Wafer Singulation via Trench Etching and Conductive Support
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Solution Overview
Problem
The existing methods for dicing semiconductor wafers, such as sawing through III-nitride materials, are time-consuming and can cause damage to the devices, reducing yield.
Innovation Solution
A method that involves growing trenches through the entire thickness of the semiconductor structure to reveal the growth substrate, followed by the formation of a thick conductive layer for mechanical support and electrical connection, allowing for the removal of the growth substrate without mechanical or laser dicing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical dicing (sawing) is used to separate semiconductor devices on a wafer, then the devices can be singulated into individual units, but the process is time-consuming and can cause damage to the devices
Solution Approach 1:
The patent replaces the mechanical dicing system (sawing through III-nitride materials) with a chemical etching system. Trenches are formed by etching through the semiconductor structure using chemical solutions, which eliminates the mechanical contact and vibration that cause device damage while enabling parallel processing of multiple devices simultaneously, thus improving both productivity and reliability
Solution Approach 2:
The patent introduces a thick conductive layer as an intermediary mechanical support structure between the semiconductor devices and the growth substrate. This support layer allows the growth substrate to be removed without compromising device integrity, enabling chemical etching instead of mechanical dicing, and thus resolves the contradiction between fast singulation and device protection
2Strength
If a thick conductive layer is formed on the semiconductor structure, then mechanical support is provided during substrate removal, but additional processing steps are required
Solution Approach 1:
The thick conductive layer serves multiple functions simultaneously: it provides mechanical support during substrate removal, acts as an electrical connection path for the semiconductor devices, and serves as a thermal management pathway. By combining these functions into a single structure, the patent adds minimal process complexity while achieving the required mechanical strength
Solution Approach 2:
The patent merges the mechanical support function with the existing electrical contact structure by forming the thick conductive layer as part of the electrical contact system. This integration means that the same layer that provides electrical connectivity also provides mechanical support, eliminating the need for separate support structures and minimizing additional process steps
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 enables efficient singulation of semiconductor devices without damage, improving yield and reducing processing time by supporting the structure during substrate removal and providing a thermal pathway for improved device efficiency.
Implementation Method 1
The thick conductive layer is configured to support the semiconductor structure when the growth substrate is removed
Implementation Method 2
providing a thermal pathway for improved device efficiency
Data Source
AI summary
A method according to embodiments of the invention includes providing a wafer comprising a semiconductor structure grown on a growth substrate. The semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. The wafer includes trenches defining individual semiconductor devices. The trenches extend through an entire thickness of the semiconductor structure to reveal the growth substrate. The method further includes forming a thick conductive layer on the semiconductor structure. The thick conductive layer is configured to support the semiconductor structure when the growth substrate is removed. The method further includes removing the growth substrate.