Substrate Support Heating Zones for Uniform CVD Processing
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Solution Overview
Problem
Conventional substrate support heaters in CVD and ALD chambers experience high heat loss at high temperatures, leading to non-uniform substrate processing due to radiation at the bottom and side surfaces, resulting in uneven heating and processing outcomes.
Innovation Solution
The substrate support features a body with a first heater having multiple heating zones with varying winding pitches to define a predetermined heating ratio, and an additional outer heater positioned outside the substrate diameter to minimize heat loss, along with an asymmetrical purge gas channel pattern for uniform gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional substrate support heaters are operated at high temperatures, then deposition rate and productivity are improved, but heat loss through radiation increases causing non-uniform heating
Solution Approach 1:
The heating system is divided into multiple independent heating zones (first heating zone, second heating zone, third heating zone) with distinct heating elements. Each zone can be controlled independently to compensate for radiative heat losses at different locations, maintaining uniform temperature distribution while operating at high temperatures for improved productivity.
Solution Approach 2:
Different regions of the substrate support are provided with different heating characteristics through varying coil winding pitches in different heating zones. The first heating coil has varying pitch to define predetermined heating ratios between zones, allowing localized temperature control to counteract position-dependent radiative heat losses and achieve uniform substrate heating.
2Manufacturing precision
If heating power is increased to compensate for heat loss, then temperature uniformity improves, but energy consumption and heat loss increase
Solution Approach 1:
Rather than uniformly increasing heating power across the entire substrate support, the invention applies localized heating adjustments through different coil winding pitches in different zones. This targets energy input precisely where needed to maintain temperature uniformity, avoiding unnecessary energy consumption in regions that already have adequate heating.
Solution Approach 2:
The coil winding pitch parameter is varied across different heating zones to optimize heat distribution. By changing this geometric parameter rather than simply increasing overall power, the system achieves better temperature uniformity with more efficient energy utilization, reducing total energy consumption while maintaining manufacturing precision.
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 configuration provides more uniform heating of the substrate, enhancing processing uniformity and mitigating heat loss, thereby improving the consistency of deposited films in chemical vapor deposition processes.
Implementation Method 1
a first heater disposed within the body and having a first heating coil and multiple heating zones, wherein a pitch of windings of the first heating coil vary among each of the multiple heating zones
Implementation Method 2
high heat loss when operated at high temperatures (e.g., greater than about 350° C.) due to radiation at the bottom and side surfaces of the substrate support and support shaft
Data Source
AI summary
Embodiments of substrate supports are provided herein. In some embodiments, a substrate support may include a body having a support surface; and a first heater disposed within the body and having a first heating coil and multiple heating zones, wherein a pitch of windings of the first heating coil vary among each of the multiple heating zones to define a predetermined heating ratio between the multiple heating zones.