Through-silicon via, commonly called TSV, is a vertical electrical connection that passes completely through a Silicon Wafer or die. It has become a foundational technology for advanced semiconductor packaging, allowing multiple chips to be stacked in a compact structure with shorter signal paths and reduced power loss. Understanding how TSV works helps clarify why it is widely used in 3D integrated circuits, high-bandwidth memory, and advanced logic packages.

Structure of a TSV

A TSV begins as a precisely etched cylindrical hole inside a silicon substrate. This hole is later filled with a conductive material that enables electrical transmission. The design is engineered to maintain mechanical stability, electrical reliability, and heat performance within a multilayer semiconductor stack. A simplified view of its structure is shown below:

How TSV Works in a 3D Integrated Structure

TSV works by shortening the interconnection length between chips. Instead of relying on long horizontal traces or wire bonding, TSVs act like ultra-short vertical highways that carry signals, power, and ground directly through the silicon.

The process begins with deep reactive-ion etching, which creates vertical channels inside the wafer. These channels are coated with insulation to prevent leakage. A barrier layer is added to protect the structure from copper migration. The hole is then filled with metal, forming a low-resistance path. Finally, the wafer surface is polished to ensure electrical contact points remain even and reliable.

When multiple chips are stacked, TSVs align with micro-bumps or redistribution layers. This alignment enables direct vertical communication between dies, supporting extremely high bandwidth and low latency. Compared with older packaging technologies, the signal distance is significantly reduced, lowering energy consumption and improving data integrity.

Performance Advantages of TSV Interconnects

One core advantage of TSV is its ability to minimize parasitic capacitance and resistance. Vertical routing reduces path length, which helps maintain high signal quality. The reduced wire length can significantly lower power dissipation, particularly in memory and processor integration. TSV also supports superior thermal routing because heat can move more efficiently through vertically stacked structures. This is important for high-density chips that generate substantial heat during operation.

Additionally, TSV-based stacks enable compact and lightweight architectures. As semiconductor devices become smaller, TSV supports increased transistor density without requiring larger packages.

Typical Use Cases in Modern Semiconductor Packaging

TSV is used in applications that require fast and dense communication between stacked dies. High-bandwidth memory relies heavily on TSV to achieve the throughput required for AI, graphics, and data-center workloads. Image sensors also use TSV to separate the photodiode layer from the processing layer, allowing improved performance without enlarging the sensor size. Many advanced logic-plus-memory integrations depend on TSVs to deliver the speed and efficiency expected in modern devices.

Manufacturers focused on 3D packaging solutions, such as Plutosemi, provide TSV-enabled processes that meet strict reliability and performance standards for next-generation semiconductor products.

Summary

TSV works by creating a vertical conductive path through a silicon wafer, enabling stacked dies to communicate with minimal signal loss. Its structure includes an etched hole, insulation, barrier layers, and a conductive metal filling. The technology greatly shortens interconnection lengths, improves speed, enhances power efficiency, and supports compact 3D chip integration. As semiconductor devices continue to demand higher performance within smaller footprints, TSV remains one of the most important interconnect solutions in the industry.