Semiconductor Substrate Trench Formation for IGBT Junction Control
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Solution Overview
Problem
Existing techniques for reducing the distance between the collector region and the body region in insulated gate bipolar transistors are not optimal, limiting further improvements in device performance.
Innovation Solution
A process involving the thinning of a semiconductor substrate to define trenches on the opposite side, allowing for better control over junction depths and the formation of doped regions and conductive structures within these trenches, which includes forming doped regions adjacent to the trenches and conductive structures that can be pillars within the trenches, enhancing process control and reducing implant-induced damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional techniques are used to reduce the distance between collector region and body region, then device performance improves, but the control over junction depths deteriorates and implant-induced damage increases
Solution Approach 1:
The substrate is divided into two sides: the first major side where the electronic component is formed with proper control, and the second major side where trenches are selectively removed. This segmentation allows the trench removal process to be performed separately and precisely controlled from the opposite side, improving junction depth control without compromising device performance.
Solution Approach 2:
The invention approaches the junction formation from a different dimensional perspective by removing trenches from the second major side (opposite side) rather than attempting to control junction depths directly from the first major side. This dimensional change enables better precision in junction depth control while reducing implant-induced damage to the electronic component.
2Reliability
If traditional techniques are used to reduce the distance between collector region and body region, then device performance improves, but implant-induced damage increases
Solution Approach 1:
By segmenting the substrate processing into two separate sides, the implant process can be performed from the second major side without directly impacting the electronic component formed on the first major side. This reduces implant-induced damage while still achieving the desired reduction in distance between collector region and body region for improved device performance.
Solution Approach 2:
The trenches act as an intermediary structure that mediates between the implant process and the electronic component. By removing material from the second major side to create trenches, the implant ions can be directed precisely without causing excessive damage to the sensitive electronic component regions, thus reducing implant-induced damage while maintaining device performance improvements.
3Manufacturing precision
If trenches are removed from the opposite side of the substrate, then control over junction depths improves, but the process complexity increases
Solution Approach 1:
The process is segmented into distinct stages: forming the electronic component on the first major side, then separately removing trenches from the second major side. This segmentation allows each process to be optimized independently, improving junction depth control through precise trench removal while managing overall process complexity by clearly defining process boundaries and sequences.
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 provides improved control over device dimensions and performance, reduces implant-induced damage, and allows for more precise activation of doped regions, resulting in higher-quality electronic devices with less variation in performance across different substrates.
Implementation Method 1
thinning the semiconductor substrate to define a second major surface along a second major side opposite the first major side
Implementation Method 2
selectively removing a portion of the semiconductor substrate along the second major side to define a trench
Implementation Method 3
forming a doped region adjacent to a distal surface of the trench, wherein forming the doped region is performed along the second major side of the semiconductor substrate after thinning the semiconductor substrate
Data Source
AI summary
In an embodiment, a process of forming an electronic device can include providing a semiconductor substrate having a first major side and an electronic component at least partly within the semiconductor substrate along the first major side; The process can further include thinning the semiconductor substrate to define a second major surface along a second major side opposite the first major side; and selectively removing a portion of the semiconductor substrate along the second major side to define a trench having a distal surface. The process can further include forming a feature adjacent to or within the trench. The feature can include a doped region, a conductive structure, or the like. In another embodiment, an electronic device can include the semiconductor substrate and a conductive structure within a trench. The conductive layer can laterally surround a pillar within the trench.