Substrate Heater Resistance Mapping for Precise Wafer Temperature Control
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Solution Overview
Problem
Existing substrate processing systems face challenges in accurately controlling the temperature of semiconductor wafers during processing, which affects the quality of the manufacturing process.
Innovation Solution
A substrate processing system and method that utilizes a controller to store conversion tables associating resistance values with temperatures, measures reference and adjustment resistance values, and adjusts power supply based on these values to achieve precise temperature control using heaters and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple heaters are provided to independently adjust temperatures of different regions, then temperature control accuracy is improved, but device complexity increases
Solution Approach 1:
The heating system is divided into multiple independent heaters (first heater and second heater) that can be controlled separately. Each heater corresponds to different regions of the substrate, allowing independent temperature adjustment for each region to achieve high temperature uniformity across the substrate surface
Solution Approach 2:
Different heaters are assigned to different regions of the substrate based on local temperature requirements. The controller independently adjusts the power supply to each heater according to temperature measurements from corresponding thermocouples, enabling localized temperature optimization without affecting other regions
2Measurement precision
If temperature measurement is performed during heater operation, then temperature control accuracy is improved, but measurement precision deteriorates due to self-heating effects
Solution Approach 1:
The system performs periodic temperature measurements at specific intervals during the heating process. The controller measures temperatures at predetermined time points after power supply adjustments, allowing the heater temperature to stabilize before measurement, thereby avoiding self-heating errors while maintaining continuous temperature control
Solution Approach 2:
The system performs preliminary power supply adjustments before temperature measurements. The controller adjusts heater power in advance, waits for temperature stabilization, and then performs measurements, ensuring that temperature readings reflect the actual operational state rather than transient self-heating effects
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
Enables high-accuracy temperature adjustment of substrates, ensuring consistent and accurate processing results by minimizing temperature variations.
Implementation Method 1
a heater configured to heat the substrate by being supplied with power
Implementation Method 2
a sensor configured to measure a resistance value of the heater; store a conversion table in which a plurality of resistance values are associated with a plurality of temperatures
Data Source
AI summary
A substrate processing system includes a stage on which a substrate is placed, a heater configured to heat the substrate by being supplied with power, a power supply part configured to supply power to the heater, a sensor configured to measure a resistance value of the heater, and a controller. The controller is configured to: store a conversion table in which a plurality of resistance values are associated with a plurality of temperatures; and acquire a reference resistance value measured by the sensor when a heater temperature is equal to a reference temperature. The controller is further configured to: acquire a temperature adjustment resistance value measured by the sensor after the substrate is heated by the heater; and control the power supply part based on the conversion table, the reference temperature, the reference resistance value, and the temperature adjustment resistance value.