Photonic Localization Techniques
Abstract Tutorial:
In the development of Integrated Circuits (ICs), after circuit design a critical phase comes when it is at first realized on Silicon. Then, the electrical test usually shows fails. As the test can only indicate input and output of the IC, an overlay of several signal paths can narrow down the critical area, but usually not identify the faulty node. For that reason, contactless fault isolation (CFI) techniques are necessary, before the physical failure analysis can identify the root cause.
This tutorial is dealing with the full spectrum of optical interaction for CFI, focusing on electroluminescent photon emission. The role of absorption will be discussed for the proper selection of the desired interaction phenomena. Based upon an inspection of the principles, the mechanisms of photon emission microscopy, laser stimulation varieties, electro-optical probing and thermography will be derived.
A special feature addresses the most important application in Integrated Circuits, the signal acquisition through chip backside with the respective spectral requirements.
After talking about the wide application range of optical interaction with electronic devices for localization of device (mal-) functions, the focus is set on crucial topics for state of the art (FinFET) chip technologies. Solutions with proper image resolution for nanoscale feature size identification - with respect to sample preparation, for signal sensitivity in low power applications and readiness for GHz regime are discussed.
Today, CFI techniques pose a severe risk to hardware security. Risk assessment and protection strategies will be a chapter in this tutorial as well.
The tutorial will include some real case studies using the tool and techniques.
Bio C. Boit:
Prof. Christian Boit retired 2018 from Chair of Semiconductor Devices Department at Technische Universitaet Berlin, Germany. His research focuses on IC failure analysis (FA) and contactless fault isolation (CFI). In recent years, he was also investigating hardware security risks introduced by CFI. Chris started at Siemens Semiconductors 1986 and participated 1990 -1993 in IBM / Siemens DRAM project East Fishkill, NY. Later, he was Director of FA at Infineon Technologies until taking the university position in 2002. Chris is an active supporter of the FA community. He was co-founder of EDFAS and General Chair of ISTFA 2002 and ESREF 2014. He is appointed Fellow of ASM in the class of 2023 and is member of German ACATECH, the National Academy of Science and Engineering.
Photonic Localization Techniques with special focus on Photon Emission (PE) was his favorite topic starting at his PhD phase when he investigated power devices and their dynamic carrier density with forward bias photon emission. In 1989, he was a pioneer of PE for IC Failure Analysis (FA) at Siemens Semiconductor, presenting his findings on PE as indicator of parasitic bipolar at 1990 IEEE IRPS.and freshly founded ESREF. At the same time, he started spectral investigations that were published in J Appl Phys. 1992. With the assignment as manager and then director of FA at Siemens / Infineon Technologies, he shifted gears with a more strategic view and research of photonic localization techniques progressing to backside access and all the necessary paradigm shifts that came with this changes. After his move to university he put an even stronger focus on photonic backside CFI techniques. He also developed a quantitatively evaluable spectral PE set up that helped understand why with lower supply voltage the PE spectrum shifts further into infra red. Another focus of his CFI oriented research was to make high resolution techniques like E beam probing operable through chip backside as well.
Chris has another –still active - research activity in assessment of CFI techniques as hardware security risk, This research also incudes protection strategies.
All the listed aspects of Chris’ experience feed the tutorial.