LED Substrate Heater With Pinhole Optics for Uniform Deposition Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate heating methods in semiconductor processing systems face limitations in achieving localized and recipe-controllable heating, with resistively heated pedestals struggling to balance thermal uniformity and efficiency, while ceramic materials lack sufficient thermal resistance and fracture toughness.
Innovation Solution
An optical array using LEDs is integrated into the pedestal, employing a pinhole array and reflective coatings to enhance optical heating efficiency by maximizing light transmission to the substrate and minimizing heat loss, with a monolithic window and pinhole assembly to focus and reflect light effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If resistively heated pedestals are used for substrate heating, then heating capability is provided, but thermal uniformity and efficiency cannot be balanced
Solution Approach 1:
The patent replaces the resistive heating system (electrical/thermal field) with an optical heating system using LED arrays. The LED array emits light that is focused onto the substrate through optical elements (lenses, mirrors, or elliptical geometries), converting electrical energy to optical energy and then to thermal energy on the substrate surface. This substitution achieves higher thermal efficiency by directly heating the substrate rather than heating a pedestal that must then conduct heat to the substrate.
2Loss of energy
If optical elements are added to enhance heating efficiency, then light transmission to substrate is maximized, but device complexity increases
Solution Approach 1:
The patent integrates multiple optical elements (LEDs, lenses, mirrors, or elliptical structures) into a unified optical array system where all components work together to focus light onto the substrate. The optical elements are arranged in coordinated patterns (such as concentric circles or elliptical geometries) that combine their individual light-focusing capabilities to achieve high concentration of optical energy on the substrate surface, maximizing heating efficiency while managing system complexity through integrated design.
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 provides highly tunable, efficient substrate heating with improved thermal uniformity and reduced heat loss, enabling higher operating temperatures and reduced energy waste, while maintaining chamber cleanliness through purging and coating designs.
Implementation Method 1
The optical elements are configured to emit light. The pinholes are vertically aligned with the optical elements to direct the light emitted by the optical elements through the window to heat the substrate.
Implementation Method 2
The array of pinholes is coated with a reflective material on a side facing the window. The reflective material does not cover the pinholes.
Implementation Method 3
The window is coated with an antireflective material on a side facing the optical elements
Implementation Method 4
the window is coated with an antireflective material on a side facing the optical elements and a material that is antireflective for wavelengths of the light emitted by the optical elements and that is reflective for infrared wavelengths on a side facing the substrate
Data Source
AI summary
An optical array arranged in a pedestal configured to deposit material on a substrate includes a plurality of optical elements, a window, and an array of pinholes. The optical elements are arranged on a printed circuit board (PCB). The optical elements are configured to emit light. The window comprises an optically transparent material covering the optical elements arranged on the PCB. The array of pinholes is disposed between the optical elements and the window. The pinholes are vertically aligned with the optical elements to direct the light emitted by the optical elements through the window to heat the substrate.