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Resonant Distance Spectroscopic Scanning Probe Microscopy

      State-of-the-art scanning probe microscopy (SPM) systems, including microwave impedance microscopy (MIM) and near-field scanning microscopy (NSOM), typically operate in a dynamic, non-contact “tapping” mode. Lock-in detection at the probe cantilever’s resonant mechanical oscillation frequency mitigates effects of drift and achieves high measurement sensitivity of local material characteristics. Electrical, mechanical, or other material properties can be measured down to the nanoscale. However, a full time-domain tip-sample response would yield a much richer data set. Unfortunately, existing methodologies require moving the entire scan head to sweep the tip-sample separation at rates far below the resonant frequency of the cantilever or tuning fork—yielding slow scan speeds and outputs vulnerable to drift, 1/f noise, and stray coupling.       To overcome these challenges, UC Berkeley researchers have leveraged high-speed data acquisition, wideband detection electronics, and modern real-time computing to acquire hyperspectral datasets at twice the mechanical resonant frequency of the probe. The invention captures up to hundreds of thousands of curves per second, without sacrificing scan speed, resolution, or stability. It can be straightforwardly integrated on most commercial SPM platforms, and for a wide range of resonantly driven probes, including cantilevers, quartz tuning forks, and qPlus sensor. Among other benefits, the technique enables novel post-processing capabilities, including retrospective enhancement of spatial resolution.

Nonlinear Microwave Impedance Microscopy

      Microwave impedance microscopy (MIM) is an emerging scanning probe technique that enables non-contact, nanoscale measurement of local complex permittivity. By integrating an ultrasensitive, phase-resolved microwave sensor with a near-field probe, MIM has made significant contributions to diverse fundamental and applied fields. These include strongly correlated and topological materials, two-dimensional and biological systems, as well as semiconductor, acoustic, and MEMS devices. Concurrently, notable progress has been made in refining the MIM technique itself and broadening its capabilities. However, existing literature has focused exclusively on linear MIM based on homodyne architectures, where reflected or transmitted microwave is demodulated and detected at the incident frequency. As such, linear MIM lacks the ability to probe local electrical nonlinearity, which is widely present, for example, in dielectrics, semiconductors, and superconductors. Elucidating such nonlinearity with nanoscale spatial resolution would provide critical insights into semiconductor processing and diagnostics as well as fundamental phenomena like local symmetry breaking and phase separation.       To address this shortcoming, UC Berkeley researchers have introduced a novel methodology and apparatus for performing multi-harmonic MIM to locally probe electrical nonlinearities at the nanoscale. The technique achieves unprecedented spatial and spectral resolution in characterizing complex materials. It encompasses both hardware configurations enabling multi-harmonic data acquisition and the theoretical and calibration protocols to transform raw signals into accurate measures of intrinsic nonlinear permittivity and conductivity. The advance extends existing linear MIM into the nonlinear domain, providing a powerful, versatile, and minimally invasive tool for semiconductor diagnostics, materials research, and device development.

Intelligent Predictive Maintenance System for Manufacturing Machines

An innovative system designed to enhance manufacturing efficiency through predictive maintenance using machine learning.

Fast Electromigration Analysis For Multi-Segment Interconnects Using Hierarchical Physics-Informed Neural Network

Prof. Sheldon Tan and his team have developed a new hierarchical learning-based electro-migration analysis method called HierPINN-EM to solve for multi-segment interconnects in VLSI chips. HierPINN-EM provides much better accuracy, faster training speeds and faster inference speeds compared to current state-of-the-art techniques. 

Light-Driven Ultrafast Electric Gating

The inventors have discovered a new way to generate ultrafast back-gating, by leveraging the surface band bending inherent to many semiconductor materials. This new architecture consists of a standard bulk semiconductor material and a layered material on the surface. Optical pulses generate picosecond time-varying electric fields on the surface material. The inventors have successfully applied this method to a quantum well Rashba system, as this is considered today one of the most promising candidates for spin-based devices, such as the Datta Das spin-transistor. The technology can induce an ultrafast gate and drive time-dependent Rashba and quantum well dynamics never observed before, with switching faster than 10GHz. This approach minimizes lithography and will enable light-driven electronic and spintronics devices such as transistors, spin-transistors, and photo-controlled Rashba circuitry. This method can be applied with minimal effort to any two-dimensional material, for both exfoliated and molecular beam epitaxy grown samples. Electric field gating is one of the most fundamental tuning knobs for all modern solid-state technology, and is the foundation for many solid-state devices such as transistors. Current methods for in-situ back-gated devices are difficult to fabricate, introduce unwanted contaminants, and are unsuited for picosecond time-resolved electric field studies.  

High External-Efficiency Nanofocusing for Lens-Free Near-Field Optical Microscopy

Profs. Ruoxue Yan, Ming Liu, and their colleagues from the University of California, Riverside have developed a two-step sequential broadband nanofocusing technique with an external nanofocusing efficiency of ~50% over nearly all the visible range on a fibre-coupled nanowire scanning probe. By integrating this with a basic portable scanning tunneling microscope, the technology captured images with spatial resolution as low as one nanometer at high resolution. The high performance and vast versatility offered by this fibre-based nanofocusing technique allows for the easy incorporation of nano-optical microscopy into various existing measurement platforms.  Fig. 1: High-resolution NSOM mapping. a, scanning tunnelling microscope topographic image of single wall carbon nanotubes on a gold film. Top inset: cross-sectional profile along the dashed line. Bottom inset: the possible configurations of the bundle.  

Techniques for Creation and Insertion of Test Points for Malicious Circuitry Detection

Researchers led by Dr. Potkonjak from the UCLA Department of Computer Science have developed a technique to detect hardware Trojans in integrated circuits.

Plasma Opening Switch

UCLA researchers in the Department of Physics have developed a plasma opening switch that enables quick diversion of multi-gigawatt pulses to a protective shunt circuit.

In-Situ TEM Holder With STM Probe And Optical Fiber

Researchers at UCI have developed a fully integrated sample mount for the simultaneous high-resolution imaging and electronic and optical characterization of thin film devices.

Crystal Laser Wakefield Accelerator and Its Applications

The technology is a development of a more efficient particle accelerator in terms of energy, cost and space considerations. It is used in particle acceleration applications (cancer treatment, manufacture of components for electronic devices, etc.) The technology is an ultra-compact particle accelerator and particle source. The properties include: Laser Wakefield Accelerator in a solid medium, i.e. crystal in which the Laser Wakefield by charged particle beam bunch. The driver is a high intensity pulsed x-ray. The technology applicable to electron, proton, and ion acceleration and can be used for ultra-compact particle source (neutrons, muons, and neutrinos)

Referenceless Clock Recovery Circuit with Wide Frequency Acquisition Range

The technology is a circuit that recovers a full-rate clock signal from a random digital data signal. Properties include: achieves frequency and phase locking in a single loop and a wide acquisition range.

Superhydrophobic Induced High Numerical Plastic Lenses

The application of novel manufacturing techniques, chemical modifications and alternative materials produces the next generation of lenses. These lenses are inexpensive, contain improved numerical aperture and can be easily manufactured. Overall, these improvements create new applications for miniaturized optical and optical electronic devices.

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