Multi-zone Heater Temperature Control via Resistance Measurement
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Solution Overview
Problem
Multi-zone heaters in semiconductor processing systems face challenges in accurately measuring and controlling temperature, leading to non-uniform heat distribution and material deposition issues due to varying process conditions.
Innovation Solution
A method and apparatus that measure current and voltage simultaneously using a resistance measuring device to calculate the resistance of each zone, allowing for precise temperature determination and adjustment, enabling accurate control of the multi-zone heater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a multi-zone heater is used to provide uniform heat to the substrate, then temperature uniformity is improved, but temperature measurement and control accuracy deteriorates
Solution Approach 1:
The heater is divided into multiple independent zones that can be controlled separately. Each zone has its own power control, allowing localized temperature adjustment to compensate for edge effects and achieve uniform substrate heating.
Solution Approach 2:
The system uses measured resistance values from each heater zone to calculate temperature and adjusts the power delivered to each zone accordingly. This closed-loop feedback control maintains accurate temperature measurement and control despite the multi-zone configuration.
2Ease of operation
If power ratio multiplication method is used to determine outer zone temperature, then temperature control is simplified, but measurement accuracy deteriorates due to varying process conditions
Solution Approach 1:
The system replaces complex thermal modeling and power ratio calculations with direct electrical resistance measurements. By measuring resistance directly in each zone and using predetermined resistance-temperature relationships, the system achieves accurate temperature determination without relying on experimental power ratios that vary with process conditions.
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 approach provides improved temperature control and uniformity across the substrate, allowing for flexible temperature profiles, including center cold or hot profiles, with an accuracy of up to 0.5°C, enhancing substrate processing in semiconductor systems.
Implementation Method 1
calculating the resistance of the first zone based upon the measured current and voltage drawn by the first zone at the first time
Implementation Method 2
When current is applied to this wire or layer, the heater generates heat that is conductively transferred through the substrate support to the substrate
Implementation Method 3
determining a temperature of the first zone based upon a predetermined relationship between the resistance and the temperature of the first zone
Data Source
AI summary
Methods and apparatus for controlling the temperature of multi-zone heater in a process chamber are provided herein. In some embodiments, a method is provided to control a multi-zone heater disposed in a substrate support, wherein the multi-zone heater has a first zone and a second zone. In some embodiments, the method may include measuring a current drawn by the first zone at a first time; measuring a voltage drawn by the first zone at the first time; calculating the resistance of the first zone based upon the measured current and voltage drawn by the first zone at the first time; determining a temperature of the first zone based upon a predetermined relationship between the resistance and the temperature of the first zone; and adjusting the temperature of the first zone in response to the temperature determination.