PN Junction Singulation with Edge Recombination Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The separation of semiconductor components with a pn junction leads to increased recombination rates and reduced electronic quality due to the separation surface, causing inefficiencies in photovoltaic solar cells and computing processors, and existing methods are either time-consuming or costly.
Innovation Solution
A method involving the formation of a transverse conduction avoidance region with reduced conductivity by at least a factor of 10, where the separating surface penetrates or adjoins this region, preventing charge carrier flow to the interface and minimizing recombination, which can be achieved through techniques like laser ablation or counter-diffusion to increase sheet resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor components are separated by dicing through the substrate, then the components are successfully singulated, but recombination losses at the separation surface significantly reduce electronic quality
Solution Approach 1:
The patent applies preliminary action by forming a through-conductivity avoidance region before the dicing step. This region, extending from the front surface through the substrate to the back surface, pre-prevents charge carrier cross-conduction paths that would otherwise lead to recombination losses at the separation surface during subsequent component separation.
Solution Approach 2:
The through-conductivity avoidance region acts as an intermediary structure between the front and back surfaces of the substrate. It mediates the electrical behavior at the separation surface by providing a dedicated path that prevents charge carriers from crossing into adjacent components, thereby reducing recombination without interfering with the mechanical dicing process.
2Reliability
If a strong doping layer is formed to prevent recombination at the interface, then electronic quality is improved, but the process becomes very time-consuming
Solution Approach 1:
The patent transitions from a two-dimensional surface doping approach to a three-dimensional through-conductivity avoidance region that extends vertically through the entire substrate thickness. This dimensional change allows the conductivity avoidance effect to be achieved through structural geometry rather than relying solely on time-consuming diffusion processes.
Solution Approach 2:
The patent changes the conductivity parameter of the through-conductivity avoidance region by forming it with different doping characteristics than the bulk substrate. This parameter change creates a region with sufficiently high resistance to prevent charge carrier cross-conduction, achieving the electronic quality improvement without requiring the extensive time of strong doping layer formation.
3Reliability
If emitter windows are formed by masking processes to reduce edge recombination, then electronic quality is improved, but additional masking steps increase production time and costs
Solution Approach 1:
The patent extracts the conductivity avoidance function from the emitter window structure and implements it as a separate through-conductivity avoidance region. This extraction eliminates the need for complex masking processes to create emitter windows, as the through-conductivity avoidance region can be formed independently using simpler techniques that extend through the substrate.
Solution Approach 2:
The through-conductivity avoidance region is formed as a preliminary structure before final component separation and contact formation. This preliminary action establishes the conductivity avoidance pattern early in the process, eliminating the need for subsequent masking steps that would be required to create emitter windows and reduce edge recombination.
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 reduces the negative influence of the separation surface on electronic quality, allowing for efficient separation of semiconductor components while maintaining high electronic performance, and can be implemented cost-effectively in industrial production.
Implementation Method 1
A method for singulating a semiconductor component with a pn junction comprises forming a transverse conduction avoidance region with reduced conductivity by at least a factor of 10
Implementation Method 2
techniques like laser ablation or counter-diffusion to increase sheet resistance
Implementation Method 3
techniques like laser ablation or counter-diffusion to increase sheet resistance
Data Source
Figure 1a~1e
Figure 2~3
AI summary
The invention relates to a semiconductor component (1a, 1b, 1c, 1d, 1e) having at least one emitter (2a, 2b, 2c), at least one base (3a, 3b, 3c, 3d, 3e), wherein a pn junction (4a, 4b, 4c) is formed between emitter and base (3a, 3b, 3c, 3d, 3e), having at least one nonmetallic transverse conduction layer for the transverse conduction of majority charge carriers of the emitter, wherein the emitter (2a, 2b, 2c) comprises the transverse conduction layer and/or the transverse conduction layer is formed parallel to the emitter (2a, 2b, 2c) and in a manner electrically conductively connected thereto, and having a break side, at which the semiconductor component (1a, 1b, 1c, 1d, 1e) was singulated. What is essential is that a transverse conduction avoidance region (5a, 5b, 5c, 5d, 5e) is formed and arranged at the break side in such a way that the transverse conductivity is reduced by at least a factor of 10, wherein the transverse conduction avoidance region (5a, 5b, 5c, 5d, 5e) has a depth (TQ) in the range of 5 µm to 500 µm, in particular 10 µm to 200 µm, perpendicular to the break side. The invention furthermore relates to a method for singulating a semiconductor component.