Extracting signals in crosstalk environments through Laser Perturbation Probing
Extracting signals in crosstalk environments through Laser Perturbation Probing
Monday, October 5, 2026: 10:50 AM
Summary:
Laser probing enables detection of transistor-level activity by focusing infrared lasers through the silicon substrate. Although widely used for fault isolation and post-silicon debug, the technique is fundamentally limited by optical resolution. At sub 10 nm technology nodes, where transistor dimensions are below 50 nm, multiple devices fall within the probe spot, resulting in significant signal crosstalk that obscures the behavior of the target transistor. We introduce Laser Perturbation Probing (LPP), a technique that leverages controlled laser stimulation to isolate a target transistor’s response from its surrounding background. By independently controlling two laser beams, one for stimulation and one for observation, LPP enables real-time detection of perturbation-induced changes along a selected signal path. This approach allows, for the first time, in situ measurement of laser effects on asynchronous downstream paths and provides an effective solution to optical resolution limitations at advanced technology nodes.
Laser probing enables detection of transistor-level activity by focusing infrared lasers through the silicon substrate. Although widely used for fault isolation and post-silicon debug, the technique is fundamentally limited by optical resolution. At sub 10 nm technology nodes, where transistor dimensions are below 50 nm, multiple devices fall within the probe spot, resulting in significant signal crosstalk that obscures the behavior of the target transistor. We introduce Laser Perturbation Probing (LPP), a technique that leverages controlled laser stimulation to isolate a target transistor’s response from its surrounding background. By independently controlling two laser beams, one for stimulation and one for observation, LPP enables real-time detection of perturbation-induced changes along a selected signal path. This approach allows, for the first time, in situ measurement of laser effects on asynchronous downstream paths and provides an effective solution to optical resolution limitations at advanced technology nodes.