X-Sectional Scanning Capacitance Microscopy (SCM) Applications on Deep Submicron Devices at Specific Sites

Author(s):  
Xiang-Dong Wang ◽  
Yuk Tsang ◽  
Clifford Howard

Abstract In this paper, we present our recent applications of scanning capacitance microscopy (SCM) on specific devices with sampling window as small as 100nm. The dopant related root causes were successfully identified on those devices fabricated with 90nm CMOS technology. The key step in our approach is the development of a sample preparation technique that allows us to precisely x-section through a transistor without being affected by focused ion beam (FIB) artifacts. FIB was used to mark the area of interest with high precision, but it did not expose the devices of interest. Optical microscope and atomic force microscope (AFM) were used to inspect the mechanically polished surface, thus avoiding beam effects from FIB or SEM. In the first application, a doping anomaly was identified in a PFET poly gate, in a single bit failed SRAM cell. In the second application, an asymmetry of a PWell implant profile in a window of 150nm was identified as the cause of leakage in a capacitor array. Our approach may be applied to other scanning probe microscopy (SPM) techniques in the same category, i.e., scanning spreading resistance microscopy (SSRM) or scanning microwave microscopy (SMM).

Author(s):  
Y. S. Huan ◽  
Y. L. Kuo ◽  
Y.T. Lin ◽  
Jeff Chen ◽  
K.Y. Lee

Abstract Wire bonding is the most highly used interconnection technology in the packaging of integrated circuits. One of the potential risks of wire bonding is the damage on the oxide layers underneath the bond pad. Oxide damage monitoring is necessary to ensure bonding has no impact on the oxide layers under the bond pad. Since the oxide layer is not seen by visual inspection, bond pad stripping is necessary. Three bond pad stripping chemicals KOH, Aqua regia, and phosphoric acid were investigated in this study. Results obtained by dipping the chemicals at different temperatures, and time scales will be given. An optical microscope (OM) and scanning electron microscope (SEM) are used to observe the oxide conditions from the top view. To understand the mechanism of the oxide damage caused by wire bonding, a focused ion beam was used to observe the cross-section of the defect.


2001 ◽  
Vol 7 (S2) ◽  
pp. 942-943
Author(s):  
Lucille A. Giannuzzi ◽  
Henry J. White ◽  
Wayne C. Chen

The FIB lift-out (LO) technique has been applied to a sample that been pulled to failure by tensile testing. An aluminum alloy (5083) was cold deformed using DSI's Maxistrain technology [1]. The alloy was cut with a low speed diamond coated wafering blade such that the fracture surface would fit inside the focused ion beam (FIB) specimen chamber. The sample was then mounted and placed in an FEI 200TEM FIB instrument. An FIB image of the tip of the fracture surface is shown in figure 1. A region for TEM specimen preparation was chosen such that the specimen would be in the plane of the tensile axis. The area of interest was chosen to ensure that FIB undercutting of the specimen could be accomplished upon tilting inside the FIB, and to ensure that the micromanipulator needle would have access to the FIB prepared specimen. A region of interest was coated with Pt using the FIB. A TEM specimen was then prepared in the usual LO manner [2,3]. The location of the finished LO specimen is circled in figure 1. After FIB milling was completed, the sample was removed from the FIB and placed on a light optical microscope stage. The electron transparent membrane was removed from the deformed sample using a glass rod attached to a micromanipulator. While the successful LO was performed, it should be noted that the micromanipulation was non-trivial due to the rough fracture surface combined with the poor depth of field of the light optical microscope.


Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.


Author(s):  
Jim B. Colvin

Abstract A new method of preparation will be shown which allows traditional fixturing such as test heads and probe stations to be utilized in a normal test mode. No inverted boards cabled to a tester are needed since the die remains in its original package and is polished and rebonded to a new package carrier with the polished side facing upward. A simple pin reassignment is all that is needed to correct the reverse wire sequence after wire to wire bonding or wire to frame bonding in the new package frame. The resulting orientation eliminates many of the problems of backside microscopy since the resulting package orientation is now frontside. The low profile as a result of this technique allows short working distance objectives such as immersion lenses to be used across the die surface. Test equipment can be used in conjunction with analytical tools such as the emission microscope or focused ion beam due to the upright orientation of the polished backside silicon. The relationship between silicon thickness and transmission for various wavelengths of light will be shown. This preparation technique is applicable to advanced packaging methods and has the potential to become part of future assembly processes.


Author(s):  
Alexander Richards ◽  
Matthew Weschler ◽  
Michael Durller

Abstract To help solve the navigational problem, i.e., being able to successfully locate a circuit for probing or editing without destroying chip functionality, a near-infrared (NIR), near-ultraviolet (NUV), and visible spectrum camera system was developed that attaches to most focused ion beam (FIB) or scanning electron microscope vacuum chambers. This paper reviews the details of the design and implementation of the NIR/NUV camera system, as instantiated upon the FEI FIB 200, with a particular focus on its use for the visualization of buried structures, and also for non-destructive real time area of interest location and end point detection. It specifically considers the use of the micro-optical camera system for its benefit in assisting with frontside and backside circuit edit, as well as other typical FIB milling activities. The quality of the image obtained by the IR camera rivals or exceeds traditional optical based imaging microscopy techniques.


Microscopy ◽  
2020 ◽  
Author(s):  
Kazuo Yamamoto ◽  
Satoshi Anada ◽  
Takeshi Sato ◽  
Noriyuki Yoshimoto ◽  
Tsukasa Hirayama

Abstract Phase-shifting electron holography (PS-EH) is an interference transmission electron microscopy technique that accurately visualizes potential distributions in functional materials, such as semiconductors. In this paper, we briefly introduce the features of the PS-EH that overcome some of the issues facing the conventional EH based on Fourier transformation. Then, we present a high-precision PS-EH technique with multiple electron biprisms and a sample preparation technique using a cryo-focused-ion-beam, which are important techniques for the accurate phase measurement of semiconductors. We present several applications of PS-EH to demonstrate the potential in organic and inorganic semiconductors and then discuss the differences by comparing them with previous reports on the conventional EH. We show that in situ biasing PS-EH was able to observe not only electric potential distribution but also electric field and charge density at a GaAs p-n junction and clarify how local band structures, depletion layer widths, and space charges changed depending on the biasing conditions. Moreover, the PS-EH clearly visualized the local potential distributions of two-dimensional electron gas (2DEG) layers formed at AlGaN/GaN interfaces with different Al compositions. We also report the results of our PS-EH application for organic electroluminescence (OEL) multilayers and point out the significant potential changes in the layers. The proposed PS-EH enables more precise phase measurement compared to the conventional EH, and our findings introduced in this paper will contribute to the future research and development of high-performance semiconductor materials and devices.


Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
R. Li ◽  
M.L. Ray ◽  
P.E. Fischione ◽  
...  

Abstract Fast and accurate examination from the bulk to the specific area of the defect in advanced semiconductor devices is critical in failure analysis. This work presents the use of Ar ion milling methods in combination with Ga focused ion beam (FIB) milling as a cutting-edge sample preparation technique from the bulk to specific areas by FIB lift-out without sample-preparation-induced artifacts. The result is an accurately delayered sample from which electron-transparent TEM specimens of less than 15 nm are obtained.


2002 ◽  
Vol 716 ◽  
Author(s):  
Larry Rice

AbstractMicroscopists are faced with many challenges in locating and examining failure sites in the ever-shrinking semiconductor device. The site must be located using electrical characterization techniques like electron beam induced current (EBIC), photo emission microscopy (PEM) or liquid crystal (LC) and then cross-sectioned with a focused ion beam (FIB). Both PEM and LC require the semiconductor circuit to be running near operating conditions which has been observed to locally melt the area of interest, frequently destroying evidence of the failure mechanism. In contrast, EBIC typically can be accomplished at low or no applied voltage eliminating further damage to the circuit. EBIC has been applied to locate leakage sites in high voltage metal oxide semiconductor (MOS) electro static discharge (ESD) reliability failures. In addition to a brief revisit of the basic principles of EBIC and describing a technique to successfully cross section ‘hot spots’ for transmission electron microscopy (TEM) observation, focus will be placed on a case study of the reliability testing failure analysis of ESD power transistors using EBIC, SEM, focused ion beam (FIB), and XTEM.


2017 ◽  
Vol 23 (3) ◽  
pp. 484-490 ◽  
Author(s):  
Andrey Denisyuk ◽  
Tomáš Hrnčíř ◽  
Jozef Vincenc Oboňa ◽  
Sharang ◽  
Martin Petrenec ◽  
...  

AbstractWe report on the mitigation of curtaining artifacts during transmission electron microscopy (TEM) lamella preparation by means of a modified ion beam milling approach, which involves altering the incident angle of the Ga ions by rocking of the sample on a special stage. We applied this technique to TEM sample preparation of a state-of-the-art integrated circuit based on a 14-nm technology node. Site-specific lamellae with a thickness <15 nm were prepared by top-down Ga focused ion beam polishing through upper metal contacts. The lamellae were analyzed by means of high-resolution TEM, which showed a clear transistor structure and confirmed minimal curtaining artifacts. The results are compared with a standard inverted thinning preparation technique.


1997 ◽  
Vol 480 ◽  
Author(s):  
L. A. Giannuzzi ◽  
J. L. Drown ◽  
S. R. Brown ◽  
R. B. Irwin ◽  
F. A. Stevie

AbstractA site specific technique for cross-section transmission electron microscopy specimen preparation of difficult materials is presented. Focused ion beams are used to slice an electron transparent sliver of the specimen from a specific area of interest. Micromanipulation lift-out procedures are then used to transport the electron transparent specimen to a carbon coated copper grid for subsequent TEM analysis. The experimental procedures are described in detail and an example of the lift-out technique is presented.


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