The Failure Analysis of Specific Source-to-Drain Dislocation and Case Study

Author(s):  
C. H. Wang ◽  
S.W. Lai ◽  
C.Y. Wu ◽  
B.T. Chen ◽  
J.Y. Chiou ◽  
...  

Abstract A failure incurred in the front-end is typically a bottleneck to production due the need for physical failure analysis (PFA). Often the challenge is to perform timely localization of the front-end defect, or finding the exact physical defect for process improvement. Many process parameters affect the device behaviour and cause the front-end defect. Simply, the failures are of two types: high-resistance and leakage. A leakage mode defect is the most difficult to inspect. Although conductive atomic force microscopy and six probes nano-probing are popular tools for front-end failure inspection, some specific defects still need more effort. The electrical phenomenon and analysis of a crystalline defect will be demonstrated in this paper. The details will be discussed below.

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

Abstract This article describes the electrical and physical analysis of gate leakage in nanometer transistors using conducting atomic force microscopy (C-AFM), nano-probing, transmission electron microscopy (TEM), and chemical decoration on simulated overstressed devices. A failure analysis case study involving a soft single bit failure is detailed. Following the nano-probing analysis, TEM cross sectioning of this failing device was performed. A voltage bias was applied to exaggerate the gate leakage site. Following this deliberate voltage overstress, a solution of boiling 10%wt KOH was used to etch decorate the gate leakage site followed by SEM inspection. Different transistor leakage behaviors can be identified with nano-probing measurements and then compared with simulation data for increased confidence in the failure analysis result. Nano-probing can be used to apply voltage stress on a transistor or a leakage path to worsen the weak point and then observe the leakage site easier.


Author(s):  
Chuan Zhang ◽  
Yinzhe Ma ◽  
Gregory Dabney ◽  
Oh Chong Khiam ◽  
Esther P.Y. Chen

Abstract Soft failures are among the most challenging yield detractors. They typically show test parameter sensitive characteristics, which would pass under certain test conditions but fail under other conditions. Conductive-atomic force microscopy (CAFM) emerged as an ideal solution for soft failure analysis that can balance the time and thoroughness. By inserting CAFM into the soft failure analysis flow, success rate of such type of analysis can be significantly enhanced. In this paper, a logic chain soft failure and a SRAM local bitline soft failure are used as examples to illustrate how this failure analysis methodology provides a powerful and efficient solution for soft failure analysis.


2018 ◽  
Author(s):  
Lucile C. Teague Sheridan ◽  
Tanya Schaeffer ◽  
Yuting Wei ◽  
Satish Kodali ◽  
Chong Khiam Oh

Abstract It is widely acknowledged that Atomic force microscopy (AFM) methods such as conductive probe AFM (CAFM) and Scanning Capacitance Microscopy (SCM) are valuable tools for semiconductor failure analysis. One of the main advantages of these techniques is the ability to provide localized, die-level fault isolation over an area of several microns much faster than conventional nanoprobing methods. SCM, has advantages over CAFM in that it is not limited to bulk technologies and can be utilized for fault isolation on SOI-based technologies. Herein, we present a case-study of SCM die-level fault isolation on SOI-based FinFET technology at the 14nm node.


Author(s):  
Chuan Zhang ◽  
Oh Chong Khiam ◽  
Esther P.Y. Chen

Abstract The increase in complexity of process, structure, and design not only increases the amount of failure analysis (FA) work significantly, but also leads to more complicated failure modes. To meet the need of high success rate and fast throughput FA operation at the leading-edge nodes, novel FA techniques have to be explored and incorporated into the routine FA flow. One of the novel techniques incorporated into the presented scan logic FA flow is the conductive-atomic force microscopy (CAFM) technique. This paper demonstrates CAFM technique as a powerful and efficient solution for scan logic failure analysis at advanced technology nodes. Several failure modes in scan logic FA are used as examples to illustrate how CAFM provides excellent solutions to some of the very challenging FA problems. The gate to active short in nFET devices, resistive contact, and open defect on gate contact are some modes used.


Author(s):  
C.H. Chen ◽  
C.M. Shen ◽  
C.M. Huang ◽  
Y.F. Hsia

Abstract The passive voltage contrast (PVC) in this experiment was widely used to detect open/short issues for most failure analyses. However, most of back-end particles were visible, but front-end particles were not. And sometimes only used PVC image, the failure mechanism was un-imaginable. As a result, we needed to collect some electrical data to explain complex PVC image, before physical failure analysis (PFA) was started. This paper shows how to use the scanning probe microscope (SPM) tool to make up PVC method and overcome the physical failure analysis challenge. From our experiment, the C-AFM could provide more information of the defect type and give faster feedback to production lines.


Author(s):  
Chuan Zhang ◽  
Esther P.Y. Chen

Abstract A variety of parametric test structures were designed with the purpose of characterizing parameters tied to failure modes for specific structures, and the electrical test of the parametric test structures are typically conducted earlier inline, which could be months ahead of the functional test. Due to the unique advantages, conductive-atomic force microscopy (CAFM) was introduced to parametric test structure failure analysis during advanced technology development, and has been proven to be a powerful solution to many challenging failure analysis (FA) problems. This paper uses several case studies to illustrate how CAFM can be used to successfully localize defects in challenging parametric test structures that would otherwise be invisible with conventional FA techniques.


Author(s):  
Kun Lin ◽  
Hang Zhang ◽  
Shey-shi Lu

Abstract Conductive Atomic Force Microscopy (C-AFM) is a useful tool for both electrical failure analysis (EFA) and physical failure analysis (PFA). In this paper, the root cause of a physical failure in an analysis image was verified from the evidence of two-dimensional AFM profile depth measurement. The other analysis technique, which is electrical parameter extraction by contacting I-V spectroscopy measurement, was also utilized to locate the possible defects. As a result, the failure mechanism was illustrated with an AFM topography image, which showed the silicon surface profile after removal of cobalt salicide (self-alignment silicide) by dilute HF. The vertical junction leakage path was identified with a C-AFM image.


Author(s):  
Hung-Sung Lin ◽  
Wen-Tung Chang ◽  
Chia-Hsing Chao ◽  
Jesse Wang ◽  
Chang-Tan Lin ◽  
...  

Abstract Single column failure [1], one of the complex failure modes in SRAM is possibly induced by multiform defect types at diverse locations. Especially, soft single column failure is of great complexity. As physical failure analysis (PFA) is expensive and time-consuming, thorough electrical failure analysis (EFA) is needed to precisely localize the failing area to greater precision before PFA. The methodology involves testing for failure mode validation, understanding the circuit and using EFA tools such as IR-OBIRCH (InfraRed-Optical Beam Induced Resistance CHange) and MCT (MerCad Telluride, HgCdTe) for analysis. However, the electrical failure signature for soft single column failure is usually marginal, so additional techniques are needed to obtain accurate isolation and electrical characterization instead of blindly looking around. Thus in this discussion, we will also present the use of internal probing techniques like C-AFM [2] (Conductive Atomic Force Microscopy) and a nanoprobing technique [3] for characterizing electrical properties and understanding the root cause.


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