Light-Diffusing Window for Uniform Substrate Heating
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Solution Overview
Problem
Rapid thermal processing chambers experience uneven heating of substrates due to non-uniform irradiance patterns from lamps, leading to thermal hot spots and substrate uniformity issues.
Innovation Solution
Incorporating optically transparent windows with light-diffusing structures, such as scalloped, dimpled, or frosted surfaces, between the substrate support and radiant heat source to distribute thermal energy more uniformly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional lamps are used to provide thermal energy to substrates, then heating capability is achieved, but uneven irradiance patterns cause non-uniform substrate heating
Solution Approach 1:
The patent introduces an optically transparent window with light-diffusing structures as an intermediary element between the lamp and substrate. This window diffuses the radiant energy from the lamp, transforming the non-uniform irradiance pattern into a more uniform distribution across the substrate surface, thereby resolving the contradiction between achieving heating capability and maintaining irradiance uniformity
Solution Approach 2:
The patent modifies the optical parameters of the window by incorporating light-diffusing structures with specific geometric features (scalloped, dimpled, or frosted surfaces). These structural modifications change the way light propagates through the window, altering the irradiance distribution pattern to achieve more uniform substrate heating
2Power
If lamps are arranged in lamp heads to direct energy towards substrate, then thermal processing capability is provided, but geometry of arrangement causes uneven irradiance patterns
Solution Approach 1:
The optically transparent window acts as a mediator that receives concentrated radiant energy from the lamp arrangement and redistributes it uniformly across the substrate. The light-diffusing structures on the window interface transform the directional energy flow into omnidirectional diffusion, maintaining power delivery while improving irradiance distribution
Solution Approach 2:
The patent introduces a new dimensional aspect to the optical system by adding surface topography (scalloped, dimpled, or frosted structures) to the window. This third dimension of surface geometry creates multiple light scattering paths, converting the two-dimensional lamp arrangement pattern into a three-dimensionally diffused irradiance field that uniformly covers the substrate
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 light-diffusing structures reduce thermal hot spots and enhance substrate uniformity by smoothing out irradiance patterns, resulting in more consistent heating during thermal processing.
Implementation Method 1
The optically transparent window includes one or more light diffusing structures thereon. The light diffusing structures may include a scalloped or dimpled surface having protruding or indented features, or a frosted surface. The light-diffusing structures facilitate more uniform heating of substrates by reducing thermal hot spots caused by uneven irradiation by lamps.
Data Source
AI summary
Embodiments of the present disclosure generally relate to optically transparent windows and processing chambers including the same. The optically transparent window includes light-diffusing structures formed thereon. The light diffusing structures may include a scalloped or dimpled surface having protruding or indented features, or a frosted surface. The light-diffusing structures facilitate more uniform heating of substrates by reducing thermal hot spots caused by uneven irradiation by lamps.