TDV (Through-Diamond Via) Technology

TDV (Through-Diamond Via) Technology

Through-Diamond Via (TDV) is an advanced vertical interconnection technology that enables electrical connectivity through electrically insulating diamond substrates. By fabricating micro-scale through-holes and filling them with conductive metals, typically copper, TDV establishes vertical pathways for signal and power transmission while preserving diamond's exceptional thermal conductivity.

As semiconductor packaging advances toward higher integration density and increasingly complex 2.5D/3D architectures, diamond offers significant potential as an alternative interposer material. With thermal conductivity typically ranging from 1,000 to 2,000 W/m·K, diamond provides outstanding heat spreading capabilities. However, its electrical insulating properties require engineered conductive pathways to support vertical interconnection between stacked dies and multilayer structures.

Key TDV Manufacturing Technologies

The fabrication process involves several critical steps:

1. Laser Microvia Drilling: UV nanosecond laser processing is used to create high-aspect-ratio through-holes in diamond substrates. Research has demonstrated via diameters of approximately 20 μm with an aspect ratio of 10:1, corresponding to a via depth of approximately 200 μm.

2. Sidewall Modification: Ar/O plasma treatment modifies the diamond surface to improve metallization conditions and metal adhesion.

3. Seed Layer Deposition: PVD deposition of Cr/Au conductive seed layers provides an electrical foundation for subsequent metal electroplating.

4. Copper Filling: Bottom-up copper electroplating enables dense metal filling while minimizing internal voids and ensuring electrical continuity.

Demonstrated Technical Performance

These parameters demonstrate the feasibility of fabricating high-aspect-ratio, electrically conductive vias in diamond substrates.

Applications and Technical Significance

TDV combines two essential functions within one substrate architecture: vertical electrical interconnection through copper-filled vias and high-efficiency thermal spreading through the surrounding diamond matrix. This makes it particularly attractive for AI processors, high-performance computing, chiplet integration, HBM packaging, and advanced 3D semiconductor systems.

By integrating precision microvia fabrication, reliable metallization, and low-resistance copper filling, TDV represents an important step toward transforming diamond from a high-performance thermal management material into a multifunctional interposer platform for next-generation semiconductor packaging.

Note: The technical figures above represent demonstrated research results, not established DIASEMI mass-production specifications.