma profiles, reduces development time for new PVD processes, and allows for controlled deposition rates and film properties, including full face erosion of the target material and multi-layer film deposition.
Implementation Method 1
A first EM coil is inside the interior volume of the cathode housing. The first EM coil has a first inner diameter and a first outer diameter defining a first coil width... A second EM coil is inside the interior volume of the cathode housing. The second EM coil has a second inner diameter and a second outer diameter defining a second coil width...
Implementation Method 2
a magnetron positioned at the back of the sputtering target including at least two magnets of opposing poles magnetically coupled at their back through a magnetic yoke to project a magnetic field into the processing space to increase the density of the plasma and enhance the sputtering rate from a front face of the target
Implementation Method 3
The sputtering target is cooled by contacting a target backing plate with cooling fluid
Data Source
AI summary
Apparatus and methods for controlling plasma profiles during PVD deposition processes are disclosed. Some embodiments utilize EM coils placed above the target to control the plasma profile during deposition.