SiPh, AI, probe, LiDAR, SOI

1. Industry Trends: The Inevitable Shift from Electrical to Optical Interconnects

As Generative AI and High-Performance Computing (HPC) accelerate toward trillion-parameter models, data transmission has become the core bottleneck limiting the evolution of computing power. Faced with the explosive demand for bandwidth and ultra-low latency within computing clusters, traditional copper-based electronic interconnects are hitting physical "Power Walls" and significant signal degradation challenges.

Silicon Photonics (SiPh) technology, with its high bandwidth density, ultra-low latency, and superior energy efficiency, has become the core infrastructure for AI data centers, enabling a paradigm shift from electrons to photons as the primary carriers of information.

2. Technical Deep-Dive: Leveraging the Silicon Platform for Scale

By integrating complex optical functions—such as modulation, detection, and routing—onto a Silicon-on-Insulator (SOI) wafer, SiPh achieves a deep fusion of mature semiconductor fabrication and photonic characteristics.

CMOS Compatibility: Utilizing established 8/12-inch semiconductor fabrication lines, SiPh chips achieve economies of scale and cost optimization previously unreachable in the traditional optics industry.
High Integration Density: It enables the integration of thousands of photonic components and electronic circuits on a single, monolithic chip.
Clear Evolutionary Roadmap: With single-channel rates exceeding 200 Gb/s, SiPh provides a solid foundation for the mass-market deployment of 1.6T and 3.2T optical transceivers.
Versatile Applications: Beyond data centers, SiPh applications are expanding into autonomous driving (solid-state LiDAR) and healthcare sensing (wearable monitoring devices).

3. Core Challenges: Overcoming the "Last Mile" of Wafer-Level Testing

While SiPh manufacturing processes have matured, wafer-level testing remains the primary barrier to yield optimization and High-Volume Manufacturing (HVM).

Sub-micron Coupling Precision: Aligning a fiber probe to a waveguide (via grating couplers) requires sub-micron accuracy. A coupling efficiency fluctuation of even 0.1 dB can lead to test misjudgments, placing extreme demands on the mechanical stability and motion control of the prober.
Complex Mixed-Signal Testing: Systems must simultaneously coordinate Optical-Optical (O/O), Optical-Electrical (O/E), and Electrical-Electrical (E/E) signals at the wafer stage to accurately measure parameters such as responsivity, extinction ratio, and insertion loss.
Rigorous Thermal Simulation: Because SiPh devices are highly temperature-sensitive, the testing environment must remain highly stable across a range of 25°C to 150°C to validate chip performance under real-world, high-load AI workloads.

4. Nexustest Solution: sCT9002 Fully Automatic SiPh Wafer Test System

To bridge the gap from R&D to HVM, Nexustest has introduced the sCT9002. This "one-stop" SiPh wafer testing platform integrates high efficiency, stability, and intelligence, featuring the following core competencies:

Automated HVM Architecture: Engineered for seamless 8–12 inch wafer handling with automated loading and versatile support for wafer thicknesses ranging from 200 to 2000 μm.
Superior Thermal Control: Provides a dark, shielded environment with a temperature-controlled chuck (25°C to 150°C) maintaining a uniformity of ±0.1°C.
Intelligent and Precise Alignment: Compatible with single fibers and Fiber Array Unit (FAU), supporting automated sub-micron alignment for both grating and edge coupling with integrated collision avoidance.
Rapid In-Situ Calibration: Utilizes a proprietary high-precision optical prism design to support one-click automated FAU calibration, reducing change-over downtime to under 3 minutes.
Integrated High-Performance Hardware: Equipped with in-house, multi-channel Source Measure Units (SMUs) optimized for SiPh and a 6-axis high-precision positioning system to deliver a perfect balance of accuracy, throughput and cost-efficiency.
Production-Grade Analytics Software: Features an intuitive visual Wafer Map and automated Binning (pass/fail classification), as well as granular sub-die level characterization for advanced data analysis.

5. Conclusion: Support the Future of Computing with Precision in Testing

In the race for AI computing power, design defines the performance ceiling of a SiPh chip, but testing secures its reliability floor. Every chip must cross a rigorous threshold of verification before delivery. The Nexustest sCT9002 system, with its exceptional precision, efficiency, and stability, provides the essential foundation for SiPh technology to transition from R&D breakthroughs to large-scale applications in AI data center and all other segments.