John D. Sylvestri

On-chip power supply noise measurement using Time Resolved Emission (TRE) waveforms of Light Emission from Off-State Leakage Current (LEOSLC)

In this paper, a new emission-based method for measuring the amplitude of on-chip power supply noise is presented. This technique uses Time Resolved Emission (TRE) waveforms of Light Emission from Off-State Leakage Current (LEOSLC) from CMOS gates, which are used as local probe points for the noise. In order to demonstrate the capabilities of this technique, we discuss the results obtained for two early microprocessor chips fabricated in 65 nm and 45 nm Silicon On Insulator (SOI) technologies.

Revealing SRAM memory content using spontaneous photon emission

This paper presents a novel methodology that allows one to reveal SRAM memory content by observing the spontaneous photon emission collected from the backside of the chip. This method is based on our proposed tester-based optical methodology [1] that combines different test patterns, time-integrated and time-resolved emission measurements to localize gates, detect logic states, and identify functional block activity inside a chip in a non-invasive fashion. In this paper, the capability of the technique is demonstrated using a 64 Mb SRAM test chip fabricated in 14 nm SOI technology node. This technique has useful applications for chip debugging, reverse engineering, hardware and software security applications.

Angular spectrum tailoring in solid immersion microscopy

We present a technique that involves tailoring the angular spectrum in optical microscopy of silicon integrated circuits, with a solid immersion lens. Spatial light modulation to select only supercritical light at the substrate/dielectric interface, yields only evanescent and scattered light in the interconnect layers. We demonstrated the technique in optical excitation microscopy of 65nm silicon-on-insulator circuits, which enabled localization of a fault during microprocessor development. Acquiring images with and without angular spectrum tailoring allowed longitudinal localization of the electrical response to optical excitation. Lateral registration of electrical response and confocal reflection images to the circuit layout was also significantly improved.