Multi-zone Electrostatic Chuck Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, achieving uniform temperature control across substrates is challenging due to chamber asymmetries and non-homogeneous electrostatic chuck structures, leading to local hot and cold spots, which affect processing results.
Innovation Solution
A substrate support assembly with lateral and azimuthal tuning of heat transfer, incorporating multiple resistive heating elements and temperature sensors to monitor and adjust temperature at various discrete regions, enabling precise control of the substrate's temperature profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional substrate supports with edge to center temperature control are used, then the structure is simple, but local hot and cold spots within the electrostatic chuck cannot be compensated for, resulting in non-uniform temperature distribution
Solution Approach 1:
The heater assembly is divided into multiple independently controllable heating zones with discrete heating elements arranged in specific patterns. Each heating zone can be controlled separately to compensate for local temperature variations, transforming a single uniform heating system into a segmented, locally-adjustable system that eliminates hot and cold spots.
Solution Approach 2:
Different regions of the substrate support assembly are provided with different heating characteristics through strategically placed heating elements. The heater assembly includes regions with different densities of heating elements and different thermal conductivities, allowing local temperature optimization in different areas of the electrostatic chuck.
2Ease of manufacture
If the electrostatic chuck has non-homogeneous construction with gas holes, lift pin holes, and offset electrodes, then the chucking and cooling functions are achieved, but uniform heat transfer between the chuck and substrate is complicated, resulting in local hot and cold spots
Solution Approach 1:
The heater assembly is designed with spatially varying properties to match the non-homogeneous chuck structure. Different regions have different heating element densities, thermal conductivities, and heat transfer characteristics tailored to compensate for the local structural variations in the chuck, including areas with gas holes, lift pin holes, and electrode offsets.
Solution Approach 2:
The system dynamically adjusts heating parameters (power, duration, distribution) across different zones of the heater assembly to compensate for the fixed structural non-uniformities in the chuck. By changing heating parameters locally rather than uniformly, the system achieves uniform substrate temperature despite the chuck's heterogeneous construction.
3Manufacturing precision
If multiple spatially tunable heating elements and temperature sensors are incorporated in the heater assembly, then precise temperature control to within ±0.3 degrees Celsius is achieved, but the device complexity increases
Solution Approach 1:
The heater assembly is segmented into multiple independently controllable heating zones with discrete heating elements and corresponding temperature sensors. This segmentation allows precise local temperature control in each zone, enabling critical dimension uniformity across the substrate while managing overall system complexity through modular zoned control.
Solution Approach 2:
Temperature sensors are placed in thermal communication with different regions of the electrostatic chuck to provide real-time temperature feedback. This feedback is used to dynamically adjust the heating power distribution across different zones, enabling closed-loop control that achieves ±0.3°C temperature uniformity while optimizing the complexity-precision tradeoff.
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 allows for uniform temperature control across substrates to within ±0.3 degrees Celsius, reducing critical dimension variations and improving processing consistency by compensating for chamber non-uniformities and local temperature asymmetries.
Implementation Method 1
one or more main resistive heating elements disposed in the body... a plurality of additional resistive heating elements disposed in the body
Implementation Method 2
a plurality of temperature sensors disposed in the body, wherein each of the plurality of temperature sensors is disposed proximate to one of the plurality of additional resistive heating elements
Implementation Method 3
enables both lateral and azimuthal tuning of the heat transfer between an electrostatic chuck and a heating assembly
Data Source
AI summary
A substrate support assembly comprises a plurality of zones, a chuck comprising a ceramic body, and an additional assembly bonded to a lower surface of the chuck. The additional assembly comprises a second body and a plurality of temperature sensors disposed in or on the second body, wherein each zone of the plurality of zones includes at least one of the plurality of temperature sensors. A plurality of spatially tunable heating elements are disposed a) in or on the ceramic body or b) in or on the second body.