Linear Evaporation Source with Adjustable Lateral Reflectors
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Solution Overview
Problem
Linear evaporation sources in vacuum deposition apparatuses face challenges in maintaining uniform temperature across the crucible, leading to non-uniform thin film formation due to temperature differences at the ends.
Innovation Solution
A linear evaporation source with a crucible, a heater unit, and lateral reflectors with adjustable open ratios to control temperature, allowing independent adjustment of the reflectors' positions and sizes to maintain uniform heating across the crucible.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a linear evaporation source uses a heater unit surrounding the crucible, then heating efficiency is improved, but temperature uniformity across the crucible deteriorates due to temperature differences at the ends
Solution Approach 1:
The heater unit is divided into multiple independent heater elements (first heater, second heater, third heater, fourth heater) positioned at different locations around the crucible. Each heater can be independently controlled to compensate for temperature differences at the ends of the crucible, thereby maintaining temperature uniformity while preserving heating efficiency.
Solution Approach 2:
Different regions of the crucible are heated with different heating intensities by positioning heater elements at specific locations. The end regions receive additional heating from dedicated heater elements to compensate for heat loss, while the central region receives appropriate heating to maintain overall temperature uniformity across the crucible.
2Temperature
If lateral reflectors are added to control temperature distribution, then temperature uniformity is improved, but device complexity increases
Solution Approach 1:
The lateral reflectors are designed to be movable rather than fixed, allowing their positions to be adjusted dynamically. This enables the reflectors to be optimized for different heating conditions and crucible configurations, improving temperature uniformity control while maintaining relatively simple device structure through versatile, adjustable components.
Solution Approach 2:
The lateral reflectors serve multiple functions: they reflect thermal radiation from the heater unit to the crucible, block direct line-of-sight between the heater and the chamber walls to prevent heat loss, and can be adjusted to optimize heating for different crucible positions and configurations. This multi-functionality reduces the need for additional separate components.
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 solution enables uniform temperature control of the crucible, enhancing deposition uniformity and ensuring consistent thin film thickness.
Implementation Method 1
a heater unit surrounding the crucible and heating the crucible
Implementation Method 2
a plurality of lateral reflectors surrounding a lateral surface of the heater unit
Implementation Method 3
a temperature sensing unit fixed to the heater frame and disposed between the crucible and the heater
Implementation Method 4
a thin film is formed on a substrate by means of physical vapor deposition (PVD)
Data Source
AI summary
A linear evaporation source is disclosed. In one aspect, the source includes a crucible storing an evaporated material, a heater unit surrounding the crucible and heating the crucible, and a plurality of lateral reflectors surrounding a lateral surface of the heater unit. Each of the lateral reflectors includes a first reflector combined with the heater unit while being spaced apart from the heater unit and having a plurality of first openings and a second reflector movably combined with the first reflector and having a second opening. Open ratios of the lateral reflectors are independently adjusted to control a temperature of the crucible according to areas of the crucible. Thus, deposition uniformity of the linear evaporation source is enhanced.