Active Cooling Substrate Support for PECVD Temperature Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In flat panel display fabrication, substrate supports made of ceramic materials are poor thermal conductors, leading to temperature gradients and deflection issues, which result in non-uniform film deposition and temperature variations during plasma enhanced chemical vapor deposition (PECVD) processes, affecting the quality of large area substrates.
Innovation Solution
A substrate support assembly with a thermally conductive body embedded with heating elements and cooling channels, configured in a spiral or vortex pattern, to maintain consistent temperature across large area substrates, using gaseous cooling materials and controlled heating to adjust temperature settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If ceramic material is used for support plate, then structural stability is improved, but thermal conductivity deteriorates leading to temperature gradient
Solution Approach 1:
The invention uses a composite structure combining ceramic support plate with metal susceptor (aluminum or graphite). The ceramic plate provides structural stability while the metal susceptor provides thermal conductivity. This composite approach resolves the contradiction by integrating materials with complementary properties - ceramic for mechanical strength and metal for heat distribution.
2Ease of manufacture
If single rectangular plate design is used, then manufacturing simplicity is improved, but temperature distribution deteriorates
Solution Approach 1:
The invention introduces heating elements at specific locations (center and perimeter) and cooling channels strategically positioned within the support structure. This local quality approach ensures that temperature is controlled at critical zones, achieving uniform temperature distribution across the large substrate area while maintaining a relatively simple overall plate design.
3Temperature
If heating elements are embedded, then temperature control capability is improved, but device complexity increases
Solution Approach 1:
The invention combines heating elements, cooling channels, and temperature sensors into an integrated support plate assembly. By merging these temperature control components into a single unified structure rather than separate systems, the invention achieves comprehensive temperature control while minimizing the increase in device complexity.
4Temperature
If cooling channels are added, then temperature spike control is improved, but manufacturing complexity increases
Solution Approach 1:
The invention uses fluid-based cooling channels embedded within the support plate to efficiently remove heat and control temperature spikes during plasma processing. This pneumatic/hydraulic cooling system provides effective temperature control while the channels are integrated into the plate structure during manufacturing, balancing cooling performance with manufacturing feasibility.
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 solution ensures temperature uniformity of +/-5°C across the substrate, maintaining consistent film thickness and preventing temperature spikes, thereby improving the quality and consistency of deposited films on large area substrates.
Implementation Method 1
one or more cooling channels embedded within the thermally conductive body above the one or more heating elements
Implementation Method 2
flowing a gaseous cooling material constantly inside the one or more cooling channels
Implementation Method 3
one or more heating elements embedded within the thermally conductive body
Implementation Method 4
maintaining the temperature of the large area substrate by adjusting the heating power of the one or more heating elements
Implementation Method 5
Plasma enhanced chemical vapor deposition (PECVD) is frequently employed in flat panel display fabrication to deposit thin film on a substrate. PECVD is generally accomplished by introducing a precursor gas into a vacuum process chamber to be energized (e.g., excited) into a plasma
Implementation Method 6
Reactive precursor gases flowing into a diffuser plate 16 through a gas inlet 14 near the top of the process chamber 2 are excited to form a layer of material on the surface of the substrate 12
Data Source
AI summary
A substrate support assembly and method for controlling the temperature of a substrate within a process chamber with a temperature uniformity of +/−5° C. are provided. A substrate support assembly includes a thermally conductive body comprising an aluminum material, a substrate support surface on the surface of the thermally conductive body and adapted to support the large area glass substrate thereon, one or more heating elements embedded within the thermally conductive body, and one or more cooling channels embedded within the thermally conductive body and positioned around the one or more heating elements. A process chamber comprising the substrate support assembly of the invention is also provided.