Fabrication, Testing and Validation Capabilities

The MESAFab complex develops and maintains core semiconductor processing capabilities and capacity that enable our customers to build differentiating Microsystems products

Custom Solutions

MESA

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Sandia’s primary mission is ensuring the U.S. nuclear arsenal is safe, secure, reliable, and can fully support the Nation’s deterrence policy. Employing only the most advanced and failsafe technologies to fulfill our responsibilities as stewards of the nuclear stockpile, Sandia is responsible for the development, design and maintenance of approximately 90 percent of the several thousand parts found in any given weapon system, including radiation-hardened microelectronics. In support of this mission, Sandia National Laboratories has a significant role in advancing the “state-of-the-art” in microsystems research and development and in introducing microsystems into the nuclear stockpile. Microsystems incorporate radiation-hardened microelectronics as well as other advanced components such as micromachines, optoelectronics, and photonic systems. The MESA Complex is designed to integrate the numerous scientific disciplines necessary to produce functional, robust, integrated microsystems and represents the center of Sandia’s investment in microsystems research, development, and prototyping activities. This suite of facilities encompasses approximately 400,000 square feet and includes cleanroom facilities, laboratories and offices.

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In support of its primary mission as steward of the U.S. nuclear stockpile, Sandia has developed and delivered microelectronic products for over three decades. This expertise has also been applied to other national security needs. These include ensuring the nonproliferation of nuclear weapons and materials, reducing the threat from chemical and biological weapons, and providing advanced custom designs for other agencies involved in national defense. Sandia’s Application-Specific Integrated Circuit (ASIC) development team provides custom microelectronic products and engineering services that fulfill the needs of a diverse set of customers.

III-V Compound Semiconductor Fabrication


Sandia provides custom compound semiconductor microelectronics solutions. These include surface-normal and guided-wave optoelectronics, optical and microwave microelectromechanical devices and systems, compound semiconductor epitaxy, and rad-hard and high-power density microelectronics. Examples of device and circuit technologies we have researched, developed and delivered include:

• A wide variety of specialty semiconductor lasers
• Integrated VCSEL-RCPD circuits (vertical-cavity surface-emitting lasers, resonant-cavity photodiodes)
• Photonic integrated circuits (GaAs, InP)
• Planar lightwave circuits (SiON materials set) such as various optical guided-wave filters and switches
• Optical data links
• Micromirror arrays and subsystems for switch matrices and adaptive optics
• Radio-frequency switches and networks that include phase shifters and tunable filters
• Power amplifiers
• Low-noise amplifiers
• Rad-hard heterojunction bipolar transistors
• High-electron mobility transistors

(1) Amplifiers
(2) Heterojunction Bipolar Transistor (HBT)
(3) Optoelectronics/VCSELs

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Sandia National Laboratories’ Metal Micromachining Program specializes in the fabrication of small innovative devices. Its technologies have been applied to diverse fields including quantum computing, photovoltaics, kilohertz waveguide development, nuclear magnetic resonance imaging, and phase contrast imaging. With expertise in the fabrication of thick, high aspect ratio uniform metal and metal alloy structures too small for traditional machining, the Program maintains a suite of tools and capabilities that transform big ideas into little devices.

For more information: Metal Micromachining Program

MesaFab

The SiFab has 34,500 square feet of clean room space and state-of-the-art equipment for processing wafers up to 6 inches in diameter. Class 1 clean room processing (less than 1 particle 0.5 micron or larger per cubic foot of air) is available in bays totaling over 12,000 square feet of space.

The flexible layout also allows the SiFab engineers to work efficiently on many projects that require some degree of isolation, such as benchmarking of advanced process tools, development of state-of-the-art micromachining techniques, and research into materials science and surface chemistries for advanced silicon technology development.

The SiFab’s professional staff includes a core of Ph.D. and Master’s level engineers and scientists experienced in a broad range of disciplines including microelectronic and micromachining process development, equipment design, materials engineering, device physics, chemical engineering, sensor science, circuit design, computer science, failure analysis, reliability physics, and industrial hygiene.

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Packaging

Packaging and assembly involves interconnecting ICs and/or other components to a plastic or ceramic substrate, and subsequently integrating that package into a system. Over the span of four decades, the Microsystems Integration Department has developed core competencies in microsystems packaging and assembly. Strategic partnerships within Sandia, and with national laboratories, universities, commercial packaging houses, and private industry enable the development and implementation advanced microsystems packaging solutions with the greatest value to our customers.

Packaging Technologies:

• Hermetic ceramic and plastic high reliability packaging (all standard configurations)
• RF and optoelectronics packaging
• MEMS packaging
• Flex and surface mount assembly
• Rapid hybrid microsystems prototyping
• Ultra-miniaturization (3-D packaging and 3-D Integration)

Testing and Assurance

The Microsystems Integration and Failure Analysis departments collaborate closely to qualify and test products to evaluate performance and reliability.

Capabilities include:

Silicon Photonics Fabrication

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Sandia’s Silicon Photonics devices are fabricated in the SiFab at Sandia’s Microsystems and Engineering Sciences Applications (MESA) Complex, leveraging our production equipment and capabilities for radiation-hardened CMOS integrated circuits. We have developed a Silicon Photonics Design Manual that allows designers to create photonic prototypes.

In 2014, we successfully completed our first multi-user project wafer in collaboration with NSF funded Center for Integrated Access Networks (CIAN) where 5 university groups submitted designs and received working devices.

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Validation

Sandia’s experienced in-house Test Engineering group develops custom test programs for electrical test of digital, analog and mixed signal semiconductor devices. The group performs semiconductor wafer-level electrical testing of individual dice, as well as packaged part electrical testing across the full specified temperature range. The group performs prototype, characterization and production testing of custom ASIC devices and commercial off-the-shelf devices (COTs).

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(left)EG4090u+: Wafer Prober capable of handling 6” and 8” semiconductor wafers; interfaces to Automated Test Equipment (ATE) for electrical testing.

(right)Temptronic Thermostream: Provides capability to test devices across the full Military Standard temperature range.

Digital Automated Test Equipment

  • EXA3000
    • 496 Digital Channels
    • 8 LVDS Pairs
    • 300MHz Maximum Frequency
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Mixed Signal Automated Test Equipment

  • Teradyne Catalyst
    • 384 Digital Channels
    • 400MHz Maximum Frequency
    • Analog Source and Capture Instrumentation
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  • Advantest V93K
    • 512 PS800 Digital Channels
    • 200MHz (<=3V) 400MHz (<=1V) Maximum Frequencies
    • 96 PS3600 Digital Channels
    • 1.6GHz Maximum Frequency
    • Analog Source and Capture Instrumentation
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Burn-in


Burn-in is a process where semiconductor components are exercised prior to being placed into service. This method of testing forces certain failures to occur under known environments and test conditions. The intention is to detect components that would exhibit a high failure rate and ensure they are not put into service. Understanding the performance capabilities of the semiconductor components enables engineers to optimize functionality during service.

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Typical bath-tub curve depicting early or “infant mortality” failures followed by the constant or “random” failures, then the increasing wear out failures over time.

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At Sandia, burn in ovens used to electrically test packaged devices at elevated temperatures. Three MCC HPB5 ovens and a pre-screen station are used for Diagnostics and burn in.

Reliability

Ultra-high reliability is critical for CMOS7 technology and other NW parts. It is achievable only through tight manufacturing quality control, circuit design that ensures margins for component aging, and effective linking of failure detection under stress with root cause analysis and implementation of corrective actions. The concern is that ICs may pass the final acceptance tests but lack enough margins for aging-induced degradation. Degradation can be caused by gate oxide failure, hot carrier degradation, electromigration, negative bias temperature instabilities, corrosion, or stress-induced voiding. Several strategies are pursued to ensure that such margin is allowed for and that “life” tests are performed to prove reliability throughout the expected life of a part.

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The figures above show electromigration and stress induced voids in the metallization under passivation. The stress induced voids occurred after the part was stored at 250C for 5000 hours.

Failure Analysis

– A failing to do or perform
– Examination of a thing to determine its parts or elements

Failure Analysis is a diagnostic process for determining the root cause of failure.

At Sandia, we have experts who invent, develop and utilize different tools and techniques for root cause failure analysis. Our expertise is in Silicon CMOS, III-V Compound Semiconductors, MEMS, Photovoltaics and Optoelectronics. We support our customers through the product life cycle. A basic FA process flow through the product life cycle is shown below:

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Role of FA:

In product design and development, failure analysis assists with design debug to examine non-functioning or partially functioning devices. This effort requires close teaming with designers to expedite development times and bring the product to market more quickly.

Failure analysis of test structures & full product from yield failures during the semiconductor manufacturing process provides critical insight into manufacturing problems. Successful analysis and feedback leads to rapid yield ramping and improvements in the process flow. Requires close teaming with process engineers.

During qualification and reliability evaluation, failure analysis provides critical information on how the device failed during those operating conditions. Requires close teaming with product and reliability engineers.

Failure analysis of customer returns is critical to keeping consumer confidence in your product and company high. Failures are typically one of a kind requiring special handling so mistakes are not acceptable.

Failure Classification

Failures are classified as either hard, soft or intermittent fails.

Hard failures are those that are damaged or exhibit a significant loss of functionality.
• Shorts, opens and some semiconductor defects

Soft failures are failures that occur under certain environmental or operating conditions but not all operating conditions
• Temperature, voltage or frequency dependent failures

Intermittent failures occur under seemingly random conditions and are difficult to reproduce under the same operating conditions

Many tools and techniques used by Sandia for root cause failure analysis are listed below:

Failure analysis of semiconductor devices requires inspection and stimulation. Optical microscopy techniques are one tool used to visually inspect semiconductor devices at the system, sub-system, package, die or wafer level. Optical techniques such as bright field, dark field or Nomarski are used to provide information on structural anomalies, contamination and other features of a device.

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Bright field optical image of a depcapsulated IC exposing the die and wire bonds

Nomarski optical images of cracks in the passivation on the surface of an IC

Dark-field image

Light Emission (LE): failure analysis capability used to detect and localize photon emitting defects in semiconductor devices. Normal operating devices also produce light under certain conditions, defects such as hot carrier production, gate oxide shorts, saturated transistors, leaky junctions, latch-up, snap-back etc. can emit light. LE can be applied at wafer, package or board level.

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Light emission system mounted in a probe station for die, package or board level FA.

LE indicates general location of possibledefect. Scattering from upper metal layers prevents precise localization

High current in a microcontroller emitting light at multiple sites

Electrical characterization techniques are employed to determine the electrical properties and/or behavior of a device to diagnose internal fault locations. Often used in failure validation/verification. External chip data such as scan-based diagnostics, fault dictionaries, schmoo plots, IDDQ versus pattern, timing, voltage, temp, and memory bit-fail maps are a few tools available for failure verification. Other less complicated techniques such as curve tracing, I-V and C-V profiling, 2 and 4 point probing can be used to determine resistivity, carrier concentration, mobility, contact resistance, depletion width and more.

At Sandia, many tools are used to electrically stimulate or measure the response of a semiconductor device for root cause failure analysis. Equipment such as parametric analyzers, waveform generators, curve tracers, automated test equipment, etc., have been used for root cause failure analysis.

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I-V curve showing n-channel MOSFET output is much larger than p-channel output

Electrical test data showing transistor I-V curves changing with applied bias

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Power supplies and semiconductor parametric analyzer used to bias and measure the output from a probed device

Teseda test system with oscilloscope analyzing a device subjected to a subset of test vectors

Failure analysis techniques performed using a Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) or Focused Ion Beam (FIB) use signals generated from an electron or ion beam source to produce an image. These signals such as secondary or backscattered electrons and characteristic x-rays are used to examine the structure or electrical activity of a device. Tools and techniques employed at Sandia include:

Failure analysis techniques performed using a Infrared Thermography/Thermal Imaging or Lock-In Thermography use heat or thermal signals generated from a device during operation. Small leakage currents typically cause elevated temperature during operation of a device. A special camera is used to detect signals generated in the near-infrared to infrared range. Tools and techniques employed at Sandia include:

Deprocessing

Many failure analysis techniques require direct access to the device or deprocessing for defect localization. At Sandia, we use a variety of techniques to gain access to a device. Some deprocessing capabilities used in FA include:

  • Sawing – for component removal from boards, etc.
  • Polishing
  • Jet etching – locally removing plastic from a package while keeping the device functional
  • Chemical etching
  • Staining – use of acids and bases to delineate defects in materials
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Polishing tool used for package and die level deprocessing

Jet etch tool for plastic package decapsulation

Decapsulated package exposing the die

Fact Sheets, Publications, References, Animations, Licensing IP Opportunities

Failure Analysis Publications and Patents