Electrical Failure Analysis of Speckled Shmoo and Shmoo Stripping failures
Electrical Failure Analysis of Speckled Shmoo and Shmoo Stripping failures
Thursday, November 20, 2025: 10:20 AM
1 (Pasadena Convention Center)
Summary:
The increasing complexity of System-on-Chip (SOC) Design, alongside optimized clocking architectures driven by asynchronous independent clock domains and continued device scaling, has led to a rise in failures characterized by speckles or stripes in shmoo plots. This paper explores the various root causes of different types of failing shmoo stripes and speckles, providing insight into the underlying issues behind these failures. The work outlines a range of failure causes, including data setup violations, timing violations, aggressive clock speeds, clock skews, glitch propagation, design and timing marginalities, metastable states, and cross-domain clocking issues. Additionally, it presents a case study involving a sub-10nm technology device that exhibited a speckled shmoo failure related to the Streaming Scan Network transition delay (SSN-TD) pattern, where two independent clocking domains influenced the speckled shmoo. In this paper, we explore various electrical failure analysis methodologies to identify the root cause of the speckled shmoo failure through a detailed case study. Additionally, we compare waveforms collected with a 785 nm laser to those obtained using a 1064 nm laser.
The increasing complexity of System-on-Chip (SOC) Design, alongside optimized clocking architectures driven by asynchronous independent clock domains and continued device scaling, has led to a rise in failures characterized by speckles or stripes in shmoo plots. This paper explores the various root causes of different types of failing shmoo stripes and speckles, providing insight into the underlying issues behind these failures. The work outlines a range of failure causes, including data setup violations, timing violations, aggressive clock speeds, clock skews, glitch propagation, design and timing marginalities, metastable states, and cross-domain clocking issues. Additionally, it presents a case study involving a sub-10nm technology device that exhibited a speckled shmoo failure related to the Streaming Scan Network transition delay (SSN-TD) pattern, where two independent clocking domains influenced the speckled shmoo. In this paper, we explore various electrical failure analysis methodologies to identify the root cause of the speckled shmoo failure through a detailed case study. Additionally, we compare waveforms collected with a 785 nm laser to those obtained using a 1064 nm laser.