Bipolar Electrostatic Chuck Heater for Edge Temperature Uniformity
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Solution Overview
Problem
Ceramic heaters used in semiconductor processing face issues with deposition uniformity due to gas flow vortices between the substrate and the heater, leading to inconsistent heating and poor edge coverage.
Innovation Solution
An electrostatic chuck heater with a bipolar structure, featuring an internal and external electrode system that can selectively perform RF grounding or electrostatic chuck functions based on semiconductor process modes, improving temperature and deposition uniformity by adaptively managing electrode functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a pocket structure is formed on the upper portion of the ceramic heater to support the wafer, then the wafer can be stably mounted, but a vortex of gas flow is generated through the space between the heater and wafer edge, causing deteriorated deposition uniformity at the wafer edge
Solution Approach 1:
The heater is divided into two functional zones: a central pocket region for stable wafer mounting and an outer flat region for uniform gas flow and deposition. This segmentation allows each zone to perform its specific function optimally without interfering with the other.
Solution Approach 2:
Different regions of the heater are given different structural properties: the central region has a pocket structure for mechanical support, while the outer region maintains a flat surface to prevent gas flow vortices. This local differentiation resolves the contradiction between mounting stability and deposition uniformity.
2Temperature
If a ceramic heater with ground electrode and heating element is used, then precise temperature control is achieved, but the structure cannot adaptively select between RF grounding function and electrostatic chuck function according to different semiconductor process modes
Solution Approach 1:
The heater incorporates a bipolar electrode structure that can function as either a ground electrode or an electrostatic chuck electrode depending on the applied voltage polarity. This multi-functionality allows the same device to serve different semiconductor process modes (plasma and non-plasma) while maintaining precise temperature control.
Solution Approach 2:
The electrode function is made dynamic and switchable through bipolar voltage control. By changing the voltage polarity and magnitude, the electrode can adaptively transition between RF grounding mode and electrostatic chucking mode, providing versatility across different process requirements.
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 electrostatic chuck heater enhances temperature uniformity and deposition uniformity on semiconductor wafers by selectively utilizing RF grounding and electrostatic chuck functions, reducing temperature fluctuations at the wafer edges and improving contact with the heater surface.
Implementation Method 1
an internal electrode and an external electrode spaced apart from the internal electrode by a predetermined distance on a same plane as the internal electrode... configured to selectively perform any one of an RF grounding function and an electrostatic chuck function
Implementation Method 2
configured to selectively perform any one of an RF grounding function and an electrostatic chuck function according to a semiconductor process mode
Implementation Method 3
a heating element 13 for generating thermal energy for heating the substrate
Data Source
AI summary
The present invention relates to an electrostatic chuck heater having a bipolar structure, the electrostatic chuck heater comprising: a heater body having an internal electrode and an external electrode for selectively performing any one of an RF grounding function and an electrostatic chuck function according to a semiconductor process mode; and a heater support mounted below the heater body so as to support the heater body.