Multi-Frequency RF Sputtering Apparatus for Thin Film Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in efficiently depositing thin films and cleaning sputtering targets due to defects and inefficiencies in sputtering processes, particularly in the use of magnetic memory elements which require high-speed and low-power operations.
Innovation Solution
A sputtering apparatus utilizing multiple radio frequency (RF) sources with different frequencies for enhanced process efficiency and a gas inlet at the chamber's upper portion to prevent particle dispersion, along with a cleaning process to reduce defects and improve target surface conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single RF source is used for sputtering, then the device complexity is reduced, but the productivity and process efficiency deteriorate
Solution Approach 1:
The patent divides the RF power source into multiple independent RF sources (first RF source and second RF source) operating at different frequencies. Each RF source can independently control a sputter gun, enabling simultaneous or sequential execution of sputtering and cleaning processes without interference, thereby improving overall process efficiency while managing device complexity through modular architecture
Solution Approach 2:
The first sputter gun is designed to perform multiple functions by switching between different RF frequencies: it can conduct sputtering deposition using the first RF source and perform target cleaning using the second RF source. This multi-functionality eliminates the need for separate dedicated cleaning equipment, improving productivity without proportionally increasing device complexity
2Reliability
If gas inlet is positioned at the lower portion of the chamber, then the installation is simplified, but particles attached to the chamber shield disperse and cause process defects
Solution Approach 1:
The patent inverts the conventional gas inlet positioning by placing it at the upper portion of the chamber instead of the lower portion. This inversion creates a downward gas flow that prevents particles from dispersing along the chamber shield, thereby reducing process defects. The chamber shield design with inclined sidewalls further complements this inverted approach by guiding particle settlement away from the substrate area
3Manufacturing precision
If the sputtering process is performed without frequent target cleaning, then the process time is reduced, but the manufacturing precision and film quality deteriorate
Solution Approach 1:
The patent implements preliminary target cleaning by using a second RF source to clean the sputtering target surface before the main sputtering deposition process begins. This preliminary cleaning action removes contaminants and oxides that would otherwise degrade film quality, ensuring high manufacturing precision from the start of the deposition process without requiring multiple interruption cycles
Solution Approach 2:
The patent enables continuous operation by allowing the first sputter gun to perform both sputtering deposition and target cleaning functions through frequency switching. The cleaning process can be executed continuously or periodically during the sputtering cycle without stopping the overall process, maintaining continuous useful action while preserving target surface quality for high-precision film deposition
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 enhances process efficiency by using multiple RF frequencies for sputtering and cleaning, reducing defects and improving the quality of thin film deposition, thereby supporting the development of high-speed and low-power semiconductor devices.
Implementation Method 1
a first sputter gun configured to provide a sputtering source to an inside of the chamber
Implementation Method 2
cleaning a lower surface of a target exposed at a lower portion of the first sputter gun by using the second power
Data Source
AI summary
A sputtering apparatus including a chamber, a stage inside the chamber and configured to receive a substrate thereon, a first sputter gun configured to provide a sputtering source to an inside of the chamber, a first RF source configured to provide a first power having a first frequency to the first sputter gun, and a second RF source configured to provide a second power having a second frequency to the first sputter gun, the second frequency being lower than the first frequency may be provided.