Studies of Buried Voids Capturing with e-Beam Inspection System and Confirmation with Physical Failure Analysis

Author(s):  
Hong Xiao ◽  
Ximan Jiang

Abstract In this paper, a novel inspection mode of electron beam inspection (EBI) that can effectively detect buried voids in tungsten (W) plugs is reported for the first time. Buried voids in metal are a defect of interest (DOI) that cannot be captured by either optical inspection or traditional EBI modes. The detection of buried voids is achieved by using energetic electron beam (e-beam) with energy high enough to penetrate into metal and reach the buried void. By selecting desired secondary electrons to form the inspection images, strong contrast between the defective tungsten plugs and normal ones can be achieved. Failure analysis was performed on the DOI that is unique to this new EBI mode. After optical microscope locating and laser marking, we successfully recaptured DOI with scanning electron microscope (SEM) and capped the DOI with e-beam assisted platinum (Pt) deposition. Later a dual-beam focused ion beam (FIB) system was used to re-locate the Pt-capped DOI and prepare samples for transmission electron microscope (TEM). TEM images confirmed the unique DOI were buried voids in the metal plugs, which could affect resistance of interconnect in integrated circuit (IC) chip and impact the IC yield.

Author(s):  
Julien Goxe ◽  
Béatrice Vanhuffel ◽  
Marie Castignolles ◽  
Thomas Zirilli

Abstract Passive Voltage Contrast (PVC) in a Scanning Electron Microscope (SEM) or a Focused Ion Beam (FIB) is a key Failure Analysis (FA) technique to highlight a leaky gate. The introduction of Silicon On Insulator (SOI) substrate in our recent automotive analog mixed-signal technology highlighted a new challenge: the Bottom Oxide (BOX) layer, by isolating the Silicon Active Area from the bulk made PVC technique less effective in finding leaky MOSFET gates. A solution involving sample preparation performed with standard FA toolset is proposed to enhance PVC on SOI substrate.


2011 ◽  
Vol 17 (6) ◽  
pp. 889-895 ◽  
Author(s):  
Lynne M. Gignac ◽  
Surbhi Mittal ◽  
Sarunya Bangsaruntip ◽  
Guy M. Cohen ◽  
Jeffrey W. Sleight

AbstractThe ability to prepare multiple cross-section transmission electron microscope (XTEM) samples from one XTEM sample of specific sub-10 nm features was demonstrated. Sub-10 nm diameter Si nanowire (NW) devices were initially cross-sectioned using a dual-beam focused ion beam system in a direction running parallel to the device channel. From this XTEM sample, both low- and high-resolution transmission electron microscope (TEM) images were obtained from six separate, specific site Si NW devices. The XTEM sample was then re-sectioned in four separate locations in a direction perpendicular to the device channel: 90° from the original XTEM sample direction. Three of the four XTEM samples were successfully sectioned in the gate region of the device. From these three samples, low- and high-resolution TEM images of the Si NW were taken and measurements of the NW diameters were obtained. This technique demonstrated the ability to obtain high-resolution TEM images in directions 90° from one another of multiple, specific sub-10 nm features that were spaced 1.1 μm apart.


Author(s):  
Jim Shearer ◽  
Kim Le ◽  
Xiaoyu Yang ◽  
Monty Cleeves ◽  
Al Meeks

Abstract This article presents a case study to solve an IDDQ leakage problem using a variety of failure analysis techniques on a product. The product is fabricated using a 3-metal-layer 0.25 μm CMOS process with the addition of Matrix's proprietary 3-D memory layers. The failure analysis used both top and backside analytical techniques, including liquid crystal, photon emission microscopy from both front and back, dual-beam focused ion beam cross-sectioning, field emission scanning electron microscopy imaging, parallel-lap/passive voltage contrast, microprobing of parallel-lapped samples, and scanning capacitance microscopy. The article discusses how the application of each of the techniques narrowed down the search for this IDDQ leakage path. This leakage path was eliminated using the two corrective actions: The resist is pre-treated prior to ion implantation to produce a consistent resist sidewall profile; and the Nwell boundaries were adjusted in the next Nwell mask revision.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000469-000473 ◽  
Author(s):  
J. Gaudestad ◽  
A. Orozco ◽  
I. De Wolf ◽  
T. Wang ◽  
T. Webers ◽  
...  

In this paper we show an efficient workflow that combines Magnetic Field Imaging (MFI) and Dual Beam Plasma Focused Ion Beam (DB-PFIB) for fast and efficient Fault Isolation and root cause analysis in 2.5/3D devices. The work proves MFI is the best method for Electric Fault Isolation (EFI) of short failures in 2.5/3D Through Silicon Via (TSV) triple stacked 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 DB-PFIB system was used for cross sectioning and volume analysis of the TSV structures and high resolution imaging of the identified defects. With a DB-PFIB, the fault is exposed and analyzed without any sample prep artifacts seen in mechanical polishing or laser preparation techniques and done in a considerably shorter amount of time than that required when using a traditional Gallium Focused Ion Beam (FIB).


Author(s):  
Jian Ma ◽  
Weiwei Zhao ◽  
Lei Liu ◽  
Jingjie Sha ◽  
Yunfei Chen

Solid-state nanopore has already shown success of single molecule detection and graphene nanopore is potential for successful DNA sequencing. Here, we present a fast and controllable way to fabricate sub-5 nm nanopore on graphene membrane. The process includes two steps: sputtering a large size nanopore using a conventional focused ion beam (FIB) and shrinking the large nanopore to a few nanometers using scanning electron microscope (SEM). We also demonstrated the ability of the graphene nanopores fabricated in this manner to detect individual 48Kbp λ-DNA molecules.


Author(s):  
Ann N. Campbell ◽  
William F. Filter ◽  
Nicholas Antoniou

Abstract Both the increased complexity of integrated circuits, resulting in six or more levels of integration, and the increasing use of flip-chip packaging have driven the development of integrated circuit (IC) failure analysis tools that can be applied to the backside of the chip. Among these new approaches are focused ion beam (FIB) tools and processes for performing chip edits/repairs from the die backside. This paper describes the use of backside FIB for a failure analysis application rather than for chip repair. Specifically, we used FIB technology to prepare an IC for inspection of voided metal interconnects (“lines”) and vias. Conventional FIB milling was combined with a superenhanced gas assisted milling process that uses XeF2 for rapid removal of large volumes of bulk silicon. This combined approach allowed removal of the TiW underlayer from a large number of M1 lines simultaneously, enabling rapid localization and plan view imaging of voids in lines and vias with backscattered electron (BSE) imaging in a scanning electron microscope (SEM). Sequential cross sections of individual voided vias enabled us to develop a 3D reconstruction of these voids. This information clarified how the voids were formed, helping us identify the IC process steps that needed to be changed.


Author(s):  
Lihong Cao ◽  
Loc Tran ◽  
Wallace Donna

Abstract This article describes how Focused Ion Beam (FIB) milling methodology enhances the capability of package-level failure analysis on flip-chip packages by eliminating the artifacts induced by using conventional mechanical techniques. Dual- Beam Focused Ion Beam (DB FIB) cross sections were successful in detecting failure mechanisms related either to the die/C4 bump or package defect inside the organic substrate. This paper outlines detailed sample preparation techniques prior to performing the DB FIB cross-sections, along with case studies of DB FIB cross-sections.


Author(s):  
Tae-Sun Back ◽  
Jong-Hyeop Kim ◽  
Soon-Ju Lee ◽  
Jin-Woo Jung ◽  
Te-O Jung ◽  
...  

Abstract Scanning electron microscope (SEM) and high resolution transmission electron microscope analysis combined with focused ion beam have been used to locate the physical defect. Visualizing the defect by these techniques was found to be difficult. This paper introduces a novel physical failure analysis technique using 3D rotation STEM imaging. It describes the electrical method of analyzing the cause of failure. Trying to determine with 2D imaging if the defect was a crystalline or not was problematical. To resolve the issue, a pillar type of specimen was made by utilizing a 3D rotation holder and observed with the sample from different directions. Results confirmed that the generation of dislocations can occur according to the variation of the stress transferred to the bulk Si. The variation was due to stress intensity and pattern isolation as a function of the film volume of spin on dielectric material and shallow trench isolation size.


2001 ◽  
Vol 7 (S2) ◽  
pp. 514-515 ◽  
Author(s):  
Larry Rice

Electron beam induced current (EBIC) is the common term used in the semiconductor industry for the failure analysis and yield enhancement of semiconductor devices using SEM to electrically pinpoint leakage sites. EBIC is a useful technique for locating defects in diodes, transistors, and capacitors where the scanning electron microscope beam is used to generate a signal and the sample is the detector. Often during yield enhancement efforts the failure analyst is asked to determine the mechanism for which a PC structure (which may contain as many as a few hundred thousand structures in one device) is failing tests. Blind cross sections rarely give evidence of the failure mechanism. EBIC can be used to pinpoint the bad site which is then precision cross-sectioned using the focused ion beam (FIB).When an electron beam impinges on a semiconductor such as silicon, electron-hole pairs are created when the incident beam transfers enough energy to promote an electron from the valance band to the conduction band.


2020 ◽  
Vol 26 (2) ◽  
pp. 211-219
Author(s):  
Majid Ahmadi ◽  
Frans D. Tichelaar ◽  
Andreas Ihring ◽  
Michael Kunze ◽  
Sophie Billat ◽  
...  

AbstractIn microstructural corrosion studies, knowledge on the initiation of corrosion on an nm-scale is lacking. In situ transmission electron microscope (TEM) studies can elucidate where/how the corrosion starts, provided that the proper corrosive conditions are present during the investigation. In wet corrosion studies with liquid cell nanoreactors (NRs), the liquid along the electron beam direction leads to strong scattering and therefore image blurring. Thus, a quick liquid removal or thickness control of the liquid layer is preferred. This can be done by the use of a Peltier element embedded in an NR. As a prelude to such in situ work, we demonstrate the local wetting of a TEM sample, by creating a temperature decrease of 10 ± 2°C on the membrane of an NR with planar Sb/BiSb thermoelectric materials for the Peltier element. TEM samples were prepared and loaded in an NR using a dual-beam focused ion beam scanning electron microscope. A mixture of water vapor and carrier gas was passed through a chamber, which holds the micro-electromechanical system Peltier device and resulted in quick formation of a water layer/droplets on the sample. The TEM analysis after repeated corrosion of the same sample (ex situ studies) shows the onset and progression of O2 and H2S corrosion of the AA2024-T3 alloy and cold-rolled HCT980X steel lamellae.


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