Sputtering Target Cooling Grooves for Uniform Deposition
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Solution Overview
Problem
In semiconductor device fabrication, the physical vapor deposition process often leads to overheating and deformation of the target and surrounding components due to argon ion bombardment, resulting in chamber downtime and non-uniform deposition.
Innovation Solution
The implementation of a smart cooling system featuring cooling grooves in various patterns on the target surface, coupled with a coolant circulation system, effectively transfers and releases heat generated during the sputtering process, maintaining the target and components within a predetermined temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If sputtering process is used to deposit materials on substrate, then deposition quality is improved, but target and components are overheated and deformed
Solution Approach 1:
The target is segmented with multiple cooling grooves of different depths arranged in specific patterns (concentric circles, spirals, or radial patterns). These grooves divide the target into zones with different thermal management characteristics, allowing localized heat dissipation while maintaining deposition quality across the entire target surface.
Solution Approach 2:
Different regions of the target are given different local properties through varying groove depths and patterns. The cooling grooves create zones with enhanced heat dissipation capacity in areas experiencing highest ion bombardment, while maintaining structural integrity in other regions. This local differentiation allows optimal thermal management without compromising overall deposition performance.
2Productivity
If continuous sputtering is performed to increase productivity, then deposition rate is improved, but target deformation occurs due to accumulated heat
Solution Approach 1:
Cooling grooves are pre-formed in the target structure before the sputtering process begins. These grooves are strategically positioned and depth-varied to anticipate and prevent heat accumulation in high-stress regions, enabling continuous high-rate deposition without target deformation or structural failure.
Solution Approach 2:
The cooling grooves act as intermediary structures that facilitate heat transfer from the target bulk to the cooling channels. By providing dedicated thermal pathways, these grooves mediate between the heat generation from ion bombardment and the heat dissipation system, allowing sustained high-productivity operation while maintaining target structural stability.
3Temperature
If cooling grooves are added to target to manage heat, then target temperature control is improved, but device complexity increases
Solution Approach 1:
The cooling grooves serve multiple functions simultaneously: they act as heat dissipation channels, structural reinforcement elements, and deposition pattern controllers. By integrating these diverse functions into a single feature set, the design achieves effective temperature control without proportionally increasing device complexity.
Solution Approach 2:
The target incorporates a groove-based porous or channelled structure that enhances heat dissipation efficiency. The grooves create internal surface area for heat exchange while maintaining overall target integrity. This porous-like architecture provides superior thermal management with relatively simple geometric modifications to the target body.
4Temperature
If deep cooling grooves are used to enhance heat dissipation, then cooling efficiency is improved, but target structural strength is reduced
Solution Approach 1:
The cooling grooves are designed with asymmetric depth distributions rather than uniform depths across the target. Deeper grooves are positioned in regions requiring maximum cooling, while shallower grooves or no grooves are used in structurally critical areas. This asymmetric configuration optimizes the balance between heat dissipation efficiency and structural strength retention.
Solution Approach 2:
Instead of applying uniform deep cooling throughout the target, the design uses partial cooling action with varying groove depths. This selective approach applies maximum cooling only where heat generation is highest, while preserving structural strength in regions where deep grooves would be detrimental. The partial action principle prevents over-cooling in non-critical areas.
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 reduces the likelihood of target deformation and extends the lifetime of the target and chamber components by maintaining optimal temperature conditions, thereby ensuring uniform deposition results and minimizing downtime.
Implementation Method 1
The implementation of a smart cooling system featuring cooling grooves in various patterns on the target surface, coupled with a coolant circulation system, effectively transfers and releases heat generated during the sputtering process
Implementation Method 2
coupled with a coolant circulation system, effectively transfers and releases heat
Implementation Method 3
When the positively charged argon ions strike the target surface, the momentum of the positively charged argon ions transfers to the target material to dislodge one or more atoms of the target material which eventually deposit on the substrate
Implementation Method 4
sputtering, a form of the PVD, is commonly used in the semiconductor fabrication process to deposit complex alloys and metals
Data Source
AI summary
A deposition system is provided capable of extending the chamber running time by preventing the target and other components from deformation due to thermal stress from the sputtering process by maintaining the temperature within the predetermined temperature range. The deposition system includes a substrate process chamber, a target within the substrate process chamber, and a plurality of grooves formed on the target in a circular formation. The plurality of grooves includes a first groove on a center portion of the target and a second groove on a periphery portion of the target.