Semiconductor Substrate Separation Using Ion Damage and Stress Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ion cut techniques face challenges in separating semiconductor substrates like SiC due to difficulties in achieving strong bonding between acceptor and donor substrates, depth of ion implantation, and ion dose, leading to high costs and defects in third-generation semiconductor devices.
Innovation Solution
A process involving ion implantation to form an ion damage layer, followed by the formation of a tensile-stressed stress-inducing layer to separate the semiconductor substrate from the functional layer, eliminating the need for precise control of stress and tape usage, and allowing for direct building of electronic devices on the original substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ion cut technique is used to separate semiconductor substrates, then film transfer can be achieved, but bonding between acceptor and donor substrates is difficult and costly
Solution Approach 1:
The patent extracts the bonding step from the conventional ion cut process by using a support layer that provides mechanical strength without requiring bonding between substrates. The support layer is removed after separation, leaving the functional layer intact on the new substrate.
Solution Approach 2:
The support layer acts as an intermediary that provides mechanical support during the separation process. It allows the functional layer to be separated from the donor substrate without requiring strong bonding between the acceptor and donor substrates, as the support layer carries the mechanical load.
2Manufacturing precision
If ion implantation is performed to create ion damage layer, then separation can be achieved, but precise control of ion dosage and depth is required
Solution Approach 1:
The patent changes the parameter being controlled from ion dosage and depth to support layer thickness. By controlling the thickness of the support layer, the separation depth is indirectly controlled, simplifying the process while maintaining precision.
Solution Approach 2:
The patent replaces the complex ion implantation control system with a simpler mechanical system based on support layer thickness. The mechanical strength and thickness of the support layer determine the separation characteristics, eliminating the need for precise ion dosage control.
3Reliability
If donor and acceptor substrates are bonded tightly, then film support during annealing is improved, but surface flatness requirements become more stringent
Solution Approach 1:
The patent extracts the film support function from the acceptor substrate bonding and transfers it to the support layer. The support layer provides the necessary mechanical support during annealing without requiring tight bonding between substrates, thus relaxing surface flatness requirements.
4Reliability
If separated surface undergoes heat annealing or polishing, then ion damage is repaired, but additional processing steps and costs are incurred
Solution Approach 1:
The patent performs preliminary action by creating the ion damage layer at a controlled depth within the support layer thickness. This preliminary structuring allows the support layer to be removed cleanly without requiring subsequent annealing or polishing to repair surface damage.
Solution Approach 2:
The patent extracts the damaged portion containing the ion damage layer along with the support layer. By removing the support layer that contains the ion damage, the need for surface repair processes is eliminated, as the damage is removed rather than repaired.
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 process, reduces production costs, and minimizes separation defects, enabling efficient separation of hard semiconductor substrates like SiC with fewer re-treatment needs and no gas bubble damage, facilitating large-scale production.
Implementation Method 1
Implant ions into a semiconductor substrate through a top surface of the semiconductor substrate to form an ion damage layer in the semiconductor substrate
Implementation Method 2
Form a stress inducing layer on the functional layer, the stress inducing layer being tensile stressed and introducing compressive stress to the function layer
Data Source
Figure 1~6
Figure 7~8
AI summary
A process separates a main body of a semiconductor substrate from a functional layer. The method includes the steps of implanting ions into a semiconductor substrate through a top surface of the semiconductor substrate to form an ion damage layer 0.1-100 µm underneath the top surface of the semiconductor substrate. After the ions are implanted into the semiconductor substrate, a functional layer is formed on the top surface of the semiconductor substrate. The main body of the semiconductor substrate is then separated from the functional layer. The method also includes forming the functional layer on the semiconductor substrate after ion implanting and then separating the functional layer from the main body of the substrate at the ion damage layer. This method avoids bonding in SOI and can thus reduce process steps and cost.