Rotating Substrate Pulse Heating for Non-Radial Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rapid thermal processing (RTP) systems face challenges in achieving uniform temperature profiles across semiconductor substrates due to non-radial temperature non-uniformities, which are exacerbated by substrate misalignment, thermal properties variations, and patterned substrate structures, leading to significant temperature deviations.
Innovation Solution
The implementation of a thermal processing chamber with pulse heating elements and a sensor assembly to measure substrate temperatures, allowing for adjustments in the frequency, phase, and amplitude of the heating energy to achieve uniformity, along with backside heating and azimuthally controlled heating zones to address non-radial non-uniformities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional radial heating zones are used in RTP systems, then radial temperature uniformity is improved, but non-radial temperature non-uniformities caused by substrate misalignment and patterned structures cannot be resolved
Solution Approach 1:
The heating system is divided into multiple independently controllable heating zones arranged azimuthally around the substrate. Each zone can be controlled separately to address specific non-uniformity patterns, transforming a single radial control approach into a multi-dimensional heating control system that can handle both radial and non-radial temperature variations
Solution Approach 2:
Different heating zones are applied to different azimuthal locations based on measured temperature non-uniformities. The system adjusts heating power locally at each zone to compensate for position-specific temperature deviations caused by substrate misalignment or patterned structures, rather than applying uniform radial heating
2Temperature
If substrate rotation is used to improve temperature uniformity, then radial heating effectiveness is enhanced, but non-radial non-uniformities due to misalignment are exacerbated
Solution Approach 1:
Temperature sensors continuously measure the temperature distribution on the substrate during rotation. The measured temperature data is fed back to the control system, which adjusts the power supplied to each heating zone in real-time to compensate for non-uniformities, creating a closed-loop control system that maintains temperature precision despite substrate rotation and misalignment
Solution Approach 2:
The system utilizes the periodic rotation of the substrate to systematically expose different azimuthal locations to the heating zones. By synchronizing heating pulse timing with substrate rotation position, the system can apply corrective heating to specific locations during their periodic passage under the heating zones, improving temperature uniformity over multiple rotation cycles
3Productivity
If high power heating is used to achieve rapid heating, then processing speed is improved, but temperature non-uniformities increase
Solution Approach 1:
The heating system transitions from static, uniform radial heating to dynamic, spatially-varying heating control. The power supplied to each heating zone is continuously adjusted based on real-time temperature measurements and substrate position, allowing the system to maintain high overall heating power for rapid heating while dynamically redistributing power to maintain temperature uniformity across the substrate surface
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 effectively reduces temperature non-uniformities by synchronizing the heating energy with substrate rotation and using pulse heating elements to correct temperature variations, resulting in improved thermal processing uniformity across the substrate.
Implementation Method 1
During RTP, thermal radiation is generally used to rapidly heat a substrate in a controlled environment to a maximum temperature of up to about 1350° C. High intensity tungsten halogen lamps are commonly used as the source of heat radiation.
Implementation Method 2
a substrate support configured to rotate the substrate
Implementation Method 3
a sensor assembly configured to measure temperature of the substrate at a plurality of locations
Implementation Method 4
The substrate may be provided additional heat by a heated susceptor conductively coupled to the substrate.
Data Source
AI summary
Embodiments of the present invention provide apparatus and method for reducing non uniformity during thermal processing. One embodiment provides an apparatus for processing a substrate comprising a chamber body defining a processing volume, a substrate support disposed in the processing volume, wherein the substrate support is configured to rotate the substrate, a sensor assembly configured to measure temperature of the substrate at a plurality of locations, and one or more pulse heating elements configured to provide pulsed energy towards the processing volume.