Semiconductor Boule Separation Using Laser Damage Layers
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Solution Overview
Problem
Existing methods for separating semiconductor substrates from a boule face challenges, particularly when the boule becomes thin, as creating a significant thermal gradient becomes difficult, leading to unusable material and reduced wafer singulation efficiency.
Innovation Solution
The method involves creating damage layers in the boule using laser irradiation and applying thermal gradients by heating and cooling, with the use of liquid nitrogen, to facilitate the separation of semiconductor substrates at these damage layers, optimizing the separation process and increasing the number of usable wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional thermal gradient methods are used to separate substrates from a thin boule, then separation efficiency decreases, but the boule becomes unusable material
Solution Approach 1:
A damage layer is created in the boule prior to the separation process using laser irradiation or mechanical means. This preliminary action weakens the bond between substrates and the boule, enabling effective separation even when the boule is thin and conventional thermal gradient methods would fail.
2Reliability
If laser irradiation is applied to create damage layers, then separation effectiveness improves, but process complexity increases
Solution Approach 1:
The conventional mechanical or simple thermal separation method is replaced with laser irradiation to create damage layers. Although this introduces a more complex process step, it significantly improves separation effectiveness and enables processing of thin boules that would otherwise be unusable.
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 approach enhances the efficiency of semiconductor substrate separation by creating stress and cracks in the boule, allowing for more effective separation of wafers, even from thin sections, thereby optimizing the yield of usable substrates.
Implementation Method 1
The damage layer may be created through laser irradiation
Implementation Method 2
The thermal gradient between the first end and a bulk material of the boule may assist the one or more semiconductor substrates with separating from the boule at the damage layer
Implementation Method 3
Cooling the boule further may include contacting the boule with liquid nitrogen
Data Source
AI summary
Implementations of a method of separating a semiconductor substrate from a boule including a semiconductor material may include creating a damage layer in a first end of a boule including semiconductor material; heating the boule; and cooling the boule to separate one or more semiconductor substrates from the boule at the damage layer.