Pixelated Cooling Base for Substrate Temperature Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, achieving uniform temperature control across substrates is challenging due to asymmetries in electrostatic chucks and conventional cooling bases, leading to non-uniform heat transfer and processing results.
Innovation Solution
A pixelated substrate support assembly with a cooling base featuring independently controllable heat transfer fluid flow through cells, separated by thermal chokes, allows for both lateral and azimuthal tuning of heat transfer, enabling precise temperature control across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling bases with edge to center temperature control are used, then the structure is simple, but uniform temperature control across the substrate cannot be achieved due to local hot and cold spots
Solution Approach 1:
The cooling base is divided into multiple independently controllable cooling zones or cells arranged in a grid pattern. Each cell can be controlled separately to compensate for local hot and cold spots, transforming a single uniform temperature control system into multiple localized control regions that can be independently adjusted to achieve overall temperature uniformity across the substrate surface
Solution Approach 2:
Different regions of the cooling base are provided with different cooling characteristics through independent control of each cell. This allows local adjustment of temperature in specific areas to compensate for asymmetries in the electrostatic chuck and chamber, providing non-uniform local cooling that results in uniform overall temperature distribution across the substrate
2Reliability
If the electrostatic chuck has non-homogeneous construction with gas holes, lift pin holes, and electrode regions, then the chucking function is achieved, but uniform heat transfer between the chuck and substrate becomes difficult
Solution Approach 1:
The pixelated cooling base provides locally differentiated cooling to different regions of the electrostatic chuck. By independently controlling the cooling intensity in each cell, the system compensates for the non-uniform heat generation and heat transfer characteristics caused by the chuck's functional regions (gas holes, lift pin holes, electrode regions), thereby achieving uniform substrate temperature despite the chuck's heterogeneous structure
Solution Approach 2:
The cooling base proactively compensates for known heat transfer asymmetries in the electrostatic chuck by pre-programming or dynamically adjusting the cooling intensity in each cell to counteract the expected hot and cold spots, preventing temperature non-uniformity before it affects the substrate processing
3Manufacturing precision
If lateral and azimuthal uniformity of heat transfer is required, then processing precision improves, but conventional cooling bases lack the capability to compensate for local variations
Solution Approach 1:
The cooling base is segmented into multiple independently controllable cells that can be adjusted to provide different cooling intensities in different directions (laterally and azimuthally). This segmentation enables precise tuning of heat transfer characteristics in specific directions to compensate for chamber asymmetries and achieve uniform critical dimensions across the substrate
Solution Approach 2:
The cooling base provides dynamic temperature control by independently adjusting the cooling intensity in each cell during the processing cycle. This dynamic adaptability allows the system to respond to real-time temperature variations and compensate for lateral and azimuthal asymmetries, thereby improving critical dimension consistency through versatile heat transfer tuning
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 achieves temperature uniformity to within ±1 degrees Celsius across a 60-degree temperature differential, effectively compensating for chamber non-uniformities and improving critical dimension (CD) consistency during processing.
Implementation Method 1
The first surface of the base body is coupled to the second surface of the substrate support member... uniform temperature control across the surface of the substrate
Implementation Method 2
Each cell is configured to receive an independently controllable flow of heat transfer fluid... flowing a heat transfer fluid into a first cell formed in a cooling base
Data Source
AI summary
Implementations described herein provide a pixelated substrate support assembly which enables both lateral and azimuthal tuning of the heat transfer between an electrostatic chuck and a cooling base comprising the substrate support assembly, which in turn, allows both lateral and azimuthal tuning of a substrate processed on the substrate support assembly. A processing chamber having a pixelated substrate support assembly and method for processing a substrate using a pixelated substrate support assembly are also provided.