Reduced Wire Count Heater Array Block for Semiconductor Processing

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Solution Overview

Problem

In semiconductor processing, existing thermal systems face challenges in maintaining precise and uniform temperature profiles across substrates, leading to processing variations and inefficiencies due to heat loss and other variations during plasma processing steps.

Innovation Solution

A thermal system comprising a base heater layer and a tuning heater layer with independently controlled heating elements, where the tuning layer provides fine-tuning of heat distribution and can also function as temperature sensors, allowing for precise temperature control and compensation for thermal changes, using materials like polyimide and Nickel-Iron alloys to enhance thermal conductivity and sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single heater layer is used, then the device complexity is reduced, but the temperature uniformity and control precision deteriorate

Engineering Contradiction:
Improveheater structureVSAvoidtemperature uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The heater is divided into two distinct layers: a base heater layer providing overall heating and a tuning heater layer providing localized temperature adjustment. This segmentation allows each layer to perform its specific function independently, achieving better temperature uniformity without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tuning heater layer is strategically positioned and configured to provide localized heating or cooling at specific regions of the substrate. This allows different zones of the substrate to receive customized thermal treatment, improving temperature uniformity across the entire substrate surface

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If more thermal elements are added to improve temperature control, then the temperature uniformity improves, but the wire count and device complexity increase

Engineering Contradiction:
Improvetemperature control precisionVSAvoidwire count
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple thermal elements within the same layer are electrically connected in parallel and controlled through common wiring. This merging approach allows multiple heating zones to be controlled with fewer wires, reducing device complexity while maintaining precise temperature control capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The tuning heater layer serves multiple functions: it provides localized temperature adjustment, compensates for heat loss at specific zones, and can operate independently or in conjunction with the base heater layer. This multi-functionality reduces the need for additional dedicated components

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If the heater provides high heat flux to reduce processing time, then the productivity improves, but the temperature uniformity deteriorates due to heat loss variations

Engineering Contradiction:
Improveprocessing timeVSAvoidtemperature uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The base heater layer is configured to provide preliminary overall heating to the substrate, bringing it close to the target temperature before the tuning heater layer performs fine adjustments. This preliminary action reduces the total processing time while the subsequent tuning phase ensures temperature uniformity is maintained

Inventive Principle:
Principle #10Preliminary action

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 system achieves improved temperature uniformity and reduced processing time by allowing for precise control of heat flux and thermal impedance, effectively addressing variations and maintaining optimal substrate temperatures during semiconductor processing.

Implementation Method 1

A heater is secured to the heater plate or target 16, which may be an etched-foil heater, by way of example. This heater assembly is bonded to a cooling plate 22

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the electrostatic chuck 12 through an adhesive layer 18, which is typically a silicone adhesive. A heater 20 is secured to the heater plate or target 16, again through an adhesive layer 24 that is typically a silicone adhesive

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3387671B1Reduced wire count heater array block
Publication Date: 2020.07.29 WATLOW ELECTRIC MANUFACTURING CO
  • EP3387671B1 patent drawingFigure 1
  • EP3387671B1 patent drawingFigure 2A~2B
  • EP3387671B1 patent drawingFigure 2C~2D

AI summary

A thermal system includes a plurality of thermal elements. In one form, each of the thermal elements define a resistor and a current limiting device. The plurality of thermal elements have at least a first subset of parallel thermal elements and at least a second subset of parallel thermal elements. The system also has a plurality of power lines connected to the plurality of thermal elements. The power lines are configured in pairs for providing power to a subset of the plurality of thermal elements that are connected in a parallel set. Each of the pairs of power lines share a common power line with an adjacent parallel set of thermal elements within a subset. Additionally, each of the current limiting devices in the adjacent parallel sets of thermal elements within a subset are opposed. The first and second subsets of parallel thermal elements share the common power line.