Exploring the Physical Limits of Gallium-Based Focused Ion Beam Chip Circuit Editing

Abstract

This paper describes a circuit editing procedure in which the authors used a gallium column Focused Ion Beam (FIB) tool to divide a merged 32nm multi-finger planar transistor into two separate operating components. Rather than rely on live imaging or the various endpoint detection techniques commonly used during an active mill, the authors opted for a ‘blind’ dose-driven technique. The paper explains how the authors made multiple attempts on practice material in order to determine the exact beam placement location and the depth of cut required to perform the operation with a minimum of lateral damage. The loss of a pair of poly gate fingers in the middle of the multi-gate structure seemed to have minimal impact on the final electrical parameters and the separate data paths worked per design specifications.