Short Localization in 2.5D Microchip with Interposer Using Magnetic Current Imaging

Author(s):  
J. Gaudestad ◽  
D. Nuez ◽  
P. Tan

Abstract Interposers used in 2.5D technologies introduce new challenges for Electric Fault Isolation (EFI) due to the multiple layers of silicon, metal layers, Through Silicon Vias (TSV), solder bumps and/or copper pillars making it hard for standard EFI techniques, such as thermal and optical techniques, to localize failures due to the opaqueness of these materials [1, 2, 3]. In this paper we show that shorts in 2.5D Integrated Circuits (IC) technologies can be localized accurately in x, y and z-direction using Magnetic Current Imaging (MCI) while injecting a low power current and showing that the materials used in 2.5D semiconductor manufacturing are fully transparent to magnetic fields.

Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.


Author(s):  
Steve K. Hsiung ◽  
Kevan V. Tan ◽  
Andrew J. Komrowski ◽  
Daniel J. D. Sullivan ◽  
Jan Gaudestad

Abstract Scanning SQUID (Superconducting Quantum Interference Device) Microscopy, known as SSM, is a non-destructive technique that detects magnetic fields in Integrated Circuits (IC). The magnetic field, when converted to current density via Fast Fourier Transform (FFT), is particularly useful to detect shorts and high resistance (HR) defects. A short between two wires or layers will cause the current to diverge from the path the designer intended. An analyst can see where the current is not matching the design, thereby easily localizing the fault. Many defects occur between or under metal layers that make it impossible using visible light or infrared emission detecting equipment to locate the defect. SSM is the only tool that can detect signals from defects under metal layers, since magnetic fields are not affected by them. New analysis software makes it possible for the analyst to overlay design layouts, such as CAD Knights, directly onto the current paths found by the SSM. In this paper, we present four case studies where SSM successfully localized short faults in advanced wire-bond and flip-chip packages after other fault analysis methods failed to locate the defects.


Author(s):  
Jeremy A. Walraven ◽  
Mark W. Jenkins ◽  
Tuyet N. Simmons ◽  
James E. Levy ◽  
Sara E. Jensen ◽  
...  

Abstract Manufacturing of integrated circuits (ICs) using a split foundry process expands design space in IC fabrication by employing unique capabilities of multiple foundries and provides added security for IC designers [1]. Defect localization and root cause analysis is critical to failure identification and implementation of corrective actions. In addition to split-foundry fabrication, the device addressed in this publication is comprised of 8 metal layers, aluminum test pads, and tungsten thru-silicon vias (TSVs) making the circuit area > 68% metal. This manuscript addresses the failure analysis efforts involved in root cause analysis, failure analysis findings, and the corrective actions implemented to eliminate these failure mechanisms from occurring in future product.


Author(s):  
Frederick S. Felt

Abstract SQUID and MR magnetic sensors have separately been used for fault isolation of shorts and resistive opens in integrated circuits and packages. These two technologies were once considered to be mutually exclusive, although recent studies [1] rather pointed to their complementary character. This paper shows, for the first time, the use of these two sensors together to isolate a low resistance short in a Quad-NAND gate microcircuit. Electrical test confirmed low resistance shorts between three of the device pins. However, internal optical inspection found no evidence of failure. The low resistance of the shorts was deemed insufficient for liquid crystal analysis. Magnetic current imaging with a SQUID sensor confirmed current flow through the package lead frame and isolated the defect to the microcircuit. Due to package design and the resulting distance of the scan plane, the SQUID was unable to resolve the current path on the microcircuit. In parallel with the SQUID, a magnetoresistive (MR) probe was employed to fit inside the device cavity, make direct contact with the microcircuit, and map high-resolution current images. Two sites with high-current density were accurately identified by MCI in input transistors. Subsequent deprocessing revealed that the defects were located under a broad sheet of aluminum metallization which blocked optical detection, and rendered detection by thermal emission difficult.


2018 ◽  
Author(s):  
Daechul Choi ◽  
Yoonseong Kim ◽  
Jongyun Kim ◽  
Han Kim

Abstract In this paper, we demonstrate cases for actual short and open failures in FCB (Flip Chip Bonding) substrates by using novel non-destructive techniques, known as SSM (Scanning Super-conducting Quantum Interference Device Microscopy) and Terahertz TDR (Time Domain Reflectometry) which is able to pinpoint failure locations. In addition, the defect location and accuracy is verified by a NIR (Near Infra-red) imaging system which is also one of the commonly used non-destructive failure analysis tools, and good agreement was made.


Author(s):  
Dan Bodoh ◽  
Kent Erington ◽  
Kris Dickson ◽  
George Lange ◽  
Carey Wu ◽  
...  

Abstract Laser-assisted device alteration (LADA) is an established technique used to identify critical speed paths in integrated circuits. LADA can reveal the physical location of a speed path, but not the timing of the speed path. This paper describes the root cause analysis benefits of 1064nm time resolved LADA (TR-LADA) with a picosecond laser. It shows several examples of how picosecond TR-LADA has complemented the existing fault isolation toolset and has allowed for quicker resolution of design and manufacturing issues. The paper explains how TR-LADA increases the LADA localization resolution by eliminating the well interaction, provides the timing of the event detected by LADA, indicates the propagation direction of the critical signals detected by LADA, allows the analyst to infer the logic values of the critical signals, and separates multiple interactions occurring at the same site for better understanding of the critical signals.


Author(s):  
A. Orozco ◽  
N.E. Gagliolo ◽  
C. Rowlett ◽  
E. Wong ◽  
A. Moghe ◽  
...  

Abstract The need to increase transistor packing density beyond Moore's Law and the need for expanding functionality, realestate management and faster connections has pushed the industry to develop complex 3D package technology which includes System-in-Package (SiP), wafer-level packaging, through-silicon-vias (TSV), stacked-die and flex packages. These stacks of microchips, metal layers and transistors have caused major challenges for existing Fault Isolation (FI) techniques and require novel non-destructive, true 3D Failure Localization techniques. We describe in this paper innovations in Magnetic Field Imaging for FI that allow current 3D mapping and extraction of geometrical information about current location for non-destructive fault isolation at every chip level in a 3D stack.


Author(s):  
J. Gaudestad ◽  
F. Rusli ◽  
A. Orozco ◽  
M.C. Pun

Abstract A Flip Chip sample failed short between power and ground. The reference unit had 418Ω and the failed unit with the short had 16.4Ω. Multiple fault isolation techniques were used in an attempt to find the failure with thermal imaging and Magnetic Current Imaging being the only techniques capable of localizing the defect. To physically verify the defect location, the die was detached from the substrate and a die cracked was seen using a visible optical microscope.


Author(s):  
Mayue Xie ◽  
Zhiguo Qian ◽  
Mario Pacheco ◽  
Zhiyong Wang ◽  
Rajen Dias ◽  
...  

Abstract Recently, a new approach for isolation of open faults in integrated circuits (ICs) was developed. It is based on mapping the radio-frequency (RF) magnetic field produced by the defective part fed with RF probing current, giving the name to Space Domain Reflectometry (SDR). SDR is a non-contact and nondestructive technique to localize open defects in package substrates, interconnections and semiconductor devices. It provides 2D failure isolation capability with defect localization resolution down to 50 microns. It is also capable of scanning long traces in Si. This paper describes the principles of the SDR and its application for the localization of open and high resistance defects. It then discusses some analysis methods for application optimization, and gives examples of test samples as well as case studies from actual failures.


Author(s):  
R.K. Jain ◽  
T. Malik ◽  
T.R. Lundquist ◽  
Q.S. Wang ◽  
R. Schlangen ◽  
...  

Abstract Backside circuit edit techniques on integrated circuits (ICs) are becoming common due to increase number of metal layers and flip chip type packaging. However, a thorough study of the effects of these modifications has not been published. This in spite of the fact that the IC engineers have sometimes wondered about the effects of backside circuit edit on IC behavior. The IC industry was well aware that modifications can lead to an alteration of the intrinsic behavior of a circuit after a FIB edit [1]. However, because alterations can be controlled [2], they have not stopped the IC industry from using the FIB to successfully reconfigure ICs to produce working “silicon” to prove design and mask changes. Reliability of silicon device structures, transistors and diodes, are investigated by monitoring intrinsic parameters before and after various steps of modification.


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