Segmented Heater Control for Oxygen Uniformity in Single Crystal Silicon
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Solution Overview
Problem
Current methods for controlling oxygen concentration in single crystal silicon during manufacturing have limited control width and yield, with existing heater configurations unable to achieve uniform oxygen distribution, leading to suboptimal semiconductor product yield and high costs associated with magnetic field generation devices.
Innovation Solution
A single crystal semiconductor manufacturing apparatus with multiple heaters disposed vertically around the crucible, where each heater has a different resistance value and current-carrying cross-sectional area, allowing for independent power supply to adjust heat generation, thereby expanding the temperature distribution and oxygen concentration control range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single heater is used around the quartz crucible, then the structure is simple, but the temperature distribution control in the vertical direction is limited and oxygen concentration uniformity cannot be achieved
Solution Approach 1:
The single heater is divided into multiple heaters arranged vertically around the quartz crucible. Each heater can be independently controlled to adjust the temperature distribution in the vertical direction, enabling precise control of oxygen concentration uniformity in the single crystal silicon during growth.
Solution Approach 2:
The heater system is made dynamically controllable by supplying different electric powers to each heater segment. This allows the temperature distribution to be adjusted in real-time during the crystal growth process, optimizing oxygen concentration control for different growth stages.
2Adaptability or versatility
If multiple heaters are added vertically to increase oxygen concentration control width, then oxygen control capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
Different regions of the heater system are designed with different properties. Each heater segment can have different resistance values and heat generation characteristics tailored to the specific thermal requirements of its vertical position, enabling precise local control of temperature and oxygen concentration.
3Adaptability or versatility
If electric power to heaters is adjusted to control oxygen concentration, then oxygen control is achieved, but the control width remains limited with a single heater
Solution Approach 1:
The heater is segmented into multiple independently controllable units arranged vertically. This segmentation allows differential power adjustment across different vertical zones, expanding the oxygen concentration control width while maintaining precise temperature distribution control through coordinated power management of each segment.
4Manufacturing precision
If magnetic field generation devices are used to control oxygen concentration, then oxygen control capability is improved, but manufacturing cost increases significantly
Solution Approach 1:
The magnetic field generation device is replaced with a thermally-based heater system. Instead of using complex magnetic fields to control oxygen concentration, the invention uses controlled thermal fields from multiple heaters to achieve the same objective, significantly reducing manufacturing cost while maintaining control precision.
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
This configuration significantly increases the control width of oxygen concentration, improving the yield of single crystal silicon by allowing for a larger range of oxygen concentrations to meet device standards, thus enhancing the manufacturing efficiency and reducing costs compared to magnetic field methods.
Implementation Method 1
the individual heaters are separately supplied with electric power and configured of a conductor which generates heat when electric power is applied
Implementation Method 2
The oxygen dissolves from the quartz crucible 3 into the silicon melt 5 and is taken into the single crystal silicon 6 when it is pulled up
Data Source
AI summary
An upper side heater 10 is configured so that a current passage width becomes larger at a heater lower part than at a heater upper part. Thus, the upper side heater 10 has a current-carrying cross-sectional area which becomes larger at the heater lower part than at the heater upper part, a resistance value becomes accordingly smaller at the heater lower part than at the heater upper part, and a heat generation amount becomes relatively smaller at the heater lower part than at the heater upper part. Meanwhile, a lower side heater 20 is configured so that the current passage width becomes larger at the heater upper part than at the heater lower part. Thus, the current-carrying cross-sectional area of the lower side heater 20 becomes larger at the heater upper part than at the heater lower part, a resistance value becomes accordingly smaller at the heater upper part than at the heater lower part, and a heat generation amount becomes relatively smaller at the heater upper part than at the heater lower part.