Leveraging Root Cause Deconvolution Analysis for Logic Yield Ramping

Author(s):  
Yan Pan ◽  
Atul Chittora ◽  
Kannan Sekar ◽  
Goh Szu Huat ◽  
You Guo Feng ◽  
...  

Abstract The root cause deconvolution (RCD) provides an easy-to-understand defect Pareto, together with targeted physical failure analysis candidates. Unfortunately, even the RCD analysis also has some assumptions and limitations, and its result cannot always be interpreted literally. This calls for a variety of conventional yield analysis techniques to be adopted in parallel to improve the confidence in the RCD results. This paper briefly introduces the RCD analysis and explains how it distinguishes itself from other conventional volume diagnosis analysis techniques. Its typical inputs and outputs are discussed as well. Next, the paper focuses on two case studies where the authors leverage RCD for logic yield improvement together with other conventional analysis techniques. It then proposes a comprehensive analysis system that is backed up by accumulating RCD results over time and across different design IPs.

Author(s):  
James B. Riddle

Abstract This paper will examine semiconductor wear out at San Onofre Nuclear Generation Station (SONGS). The topics will include case studies, failure mechanisms, diagnostic techniques, failure analysis techniques and root cause corrective actions. Nuclear power plants are unique in that instrumentation and control circuits are continuously energized, are periodically tested, and have been in operation for greater than 25 years. Root cause evaluations at SONGS have identified numerous semiconductor failures due to wear out. Case studies include light output deterioration in opto-isolators, junction alloying failures of transistors and integrated circuits and parametric shifts in operational amplifiers. In most cases the devices do not fail catastrophically but degraded to the point of circuit level functional failure. Failure analysis techniques include circuit analysis, board level troubleshooting to identify the degraded components. Intermittent failures require power cycling, thermal cycling, and long term monitoring to identify the responsible components. Corrective actions for semiconductor wear out at SONGS include enhanced monitoring and proactive change out of identified part types.


Author(s):  
E. H. Yeoh ◽  
W. M. Mak ◽  
H. C. Lock ◽  
S. K. Sim ◽  
C. C. Ooi ◽  
...  

Abstract As device interconnect layers increase and transistor critical dimensions decrease below sub-micron to cater for higher speed and higher packing density, various new and subtle failure mechanisms have emerged and are becoming increasingly prevalent. Silicon dislocation is a new failure mechanism that falls in this category and was for the first time, uncovered in submicron multilayered CMOS devices. This mechanism was responsible for a systematic yield problem; identified as the 'centre GFA wafer' functional failure problem. In this paper, several breakthrough failure analysis techniques used to narrow down and identify this new mechanism will be presented. Root cause determination and potential solution to this problem will also be discussed.


Author(s):  
Shirleen Horley ◽  
Joseph Rascon

Abstract The longer defective units are in the manufacturing pipeline before they are detected, the more expensive it becomes. Economic pressures drive the requirement to capture failures and perform root cause analysis further upstream in the product manufacturing cycle. This places greater emphasis on the ability to identify failures and perform value add analysis to drive product improvements as early as possible. This paper describes the method used to develop a reliable Unified Data Stream (UDS) that feeds the failure analysis process which in turn provides actionable information to product development teams in the Personal Computer (PC) environment. This manuscript describes the development and implementation of the Unified Data Stream designed to replace ambiguity and uncertainty with a defect trend and symptom pareto that drives action upstream. Focus will be on the output of UDS enabling the prioritization of product defects that feed the failure analysis system. Additionally, this paper will touch on the application of the UDS system for different types of pc components. The future of UDS is without bounds as it can also be applied to a wide range of products.


Author(s):  
Vanessa Grace Martinez ◽  
Alden Almero ◽  
Gerard Gador

Abstract A comparison of the electrical performance and effect of different types of flux to Micro Ball Grid Array (ìBGATM) solder ball quality was conducted. The units using no clean flux were found to exhibit opens failures during off-board testing and programming. Initial analysis conducted showed that the failures were due to contact problems between the solder balls and the test/programming sockets resulting from the presence of a transparent residue on the solder balls. In-depth failure analysis, in parallel with experiments conducted in the assembly line, was performed to determine the root cause of the solder ball contamination. Three failure analysis techniques were employed, namely: Scanning Electron Microscopy (SEM), Energy Dispersive Xray Analysis (EDX), and Fourier Transform Infrared (FTIR) Spectroscopy. An initial experiment was conducted to isolate the cause of the contamination by examining the different modules in the ìBGATM assembly. Failure analysis and experimental data proved that the opens failures were due to the no clean flux residue that was deposited on the surface of the solder ball after the reflow process.


Author(s):  
Chao-Chi Wu ◽  
Jon C. Lee ◽  
Jung-Hsiang Chuang ◽  
Tsung-Te Li

Abstract In general failure analysis cases, a less invasive fault isolation approach can be utilized to resolve a visual root cause defect. In the case of nano technology, visual defects are not readily resolved, due to an increase in non-visible defects. The nonvisible defects result in a lower success rate since conventional FA methods/tools are not efficient in identifying the failure root cause. For the advanced nanometer process, this phenomenon is becoming more common; therefore the utilization of advanced techniques are required to get more evidence to resolve the failure mechanism. The use of nanoprobe technology enables advanced device characterization h order to obtain more clues to the possible failure mechanism before utilizing the traditional physical failure analysis techniques.


Author(s):  
Jose Z. Garcia ◽  
Kris Dickson

Abstract This paper describes how a DDR loopback test failure was analyzed successfully after being repackaged from an MBGA into a TBGA package substrate. DDR loopback test methodology is discussed as well as the advanced failure analysis techniques that were used to identify the root cause of failure.


Author(s):  
Zhigang Song ◽  
Oliver D. Patterson ◽  
Qian Xu

Abstract Process defects, either random or systematic, are often the top killers of any semiconductor device. Process defect learning and reduction are the main focuses in both technology development stage and product manufacturing yield ramp stage. In order to achieve fast defect learning, in-line defect inspection is implemented in critical layers during wafer manufacturing. In-line defect inspection is able to detect defects. However, in-line defect inspection alone cannot predict the impact of defects on device functional yield. Failure analysis is an effective method of finding the defects which really cause device functional failures. However, often, the defects found by failure analysis are very different from the original defects, making it difficult to understand the root cause. This paper will describe a methodology how to combine in-line defect inspection and failure analysis together to found the top killer defects and accelerate their root cause identification for fast defect learning and yield improvement.


Author(s):  
Z. G. Song ◽  
S. B. Ippolito ◽  
P. J. McGinnis ◽  
A. Shore ◽  
B. Paulucci ◽  
...  

Abstract It is generally accepted that the fault isolation of Vdd short and leakage can be globally addressed by liquid crystal analysis (LCA), photoemission analysis and/or laser stimulating techniques such as OBIRCH or TIVA. However, the hot spot detected by these techniques may be a secondary effect, rather than the exact physical defect location. Further electrical probing with knowledge of the circuit schematic and layout may still be required to pinpoint the exact physical defect location, so that a suitable physical analysis methodology can be chosen to identify the root cause of the failure. This paper has described a thorough analysis process for Vdd leakage failure by a combination of various failure analysis techniques and finally the root cause of the Vdd leakage was identified.


Author(s):  
Hua Younan ◽  
Chu Susan ◽  
Gui Dong ◽  
Mo Zhiqiang ◽  
Xing Zhenxiang ◽  
...  

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.


Author(s):  
Amy Poe ◽  
Steve Brockett ◽  
Tony Rubalcava

Abstract The intent of this work is to demonstrate the importance of charged device model (CDM) ESD testing and characterization by presenting a case study of a situation in which CDM testing proved invaluable in establishing the reliability of a GaAs radio frequency integrated circuit (RFIC). The problem originated when a sample of passing devices was retested to the final production test. Nine of the 200 sampled devices failed the retest, thus placing the reliability of all of the devices in question. The subsequent failure analysis indicated that the devices failed due to a short on one of two capacitors, bringing into question the reliability of the dielectric. Previous ESD characterization of the part had shown that a certain resistor was likely to fail at thresholds well below the level at which any capacitors were damaged. This paper will discuss the failure analysis techniques which were used and the testing performed to verify the failures were actually due to ESD, and not caused by weak capacitors.


Sign in / Sign up

Export Citation Format

Share Document