Systematic EFA Approach in Locating Floating Nodes in Analog Mixed Signal Devices

Author(s):  
Sagar Karki

Abstract With advancements in technology, it is nearly impossible to find the defects in integrated circuits without applying appropriate failure isolation techniques. Failure isolation is a critical step in identifying the physical defect on integrated circuits. This paper addresses the challenges imposed by floating node conditions on both analog and digital circuitry, and a case study for each circuit type is presented. Different approaches along with the challenges involved in isolating each case in a very timely manner are addressed. Finally, the usefulness of global isolation tools, such as PEM (Photon Emission Microscopy), FIB (Focused Ion Beam), and micro-probing, is also discussed.

Author(s):  
Valery Ray

Abstract Gas Assisted Etching (GAE) is the enabling technology for High Aspect Ratio (HAR) circuit access via milling in Focused Ion Beam (FIB) circuit modification. Metal interconnect layers of microelectronic Integrated Circuits (ICs) are separated by Inter-Layer Dielectric (ILD) materials, therefore HAR vias are typically milled in dielectrics. Most of the etching precursor gases presently available for GAE of dielectrics on commercial FIB systems, such as XeF2, Cl2, etc., are also effective etch enhancers for either Si, or/and some of the metals used in ICs. Therefore use of these precursors for via milling in dielectrics may lead to unwanted side effects, especially in a backside circuit edit approach. Making contacts to the polysilicon lines with traditional GAE precursors could also be difficult, if not impossible. Some of these precursors have a tendency to produce isotropic vias, especially in Si. It has been proposed in the past to use fluorocarbon gases as precursors for the FIB milling of dielectrics. Preliminary experimental evaluation of Trifluoroacetic (Perfluoroacetic) Acid (TFA, CF3COOH) as a possible etching precursor for the HAR via milling in the application to FIB modification of ICs demonstrated that highly enhanced anisotropic milling of SiO2 in HAR vias is possible. A via with 9:1 aspect ratio was milled with accurate endpoint on Si and without apparent damage to the underlying Si substrate.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexey A. Polilov ◽  
Anastasia A. Makarova ◽  
Song Pang ◽  
C. Shan Xu ◽  
Harald Hess

AbstractModern morphological and structural studies are coming to a new level by incorporating the latest methods of three-dimensional electron microscopy (3D-EM). One of the key problems for the wide usage of these methods is posed by difficulties with sample preparation, since the methods work poorly with heterogeneous (consisting of tissues different in structure and in chemical composition) samples and require expensive equipment and usually much time. We have developed a simple protocol allows preparing heterogeneous biological samples suitable for 3D-EM in a laboratory that has a standard supply of equipment and reagents for electron microscopy. This protocol, combined with focused ion-beam scanning electron microscopy, makes it possible to study 3D ultrastructure of complex biological samples, e.g., whole insect heads, over their entire volume at the cellular and subcellular levels. The protocol provides new opportunities for many areas of study, including connectomics.


2000 ◽  
Vol 6 (S2) ◽  
pp. 516-517
Author(s):  
Youren Xu ◽  
Chris Schwappach ◽  
Ron Cervantes

Focused ion beam lift-out technique has become increasingly attractive to the TEM community due to its unique advantage of no mechanical grinding/polishing involved in the process [1-3]. The technique essentially consists of two parts: preparation of membrane using focused ion beam (FIB) and transfer of the membrane (lift-out) to a grid. Up to date, this technique has only been demonstrated on single beam FIB systems. From a practical standpoint, overall sample quality (thickness) and lack of end-point precision are two major issues associated with the conventional single beam FIB technique. These issues are primarily related to ion beam damage and endpoint control encountered during the final stages of specimen thinning. As a result, the widespread use of FIB lift-out technique for high precision TEM specimen preparation has been limited. Recent technological advances have made it possible to combine both an electron beam column and an ion beam column into an integrated dual beam-focused ion beam (DB-FIB) system.


2005 ◽  
Vol 03 (supp01) ◽  
pp. 223-228 ◽  
Author(s):  
WEN-CHANG HUNG ◽  
A. ADAWI ◽  
A. TAHRAOUI ◽  
A. G. CULLIS

In order to control light, different strategies have been applied by placing an optically active medium into a semiconductor resonator and certain applications such as LEDs and laser diodes have been commercialized for many years. The possibility of nanoscale optical applications has created great interesting for quantum nanostructure research. Recently, single photon emission has been an active area of quantum dot research. A quantum dot is place between distributed Bragg reflectors (DBRs) within a micro-pillar structure. In this study, we shall report on an active layer composed of an organic material instead of a semiconductor. The micro-pillar structure is fabricated by a focused ion beam (FIB) micro-machining technique. The ultimate target is to achieve a single molecule within the micro-pillar and therefore to enable single photon emission. Here, we demonstrate some results of the fabrication procedure of a 5 micron organic micro-pillar via the focused ion beam and some measurement results from this study. The JEOL 6500 dual column system equipped with both electron and ion beams enables us to observe the fabrication procedure during the milling process. Furthermore, the strategy of the FIB micro-machining method is reported as well.


1995 ◽  
Vol 396 ◽  
Author(s):  
A. Wagner ◽  
P. Blauner ◽  
P. Longo ◽  
S. Cohen

AbstractFocused Ion Beams offer a new method of measuring the size of polymer resist features on integrated circuits. The short penetration range of an ion relative to an electron is shown to offer fundamental advantages for critical dimension (CD) metrology. By confining the polymer damage to the very near surface, ion beams can induce less dimensional change than scanning electron microscopes during the measurement process. This can result in improved CD measurement precision. The erosion rate of polymers to various ion species is also presented, and we show that erosion is non-linear with ion dose. The use of FIB for forming resist cross sections is also demonstrated. An H20 gas assisted etching process for polymers has been developed, and is shown to significantly improve the quality of resist cross sections.


2019 ◽  
Vol 22 (9) ◽  
pp. 1900823 ◽  
Author(s):  
Malte Lenz ◽  
Janis Wirth ◽  
Silvan Englisch ◽  
Jan Rosiwal ◽  
Nadine Buchinger ◽  
...  

1998 ◽  
Vol 4 (S2) ◽  
pp. 652-653 ◽  
Author(s):  
A. N. Campbell ◽  
J. M. Soden

A great deal can be learned about integrated circuits (ICs) and microelectronic structures simply by imaging them in a focused ion beam (FIB) system. FIB systems have evolved during the past decade from something of a curiosity to absolutely essential tools for microelectronics design verification and failure analysis. FIB system capabilities include localized material removal, localized deposition of conductors and insulators, and imaging. A major commercial driver for FIB systems is their usefulness in the design debugging cycle by (1) rewiring ICs quickly to test design changes and (2) making connection to deep conductors to facilitate electrical probing of complex ICs. FIB milling is also used for making precision cross sections and for TEM sample preparation of microelectronic structures for failure analysis and yield enhancement applications.


Author(s):  
L.R. Herlinger ◽  
S. Chevacharoenkul ◽  
D.C. Erwin

Abstract Cross-sectioning is a necessary technique for the failure analysis of integrated circuits. Historically, the majority of samples have been prepared for scanning electron microscope (SEM) analysis. Today's smaller geometry devices, however, increasingly require the improved spatial resolution afforded by the transmission electron microscope (TEM), both in imaging analysis and in elemental analysis. Specific-area cross-section TEM (SAXTEM) analysis allows the failure analyst to identify defects that may go undiscovered in the SEM. A procedure is described for a timely preparation of SAXTEM samples using a focused ion beam (FIB) instrument and a manipulator probe. This procedure extends the state-of-the-art in several key respects: A) no mechanical grinding is necessary, B) samples as large as the FIB chamber can be accommodated, e.g., whole wafers, C) multiple samples can be prepared from one die, D) the procedure is faster and more repeatable than previously reported procedures.


Author(s):  
Vincent Ballarotto ◽  
Karen Siegrist ◽  
Ellen Williams ◽  
William Vanderlinde

Abstract We report on a quantitative investigation of doping-induced contrast and topography-induced contrast in photoelectron emission microscopy (PEEM). Calibration samples were fabricated using standard photolithography and focused ion beam writing to test both types of contrast. Using a near-threshold light source, we find that the doping-induced contrast increases monotonically with B concentration over the measured range of 1017 – 2x1020 cm-3. The variation in doping-induced contrast as incident photon energy is varied was also investigated. Optimal doping-induced contrast and PEEM sensitivity is achieved by imaging with photon energy slightly above the highest nominal photothreshold of interest. The photoemission model, based on near-threshold emission, used to describe doping-induce contrast gives good agreement with the measured intensities. Thus, measuring the relative intensity ratio provides a robust technique for determining doping levels. Topography-induced contrast was investigated by imaging Ti samples of various step heights (75, 150, 290, and 550 nm). Image data suggests that edge contrast increases with step height. Numerical simulations show that non-uniform electrostatic fields at step edge are responsible for this contrast. Experimentally, we systematically vary the lateral field strength and show that edge contrast can be controlled. This technique could be useful in failure analysis by identifying breaks in metal lines.


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