III-V Semiconductor Layer Release via Laser-Access Sacrificial Etching
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Solution Overview
Problem
Current methods for removing epitaxially grown semiconductor layers from wafers are inefficient and require complex masking and alignment processes, limiting the usable component area and increasing production costs.
Innovation Solution
A method involving a laser to create precise holes in the carrier layer and underlying layers, allowing for selective wet chemical etching of a sacrificial layer, which is highly selective and eliminates the need for pre-structuring and complex mask processes, enabling efficient detachment of semiconductor layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If complex masking and alignment processes are used to remove epitaxially grown semiconductor layers, then the removal can be achieved, but the usable component area is limited and production costs increase
Solution Approach 1:
The patent divides the semiconductor layer into discrete segments by creating an array of holes through the carrier layer. Each hole serves as an independent access point for etching the sacrificial layer, allowing the semiconductor layer to be released in segmented portions rather than requiring complex full-area masking and alignment processes
Solution Approach 2:
The patent introduces an intermediary sacrificial layer between the semiconductor layer and the carrier layer. This sacrificial layer can be selectively removed through the holes to detach the semiconductor layer, eliminating the need for direct complex masking and alignment operations on the semiconductor layer itself
2Ease of manufacture
If complex masking and alignment processes are used to remove epitaxially grown semiconductor layers, then the removal can be achieved, but production costs increase
Solution Approach 1:
The patent replaces complex mechanical masking and alignment operations with a simpler process involving laser drilling of holes and liquid etchant delivery. This substitution eliminates the need for precise mechanical alignment systems and complex mask handling, thereby reducing production process complexity and costs
Solution Approach 2:
The patent changes the approach from surface-level masking operations to subsurface hole formation and etchant delivery. By changing the spatial parameter of where the removal action occurs (from surface to through-holes), the process becomes simpler and less costly while maintaining effectiveness
3Ease of manufacture
If traditional wet chemical etching is used without pre-structuring, then the process is simplified, but selective removal of the sacrificial layer becomes difficult
Solution Approach 1:
The patent applies local quality by creating holes at specific locations through the carrier layer, allowing etchant to be delivered precisely where needed. The sacrificial layer is removed only in these localized regions, achieving both process simplification and high etching selectivity through spatially differentiated treatment
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 significantly increases the usable component area, reduces production complexity, and allows for quick and easy creation of various patterns, enabling reliable and efficient removal of semiconductor layers without the need for expensive mask processes.
Implementation Method 1
a positioning device, wherein the positioning device includes a laser, is used to approach the points specified on the basis of the position data and to create holes with a bottom at at least some of the points through the carrier layer and the layers formed below the carrier layer using the laser
Implementation Method 2
In a wet chemical process step, an etching solution is introduced into the holes with the support layer in place, in order to at least partially remove the sacrificial layer and detach the semiconductor layer
Data Source
Figure 1~2
AI summary
Method for removing an epitaxially grown III-V semiconductor layer on a semiconductor wafer, the semiconductor wafer being configured as a substrate and having a top surface, wherein a buffer layer and the semiconductor layer are formed on the top surface, and a support layer is formed above the semiconductor layer, and the sacrificial layer has a higher wet-chemical etch rate compared to the semiconductor layer, wherein in one process step the semiconductor wafer is placed in a receiving device, and in one process step position data of points arranged on the top surface are read from a storage device, and in one process step a laser is used to locate the points based on the position data and holes with a bottom are created through the support layer and the layer formed below the support layer by means of the laser.wherein the bottom of the respective hole is formed within the buffer layer and, in a wet chemical process step with the support layer in place, an etching solution is introduced into the holes in order to at least partially remove the sacrificial layer and detach the semiconductor layer.