Non-contact scanning probe station for advanced wafer scale testing of photonic integrated circuits

用于光子集成电路先进晶圆级测试的非接触式扫描探针台

• 批准号: EP/W024683/1
• 负责人: Otto Lambert Muskens
• 金额: $ 92.72万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW024683%2F1
• 关键词: Non; contact; scanning; probe; station

Integrated photonics manufacturing is rapidly becoming a mature multi-billion pound global industry as photonics is underpinning an very wide range of applications aligned with UK's industrial strategy in AI and Web 5.0, the Future of Mobility, Healthcare, and Future Sensors. Test and measurement forms a critical part of most fabrication workflows both in industry and in research, for its potential of picking up deviations at the earliest stage possible and certainly before any expensive packaging and integration steps. On-wafer testing provides an early opportunity which can potentially save significant costs by preventing malfunctioning devices to continue in the processing workflow thus avoiding unnecessary waste of resources, tooling and energy. Importantly, wafer testing allows to feed back any deviations from the original design caused by failures in the fabrication process and smaller drifts exceeding the manufacturing tolerances. The semiconductor industry's leading IRDS Roadmap 2020 has identified the importance of photonics in next generation computing but has pointed out critical bottlenecks in available testing tools for addressing challenges in yield, variability, precision, and tunability of photonic chips. Fabrication imperfections are currently amongst the main limiting factors for achieving reliable high-volume photonics manufacturing.With the appearance of new photonic probe extensions to commercially available wafer probers commonly used in semiconductor electronics manufacturing, a range of sophisticated end-to-end characterisations is now available. This is ideal for a range of tests verifying performance and validating the entire circuit response against the expected output and identifying the critical outliers which are responsible for failure at the systems level. However the current generation of tools lack the capability of extracting information on what happens inside the photonic circuit. As integrated circuits become more and more complex, the lack of intermediate probe points in the circuit becomes an ever more pressing issue. Indeed this issue was addressed recently in other research projects, where groups have proposed erasable output couplers in the circuit as an option for more in-depth testing of intermediate probe points. However a more general approach is within reach as shown by us in a number of proof of principle studies leading to this project. It turns out that the semiconductors used in these photonic circuits are responsive to short-wavelength UV light, in fact responsive enough that illumination of a small microscopic point in the device gives rise to a traceable signal at the output of the circuit. By scanning this spot through the device, we can build up a detailed image of where the light is in both time and space. We can even resolve this map in wavelength, to build up a complete picture of device performance far beyond the capabilities of the commercial probe stations.While this so far has remained a basic research topic, we propose here to push this approach forward as a versatile tool for wafer-scale photonics testing. For this we need to make the techniques much faster, robust and reliable for use in a manufacturing workflow, and aligned with the actual requirements of the end users on different platforms. The majority of the project is therefore focused on developing this instrumentation, operating this with an open source Python data acquisition framework for interoperability and user customization, and generate a convincing set of tests and demonstrators for each platform that will be used to leverage the capabilities of this platform for different application areas. At the end of the project we expect that we have developed a self-contained instrument that will find use in a wide range of research and manufacturing environments around the world.

集成光电子制造正在迅速成为一个成熟的数十亿英镑的全球行业，因为光电子正在支撑与英国在AI和Web 5.0、移动性、医疗保健和未来传感器的未来产业战略保持一致的非常广泛的应用。测试和测量构成了工业和研究中大多数制造工作流程的关键部分，因为它有可能在尽可能早的阶段发现偏差，当然是在任何昂贵的封装和集成步骤之前。晶片上测试提供了一个早期机会，通过防止出现故障的设备在处理工作流程中继续进行，从而避免了不必要的资源、工具和能源浪费，从而潜在地节省了大量成本。重要的是，晶片测试允许反馈因制造过程中的故障和超出制造公差的较小漂移而导致的与原始设计的任何偏差。半导体行业领先的IRDS路线图2020确定了光子学在下一代计算中的重要性，但指出了现有测试工具在解决光子芯片的成品率、可变性、精度和可调性方面的关键瓶颈。制造缺陷是目前实现可靠的大批量光电子制造的主要限制因素之一。随着新的光子探头对通常用于半导体电子制造的商用晶片探头的扩展，一系列复杂的端到端表征现已可用。这是一系列测试的理想选择，这些测试验证性能，对照预期输出验证整个电路响应，并确定导致系统级故障的关键异常值。然而，当前一代的工具缺乏提取关于光子电路内部发生的事情的信息的能力。随着集成电路变得越来越复杂，电路中缺乏中间探针点成为一个越来越紧迫的问题。事实上，这个问题最近在其他研究项目中得到了解决，在这些项目中，研究小组提议在电路中使用可擦除输出耦合器，作为对中间探测点进行更深入测试的一种选择。然而，正如我们在导致这一项目的若干原则研究中所表明的那样，更一般的方法是可以实现的。事实证明，这些光子电路中使用的半导体对短波紫外光做出了响应，事实上，对设备中一个微小的微观点的照明足以在电路的输出端产生可追踪的信号。通过设备扫描这一点，我们可以建立光在时间和空间中所处位置的详细图像。我们甚至可以在波长上解析这个映射，以建立一个远远超出商业探测站能力的完整的器件性能图景。尽管到目前为止这仍然是一个基本的研究课题，但我们在这里建议将这种方法作为一种通用的工具来推进晶片规模的光子测试。为此，我们需要使这些技术更快、更健壮、更可靠地用于制造工作流程，并与不同平台上最终用户的实际需求保持一致。因此，该项目的大部分时间都集中在开发这一工具上，使用开放源码的Python数据采集框架进行操作，以实现互操作性和用户定制，并为每个平台生成一组令人信服的测试和演示程序，这些测试和演示程序将用于利用该平台在不同应用领域的功能。在项目结束时，我们预计我们已经开发出一种自给自足的仪器，将在世界各地的广泛研究和制造环境中使用。