Bringing Low-Frequency Noise into Focus

Key takeaways

• The challenge of acquiring high-quality, reproducible noise data becomes achievable with Primarius’ wafer-level low-frequency noise characterization solution, which is essential for advanced nodes.
• The Primarius 981X family raises the bar for low-frequency noise measurement metrology with its unique advantages demonstrated below, along with recent innovative solutions such as the 9812HF and 9812AC.
• Process engineers should use low-frequency noise as a key figure of merit for process quality monitoring and improvement during technology development. Design teams also require accurate low-frequency noise models to characterize devices and enable effective design optimization.

Noise, defined as any unwanted signal superimposed on an ideal one. Low-frequency noise is dominated by 1/f noise and RTN, both directly linked to crystalline defects in semiconductor materials. As semiconductor devices continue shrinking, even a single trap can cause current fluctuations. Consequently, this noise effect is emerging as a latent failure mechanism that threatens system performance.

Since the 28 nm technology node, low-frequency noise models have become a standard component of PDKs. Accurate RTN modeling not only supports circuit design and process optimization but also opens new avenues for statistical 1/f noise modeling and circuit simulation. High quality noise data is therefore a key modeling requirement.

Practical challenge VS Technical breakthrough

Accurate low-frequency noise characterization demands more than a sensitive amplifier.

You need:

• An instrument with ultra-low background noise.
• Wide impedance matching to cover different types of DUTs.
• High dynamic range to capture tiny fluctuations.
• The ability to report both time-domain RTN signatures and frequency-domain PSDs with traceable statistics.

One practical breakthrough for noise test systems is the automatic, signal-aware switching between AC and DC coupling. With Primarius’ advanced low-frequency noise filtering and amplification technologies, the 981X Series Noise Testing System achieves high speed, high precision, and stable data acquisition. This core technology elevates noise testing to a new performance tier.

9812DX: Golden standard

The Primarius 981X series Noise Testing System has been the golden standard for low frequency noise testing in the semiconductor industry for decades. It sets new records in measurement speed, system resolution, and coverage of different types of measurement requirements for flicker noise and RTN. The 9812DX, succeeding 9812D, has been adopted by leading foundries as the new golden tool for lowrequency noise testing. 9812DX stands out for its rare ability to measure both high impedance and low impedance devices with consistent accuracy.

Notable 9812DX highlights:

• Wide voltage and current range: 200V, 200mA
• Broad impedance matching range: 3 Ω to 30 MΩ
• Lots of device types: Suitable for devices such as MOSFETs, BJTs, FinFETs, LDMOS, JFETs, HBTs, Diodes, Resistors, etc.
• Hight resolution & bandwidth: 10 e-27A^2/Hz @ 20KHz
• Ready for all advanced process nodes: 7/5/3nm and more

9812HF: VHF reach

Launched as the high bandwidth extension of the 981X family, the 9812HF is designed to bridge traditional low-frequency noise analysis and higher frequency noise concerns. This extension matters for applications where noise mechanisms span large frequency ranges.

Notable 9812HF highlights:

• VHF bandwidth: Brings low-frequency noise measurement into 100 MHz range so designers can observe how low frequency mechanisms interact with the front-end up conversion and wideband circuits.
• Maintains series sensitivity: Keeps low-current sensitivity and wide impedance coverage as 9812DX while extending frequency reach—so you don’t trade sensitivity for bandwidth.
• Application fit:
  Meeting growing demands in satellite communications, automotive electronics, and other advanced applications requiring wideband noise analysis.

9812AC: Noise under realistic dynamic drive

Historically, most noise research and device qualification have focused exclusively on DC bias conditions. Yet, recent studies reveal that RTN under AC bias exhibits statistical properties distinct from DC-based measurements. While DC-based analysis provides a safe and conservative reliability estimate, it may unnecessarily constrain the circuit design space for advanced CMOS technologies.

To address this industry gap, Primarius launched the commercial grade 9812AC test system in 2023. The 9812AC enables designers to measure noise under dynamic operating conditions, delivering a comprehensive understanding of device behavior. This insight is crucial for making smarter design and verification trade-offs.

M9800: Industry parallel system

To meet wafer-level production demands for higher throughput and lower cost, M9800 system becomes a preferred choice for large-scale testing. Compared with conventional solutions, the M9800 increases overall test efficiency by 2-4×, accelerating process development for advanced technology nodes.

9812 & FS-Pro: Integration to speed up noise measurement

FS-Pro, Primarius’ all-in-one semiconductor parameter analyzer, is another flagship product in the portfolio. Compared with traditional IV meter or SMU, FS-Pro compact size and light weight (less than 8kg) makes it easier to be assembled with 9812DX as a whole system. While maintaining measurement accuracy and resolution, FS-Pro can significantly speed up DC measurement thus enable more efficient overall measurement with 9812DX.

Summary

Low-frequency noise has evolved from a niche laboratory characterization to a critical process and system-level metric in silicon development. Great low-frequency noise metrology can shorten the feedback loop between process engineers, device physicists, and circuit designers: it turns poorly quantified risk into actionable defect localization, process optimization, and realistic design margins.

The Primarius 981X family gives teams a practical, wafer-scale toolkit to measure what matters—across time, frequency and operating conditions—so they can design and qualify chips with less guesswork and more physics-backed evidence.