Moveable Cooling Jacket in Ingot Pullers for Defect Reduction
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Solution Overview
Problem
Existing ingot puller apparatus and methods are inadequate in reducing the number and size of defects, such as voids and oxygen precipitates, in single crystal silicon ingots, which can lead to gate-oxide-integrity failures in semiconductor devices.
Innovation Solution
An ingot puller apparatus with a moveable cooling jacket that controls the cooling profile of single crystal ingots by adjusting the position and emissivity of the cooling jacket within the growth chamber, allowing for precise temperature gradients and cooling rates to minimize defect formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a stationary cooling jacket is used, then the device complexity is reduced, but the manufacturing precision of the single crystal ingot deteriorates due to inability to control cooling profiles
Solution Approach 1:
The cooling jacket is made moveable along the growth chamber outlet, transforming it from a stationary to a dynamic component. This allows the cooling jacket to be positioned at different locations to control the cooling profile of the single crystal ingot, thereby reducing defects while managing device complexity through controlled mobility rather than complete structural complexity
Solution Approach 2:
The position of the cooling jacket is changed as a controllable parameter to optimize the cooling profile. By adjusting the location of the cooling jacket along the growth chamber outlet, the thermal parameters affecting defect formation can be modified, improving manufacturing precision without requiring complete redesign of the cooling system
2Manufacturing precision
If cooling components are added to control thermal profiles, then the manufacturing precision improves, but the device complexity increases
Solution Approach 1:
The moveable cooling jacket serves multiple functions: it provides cooling, enables thermal profile control, and can be repositioned to adapt to different growth stages. This multi-functionality improves manufacturing precision through better thermal control while avoiding the need for multiple separate cooling components that would increase device complexity
Solution Approach 2:
The cooling component is designed with mobility, allowing it to dynamically adjust its position to optimize thermal gradients. This dynamic capability provides precise thermal control for defect reduction while using a single adaptable component rather than multiple fixed 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 apparatus effectively reduces the size and number of defects in single crystal ingots, enhancing the quality of the ingots and reducing the propensity for gate-oxide-integrity failures, while maintaining consistent and repeatable cooling capabilities.
Implementation Method 1
a cooling jacket positioned in the growth chamber between the crucible and the growth chamber outlet, the cooling jacket defining a cooling passage having an inlet proximate the crucible and an outlet proximate the growth chamber outlet
Implementation Method 2
an actuator connected to the cooling jacket and operable to move the cooling jacket in the growth chamber to control a cooling profile of the single crystal ingot
Data Source
AI summary
An ingot puller apparatus for producing a single crystal ingot includes a housing defining a growth chamber and a growth chamber outlet, a crucible positioned in the growth chamber for containing a melt of semiconductor material, a cooling jacket positioned in the growth chamber between the crucible and the growth chamber outlet, the cooling jacket defining a cooling passage having an inlet proximate the crucible and an outlet proximate the growth chamber outlet, a puller positioned to contact a seed crystal with a surface of the melt and pull the single crystal ingot from the melt and through the cooling passage, and an actuator connected to the cooling jacket and operable to move the cooling jacket in the growth chamber to control a cooling profile of the single crystal ingot.