Non-Invasive Backside Failure Analysis of Integrated Circuits by Time-Dependent Light Emission: Picosecond Imaging Circuit Analysis

Author(s):  
J.A. Kash ◽  
J.C. Tsang ◽  
D.R. Knebel ◽  
D.P. Vallett

Abstract A noninvasive backside probe of integrated circuits has been developed. This new probe can diagnose at-speed failures, stuck faults, and other defects. Because it is a highly parallel imaging technique, faults may be isolated which are difficult to locate by other methods. This optical technique has been named “PICA”, for picosecond imaging circuit analysis. PICA relies on the fact that an FET in a CMOS circuit emits a picosecond pulse of light each time the logic gate changes state. The source of this emission is explained. The PICA technique, which combines optical imaging of the emission with picosecond time-resolution, is described. Because of the imaging, time-resolved emission data is acquired for many transistors in parallel. The use of the emission for failure analysis and AC characterization of integrated circuits is demonstrated. Because the emission can be detected from either the front or back side of the chip, it can be used for both front and back side analysis.

Author(s):  
Thierry Parrassin ◽  
Sylvain Dudit ◽  
Michel Vallet ◽  
Antoine Reverdy ◽  
Hervé Deslandes

Abstract By adding a transmission grating into the optical path of our photon emission system and after calibration, we have completed several failure analysis case studies. In some cases, additional information on the emission sites is provided, as well as understanding of the behavior of transistors that are associated to the fail site. The main application of the setup is used for finding and differentiating easily related emission spots without advance knowledge in light emission mechanisms in integrated circuits.


2013 ◽  
Vol 21 (3) ◽  
pp. 30-35
Author(s):  
Douglas Martin ◽  
Samuel Beilin ◽  
Brett Hamilton ◽  
Darin York ◽  
Philip Baker ◽  
...  

Failure analysis is important in determining root cause for appropriate corrective action. In order to perform failure analysis of microelectronic application-specific integrated circuits (ASICs) delidding the device is often required. However, determining root cause from the front side is not always possible due to shadowing effects caused by the ASIC metal interconnects. Therefore, back-side polishing is used to reveal an unobstructed view of the ASIC silicon transistors. This paper details how back-side polishing in conjunction with laser-scanned imaging (LSI), laser voltage imaging (LVI), laser voltage probing (LVP), photon emission microscopy (PEM), and laser-assisted device alterations (LADA) were used to uncover the root cause of failure of two ASICs.


Author(s):  
Franco Stellari ◽  
Chung-Ching Lin ◽  
Lynne Gignac ◽  
Raphael Robertazzi ◽  
Alan Weger ◽  
...  

Abstract In this paper, we discuss a set of techniques and analysis methodologies for the reverse engineering and functionality extraction of complex mixed-signal ICs with a special focus for security applications. Front and back side reflected light pattern images at different magnifications are used to identify circuit blocks. Time-integrated and time-resolved photon emission data is used to identify gate logic states, sequences of events, and specific functional activity. Backscattered electron and scanning transmission electron images mosaics are used to reverse engineer individual gates and observe local interconnects. Thermal imaging is used to aid in the functional block identification and analog gates analysis. Different advanced methodologies for tool automation, focusing, mapping, and image processing are also discussed in the context of our proposed electro-optical tester based technique.


Author(s):  
Matthew M. Mulholland ◽  
Ahmed A. Helmy ◽  
Anthony V. Dao

Abstract Post silicon validation techniques specifically Focused Ion Beam (FIB) circuit editing and Failure Analysis (FA) require sample preparation on Integrated Circuits (IC). Although these preparation techniques are typically done globally across the encapsulated and silicon packaging materials, in some scenarios with tight mechanical or thermal boundary conditions, only a local approach can be attempted for the analysis. This local approach to access the underlying features, such as circuits, solder bumps, and electrical traces can be divided into two modification approaches. The back side approach is typically done for die level analysis by de-processing through encapsulated mold compound and silicon gaining access to the silicon transistor level. On the other hand, the front side approach is typically used for package level analysis by de-processing the ball grid array (BGA) and package substrate layers. Both of these local de-processing approaches can be done by using the conventional Laser Chemical Etching (LCE) platforms. The focus of this paper will be to investigate a front side modification approach to provide substrate material removal solutions. Process details and techniques will be discussed to gain access to metal signals for further failure analysis and debug. A pulse laser will be used at various processing stages to de-process IC package substrate materials.


Author(s):  
Franco Stellari ◽  
Peilin Song ◽  
Alan J. Weger ◽  
Tian Xia

Abstract Light Emission due to Off-State Leakage Current (LEOSLC) is used in combination with the Picosecond Imaging Circuit Analysis (PICA) method to effectively diagnose and localize defects in a broken scan chain. As usual, the emission base method shows to be very effective in debugging the problem; the defect is successfully identified by the optical technique and confirmed by Physical Failure Analysis (PFA).


2005 ◽  
Vol 45 (9-11) ◽  
pp. 1476-1481 ◽  
Author(s):  
M. Remmach ◽  
A. Pigozzi ◽  
R. Desplats ◽  
P. Perdu ◽  
D. Lewis ◽  
...  

Author(s):  
John R. Devaney

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.


Author(s):  
D.S. Patrick ◽  
L.C. Wagner ◽  
P.T. Nguyen

Abstract Failure isolation and debug of CMOS integrated circuits over the past several years has become increasingly difficult to perform on standard failure analysis functional testers. Due to the increase in pin counts, clock speeds, increased complexity and the large number of power supply pins on current ICS, smaller and less equipped testers are often unable to test these newer devices. To reduce the time of analysis and improve the failure isolation capabilities for failing ICS, failure isolation is now performed using the same production testers used in product development, multiprobe and final test. With these production testers, the test hardware, program and pattern sets are already available and ready for use. By using a special interface that docks the production test head to failure isolation equipment such as the emission microscope, liquid crystal station and E-Beam prober, the analyst can quickly and easily isolate the faillure on an IC. This also enables engineers in design, product engineering and the waferfab yield enhancement groups to utilize this equipment to quickly solve critical design and yield issues. Significant cycle time savings have been achieved with the migration to this method of electrical stimulation for failure isolation.


Author(s):  
P. Schwindenhammer ◽  
H. Murray ◽  
P. Descamps ◽  
P. Poirier

Abstract Decapsulation of complex semiconductor packages for failure analysis is enhanced by laser ablation. If lasers are potentially dangerous for Integrated Circuits (IC) surface they also generate a thermal elevation of the package during the ablation process. During measurement of this temperature it was observed another and unexpected electrical phenomenon in the IC induced by laser. It is demonstrated that this new phenomenon is not thermally induced and occurs under certain ablation conditions.


Author(s):  
B.J. Cain ◽  
G.L. Woods ◽  
A. Syed ◽  
R. Herlein ◽  
Toshihiro Nomura

Abstract Time-Resolved Emission (TRE) is a popular technique for non-invasive acquisition of time-domain waveforms from active nodes through the backside of an integrated circuit. [1] State-of-the art TRE systems offer high bandwidths (> 5 GHz), excellent spatial resolution (0.25um), and complete visibility of all nodes on the chip. TRE waveforms are typically used for detecting incorrect signal levels, race conditions, and/or timing faults with resolution of a few ps. However, extracting the exact voltage behavior from a TRE waveform is usually difficult because dynamic photon emission is a highly nonlinear process. This has limited the perceived utility of TRE in diagnosing analog circuits. In this paper, we demonstrate extraction of voltage waveforms in passing and failing conditions from a small-swing, differential logic circuit. The voltage waveforms obtained were crucial in corroborating a theory for some failures inside an 0.18um ASIC.


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