A Novel Technique of Device Measurement after Cross-Sectional FIB in Failure Analysis

Author(s):  
Chih-Chung Chang ◽  
Jian-Chang Lin ◽  
Wen-Sheng Wu ◽  
Chih-Ying Tasi ◽  
Ching-Lin Chang

Abstract A dual beam FIB (Focused Ion Beam) system which provides the ion beam (i-beam) and electron beam (e-beam) function are widely used in semiconductor manufacture for construction analysis and failure cause identification. Although FIB is useful for defect or structure inspection, sometimes, it is still difficult to diagnose the root cause via FIB e-beam image due to resolution limitation especially in products using nano meter scale processes. This restriction will deeply impact the FA analysts for worst site or real failure site judgment. The insufficient e-beam resolution can be overcome by advanced TEM (Transmission Electron Microscope) technology, but how can we know if this suspected failure site is a real killer or not when looking at the insufficient e-beam images inside a dual beam tool? Therefore, a novel technique of device measurement by using C-AFM (Conductive Atomic Force Microscope) or Nano-Probing system after cross-sectional (X-S) FIB inspection has been developed based on this requirement. This newly developed technology provides a good chance for the FA analysts to have a device characteristic study before TEM sample preparation. If there is any device characteristic shift by electrical measurement, the following TEM image should show a solid process abnormality with very high confidence. Oppositely, if no device characteristic shift can be measured, FIB milling is suggested to find the real fail site instead of trying TEM inspection directly.

1995 ◽  
Vol 380 ◽  
Author(s):  
C. Deng ◽  
J. C. Wu ◽  
C. J. Barbero ◽  
T. W. Sigmon ◽  
M. N. Wybourne

ABSTRACTA fabrication process for sub-100 nm Ge wires on Si substrates is reported for the first time. Wires with a cross section of 6 × 57 nm2 are demonstrated. The wire structures are analyzed by atomic force (AFM), scanning electron (SEM), and transmission electron microscopy (TEM). Sample preparation for TEM is performed using a novel technique using both pre and in situ deposition of multiple protection layers using a Focused Ion Beam (FIB) micromachining system.


2007 ◽  
Vol 1026 ◽  
Author(s):  
Xuetian Han ◽  
Judith C. Yang

AbstractTo gain fundamental insights into metal oxidation, the dynamically formed Cu/Cu2O interface was investigated by cross-sectional TEM (Transmission Electron Microscopy) methods. Copper (001) films were oxidized in oxygen within a UHV chamber to create Cu2O islands that formed epitaxially with respect to the Cu film. The cross-sectional Cu2O/Cu TEM sample was prepared by dual beam (DB) focused ion beam (FIB) instrument and the interface was probed by high-resolution TEM (HREM) and electron energy loss spectrum (EELS). It is found that Cu2O {110} layer distance significantly decreases from the interface area to the bulk Cu2O region, which is about 3∼4 unit cell thickness in Cu2O side; while the {100Cu2O layer distance increases with increasing distance from the interface region. The chemical Cu/Cu2O interface thickness has been measured with EELS analysis, which is about 2nm where the oxidation state of Cu gradually changes from Cu0 to Cu+1. This transition region indicates the area where Cu/Cu2O interface exists and suggests the existence of metastable Cu oxides. The Cu2O island growth mechanism of predominantly anion interfacial diffusion at the initial stage oxidation has been proposed.


Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.


Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.


Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.


Author(s):  
C.H. Wang ◽  
S.P. Chang ◽  
C.F. Chang ◽  
J.Y. Chiou

Abstract Focused ion beam (FIB) is a popular tool for physical failure analysis (FA), especially for circuit repair. FIB is especially useful on advanced technology where the FIB is used to modify the circuit for new layout verification or electrical measurement. The samples are prepared till inter-metal dielectric (IMD), then a hole is dug or a metal is deposited or oxide is deposited by FIB. A common assumption is made that metal under oxide can not be seen by FIB. But a metal ion image is desired for further action. Dual beam, FIB and Scanning Electron Microscope (SEM), tools have a special advantage. When switching back and forth from SEM to FIB the observation has been made that the metal lines can be imaged. The details of this technique will be discussed below.


2007 ◽  
Vol 13 (S02) ◽  
Author(s):  
T Gutu ◽  
J Wu ◽  
C Jeffreys ◽  
C-H Chang ◽  
G Rorrer ◽  
...  

2011 ◽  
Vol 17 (6) ◽  
pp. 889-895 ◽  
Author(s):  
Lynne M. Gignac ◽  
Surbhi Mittal ◽  
Sarunya Bangsaruntip ◽  
Guy M. Cohen ◽  
Jeffrey W. Sleight

AbstractThe ability to prepare multiple cross-section transmission electron microscope (XTEM) samples from one XTEM sample of specific sub-10 nm features was demonstrated. Sub-10 nm diameter Si nanowire (NW) devices were initially cross-sectioned using a dual-beam focused ion beam system in a direction running parallel to the device channel. From this XTEM sample, both low- and high-resolution transmission electron microscope (TEM) images were obtained from six separate, specific site Si NW devices. The XTEM sample was then re-sectioned in four separate locations in a direction perpendicular to the device channel: 90° from the original XTEM sample direction. Three of the four XTEM samples were successfully sectioned in the gate region of the device. From these three samples, low- and high-resolution TEM images of the Si NW were taken and measurements of the NW diameters were obtained. This technique demonstrated the ability to obtain high-resolution TEM images in directions 90° from one another of multiple, specific sub-10 nm features that were spaced 1.1 μm apart.


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