Diode Stack Transfer with Bias-Controlled Sacrificial Layer Removal
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Solution Overview
Problem
Existing methods for removing substrates from diode stacks in electronic device manufacturing are complex and inefficient, particularly in exposing the active layers after substrate removal.
Innovation Solution
A method involving the formation of a diode stack on a sacrificial semiconductor layer between the substrate, transferring the structure to a new substrate, and electropolishing the sacrificial layer using a bias voltage to remove the original substrate, allowing for precise control and simplification of the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet etching, dry etching, or laser removal techniques are used to remove the substrate, then the substrate can be removed, but complex steps of removing buffer layers are required to expose the active layers
Solution Approach 1:
A sacrificial layer is deposited on the substrate before forming the diode stack. This preliminary action enables selective removal of the substrate while preserving the diode stack and eliminating the need for subsequent buffer layer removal steps.
Solution Approach 2:
The sacrificial layer acts as an intermediary between the substrate and the diode stack. It facilitates substrate removal through electropolishing while protecting the diode stack, thereby simplifying the overall manufacturing process by eliminating complex buffer layer removal steps.
2Productivity
If existing substrate removal methods are used, then the substrate can be removed, but the process requires multiple complex steps to expose active layers
Solution Approach 1:
The sacrificial layer is deposited in advance on the substrate before diode stack formation. This preliminary action enables a single-step electropolishing process that simultaneously removes the substrate and exposes the active layers, significantly reducing manufacturing time and improving productivity.
Solution Approach 2:
The sacrificial layer is selectively removed through electropolishing, extracting only the necessary portion (substrate) while leaving the diode stack intact. This selective extraction eliminates the need for multiple sequential removal steps, thereby reducing process time and improving efficiency.
3Device complexity
If substrate removal is performed without a sacrificial layer, then the process may be simpler, but precise control over the detachment zone is lost
Solution Approach 1:
The sacrificial layer serves as a mediator that enables precise control over the detachment zone. By applying bias voltage during electropolishing, the removal process is confined to the sacrificial layer and substrate interface, ensuring accurate exposure of active layers without damaging surrounding structures.
Solution Approach 2:
The application of bias voltage changes the electrical parameters of the electropolishing process, enabling selective and controlled removal of the sacrificial layer at the detachment zone. This parameter control ensures precise exposure of active layers while maintaining structural integrity of the diode stack.
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 method simplifies the substrate removal process, enables precise control over the detachment zone, and facilitates the exposure of active layers, improving manufacturing efficiency and reducing complexity.
Implementation Method 1
removing the first substrate by electropolishing the sacrificial layer by applying a bias voltage to the sacrificial layer via the diode stack
Implementation Method 2
transferring is performed by conductive molecular bonding on the side of a first face of the diode stack opposite the first substrate
Data Source
AI summary
A method of manufacturing an electronic device comprising the following successive steps: a) forming a structure comprising a diode stack disposed on a first substrate, and a sacrificial layer of semiconductor material interposed between the first substrate and the diode stack; b) transferring the structure to a second substrate; and c) removing the first substrate by electropolishing the sacrificial layer by applying a bias voltage to the sacrificial layer via the diode stack.