Electrostatic Chuck Power Feed Layout for Uniform Wafer Heating
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Solution Overview
Problem
Current electrostatic chucks in semiconductor manufacturing face challenges in achieving uniform in-plane temperature distribution during processing, particularly with the miniaturization of semiconductor elements, where precise temperature control is essential for accurate etching and increased integration density.
Innovation Solution
The electrostatic chuck incorporates a ceramic dielectric substrate with a heater unit featuring a first heater element with sub-zones, including a sub-heater line and power feeding portions, where the power feeding portions are strategically placed in the central region to manage temperature distribution, and a bypass layer for improved power feeding terminal arrangement and heat diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a two-layer structure of main heater and sub-heater is used, then heating speed is improved, but uniformity of in-plane temperature distribution is insufficient
Solution Approach 1:
The heater element is divided into multiple independent heating zones (first heating zone, second heating zone, third heating zone) with different power densities. Each zone can be controlled independently to achieve uniform temperature distribution across the substrate while maintaining fast heating speed.
Solution Approach 2:
Different regions of the heater are designed with different power densities - the first heating zone has higher power density for rapid heating, while the second and third heating zones have lower power densities to prevent overheating at edges and ensure uniform temperature distribution across the substrate surface.
2Ease of manufacture
If power feeding portions are placed at outer edges of heater zones, then power delivery is simplified, but temperature uniformity in central region deteriorates
Solution Approach 1:
The power feeding portions are positioned at the outer edges in the radial direction, but the heating zones are designed to extend beyond the power feeding portions in the axial direction. This dimensional arrangement allows power to be delivered at the edges while heat diffusion in the axial direction ensures uniform temperature in the central region.
Solution Approach 2:
The heater structure acts as an intermediary that converts edge-delivered power into uniform heat distribution across the substrate. The thermal conduction through the heater material and into the substrate ensures that power fed at outer edges results in uniform temperature distribution in the central region.
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 configuration enhances the uniformity of in-plane temperature distribution, supports precise temperature control, and improves the reliability of the heater unit, enabling more efficient processing and miniaturization of semiconductor elements.
Implementation Method 1
a sub-heater line generating heat by allowing a current to flow
Implementation Method 2
The electrostatic chuck applies an electrostatic clamping power to built-in electrodes and clamps a substrate such as a silicon wafer by an electrostatic force
Data Source
AI summary
An electrostatic chuck includes a ceramic dielectric substrate; a base plate; and a heater unit which heats the ceramic dielectric substrate. The heater unit includes a first heater element. The first heater element has a plurality of sub-zones. The sub-zones include a first sub-zone. The first sub-zone includes a sub-heater line generating heat by allowing a current to flow, a first sub-power feeding portion feeding a power to the sub-heater line, and a second sub-power feeding portion feeding a power to the sub-heater line. The first sub-zone has a central region located centrally in the first sub-zone and an outer peripheral region located outside the central region when viewed along a Z-direction perpendicular to the first major surface. At least one of the first sub-power feeding portion and the second sub-power feeding portion is provided in the central region.