日本大阪大学Masayoshi Tonouchi团队实现了利用太赫兹发射光谱非接触和纳米尺度测量埋在硅片中的PN结深度。2025年6月20日，《光：科学与应用》杂志发表了这一成果。

埋沟道阵列晶体管实现了快速和高密度的集成器件。硅晶片耗尽层的PN结深度和载流子动力学对其性能和可靠性有至关重要的影响。因此，快速和非接触/无损检测工具是加快半导体行业发展的必要条件。尽管人们在这一领域做出了巨大努力，但实现探测晶片内PN结处结深和载流子动力学的技术仍然具有挑战性。 

研究组提出了一种使用太赫兹（THz）发射光谱访问嵌入晶片中的PN结的新方法。太赫兹发射测量和模拟表明，太赫兹发射的幅度和极性反映了PN结处的结深和载流子动力学。它使他们能够以纳米级的精度无损地评估结深，超越了传统技术的极限。激光诱导太赫兹发射光谱是一种有前景的硅晶片灵敏、非接触/无损评估方法，将有利于现代半导体工业。

附：英文原文

Title: Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy

Author: Murakami, Fumikazu, Ueyama, Shinji, Suzuki, Kenji, Kim, Ingi, Baek, Inkeun, Bae, Sangwoo, Sung, Dougyong, Lee, Myungjun, Ryu, Sungyoon, Yang, Yusin, Tonouchi, Masayoshi

Issue&Volume: 2025-06-20

Abstract: Buried channel array transistors enable fast and high-density integrated devices. The depth of the PN junction and carrier dynamics at the depletion layer in silicon wafers have a crucial influence on their performance and reliability. Therefore, rapid and non-contact/non-destructive inspection tools are necessary to accelerate the semiconductor industry. Despite the great efforts in this field, realizing a technique to probe the junction depth and carrier dynamics at the PN junction inside wafers remains challenging. Herein, we propose a new approach to access PN junctions embedded in wafers using terahertz (THz) emission spectroscopy. THz emission measurements and simulations demonstrate that the amplitude and polarity of THz emissions reflect the junction depth and carrier dynamics at the PN junctions. It allows us to evaluate the junction depth non-destructively with nanometer-scale accuracy, surpassing the limits of traditional techniques. Laser-induced THz emission spectroscopy is a promising method for the sensitive and non-contact/non-destructive evaluation of Si wafers and will benefit the modern semiconductor industry.

DOI: 10.1038/s41377-025-01911-0

Source: https://www.nature.com/articles/s41377-025-01911-0