Processing Chamber Heating Zones for Substrate Warpage Control
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Solution Overview
Problem
SiC substrates experience significant warpage during processing due to temperature gradients and high heating/cooling rates, leading to dislodgment from the susceptor and undesired deposition/etching, which existing methods fail to adequately address.
Innovation Solution
A processing chamber with a heating assembly comprising independently controllable zones, combined with thermal and warp sensors, controls substrate temperature and warpage through closed-loop feedback, using backside and topside temperature measurements to manage temperature gradients and curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high heating or cooling rate is used to reduce processing cycle, then productivity is improved, but substrate warpage worsens due to temperature gradients
Solution Approach 1:
The heating assembly is divided into multiple independently controllable heating zones that can be adjusted to create non-uniform temperature distributions. This segmentation allows different regions of the substrate to be heated at different rates, compensating for warpage while maintaining overall high processing speeds.
Solution Approach 2:
Different heating zones apply different heating intensities to specific locations on the substrate based on real-time warpage measurements. This local quality approach ensures that areas experiencing excessive warpage receive modified heating to correct the deformation, while other areas continue heating at optimal rates for productivity.
2Productivity
If high heating rate is used to reduce processing cycle, then productivity is improved, but substrate warpage worsens due to insufficient time for temperature gradient relaxation
Solution Approach 1:
The system continuously monitors substrate warpage during heating using optical sensors and feeds this information back to the control system. Based on the feedback, the heating zones dynamically adjust their power output to maintain acceptable warpage levels even during rapid heating cycles, enabling both high productivity and shape control.
Solution Approach 2:
The heating system transitions from static, uniform heating to dynamic, spatially-varying heating that adapts in real-time to substrate response. The heating zones can rapidly change their temperature profiles during the processing cycle to counteract warpage development, allowing high heating rates without sacrificing substrate flatness.
3Manufacturing precision
If substrate is rotated to obtain uniform processing result, then manufacturing precision is improved, but substrate dislodgment risk increases due to warpage
Solution Approach 1:
The system performs preliminary warpage correction during the heating phase before the substrate reaches high rotation speeds. By pre-flattening the substrate through controlled non-uniform heating, the substrate is better positioned to withstand the centrifugal forces during subsequent high-speed rotation, ensuring both processing uniformity and substrate retention.
Solution Approach 2:
The system dynamically adjusts heating parameters (temperature distribution, heating rate) based on real-time warpage measurements to optimize substrate flatness. This parameter control ensures that the substrate maintains sufficient mechanical integrity and adhesion to the susceptor during rotation, preventing dislodgment while achieving uniform processing.
4Device complexity
If warpage control is not implemented, then device complexity is reduced, but manufacturing precision worsens due to deposition at undesired locations
Solution Approach 1:
The heating assembly serves multiple functions: it provides the necessary thermal energy for processing while simultaneously acting as a warpage control mechanism through its independently controllable zones. This multi-functionality allows the system to achieve precise deposition control without adding separate warpage correction devices, thereby limiting the increase in overall system complexity.
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
Reduces substrate warpage, prevents dislodgment, and ensures uniform processing results by maintaining precise temperature control and minimizing unwanted deposition/etching, thereby increasing throughput and reducing substrate damage.
Implementation Method 1
heating a substrate by a heating assembly
Implementation Method 2
measuring a backside temperature of a susceptor based on radiation at a first wavelength, measuring a topside temperature of the susceptor based on radiation at a second wavelength
Data Source
AI summary
Disclosed herein are a warpage control method and system for warpage control included in a processing chamber. The warpage control method includes heating a substrate by a heating assembly comprising a plurality of independently controllable heating zones, measuring a backside temperature of a susceptor based on radiation at a first wavelength, measuring a topside temperature of the substrate based on radiation at a second wavelength, measuring a curvature of the substrate based on radiation at a third wavelength, and controlling the heating assembly based on the backside temperature, the topside temperature, and the curvature. The warpage control system includes a first thermal sensor and an warp sensor disposed above a substrate, a second thermal sensor disposed below the substrate, a heating assembly, and a controller coupled with the heating assembly, the first thermal sensor, the second thermal sensor, and the warp sensor for controlling the warpage of the substrate.