Open Failure Localization by Using MOFM—Magneto-Optical Frequency Mapping System with 532 nm Light Source

2017 ◽  
Author(s):  
Tomonori Nakamura ◽  
Akihiro Otaka
Keyword(s):  
Magnetic Field ◽  
Light Source ◽  
Quantum Interference ◽  
Modulation Frequency ◽  
Optical Frequency ◽  
Weak Current ◽  
Magnetic Current ◽  
Current Path ◽  
Ac Current ◽  
The Magnetic Field

Abstract Magnetic current imaging (MCI) is an effective method for the isolation of individual integrated circuit (IC) current paths [1]. MCI is therefore useful in localizing open/short defects. In the case of a short, the failure current must be large enough to enable the detection of the magnetic field; however, in the case of the open failure, the current is very weak and detection can be limited by the wiring capacitance and modulation frequency. Often, magnetic sensor sensitivity is a function of the sensor size. Superconducting Quantum Interference Device (SQUID) sensors can detect weak current in an open failure, but the resolution is limited by the sensor size and can be difficult to utilize for IC applications. A Giant Magnetic Resistance (GMR) sensor has enough resolution [2], but cannot achieve enough sensitivity till now. This paper will present the use of Magneto-Optical Frequency Mapping (MOFM) using a 532nm light source. In addition, this paper will describe a specific IC application for an open failure measurement. For this technique, the MO crystal (sensor material) is placed directly on the DUT (a wiring test sample). This paper will demonstrate that the magnetic field modulation from AC current in open wirings can be detected. In addition, the details of the AC current path can be visualized using a Magneto-Optical based MCI measurement. Finally, the open point in the failing circuit will be shown to be isolated with an accuracy of a few tens of micrometers.

Magnetic Field Imaging for 3D applications

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001937-001965
Author(s):  
Jan Gaudestad ◽  
Antonio Orozco
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Quantum Interference ◽  
Device Fabrication ◽  
Fault Isolation ◽  
Current Path ◽  
Magnetic Field Imaging ◽  
The Magnetic Field ◽  
Field Imaging ◽  
A Current

The challenges that 3D integration present to Failure Analysis require the development of new Fault Isolation techniques that allows for non-destructive, true 3D failure localization. By injecting a current in the device under test (DUT), the current generates a magnetic field around it and this magnetic field is detected by a sensor above the device. Magnetic field imaging (MFI) is a natural candidate for 3D Fault Isolation of complex 3D interconnected devices. This is because the magnetic field generated by the currents in the DUT passes unaffected through all materials used in device fabrication; the presence of multiple metal layers, dies or other opaque layers do not have any impact on the magnetic field signal. The limitations of the technique are not affected by the number of layers in the stacked devise in samples such as wirebonded stacked memory, Through Silicon Via (TSV) stacked die or even package on package (PoP). The sample is raster scanned and magnetic field is acquired at determined steps providing a magnetic image of the field distribution. This magnetic field data is typically processed using a standard inversion technique to obtain a current density map of the device. The resulting current map can then be compared to a circuit diagram, an optical or infrared image, or a non-failing part to determine the fault location. Today, giant-magnetoresistive (GMR) sensors have been added to the Superconducting Quantum Interference Device (SQUID) sensor to allow higher resolution and Fault Isolation (FI) I at die level. Magnetic Field Imaging (MFI), using SQUID as the high sensitive magnetic sensor in combination with a high resolution GMR sensor. A solver algorithm capable of successfully reconstructing a 3D current path based on an acquired magnetic field image from both sensors has been developed. The generic 3D inverse problem has no unique solution. Given a particular 3D magnetic field distribution, there are an infinite number of current path distributions that will result in such magnetic field. This ill-posed problem has restricted, so far, the use of magnetic imaging to 2D. A different kind of 3D solver can be constructed, nevertheless capable of obtaining a single solution. The 3D solver algorithm is not only capable of extracting the 3D current path, but it also provides valuable geometrical information about the device. Accurately being able to position each current segment in a layer allows the FA engineer to follow the current as it vertically moves from one die (or layer) to another. [1,2,3]

Magnetic Field Imaging on Stacked Flash Memories by Laser Probing and SQUID Scanning

2017 ◽  
Author(s):  
K. Sanchez ◽  
G. Bascoul ◽  
F. Infante ◽  
N. Courjault ◽  
T. Nakamura
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Two Dimensions ◽  
Analysis Tool ◽  
Active Device ◽  
Current Path ◽  
3D Packaging ◽  
Magnetic Field Imaging ◽  
The Magnetic Field ◽  
Field Imaging

Abstract Magnetic field imaging is a well-known technique which gives the possibility to study the internal activity of electronic components in a contactless and non-invasive way. Additional data processing can convert the magnetic field image into a current path and give the possibility to identify current flow anomalies in electronic devices. This technique can be applied at board level or device level and is particularly suitable for the failure analysis of complex packages (stacked device & 3D packaging). This approach can be combined with thermal imaging, X-ray observation and other failure analysis tool. This paper will present two different techniques which give the possibility to measure the magnetic field in two dimensions over an active device. Same device and same level of current is used for the two techniques to give the possibility to compare the performance.

Low Frequency Measurements in Amorphous Wire for Studying GMI Effect

2011 ◽  
Vol 495 ◽  
pp. 201-204
Author(s):  
Polykseni Vourna
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Major Change ◽  
Wheatstone Bridge ◽  
Amorphous Wire ◽  
Dc Voltage ◽  
Gmi Effect ◽  
Offset Voltage ◽  
Ac Current ◽  
The Magnetic Field

When a soft ferromagnetic material is flown by an ac current and a magnetic field is applied at the same time, a major change of its impedance is occurred. The aim of this paper is to investigate the influence of low frequency (1KHz-12KHz) ac current and the applied magnetic field on an amorphous magnetic wire (Co68Fe4.35Si12.5B15) without glass coating. For this purpose an experimental configuration has been setup, based on a Wheatstone bridge which receives an ac input signal from a frequency generator. The output is connected to the amorphous wire wrapped with a coil supplied by a dc voltage for the generation of the magnetic field. The output voltage pulse is measured for two cases a) The value of ac frequency is changing while the value of dc voltage applied to the coil remains constant (the magnetic field remains unchanged) and b) the magnetic field is changing while the ac frequency remains constant to a predefined value. Experimental results of the first scenario showed that when the frequency is altered a non-linear increase of the ac signal is observed at the output which shows an increase of the GMI effect and is related to the non-linearity of the wire’s permeability. For the second scenario the results showed an increase of the output signal offset (voltage) which also indicates an increase of the GMI effect.

scholarly journals Horocycles of Light in a Ferrocell

2021 ◽  
Vol 6 (3) ◽  
pp. 30
Author(s):  
Alberto Tufaile ◽  
Michael Snyder ◽  
Adriana Pedrosa Biscaia Tufaile
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
External Magnetic Field ◽  
Light Source ◽  
Geometrical Theory ◽  
Thin Structures ◽  
Point Light Source ◽  
Geometrical Theory Of Diffraction ◽  
Point Light ◽  
The Magnetic Field

We studied the effects of image formation in a device known as Ferrocell, which consists of a thin film of a ferrofluid solution between two glass plates subjected to an external magnetic field in the presence of a light source. Following suggestions found in the literature, we compared the Ferrocell light scattering for some magnetic field configurations with the conical scattering of light by thin structures found in foams known as Plateau borders, and we discuss this type of scattering with the concept of diffracted rays from the Geometrical Theory of Diffraction. For certain magnetic field configurations, a Ferrocell with a point light source creates images of circles, parabolas, and hyperboles. We interpret the Ferrocell images as analogous to a Möbius transformation by inversion of the magnetic field. The formation of circles through this transformation is known as horocycles, which can be observed directly in the Ferrocell plane.

Localization of Dead Open in a Solder Bump by Space Domain Reflectometry

2012 ◽  
Author(s):  
David P. Vallett ◽  
Daniel A. Bader ◽  
Vladimir V. Talanov ◽  
Jan Gaudestad ◽  
Nicolas Gagliolo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Quantum Interference ◽  
Flip Chip ◽  
Solder Bump ◽  
Frequency Range ◽  
Superconducting Quantum Interference Device ◽  
Space Domain ◽  
Non Destructive ◽  
The Magnetic Field

Abstract Space Domain Reflectometry (SDR) is a newly developed non-destructive failure analysis (FA) technique for localizing open defects in both packages and dies through mapping in space domain the magnetic field produced by a radio frequency (RF) current induced in the sample, herein the name Space Domain Reflectometry. The technique employs a scanning superconducting quantum interference device (SQUID) RF microscope operating over a frequency range from 60 to 200 MHz. In this paper we demonstrate that SDR is capable of locating defective micro bumps in a flip-chip device.

Magnetic Current Imaging of a TSV short in a 3D IC

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001408-001428
Author(s):  
Jan Gaudestad ◽  
Antonio Orozco
Keyword(s):  
Quantum Interference ◽  
Semiconductor Industry ◽  
Fault Isolation ◽  
Magnetic Current ◽  
Current Path ◽  
Fine Pitch ◽  
Dual Beam ◽  
Gmr Sensor ◽  
Test Chips ◽  
Chip Chip

In this paper we show Magnetic Field Imaging (MFI) is the best method for Electric Fault Isolation (EFI) of short failures in 2.5/3D Through Silicon Via (TSV) devices in a true non-destructive way by imaging the current path. To confirm the failing locations and to do Physical Failure Analysis (PFA), a Dual Beam-Plasma FIB (DB-PFIB) system was used for cross sectioning and volume analysis of the TSV structures and high resolution imaging of the identified defects. Magnetic Current Imaging (MCI) is a sub technique of MFI which has been used by the semiconductor industry for more than a decade to find electrical shorts and leakage paths and which has the capability to “look through” all materials typically used in the semiconductor industry, allowing global imaging without the need for physical de-processing [1, 2, 3]. MCI utilizes two types of sensors: a Superconducting Quantum Interference Device (SQUID) sensor for low current and large working distances and a Giant Magneto Resistance (GMR) sensor for sub micron resolution current imaging at wafer/die level [3]. The sample investigated in this work is a triple-layer stack, in which 2 layers of 50 μm thick test chip (Chip 1 and Chip 2 in Figure 1) were assembled on a 200 μm thick bottom chip (Chip 0 in Figure 1). The test chips were manufactured by imec's standard 65 nm CMOS Back End of Line (BEOL) process, 5×50 μm via-middle TSV technology [4], and fine pitch micro bumping process [6]. Further details of the test vehicle and assembly process can be found elsewhere [5]. The sample had a short between daisy chain a1 and a2, which were supposed to be electrically separated. The probe tests that was used for this experiment is shown in Table 1. The signal was injected into the respective daisy chains by probing V+ to V− on the bottom chip. To send a signal between daisy chain a1 and a2 one could probe V− to V− and V+ to V+. The MCI scans were done using the GMR sensor only. The sample was attached to a vacuum chuck and raster scanned. From Fig. 2 one can see that the current enters the top layer (Chip 2) at TSV 18 and goes back down again to Chip 1 at TSV 28. Since the sample clearly has multiple shorts, the short located at TSV pair 23 was chosen for PFA using the PFIB. A short is found between the 2 BEOL layers of Chip 1, causing the current to leak into Chip 2 (Fig. 3).

Magnetic Sensors for Space Applications

2018 ◽  
pp. 248-283 ◽  
Author(s):  
Neoclis Hadjigergiou ◽  
Marios Sophocleous ◽  
Evangelos Hristoforou ◽  
Paul Peter Sotiriadis
Keyword(s):  
Magnetic Field ◽  
Quantum Interference ◽  
Measurement Techniques ◽  
General Information ◽  
Magnetic Sensors ◽  
Normal Operation ◽  
Space Applications ◽  
Flux Gate ◽  
Magneto Resistance ◽  
The Magnetic Field

This chapter is composed of three parts. The first is an introductory part, providing general information about magnetism and related phenomena. Magnetic materials are also discussed and presented. Afterwards, the magnetic field and various measurement techniques are discussed. In the second part, different magnetic sensors used in a laboratory or space are presented. Magnetic sensors that are discussed include anisotropic magneto-resistance (AMR), giant magneto-resistance (GMR), giant magneto-impedance (GMI), flux-gate and superconducting quantum interference device (SQUID). Although some of them may be outdated and well known, they are widespread and they still pose an excellent choice for certain applications. Magnetic cleanliness is an important factor both in calibration and in normal operation of a system; in the third part, current techniques to isolate a system from the external magnetic field providing cleanliness are discussed.

EFFECTS OF THE WIGGLER ON THE HEFEI LIGHT SOURCE STORAGE RING

2009 ◽  
Vol 24 (05) ◽  
pp. 1057-1067
Author(s):  
HE ZHANG ◽  
MARTIN BERZ
Keyword(s):  
Magnetic Field ◽  
Light Source ◽  
Storage Ring ◽  
Field Model ◽  
Beta Function ◽  
Nonlinear Effects ◽  
Magnetic Field Model ◽  
Dynamic Aperture ◽  
Linear Effects ◽  
The Magnetic Field

The Hefei light source (HLS) is a second generation synchrotron radiation light source, in which a superconducting wiggler is installed and operating. The effects of the wiggler on the beam dynamics on the HLS storage ring are studied, in order to make sure the wiggler can operate properly when the ring is working in the high brilliance mode. We generate a model of the magnetic field in the midplane of the wiggler. The 3D magnetic field model is also builded up by COSY infinity 9.0. Both the linear and nonlinear effects of the wiggler are discussed. The vertical tune is changed from 2.535 to 2.567 and the vertical beta function is heavily distorted, while a symplectic tracking study shows the dynamic aperture is only slightly affected by the wiggler. And the wiggler should be able to run on the high brilliance mode after the linear effects get compensated.

Study of Magnetic Field Distribution of Carbon Nanotubes Resulting from Current Pass by Magnetic Force Microscopy

2011 ◽  
Vol 403-408 ◽  
pp. 1103-1105
Author(s):  
Haleh Kangarloo ◽  
Mehrdad Teymurzadeh ◽  
Saeid Rafizadeh
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Field Distribution ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Magnetic Field Distribution ◽  
Force Microscopy ◽  
Current Path ◽  
Background Magnetic Field ◽  
The Magnetic Field

Recently carbon nanotubes (CNTs) are reported to be able to generate large magnetic field because of their nanometer-size-diameter[2]. The magnetic fields around CNTs current path are investigated by magnetic force microscopy (MFM). Under the consideration of the magnetic properties of magnetically coated tip of MFM, tip heights, current directions, and background magnetic field, etc., the magnetic field distribution are analyzed. The distribution of the magnetic field generated by the CNTs current is found to be asymmetric, and its distribution anomaly is found to be a kind of hysteresis effect of the MFM cantilever materials.

scholarly journals Vector Magnetic Current Imaging of an 8 nm Process Node Chip and 3D Current Distributions Using the Quantum Diamond Microscope

2021 ◽  
Author(s):  
Sean M. Oliver ◽  
Dmitro J. Martynowych ◽  
Matthew J. Turne ◽  
David A. Hopper ◽  
Ronald L. Walswort ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Failure Analysis ◽  
Flip Chip ◽  
Circuit Board ◽  
Depth Information ◽  
Magnetic Current ◽  
Current Distributions ◽  
Process Node ◽  
The Magnetic Field

Abstract The increasing trend for industry adoption of three-dimensional (3D) microelectronics packaging necessitates the development of new and innovative approaches to failure analysis. To that end, our team is developing a tool called the quantum diamond microscope (QDM) that leverages an ensemble of nitrogenvacancy (NV) centers in diamond for simultaneous wide fieldof- view, high spatial resolution, vector magnetic field imaging of microelectronics under ambient conditions [1,2]. Here, we present QDM measurements of two-dimensional (2D) current distributions in an 8 nm process node flip chip integrated circuit (IC) and 3D current distributions in a custom, multi-layer printed circuit board (PCB). Magnetic field emanations from the C4 bumps in the flip chip dominate the QDM measurements, but these prove to be useful for image registration and can be subtracted to resolve adjacent current traces on the micron scale in the die. Vias, an important component in 3D ICs, display only Bx and By magnetic fields due to their vertical orientation, which are challenging to detect with magnetometers that traditionally only measure the Bz component of the magnetic field (orthogonal to the IC surface). Using the multi-layer PCB, we demonstrate that the QDM's ability to simultaneously measure Bx, By, and Bz magnetic field components in 3D structures is advantageous for resolving magnetic fields from vias as current passes between layers. The height difference between two conducting layers is determined by the magnetic field images and agrees with the PCB design specifications. In our initial steps to provide further z depth information for current sources in complex 3D circuits using the QDM, we demonstrate that, due to the linear properties of Maxwell's equations, magnetic field images of individual layers can be subtracted from the magnetic field image of the total structure. This allows for isolation of signal from individual layers in the device that can be used to map embedded current paths via solution of the 2D magnetic inverse. Such an approach suggests an iterative analysis protocol that utilizes neural networks trained with images containing various classes of current sources, standoff distances, and noise integrated with prior information of ICs to subtract current sources layer by layer and provide z depth information. This initial study demonstrates the usefulness of the QDM for failure analysis and points to technical advances of this technique to come.

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