Presentation slides for the ISTFA 2024 Tutorial session “An Introduction to the FIB as a Microchip Circuit Edit Tool (2024 Update).”

Presentation slides for the ISTFA 2023 Tutorial session “An Introduction to the FIB as a Microchip Circuit Edit Tool (2023 Update).”

This presentation introduces the practice of focused ion beam (FIB) chip editing and its power and versatility as a problem-solving tool. It begins with a review of the features and functions of FIB systems, the role of gas chemistry in milling, etching, and deposition, and the use of IR imaging for navigation and targeting. It goes on to identify challenges due to packaging materials, chip-package interactions, and other factors, and in each case, provide alternate approaches and procedures to circumvent potential problems. It also covers advanced practices and methods and assesses potential future advancements.

This presentation introduces the practice of focused ion beam (FIB) chip editing and its power and versatility as a problem-solving tool. It begins with a review of the features and functions of FIB systems, the role of gas chemistry in milling, etching, and deposition, and the use of IR imaging for navigation and targeting. It goes on to identify challenges due to packaging materials, chip-package interactions, and other factors, and in each case, provide alternate approaches and procedures to circumvent potential problems. It also covers advanced practices and methods and assesses potential future advancements.

The journey to the circuit layer will be described by first discussing baseline processes of laser assisted chemical etching (LACE) steps before the focused ion beam (FIB) workflow. These LACE processes take advantage of a dual 532 nm continuous wave (CW) and pulse laser system, however limitations and overhead that is transferred over to the FIB operator will be demonstrated. Experiments show an additional third 355 nm ultraviolet (UV) pulse laser process introduction into the workflow can further reduce the remaining silicon thickness (RST) relieving FIB overhead. In addition, complex pulse laser patterning techniques will show a refinement to nonuniform produced silicon. Finally, other pulse laser patterning techniques such as polygon etch capability will allow laser etching around and in-between features to enhance circuit layer accessibility for debug operations.

The requirements for focused ion beam (FIB) systems to provide higher image resolution and machining precision continue to increase with the continuation of Moore’s Law. Due to the shrinking geometry and increasing complex structures and materials, it is ever more critical to scale the entire ion probe. The necessity for comprehensive analysis of the ion beam profile and understanding how the ion beam current distribution profile influences different aspects of nanomachining are becoming increasingly important and more challenging.

High resolution optical imaging is critical in assisting backside circuit edit (CE) and optical probing navigation. In this paper, we demonstrated improved optical image quality using VIS-NIR narrow band light emitting diode (LED) illumination in various FIB and optical probing platforms. The proof of concept was demonstrated with both common non-contact air gap lenses and solid immersion lenses (SIL).

Nanomachining capability scaling both in the areas of machining precision and novel gas chemistries are required for focused ion beam technology to keep pace with process technology advancement. In this paper, we review the nanomachining potential for the Helium Ion Microscope (HIM) and the Neon Ion Microscope (NIM). The paper also includes an in depth analysis of NIM imaging resolution, subsurface material interaction, and nanomachining performance.