Latent Flash Single Bit and Multiple Bits Systematic Approach to Failure Analysis

2008 ◽  
Author(s):  
Hoang-Yen To ◽  
Dat Nguyen ◽  
Clyde Dunn ◽  
Detric Davis
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Systematic Approach ◽  
Failure Modes ◽  
Fault Isolation ◽  
Wafer Fabrication ◽  
Electrical Failure ◽  
Non Volatile Memory ◽  
Different Temperatures ◽  
Volatile Memory

Abstract The flash considered for failure analysis in this paper is a non volatile memory with a NOR architecture in the array and a stacked gate for the bit cell. The flash failure was from data gain reported from various stages and at different temperatures after leaving the wafer fabrication. The failure can be single bit failure (SBF) or multiple bit failure (MBF). The FA process is comprised of two steps termed electrical failure analysis (EFA) and physical failure analysis (PFA). This paper discusses the method to differentiate failure modes and the efforts of fault isolation. Micro probing and nano probe characterization were important in the understanding of the failure mechanism. As seen in the EFA/PFA section, the reported SBF/MBF failures were actually due to a defect in the Mux and not at the bit cell.

Improved Electrical Failure Analysis/Fault Isolation Tool Development on Server Motherboard Platforms Based on Historic Failure Modes

2004 ◽  
Author(s):  
Patrick G. Opdahl
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Resource Constraints ◽  
Analysis Data ◽  
Fault Isolation ◽  
Tool Development ◽  
Success Rates ◽  
Complete Coverage ◽  
Electrical Failure ◽  
Silicon Devices

Abstract Electrical fault isolation constitutes the first steps in characterizing and isolating the failure modes and root causes of a failing motherboard. Ideally the Failure Analysis Test tools provide complete coverage of all motherboard buses and silicon devices. Time and resource constraints for tool development prevent complete coverage, however, so the challenge is to provide the highest level of debug test coverage in the shortest development schedule. A simplified Fault Isolation process has been created based on historical failure analysis data to reduce the development time and resources to create tools which allow diagnosing failure root causes on high-end server motherboards. This strategy prioritizes the most common types of electrical failure modes and the types of Electrical Failure Analysis / Fault Isolation (EFA-FI) tools best suited to diagnose these modes. The benefits of this strategy include shorter EFA-FI development times, equivalent success rates in failure root cause, lower costs, and more effective EFA-FI tools that can be used within the Design Team and at either OEM or Contract Manufacturing sites.

A New Failure Analysis Flow of Gate Oxide Integrity Failure in Wafer Fabrication

2009 ◽  
Author(s):  
Hua Younan ◽  
Chu Susan ◽  
Gui Dong ◽  
Mo Zhiqiang ◽  
Xing Zhenxiang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Gate Dielectric ◽  
Dielectric Breakdown ◽  
Defect Density ◽  
Gate Oxide ◽  
Oxide Thickness ◽  
Fault Isolation ◽  
Wafer Fabrication ◽  
Root Cause ◽  
Gate Oxide Integrity

Abstract As device feature size continues to shrink, the reducing gate oxide thickness puts more stringent requirements on gate dielectric quality in terms of defect density and contamination concentration. As a result, analyzing gate oxide integrity and dielectric breakdown failures during wafer fabrication becomes more difficult. Using a traditional FA flow and methods some defects were observed after electrical fault isolation using emission microscopic tools such as EMMI and TIVA. Even with some success with conventional FA the root cause was unclear. In this paper, we will propose an analysis flow for GOI failures to improve FA’s success rate. In this new proposed flow both a chemical method, Wright Etch, and SIMS analysis techniques are employed to identify root cause of the GOI failures after EFA fault isolation. In general, the shape of the defect might provide information as to the root cause of the GOI failure, whether related to PID or contamination. However, Wright Etch results are inadequate to answer the questions of whether the failure is caused by contamination or not. If there is a contaminate another technique is required to determine what the contaminant is and where it comes from. If the failure is confirmed to be due to contamination, SIMS is used to further determine the contamination source at the ppm-ppb level. In this paper, a real case of GOI failure will be discussed and presented. Using the new failure analysis flow, the root cause was identified to be iron contamination introduced from a worn out part made of stainless steel.

Case Study in Fault Isolation of a Metal Short for Yield Enhancement

2010 ◽  
Author(s):  
Sarven Ipek ◽  
David Grosjean
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Photon Emission ◽  
Fault Isolation ◽  
Yield Enhancement ◽  
Analysis Technique ◽  
Laser Signal ◽  
Signal Injection ◽  
Microscopy Techniques

Abstract The application of an individual failure analysis technique rarely provides the failure mechanism. More typically, the results of numerous techniques need to be combined and considered to locate and verify the correct failure mechanism. This paper describes a particular case in which different microscopy techniques (photon emission, laser signal injection, and current imaging) gave clues to the problem, which then needed to be combined with manual probing and a thorough understanding of the circuit to locate the defect. By combining probing of that circuit block with the mapping and emission results, the authors were able to understand the photon emission spots and the laser signal injection microscopy (LSIM) signatures to be effects of the defect. It also helped them narrow down the search for the defect so that LSIM on a small part of the circuit could lead to the actual defect.

Failure Analysis of Killer Defects and Yield Enhancement of Flat ROM Devices in Wafer Fabrication

2000 ◽  
Author(s):  
Y. N. Hua ◽  
Z. R. Guo ◽  
L. H. An ◽  
Shailesh Redkar
Keyword(s):  
Electron Microscope ◽  
Failure Analysis ◽  
Fault Isolation ◽  
Yield Enhancement ◽  
Wafer Fabrication ◽  
X Ray ◽  
Particle Contamination ◽  
Emission Microscopy ◽  
Microscopy Techniques ◽  
Scanning Electron

Abstract In this paper, some low yield cases in Flat ROM device (0.45 and 0.6 µm) were investigated. To find killer defects and particle contamination, KLA, bitmap and emission microscopy techniques were used in fault isolation. Reactive ion etching (RIE) and chemical delayering, 155 Wright Etch, BN+ Etch and scanning electron microscope (SEM) were used for identification and inspection of defects. In addition, energy-dispersive X-ray microanalysis (EDX) was used to determine the composition of the particle or contamination. During failure analysis, seven kinds of killer defects and three killer particles were found in Flat ROM devices. The possible root causes, mechanisms and elimination solutions of these killer defects/particles were also discussed.

Case Study Failure Analysis of an Ultra-High Vacuum Enclosure Made of a Silicon Chip and Borosilicate Glass for the Cold Atom Laboratory

2017 ◽  
Author(s):  
Gil Garteiz ◽  
Javeck Verdugo ◽  
David Aveline ◽  
Eric Williams ◽  
Arvid Croonquist ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Failure Mechanism ◽  
Borosilicate Glass ◽  
High Vacuum ◽  
Cold Atom ◽  
Fault Isolation ◽  
Ultra High Vacuum ◽  
Liquid Bath

Abstract In this paper, a failure analysis case study on a custom-built vacuum enclosure is presented. The enclosure’s unique construction and project requirement to preserve the maximum number of units for potential future use in space necessitated a fluorocarbon liquid bath for fault isolation and meticulous sample preparation to preserve the failure mechanism during failure analysis.

Fault Isolation of Large Nets Using Bridging Fault Analysis

2004 ◽  
Author(s):  
George Ontko
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Failure Mechanism ◽  
Fault Analysis ◽  
Fault Isolation ◽  
Bridging Faults ◽  
Bridging Fault

Abstract Bridging faults are a common failure mechanism in integrated circuits and scan-based diagnosis does a good job of isolating these defects. Diagnosis, however, can sometimes result in large search areas. Typically, these areas are caused by long repeater nets. When this happens, physical failure analysis will become difficult or impossible. This paper concerns itself with using a bridging fault analysis as a means of reducing these large search areas.

MBIST Driven SRAM Failure Analysis Using Laser Voltage Imaging and Laser Voltage Probing

2019 ◽  
Author(s):  
Jessica Yang ◽  
Omprakash Rengaraj ◽  
Puneet Gupta ◽  
Rudolf Schlangen
Keyword(s):  
Failure Analysis ◽  
Photon Emission ◽  
Random Access ◽  
Random Access Memory ◽  
Fault Isolation ◽  
Static Random Access Memory ◽  
Production Testing ◽  
Access Memory ◽  
Electrical Failure ◽  
Voltage Imaging

Abstract Static Random-Access Memory (SRAM) failure analysis (FA) is important during chip-level reliability evaluation and yield improvement. Single-bit, paired-bit, and quad-bit failures—whose defect should be at the failing bit-cell locations—can be directly sent for Physical Failure Analysis (PFA). For one or multiple row/column failures with too large of a suspected circuit area, more detailed fault isolation is required before PFA. Currently, Photon Emission Microscopy (PEM) is the most commonly used Electrical Failure Analysis (EFA) technique for this kind of fail [1]. Soft-Defect Localization / Dynamic Laser Stimulation (SDL/DLS) can also be applied on soft (Vmin) row/column fails for further isolation [2]. However, some failures do not have abnormal emission spots or DLS sensitivity and require different localization techniques. Laser Voltage Imaging (LVI) and Laser Voltage Probing (LVP) are widely established for logic EFA, [3] but require periodic activation via ATE which may not be possible using MBIST hardware and test-patterns optimized for fast production testing. This paper discusses the test setup challenges to enable LVI & LVP on SRAM fails and includes two case studies on <14 nm advanced process silicon.

Contact Leakage Failure Analysis by EBIC, C-AFM and Nano-probing

2019 ◽  
Author(s):  
Kuang-Tse Ho ◽  
Chien-Wei Wu ◽  
Te-Fu Chang ◽  
Chia-Hsiang Yen ◽  
Ching-Hsiang Chan
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Failure Mechanisms ◽  
Fault Isolation ◽  
Electrical Failure ◽  
Sem And Tem ◽  
Leakage Failure

Abstract This research sets up failure analysis flow to verify failure mechanisms and root causes of different kinds of contact leakage. This flow mainly uses EBIC, C-AFM and nano-probing to do fault isolation and confirm electrical failure mechanisms. Appropriate sample preparation is also mandatory for FIB, SEM and TEM inspection.

Targeted Silicon Ultra-Thinning by Contour Milling for Advanced Fault Isolation

2019 ◽  
Author(s):  
W. S. Teo ◽  
M.S. Wei ◽  
V. Narang ◽  
C. L. Gan ◽  
C. Richardson ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sample Preparation ◽  
Failure Analysis ◽  
Fault Isolation ◽  
Thin Sample ◽  
Electrical Failure ◽  
Contour Maps ◽  
Area Of Interest ◽  
Silicon Thickness ◽  
Thermal Stability Of

Abstract In this paper, we present methods for targeted silicon thinning by contour milling to overcome challenges associated with thinning large devices to under 5 µm remaining silicon thickness. Implementation of these techniques are expected to improve the yield of ultra-thin sample preparation and thermal stability of the device through electrical failure analysis for subsequent physical failure analysis. Using a computer numerical controlled milling system, the natural device bow is exploited to thin a specified area of interest by stage tilting before 2D milling. To target a larger area of interests, contour maps are rigged to thin an area preferentially while remaining compatible with existing workflows. Electrical testing have found improved thermal stability of the locally thinned samples over globally thinned samples.

MEMS Failure Analysis In Wafer Fabrication

2016 ◽  
Author(s):  
Hui Peng Ng ◽  
Angela Teo ◽  
Ghim Boon Ang ◽  
Alfred Quah ◽  
N. Dayanand ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Data Interpretation ◽  
Fault Isolation ◽  
Wafer Fabrication ◽  
Auger Analysis ◽  
Root Cause ◽  
Defect Site ◽  
Defect Localization ◽  
Cmos Chip

Abstract This paper discussed on how the importance of failure analysis to identify the root cause and mechanism that resulted in the MEMS failure. The defect seen was either directly on the MEMS caps or the CMOS integrated chip in wafer fabrication. Two case studies were highlighted in the discussion to demonstrate how the FA procedures that the analysts had adopted in order to narrow down to the defect site successfully on MEMS cap as well as on CMOS chip on MEMS package units. Besides the use of electrical fault isolation tool/technique such as TIVA for defect localization, a new physical deprocessing approach based on the cutting method was performed on the MEMS package unit in order to separate the MEMS from the Si Cap. This approach would definitely help to prevent the introduction of particles and artifacts during the PFA that could mislead the FA analyst into wrong data interpretation. Other FA tool such as SEM inspection to observe the physical defect and Auger analysis to identify the elements in the defect during the course of analysis were also documented in this paper.

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