Laser Failure Isolation Techniques Demonstrated On Test Structures

Author(s):  
Frank S. Arnold

Abstract To be better prepared to use laser based failure isolation techniques on field failures of complex integrated circuits, simple test structures without any failures can be used to study Optical Beam Induced Resistance Change (OBIRCH) results. In this article, four case studies are presented on the following test structures: metal strap, contact string, VIA string, and comb test structure. Several experiments were done to investigate why an OBIRCH image was seen in certain areas of a VIA string and not in others. One experiment showed the OBRICH variation was not related to the cooling and heating effects of the topology, or laser beam focusing. A 4 point probe resistance measurement and cross-sectional views correlated with the OBIRCH results and proved OBIRCH was able to detect a variation in VIA fabrication.

Author(s):  
Chi-Lin Huang ◽  
Yu Hsiang Shu

Abstract Conventional isolation techniques, such as Optical Beam Induced Resistance Change (OBIRCH) or photoemission microscopy (PEM) frequently fail to locate failure points when only applied to power pin of the semiconductor device. In this paper, a novel OBIRCH failure isolation technique is utilized to detect leakage failures. Different test conditions are presented to identify the differences in current when all input pins are pulled high in an OBIRCH system. In order to verify a failure point, it is necessary to perform electrical analysis of the suspected failure point in the failing sample. In general, Conductive Atomic Force Microscope (C-AFM) and a Nano-Prober is sufficient to provide the electrical data required for failure analysis. Experiment results, however, prove that this novel OBIRCH failure isolation technique is effective in locating the failure point, especially for leakage failures. The failure mechanism is illustrated using cross-sectional TEM.


2020 ◽  
Vol 10 (23) ◽  
pp. 8576
Author(s):  
Han Yang ◽  
Rui Chen ◽  
Jianwei Han ◽  
Yanan Liang ◽  
Yingqi Ma ◽  
...  

Thermal Laser Stimulation (TLS) is an efficient technology for integrated circuit defect localization in Failure Analysis (FA) laboratories. It contains Optical Beam-Induced Resistance Change (OBIRCH), Thermally-Induced Voltage Alteration (TIVA), and Seebeck Effect Imaging (SEI). These techniques respectively use the principle of laser-induced resistance change and the Seebeck effect. In this paper, a comprehensive model of TLS technology is proposed. Firstly, the model presents an analytical expression of the temperature variation in Integrated Circuits (IC) after laser irradiation, which quantificationally shows the positive correlation with laser power and the negative correlation with scanning velocity. Secondly, the model describes the opposite influence of laser-induced resistance change and the Seebeck effect in the device. Finally, the relationship between the current variation measured in the experiment and other parameters, especially the voltage bias, is well explained by the model. The comprehensive model provides theoretical guidance for the efficient and accurate defect localization of TLS technology.


Author(s):  
Jim Douglass ◽  
Sohrab Pourmand

Abstract This paper shows that by combining electrical fault isolation and characterization by microprobing with physical fault isolation techniques both what is wrong with the circuit and where the defect is located can be determined with less microprobing and more safety from electrical recovery. In the first example, the unit was powered up using the optical beam induced resistance change (OBIRCH) supply, and OBIRCH was performed to determine if there were OBIRCH site differences between the good part and the return. The second example uses a combination of electrical fault isolation and characterization with microprobing and the physical fault isolation tool of lock in thermography (LIT). With these two examples, it has been shown that the use of electrical fault isolation and microprobing can be used to enhance the physical fault isolation tools of OBIRCH and LIT.


Author(s):  
Ryan Fredrickson ◽  
Tim Kuebrich ◽  
Andrew Le ◽  
Derek Snider ◽  
Lucas Winiarski

Abstract Fault isolation is an important initial component of the failure analysis investigation as it provides the first indicator of the defect physical location. The most broadly familiar fault isolation techniques include photoemission microscopy (PEM), optical beam induced resistance change (OBIRCH) and liquid crystal analysis (LCA). Each of these techniques has their own strengths but also drawbacks which can impede the analysis by either not providing a well isolated defect location or causing damage to the defect region. For some types of defects, photoemission and liquid crystal analysis may create local heating of the device which can distort the defect and mask the root cause of the failure. These techniques also rely on optical microscopy which has low resolution compared to the feature size of current technologies. In addition, each technique may not highlight the defect site itself; only pointing the analyst to the defective circuit within the sample. Electron Beam Induced Current (EBIC) and Electron Beam Absorbed Current (EBAC) microscopy provides solutions to these complications. In this paper we describe some very effective approaches by using these beam-based techniques in conjunction with traditional methods. As introduction, we have provided some interesting case studies whereby EBIC/EBAC have been used in conjunction with FIB circuit edits and scan diagnostic results to narrow the defect search areas. We focus the paper on some less common applications of cross sectional EBIC/EBAC as well as utilizing an AC coupled configuration to activate more subtle defect sites. We conclude with two examples where AC coupled cross-sectional EBIC is needed to highlight the cause of the failure.


2021 ◽  
Author(s):  
Yunfei Wang ◽  
Hyuk Ju Ryu ◽  
Tom Tong

Abstract In this paper, we present case studies of localizing resistive open defects using various FA techniques, including two-terminal IV, two-terminal Electron-Beam Absorbed Current (EBAC), Electron Beam Induced Resistance Change (EBIRCh), Pulsed IV, Capacitance-Voltage (CV) and Scanning Capacitance Microscopy (SCM). The advantage and limitation of each technique will also be discussed.


Author(s):  
Sukho Lee ◽  
John van den Biggelaar ◽  
Marc van Veenhuizen

Abstract Laser-based dynamic analysis has become a very important tool for analyzing advanced process technology and complex circuit design. Thus, many good reference papers discuss high resolution, high sensitivity, and useful applications. However, proper interpretation of the measurement is important as well to understand the failure behavior and find the root cause. This paper demonstrates this importance by describing two insightful case studies with unique observations from laser voltage imaging/laser voltage probing (LVP), optical beam induced resistance change, and soft defect localization (SDL) analysis, which required an in-depth interpretation of the failure analysis (FA) results. The first case is a sawtooth LVP signal induced by a metal short. The second case, a mismatched result between an LVP and SDL analysis, is a good case of unusual LVP data induced by a very sensitive response to laser light. The two cases provide a good reference on how to properly explain FA results.


Author(s):  
Edward Coyne

Abstract This paper describes the problems encountered and solutions found to the practical objective of developing an imaging technique that would produce a more detailed analysis of IC material structures then a scanning electron microscope. To find a solution to this objective the theoretical idea of converting a standard SEM to produce a STEM image was developed. This solution would enable high magnification, material contrasting, detailed cross sectional analysis of integrated circuits with an ordinary SEM. This would provide a practical and cost effective alternative to Transmission Electron Microscopy (TEM), where the higher TEM accelerating voltages would ultimately yield a more detailed cross sectional image. An additional advantage, developed subsequent to STEM imaging was the use of EDX analysis to perform high-resolution element identification of IC cross sections. High-resolution element identification when used in conjunction with high-resolution STEM images provides an analysis technique that exceeds the capabilities of conventional SEM imaging.


Author(s):  
Cha-Ming Shen ◽  
Yen-Long Chang ◽  
Lian-Fon Wen ◽  
Tan-Chen Chuang ◽  
Shi-Chen Lin ◽  
...  

Abstract Highly-integrated radio frequency and mixed-mode devices that are manufactured in deep-submicron or more advanced CMOS processes are becoming more complex to analyze. The increased complexity presents us with many eccentric failure mechanisms that are uniquely different from traditional failure mechanisms found during failure analysis on digital logic applications. This paper presents a novel methodology to overcome the difficulties and discusses two case studies which demonstrate the application of the methodology. Through the case studies, the methodology was proven to be a successful approach. It is also proved how this methodology would work for such non-recognizable failures.


Author(s):  
Yongkai Zhou ◽  
Jie Zhu ◽  
Han Wei Teo ◽  
ACT Quah ◽  
Lei Zhu ◽  
...  

Abstract In this paper, two failure analysis case studies are presented to demonstrate the importance of sample preparation procedures to successful failure analyses. Case study 1 establishes that Palladium (Pd) cannot be used as pre-FIB coating for SiO2 thickness measurement due to the spontaneously Pd silicide formation at the SiO2/Si interface. Platinum (Pt) is thus recommended, in spite of the Pt/SiO2 interface roughness, as the pre-FIB coating in this application. In the second case study, the dual-directional TEM inspection method is applied to characterize the profile of the “invisible” tungsten residue defect. The tungsten residue appears invisible in the planeview specimen due to the low mass-thickness contrast. It is then revealed in the cross-sectional TEM inspection.


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