RTP Window Assembly with Linear Reflectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rapid thermal processing chambers operating at vacuum pressures face challenges in maintaining temperature control uniformity due to the need for thicker windows, which increases the distance between lamps and substrates, leading to reduced temperature control precision.
Innovation Solution
The introduction of a window assembly with linear reflectors and lenses that direct and focus radiation, reducing zonal overlap and improving temperature control uniformity, while also accommodating vacuum pressures through a pressure control region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thicker windows are used to accommodate vacuum pressure operation, then the structural integrity and pressure resistance are improved, but the distance between lamps and substrate increases which reduces temperature control uniformity
Solution Approach 1:
Linear reflectors are introduced as intermediary elements between the lamps and the substrate. These reflectors redirect and concentrate radiation onto the substrate surface, compensating for the increased distance caused by thicker vacuum-rated windows. The reflectors act as mediators that maintain effective thermal coupling despite the physical separation necessitated by pressure differential requirements.
Solution Approach 2:
The optical path parameters are modified by introducing reflective surfaces at specific angles and positions. By changing the radiation path length and direction through strategically placed linear reflectors, the effective heating distance is compensated, allowing the system to maintain temperature uniformity despite the increased physical distance from the lamp to substrate.
2Adaptability or versatility
If lamps are spaced farther from the substrate to accommodate thicker windows, then vacuum pressure operation is enabled, but temperature control precision deteriorates
Solution Approach 1:
The radiation path is segmented into multiple controlled segments by introducing linear reflectors. Instead of a single direct path from lamp to substrate, the radiation is divided and redirected through multiple segments, each optimized to deliver precise thermal energy to the substrate surface, thereby maintaining temperature control precision despite the increased overall distance.
Solution Approach 2:
The problem of increased distance in one dimension (lamp-to-substrate spacing) is compensated by adding dimensional complexity through angled reflectors. The radiation path is extended into additional spatial dimensions through reflective surfaces, allowing the system to achieve the necessary thermal coupling in a multi-dimensional optical path rather than a simple linear distance.
3Adaptability or versatility
If thicker windows are installed in the RTP chamber, then the chamber can operate at vacuum pressures, but the structural complexity and device complexity increase
Solution Approach 1:
The window assembly is designed with multi-functionality: the thicker window provides both the necessary vacuum pressure resistance and serves as a structural component that integrates with the lamp positioning system. The linear reflectors are positioned to utilize the space created by the thicker window, transforming a constraint into a functional advantage that enables both vacuum operation and effective heating.
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
Enhances temperature control uniformity and efficiency by directing radiation effectively, ensuring precise heating and cooling rates in rapid thermal processing, even at vacuum pressures.
Implementation Method 1
a plurality of linear reflectors disposed between the upper window and the lower window
Implementation Method 2
a plurality of lenses disposed on a surface of the window body
Implementation Method 3
A body portion of the RTP chamber located between the lamps and the substrate includes a window to enable transmission of radiation therethrough
Implementation Method 4
heating is performed with numerous lamps disposed in a lamphead above or below the substrate being processed
Data Source
AI summary
A window assembly for a thermal processing chamber applicable for thermal processing of a semiconductor substrate is provided. The window assembly includes an upper window, a lower window, and a plurality of linear reflectors disposed between the upper window and the lower window. The plurality of linear reflectors extend lengthwise parallel to each other and parallel to a plane of the window assembly. The window assembly includes a pressure control region defined between the upper window, the lower window, and side surfaces of each linear reflector.