Focused Ion Beam Circuit Edit on Copper Redistribution Layer

Author(s):  
Lorenzo Motta ◽  
Paolo Veneto ◽  
Mark Antolik ◽  
Donato Di Donato

Abstract Focused ion beam (FIB) circuit edit (CE) is an integral part of IC debug, fault-isolation, and low yield analysis. Regarding FIB microsurgery, complexity is growing with the shrinking of dimensions of lower level metallization while the redistribution layer (RDL) structures can increase in all three dimensions. This requires continuous development of CE processes to address these opposite dimension trends and material variations. There are two venues to address CE, accessing from the front side (FS) or from the back side (BS) of an IC. This paper describes the FS techniques and methodologies developed to edit the RDL technology. The goal of this work is to demonstrate on a Cu GND/power plane the performance of the halogen-based contamination process. Results shows that the benefit of reduced time to remove thick Cu metallization is surely advantageous for CE throughput as well as for improving edit success rates.

Author(s):  
Raymond Lee ◽  
Nicholas Antoniou

Abstract The increasing use of flip-chip packaging is challenging the ability of conventional Focused Ion Beam (FIB) systems to perform even the most basic device modification and debug work. The inability to access the front side of the circuit has severely reduced the usefulness of tradhional micro-surgery. Advancements in FIB technology and its application now allow access to the circuitry from the backside through the bulk silicon. In order to overcome the problem of imaging through thick silicon, a microscope with Infra Red (IR) capability has been integrated into the FIB system. Navigation can now be achieved using the IR microscope in conjunction with CAD. The integration of a laser interferometer stage enables blind navigation and milling with sub-micron accuracy. To optimize the process, some sample preparation is recommended. Thinning the sample to a thickness of about 100 µm to 200 µm is ideal. Once the sample is thinned, it is then dated in the FIB and the area of interest is identified using the IR microscope. A large hole is milled using the FIB to remove most of the silicon covering the area of interest. At this point the application is very similar to more traditional FIB usage since there is a small amount of silicon to be removed in order to expose a node, cut it or reconnect it. The main differences from front-side applications are that the material being milled is conductive silicon (instead of dielectric) and its feature-less and therefore invisible to a scanned ion beam. In this paper we discuss in detail the method of back-side micro-surgery and its eflkcton device performance. Failure Analysis (FA) is another area that has been severely limited by flip-chip packaging. Localized thinning of the bulk silicon using FIB technology oflkrs access to diagnosing fdures in flip-chip assembled parts.


2021 ◽  
Author(s):  
Alvina Jean Tampos ◽  
Karl Villareal

Abstract Complementary Metal-Oxide Semiconductor (CMOS) Image Sensors are gaining popularity most especially in Automotive Safety and Advanced Driver-Assistance Systems (ADAS) applications. Customer application modules involve oftentimes a third party supplier. When failures involve interaction between an image sensor die and the customer's module, the Failure Analyst has to know the exact failure mechanism to pinpoint whether root cause is in the die fabrication (fab) or packaging assembly (third party supplier). Challenges can befall the analyst: failure modes can recover which renders the unit functional and laboratories most often do not have complete sophisticated analytical laboratory equipment for electrical testing, fault isolation and sample preparation. In this paper, a case study of a CMOS Image Sensor is presented wherein the failure mode recovered which was restored and how the structural limitations were overcome for fault isolation on both front- and back-side. A modified process flow was performed to visualize the defect through backside Focused Ion Beam (FIB) cross-section.


Author(s):  
Matthew M. Mulholland ◽  
Ahmed A. Helmy ◽  
Anthony V. Dao

Abstract Post silicon validation techniques specifically Focused Ion Beam (FIB) circuit editing and Failure Analysis (FA) require sample preparation on Integrated Circuits (IC). Although these preparation techniques are typically done globally across the encapsulated and silicon packaging materials, in some scenarios with tight mechanical or thermal boundary conditions, only a local approach can be attempted for the analysis. This local approach to access the underlying features, such as circuits, solder bumps, and electrical traces can be divided into two modification approaches. The back side approach is typically done for die level analysis by de-processing through encapsulated mold compound and silicon gaining access to the silicon transistor level. On the other hand, the front side approach is typically used for package level analysis by de-processing the ball grid array (BGA) and package substrate layers. Both of these local de-processing approaches can be done by using the conventional Laser Chemical Etching (LCE) platforms. The focus of this paper will be to investigate a front side modification approach to provide substrate material removal solutions. Process details and techniques will be discussed to gain access to metal signals for further failure analysis and debug. A pulse laser will be used at various processing stages to de-process IC package substrate materials.


Author(s):  
E. Hendarto ◽  
S.L. Toh ◽  
J. Sudijono ◽  
P.K. Tan ◽  
H. Tan ◽  
...  

Abstract The scanning electron microscope (SEM) based nanoprobing technique has established itself as an indispensable failure analysis (FA) technique as technology nodes continue to shrink according to Moore's Law. Although it has its share of disadvantages, SEM-based nanoprobing is often preferred because of its advantages over other FA techniques such as focused ion beam in fault isolation. This paper presents the effectiveness of the nanoprobing technique in isolating nanoscale defects in three different cases in sub-100 nm devices: soft-fail defect caused by asymmetrical nickel silicide (NiSi) formation, hard-fail defect caused by abnormal NiSi formation leading to contact-poly short, and isolation of resistive contact in a large electrical test structure. Results suggest that the SEM based nanoprobing technique is particularly useful in identifying causes of soft-fails and plays a very important role in investigating the cause of hard-fails and improving device yield.


Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.


Author(s):  
Hui Pan ◽  
Thomas Gibson

Abstract In recent years, there have been many advances in the equipment and techniques used to isolate faults. There are many options available to the failure analyst. The available techniques fall into the categories of electrical, photonic, thermal and electron/ion beam [1]. Each technique has its advantages and its limitations. In this paper, we introduce a case of successful failure analysis using a combination of several fault localization techniques on a 0.15um CMOS device with seven layers of metal. It includes electrical failure mode characterization, front side photoemission, backside photoemission, Focused Ion Beam (FIB), Scanning Electron Microscope (SEM) and liquid crystal. Electrical characterization along with backside photoemission proved most useful in this case as a poly short problem was found to be causing a charge pump failure. A specific type of layout, often referred to as a hammerhead layout, and the use of Optical Proximity Correction (OPC) contributed to the poly level shorts.


2012 ◽  
Vol 1421 ◽  
Author(s):  
Russell J. Bailey ◽  
Remco Geurts ◽  
Debbie J. Stokes ◽  
Frank de Jong ◽  
Asa H. Barber

ABSTRACTThe mechanical behavior of nanocomposites is critically dependent on their structural composition. In this paper we use Focused Ion Beam (FIB) microscopy to prepare surfaces from a layered polymer nanocomposite for investigation using phase contrast atomic force microscopy (AFM). Phase contrast AFM provides mechanical information on the surface examined and, by combining with the sequential cross-sectioning of FIB, can extend the phase contract AFM into three dimensions.


2008 ◽  
Vol 584-586 ◽  
pp. 434-439 ◽  
Author(s):  
Anahita Khorashadizadeh ◽  
Myrjam Winning ◽  
Dierk Raabe

Obtaining knowledge on the grain boundary topology in three dimensions is of great importance as it controls the mechanical properties of polycrystalline materials. In this study, the three dimensional texture and grain topology of as-deformed ultra fine grained Cu-0.17wt%Zr have been investigated using three-dimensional orientation microscopy (3D electron backscattering diffraction, EBSD) measurements in ultra fine grained Cu-0.17wt%Zr. Equal channel angular pressing was used to produce the ultra fine grained structure. The experiments were conducted using a dual-beam system for 3D-EBSD. The approach is realized by a combination of a focused ion beam (FIB) unit for serial sectioning with high-resolution field emission scanning electron microscopy equipped with EBSD. The work demonstrates that the new 3D EBSD-FIB technique provides a new level of microstructure information that cannot be achieved by conventional 2D-EBSD analysis.


2021 ◽  
Vol 18 (182) ◽  
pp. 20210181
Author(s):  
Chiara Micheletti ◽  
Pedro Henrique Silva Gomes-Ferreira ◽  
Travis Casagrande ◽  
Paulo Noronha Lisboa-Filho ◽  
Roberta Okamoto ◽  
...  

The success of biomaterials for bone regeneration relies on many factors, among which osseointegration plays a key role. Biogran (BG) is a bioactive glass commonly employed as a bone graft in dental procedures. Despite its use in clinical practice, the capability of BG to promote osseointegration has never been resolved at the nanoscale. In this paper, we present the workflow for characterizing the interface between newly formed bone and BG in a preclinical rat model. Areas of bone–BG contact were first identified by backscattered electron imaging in a scanning electron microscope. A focused ion beam in situ lift-out protocol was employed to prepare ultrathin samples for transmission electron microscopy analysis. The bone–BG gradual interface, i.e. the biointerphase, was visualized at the nanoscale with unprecedented resolution thanks to scanning transmission electron microscopy. Finally, we present a method to view the bone–BG interface in three dimensions using electron tomography.


2020 ◽  
Vol 4 (1) ◽  
pp. 14 ◽  
Author(s):  
Tomoko G. Oyama ◽  
Atsushi Kimura ◽  
Naotsugu Nagasawa ◽  
Kotaro Oyama ◽  
Mitsumasa Taguchi

Biodevices with engineered micro- and nanostructures are strongly needed for advancements in medical technology such as regenerative medicine, drug discovery, diagnostic reagents, and drug delivery to secure high quality of life. The authors produced functional biocompatible plastics and hydrogels with physical and chemical properties and surface microscopic shapes that can be freely controlled in three dimensions during the production process using the superior properties of quantum beams. Nanostructures on a biocompatible poly(L-lactic acid) surface were fabricated using a focused ion beam. Soft hydrogels based on polysaccharides were micro-fabricated using a focused proton beam. Gelatin hydrogels were fabricated using γ-rays and electron beam, and their microstructures and stiffnesses were controlled for biological applications. HeLa cells proliferated three-dimensionally on the radiation-crosslinked gelatin hydrogels and, furthermore, their shapes can be controlled by the micro-fabricated surface of the hydrogel. Long-lasting hydrophilic concave structures were fabricated on the surface of silicone by radiation-induced crosslinking and oxidation. The demonstrated advanced biodevices have potential applications in three-dimensional cell culture, gene expression control, stem cell differentiation induction/suppression, cell aggregation into arbitrary shapes, tissue culture, and individual diagnosis in the medical field.


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