Patterned Heated Pedestal for Substrate Temperature Uniformity
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Solution Overview
Problem
Existing heated pedestals in semiconductor fabrication processes often result in non-uniform temperature distribution on substrates due to their design, leading to inconsistent heat transfer and film thickness uniformity issues.
Innovation Solution
A heated pedestal with a patterned surface featuring posts of varying heights, where the central region has shorter posts and the peripheral region has taller posts, creating a multi-level structure that enhances temperature uniformity by modifying heat transfer rates and preventing hot or cold spots on the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional heated pedestal with uniform surface is used, then the heating mechanism is simple, but the temperature distribution on the substrate is non-uniform
Solution Approach 1:
The pedestal surface is divided into multiple regions with different post heights (first region with first height, second region with second height greater than first height). This local variation in surface topology creates different heat transfer characteristics in different regions, compensating for thermal non-uniformity and achieving uniform temperature distribution across the substrate.
Solution Approach 2:
The invention transitions from a two-dimensional flat pedestal surface to a three-dimensional patterned surface with posts of varying heights. This addition of vertical dimension allows for controlled heat transfer modulation, where the post height variation creates thermal pathways that redistribute heat to achieve uniform substrate temperature.
2Temperature
If a patterned surface with varying post heights is implemented, then temperature uniformity is improved, but manufacturing complexity increases
Solution Approach 1:
The pedestal surface is segmented into distinct regions (first region and second region) with different post height characteristics. This segmentation allows for controlled manufacturing processes where different areas can be selectively processed to achieve the desired height variation, making the complex geometry more manufacturable.
Solution Approach 2:
The invention controls the manufacturing process by specifying parameter variations (post heights, region boundaries) that define the patterned surface. By establishing clear parameter specifications for the different regions, the manufacturing process becomes more predictable and controllable, reducing the actual manufacturing complexity despite the increased geometric 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
The solution significantly improves temperature uniformity on substrates, reducing temperature deltas and enhancing film thickness uniformity, which is critical for advanced semiconductor processing like PECVD, by optimizing heat transfer and substrate contact.
Implementation Method 1
a body having a heater embedded therein
Implementation Method 2
The posts have different heights across the pedestal. The modified heat transfer rates modify the temperature profile of the substrate
Data Source
AI summary
Embodiments of the present disclosure generally relate to a pedestal for increasing temperature uniformity in a substrate supported thereon. The pedestal comprises a body having a heater embedded therein. The body comprises a patterned surface that includes a first region having a first plurality of posts extending from a base surface of the body at a first height, and a second region surrounding the central region having a second plurality of posts extending from the base surface at a second height that is greater than the first height, wherein an upper surface of each of the first plurality of posts and the second plurality of posts are substantially coplanar and define a substrate receiving surface.