Humidity-Bias Driven Shorts in Multilayer Circuits: A Case Study in Failure Analysis

Author(s):  
Hei-Ruey Harry Jen ◽  
Gerald S. D’Urso ◽  
Harold Andrews

Abstract When a failure analysis (FA) involves a multiple layer structure separated by a polymeric material such as Benzocyclobutene (BCB), in a plastic package, it becomes a very challenging task to find out where the failure site is and how it failed. This is due to the fact that the chemical de-processing procedure removes BCB as well as the plastic molding compound. This paper outlines the studies carried out to determine the failure site and the root cause of the failure mechanism in a multilayer circuit and the steps taken to fix the problems. The methodology and results of this study are applicable to many other types of circuits.

Author(s):  
K. Li ◽  
P. Liu ◽  
J. Teong ◽  
M. Lee ◽  
H. L. Yap

Abstract This paper presents a case study on via high resistance issue. A logical failure analysis process EDCA (Effect, Defect, Cause, and Action) is successfully applied to find out the failure mechanism, pinpoint the root cause and solve the problem. It sets up a very good example of how to do tough failure analysis in a controllable way.


Author(s):  
Steven Loveless ◽  
Zhihong You ◽  
Tathagata Chatterjee ◽  
Badarish Subbannavar

Abstract This paper discusses a failure analysis case study in a highly integrated mixed signal device caused by inductive coupling of on-chip signals. The techniques utilized and the approach to root cause analysis are discussed in depth. The interactions between the device design and failure mechanism are identified in detail. Focus is placed on drawing conclusions from the sum of individual data points, and the discussion provides an analytical path by which similar failures can be isolated and specific device sensitivities can be identified.


Author(s):  
Erick Kim ◽  
Kamjou Mansour ◽  
Gil Garteiz ◽  
Javeck Verdugo ◽  
Ryan Ross ◽  
...  

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.


Author(s):  
Kuo Hsiung Chen ◽  
Wen Sheng Wu ◽  
Yu Hsiang Shu ◽  
Jian Chan Lin

Abstract IR-OBIRCH (Infrared Ray – Optical Beam Induced Resistance Change) is one of the main failure analysis techniques [1] [2] [3] [4]. It is a useful tool to do fault localization on leakage failure cases such as poor Via or contact connection, FEoL or BEoL pattern bridge, and etc. But the real failure sites associated with the above failure mechanisms are not always found at the OBIRCH spot locations. Sometimes the real failure site is far away from the OBIRCH spot and it will result in inconclusive PFA Analysis. Finding the real failure site is what matters the most for fault localization detection. In this paper, we will introduce one case using deep sub-micron process generation which suffers serious high Isb current at wafer donut region. In this case study a BEoL Via poor connection is found far away from the OBIRCH spots. This implies that layout tracing skill and relation investigation among OBIRCH spots are needed for successful failure analysis.


Author(s):  
Sarven Ipek ◽  
David Grosjean

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.


Author(s):  
Michael Woo ◽  
Marcos Campos ◽  
Luigi Aranda

Abstract A component failure has the potential to significantly impact the cost, manufacturing schedule, and/or the perceived reliability of a system, especially if the root cause of the failure is not known. A failure analysis is often key to mitigating the effects of a componentlevel failure to a customer or a system; minimizing schedule slips, minimizing related accrued costs to the customer, and allowing for the completion of the system with confidence that the reliability of the product had not been compromised. This case study will show how a detailed and systemic failure analysis was able to determine the exact cause of failure of a multiplexer in a high-reliability system, which allowed the manufacturer to confidently proceed with production knowing that the failure was not a systemic issue, but rather that it was a random “one time” event.


Author(s):  
Zhigang Song ◽  
Jochonia Nxumalo ◽  
Manuel Villalobos ◽  
Sweta Pendyala

Abstract Pin leakage continues to be on the list of top yield detractors for microelectronics devices. It is simply manifested as elevated current with one pin or several pins during pin continuity test. Although many techniques are capable to globally localize the fault of pin leakage, root cause analysis and identification for it are still very challenging with today’s advanced failure analysis tools and techniques. It is because pin leakage can be caused by any type of defect, at any layer in the device and at any process step. This paper presents a case study to demonstrate how to combine multiple techniques to accurately identify the root cause of a pin leakage issue for a device manufactured using advanced technology node. The root cause was identified as under-etch issue during P+ implantation hard mask opening for ESD protection diode, causing P+ implantation missing, which was responsible for the nearly ohmic type pin leakage.


2021 ◽  
Author(s):  
Song Wang ◽  
Lawrence Khin Leong Lau ◽  
Wu Jun Tong ◽  
Kun An ◽  
Jiang Nan Duan ◽  
...  

Abstract This paper elucidates the importance of flow assurance transient multiphase modelling to ensure uninterrupted late life productions. This is discussed in details through the case study of shut-in and restart scenarios of a subsea gas well (namely Well A) located in South China Sea region. There were two wells (Well A and Well B) producing steadily prior to asset shut-in, as a requirement for subsea pipeline maintenance works. However, it was found that Well A failed to restart while Well B successfully resumed production after the pipeline maintenance works. Flow assurance team is called in order to understand the root cause of the failed re-start of Well A to avoid similar failure for Well B and other wells in this region. Through failure analysis of Well A, key root cause is identified and associated operating strategy is proposed for use for Well B, which is producing through the same subsea infrastructure. Transient multiphase flow assurance model including subsea Well A, subsea Well B, associated spools, subsea pipeline and subsea riser is developed and fully benchmarked against field data to ensure realistic thermohydraulics representations of the actual asset. Simulation result shows failed restart of Well A and successful restart of Well B, which fully matched with field observations. Further analysis reveals that liquid column accumulated within the wellbore of Well A associates with extra hydrostatic head which caused failed well restart. Through a series of sensitivity analysis, the possibility of successful Well A restart is investigated by manipulating topsides back pressure settings and production flowrates prior to shut-in. These serve as a methodology to systematically analyze such transient scenario and to provide basis for field operating strategy. The analysis and strategy proposed through detailed modelling and simulation serves as valuable guidance for Well B, should shut-in and restart operation is required. This study shows the importance of modelling prior to late life field operations, in order to avoid similar failed well restart, which causes significant production and financial impacts.


Author(s):  
Gil Garteiz ◽  
Javeck Verdugo ◽  
David Aveline ◽  
Eric Williams ◽  
Arvid Croonquist ◽  
...  

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.


Author(s):  
Jakyung Hong ◽  
S.J. Cho ◽  
Y.W. Han ◽  
H.S. Choi ◽  
T.E. Kim ◽  
...  

Abstract This paper presents the process of measuring static noise margin (SNM), write noise margin (WNM) with 6 pin nanoprober, and characterization and analysis of SRAM cell stability through case studies of 45nm devices SRAM soft failures. It highlights that the local mismatch in the bit cell caused by slight variations in the transistor characteristics, such as Vth shift and Idsat, off variation, also can easily induce a soft failure. The analysis of the SNM TR characteristic is successfully demonstrated through the case study of 45nm SRAM devices. The chapter explains SNM measurement in the metal layer and transistor measurements in the CA layer. Measuring the SNM TR's characteristics is an important methodology in understanding the stability of each bit cell and failure mechanism depending on voltage, defects, and other factors. The next generation of nanoprobing analysis can be expanded.


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