Dual Pyrometer Substrate Heating for Center-Edge Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing single-zone temperature control methods in semiconductor processing result in non-uniform temperature distributions across substrates, leading to uneven film deposition and undesirable crystallographic slip, particularly affecting the substrate edge due to varying emissivity and thermal profiles.
Innovation Solution
Implementing a dual-zone temperature control system using two pyrometers to monitor and control the center and edge zones of a substrate, with a controller adjusting the heater assembly to maintain precise temperature differentials through proportional-integral-derivative control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If radiant heating is used to heat the substrate, then heating efficiency is improved, but temperature uniformity deteriorates due to hot spots and localized energy concentration
Solution Approach 1:
The heater assembly is divided into multiple independently controllable heating zones (first heating zone, second heating zone, third heating zone) corresponding to different regions of the substrate (center, edge, and intermediate areas). This segmentation allows each zone to be controlled separately to achieve uniform temperature distribution across the entire substrate surface while maintaining high heating efficiency through targeted radiant heating in each segment.
Solution Approach 2:
Different heating power levels are applied to different zones of the substrate based on their specific thermal requirements. The edge zone receives different heating intensity compared to the center zone, with independent power control for each heating element group. This local quality approach compensates for edge effects and hot spots, achieving uniform temperature distribution while maintaining overall heating efficiency.
2Device complexity
If single-zone temperature control is used, then device complexity is reduced, but manufacturing precision deteriorates due to center-to-edge temperature differentials
Solution Approach 1:
The temperature control system is segmented into multiple independent control zones, each with its own heating elements and control parameters. The substrate surface is divided into first, second, and third heating zones with independent power control, allowing precise temperature management in each region to achieve uniform film thickness while maintaining reasonable system complexity through modular control architecture.
Solution Approach 2:
The system applies heating power selectively to specific zones rather than uniformly across the entire substrate. By providing heating primarily to areas that need it (with adjustable power levels for different zones), the system achieves precise temperature control for uniform film deposition without the complexity of controlling every point on the substrate, effectively using partial action to achieve the desired precision.
3Temperature
If higher heating power is applied to the substrate edge, then temperature uniformity is improved, but energy consumption increases
Solution Approach 1:
The heating system applies different power levels to different zones based on their specific thermal needs. The edge zones receive higher heating power to compensate for heat loss and achieve temperature uniformity, while the center zone receives appropriate power levels. This localized quality approach improves temperature uniformity without unnecessarily increasing overall energy consumption by targeting heating only where needed.
Solution Approach 2:
The system applies heating power selectively and proportionally to different zones rather than uniformly. By providing excessive heating only to the edge zones that require it (while using moderate or reduced power in the center), the system achieves temperature uniformity without the energy waste of uniformly high power application across the entire substrate, effectively using partial excessive action only where necessary.
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
Achieves uniform film thickness and reduced thermal non-uniformity across the substrate, improving manufacturing yield and throughput by minimizing center-to-edge temperature differentials and enhancing film quality.
Implementation Method 1
a first pyrometer to sense a temperature of a first zone of a substrate supported in the reactor system and a second pyrometer to sense a temperature of a second zone of the substrate
Implementation Method 2
wafers are heated using resistance heating, induction heating, or radiant heating
Implementation Method 3
a controller to compare the temperatures of the first and second zones to setpoint temperatures for the first and second zones and generate control signals to control operations of a heater assembly
Data Source
AI summary
A method of operating a reactor system to provide multi-zone substrate temperature control. The method includes, with a first pyrometer, sensing a temperature of a first zone of a substrate supported in the reactor system, and, with a second pyrometer, sensing a temperature of a second zone of the substrate. The method further includes, with a controller, comparing the temperatures of the first and second zones to setpoint temperatures for the first and second zones and, in response, generating control signals to control heating of the substrate. The method also includes controlling, based on the control signals, operations of a heater assembly operating to heat the substrate.