Magnetron Homing via Arbitrary Scan Path Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetron sputtering systems face challenges in controlling complex scan patterns and maintaining synchronization of motor rotations, leading to suboptimal sputtering uniformity and efficiency, especially when dealing with deep and narrow holes or non-planar surfaces.
Innovation Solution
A system and method that control two motors to move a magnetron along a nearly arbitrary path on the sputtering target, utilizing a motion controller to execute pre-stored scanning profiles and dynamically adjust the magnetron's position through sensors, allowing for precise control of complex scan patterns without physical changes to the scan mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a planetary gear mechanism is used to produce a multi-lobed scan pattern, then the radial extent and number of lobes are established by arm lengths and gear ratio, but the scan pattern cannot be changed without changing physical parts of the scan mechanism
Solution Approach 1:
The patent applies dynamics by making the scan mechanism software-configurable rather than physically fixed. The motion controller executes stored scan profiles that define arbitrary paths, allowing the scan pattern to be dynamically changed through software parameters (arm lengths, gear ratios, number of lobes) without any physical modification to the hardware structure.
Solution Approach 2:
The invention utilizes parameter changes by allowing the scan pattern characteristics (radial extent, number of lobes, path shape) to be modified through changing control parameters in the motion controller's stored profiles. This enables flexible adjustment of scan patterns by modifying numerical values in software rather than altering physical components.
2Manufacturing precision
If two motors are controlled to move the magnetron along an arbitrary path, then precise control of complex scan patterns is achieved, but motor synchronization becomes difficult to maintain
Solution Approach 1:
The patent implements feedback by using sensors to detect the positions of both arms and providing this information back to the motion controller. The controller continuously monitors arm positions and adjusts motor commands to maintain proper synchronization, ensuring that the magnetron follows the desired arbitrary path even during high-speed operations.
Solution Approach 2:
The motion controller serves multiple functions: it stores scan profiles, generates motion commands for both motors, interprets sensor feedback, and maintains synchronization. This multi-functional approach consolidates the control system, improving reliability by centralizing synchronization logic in a single intelligent controller rather than requiring separate coordination mechanisms.
3Power
If a small magnetron is scanned near the periphery of the target, then high power density is achieved for sputtering into deep holes, but uniform sputter deposition over the entire wafer becomes difficult
Solution Approach 1:
The patent applies dynamics by implementing arbitrary scan paths that can simultaneously achieve high power density in specific regions and uniform deposition overall. The motion controller executes profiles that move the magnetron through complex trajectories, spending appropriate time in high-power-density regions near the target periphery while also covering broader areas to ensure uniform deposition across the entire wafer surface.
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
Enables precise and uniform sputtering over complex surfaces by allowing arbitrary scan paths, improving sputtering uniformity and efficiency, and maintaining motor synchronization, even during high-speed and complex scan operations.
Implementation Method 1
A typical magnetron includes a magnetic pole of one magnetic polarity surrounding another magnetic pole of the opposed magnetic polarity
Implementation Method 2
Sputtering, alternatively called physical vapor deposition (PVD), is the most prevalent method of depositing layers of metals and related materials
Data Source
AI summary
A control system and method for controlling two motors determining the azimuthal and circumferential position of a magnetron rotating about the central axis of the sputter chamber in back of its target sputtering and capable of a nearly arbitrary scan path, e.g., with a planetary gear mechanism. A system controller periodically sends commands to the motion controller which closely controls the motors. Each command includes a command ticket, which may be one of several values. The motion controller accepts only commands having a command ticket of a different value from the immediately preceding command. One command selects a scan profile stored in the motion controller, which calculates motor signals from the selected profile. Another command instructs a dynamic homing command which interrogates sensors of the position of two rotating arms to determine if the arms in the expected positions. If not, the arms are rehomed.