Multi-depth TSV via structure for semiconductor connection reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices miniaturize, the high aspect ratio of via holes for through-silicon vias (TSVs) complicates etching processing, leading to reliability issues such as faulty connections and operational malfunctions, and reduces yield due to difficulties in forming conductive paths from the back surface to the front surface of the silicon substrate.
Innovation Solution
The semiconductor device design includes multiple conductive layers extending from the back surface to the front surface, with at least one layer stopping partway through the semiconductor region, forming a pn junction to prevent current leakage, and using insulating films to isolate conductive layers, ensuring that even if one via hole does not penetrate fully, others can still establish a functional through via connection, thereby preventing open faults between the through via and electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If via holes are formed deep in the semiconductor substrate to achieve through-silicon via connections, then high-density chip mounting and high-speed data transfer are enabled, but the aspect ratio becomes higher and etching processing becomes more difficult
Solution Approach 1:
The patent divides the single deep via hole formation into multiple shallower via holes. By forming multiple via holes at different depths rather than one deep via hole, the etching aspect ratio is reduced while still achieving through-silicon connectivity. This segmentation approach makes the etching process more manageable and reliable.
Solution Approach 2:
The patent transitions from a single-dimensional deep via approach to a multi-dimensional array of via holes at varying depths. Instead of extending vertically in one dimension, the solution distributes via holes across multiple depth levels, effectively using the depth dimension differently to reduce individual via aspect ratios while maintaining overall connectivity.
2Reliability
If multiple through vias are provided to connect the interconnection layer and prevent faulty connections, then connection reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies different qualities to different regions by forming via holes with different depths at different locations. Some via holes extend fully through the substrate while others stop at intermediate depths. This local variation in via depth creates a graded structure that maintains reliability without requiring all vias to be equally complex.
3Reliability
If via holes are formed deeper in the substrate to ensure through connection, then electrical connectivity is achieved, but yield reduction occurs due to processing difficulties
Solution Approach 1:
The patent prepares for potential etching failures by forming multiple via holes with different depths before final assembly. This redundant via structure cushions against the risk of any single via failing to penetrate fully, ensuring that electrical connectivity is maintained even if some via holes do not achieve complete penetration, thereby protecting manufacturing yield.
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 design enhances the reliability and yield of semiconductor devices by preventing operational malfunctions and reducing faulty operations, even when there are variations in via hole depth, by ensuring that at least one conductive path reaches the electrode, thus stabilizing the electric potential and reducing the likelihood of current leaks.
Implementation Method 1
a first semiconductor region of a second conductivity type surrounding part of each of the plurality of conductive layers on the second surface side of the semiconductor layer
Data Source
AI summary
According to one embodiment, a semiconductor device includes: a semiconductor layer of a first conductivity type, the semiconductor layer having a first surface and a second surface on an opposite side to the first surface; a plurality of conductive layers extending in a direction from the first surface side toward the second surface side of the semiconductor layer; a first semiconductor region of a second conductivity type surrounding part of each of the plurality of conductive layers on the second surface side of the semiconductor layer, a portion other than a front surface of the first semiconductor region being surrounded by the semiconductor layer; and an insulating film provided between each of the plurality of conductive layers and the semiconductor layer and between each of the plurality of conductive layers and the first semiconductor region.