Ceramic Heater Zone Control for Wafer Temperature Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ceramic heaters face challenges in achieving uniform temperature on a wafer placement surface due to the presence of multiple terminals in the terminal collection region, which creates temperature disparities compared to the non-terminal region.
Innovation Solution
A ceramic heater design with zone heaters corresponding to terminal and non-terminal regions, allowing independent temperature control, where terminals are arranged in an arc or linearly on the ceramic plate, and the terminal collection region is located on the outermost circumference to accommodate a large number of terminals, with a cooling plate for differential heat extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple terminals are collectively arranged in a terminal collection region, then the device complexity is reduced and ease of operation is improved, but the temperature uniformity across the wafer placement surface deteriorates
Solution Approach 1:
The heater is divided into multiple independent zone heaters (first zone heater, second zone heater, etc.) corresponding to different radial zones. Each zone heater can be independently controlled to compensate for temperature differences caused by terminal concentration, thereby maintaining temperature uniformity across the wafer placement surface while keeping terminals collectively arranged.
Solution Approach 2:
Different zone heaters are designed with different heating characteristics to match local thermal conditions. The first zone heater (in the terminal collection region) and second zone heater (in the non-terminal region) have different control parameters, allowing local temperature adjustment to achieve overall temperature uniformity despite the presence of terminals in one region.
2Temperature
If zone heaters are provided for both terminal collection region and non-terminal region, then temperature uniformity is improved, but the device complexity increases
Solution Approach 1:
The heater is segmented into multiple zones with independent control, allowing temperature uniformity to be achieved through localized heating adjustments. This segmentation into first and second zone heaters provides the necessary control flexibility while maintaining a relatively simple overall structure.
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 design enables uniform temperature control across the entire wafer placement surface by allowing independent temperature adjustments of terminal and non-terminal region zone heaters, addressing the temperature disparities caused by terminal placement.
Implementation Method 1
a ceramic base is divided into multiple zones, and each zone is embedded with a heating element
Implementation Method 2
a cooling plate is joined to a lower surface of the ceramic plate. Because the magnitude of heat extraction by the cooling plate differs between the terminal collection region and the non-terminal region adjacent thereto
Data Source
AI summary
A ceramic heater includes: a ceramic plate having a wafer placement surface on a surface thereof; zone heaters embedded in the ceramic plate so as to correspond to zones defined by dividing the surface of the ceramic plate into multiple sections; terminals connected to ends of the zone heaters via internal wires of the ceramic plate; terminal collection regions in which the plurality of terminals are collectively arranged; and non-terminal regions in which no terminal is arranged. The ceramic heater includes, as the zone heaters, a terminal-collection-region zone heater provided in a zone corresponding to the terminal collection regions, and a non-terminal regions zone heater provided in a zone corresponding to the non-terminal regions.