Hexapod Pedestal Alignment for Precise Wafer Centering
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Solution Overview
Problem
Existing semiconductor processing tools have limited degrees of freedom for pedestal movement, leading to potential positioning errors and reduced confidence in wafer placement accuracy.
Innovation Solution
A hexapod-based pedestal system with a movable mount supported by six independently controllable linear actuators, allowing for six degrees of freedom and dynamic adjustment of the pedestal's position and orientation relative to the semiconductor processing chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pedestal is fixed in location or configured with only one or two degrees of freedom, then the device complexity is reduced, but the positioning precision and wafer placement accuracy deteriorate
Solution Approach 1:
The patent applies the dynamics principle by transforming the pedestal from a fixed or limited-motion structure to a dynamically controllable platform with six degrees of freedom. The hexapod mechanism enables the pedestal to actively adjust its position and orientation in three-dimensional space through coordinated movement of six linear actuators, allowing real-time compensation for positioning errors and dynamic adaptation to different wafer placement requirements.
Solution Approach 2:
The patent implements dimensionality change by expanding the pedestal's movement capability from one or two degrees of freedom to six degrees of freedom. This adds three additional dimensional parameters (two rotational and one translational degree of freedom beyond the basic vertical movement), enabling precise positioning in three-dimensional space and allowing the pedestal to correct positioning errors in multiple directions simultaneously.
2Manufacturing precision
If a hexapod mechanism with six independently controllable linear actuators is used, then the positioning precision and wafer centering capability are improved, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing the hexapod mechanism to perform multiple functions simultaneously: it provides vertical support for the pedestal, enables precise positioning in three-dimensional space, allows rotational adjustment for wafer centering, and facilitates dynamic motion during processing. This multi-functional design consolidates what would otherwise require separate mechanisms into a single integrated system.
Solution Approach 2:
The hexapod mechanism implements self-service through its ability to automatically adjust and center wafers using feedback from the processing system. The six linear actuators coordinate their movement based on real-time positioning requirements, enabling the system to self-correct positioning errors and maintain optimal wafer alignment without external intervention.
3Productivity
If the pedestal is dynamically adjusted during processing, then the productivity and throughput are improved, but the control system complexity increases
Solution Approach 1:
The patent implements feedback by integrating the hexapod mechanism with the semiconductor processing system's control architecture. Position sensors and processing parameters provide real-time feedback to the control system, which automatically adjusts the linear actuators to maintain optimal wafer positioning and orientation throughout the processing cycle, enabling continuous optimization without manual intervention.
Solution Approach 2:
The system applies preliminary action by pre-positioning the pedestal and wafer using the hexapod mechanism before the actual processing begins. This preliminary positioning ensures that wafers are correctly centered and oriented at the start of processing, eliminating the need for time-consuming adjustments during production and maximizing throughput.
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 hexapod-based pedestal system enhances wafer centering operations by allowing independent and simultaneous centering at multiple stations, reduces processing non-uniformities, and increases throughput by dynamically adjusting the pedestal's position and orientation during processing.
Implementation Method 1
each first end of each linear actuator may be pivotably connected with the stationary mount by a corresponding spherical joint
Implementation Method 2
each first end of each linear actuator may be pivotably connected with the stationary mount by a corresponding spherical joint, universal joint
Implementation Method 3
each first end of each linear actuator may be pivotably connected with the stationary mount by a corresponding spherical joint, universal joint, or biaxial flexure bearing
Implementation Method 4
The linear actuators may support the movable mount relative to the stationary mount, and the movable mount, the stationary mount, and the six independently controllable linear actuators may be arranged so as to provide a hexapod mechanism.
Data Source
AI summary
Semiconductor processing tools with hexapod-based pedestal systems are disclosed and described. Such hexapod pedestal systems may incorporate a hexapod mechanism with a stationary mount that is connected via six linear actuators with a movable mount. The movable mount may support a pedestal located within a semiconductor processing chamber. The hexapod mechanism may be controlled so as to allow the pedestal to shift laterally so as to center the pedestal on a wafer supported by a wafer handling robot, as well as to angularly align a wafer supported thereby with the underside of a showerhead and to allow a wafer supported thereby to be subjected to any of a variety of movements during wafer processing operations that may promote increased wafer uniformity.