Failure Analysis of DRAM Storage Node Trench Capacitors for 0.35-Micron and Follow-On Technologies Using the Focused Ion Beam for Electrical and Physical Analysis

1996 ◽  
Author(s):  
G. Benstetter ◽  
G. Bomberger ◽  
P. Coutu ◽  
R. Danyew ◽  
R. Douse
Keyword(s):  
High Resolution ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Substrate Material ◽  
Mechanical Polishing ◽  
Physical Analysis ◽  
Storage Node ◽  
Wet Chemical ◽  
Voltage Contrast

Abstract Reducing the cell size of DRAMs in 0.35 micron and follow-on technologies requires failure analysis techniques that can analyze single storage node trench capacitors on both test sites and actual product. A combination of electrical microprobing, probeless voltage contrast and physical delayering procedures, all based on focused- ion-beam (FIB) techniques, are described. Because of precise fail localization, high resolution scanning electron microscope (SEM) imaging enables the distinction between process defects and intrinsic breakdowns of node dielectric defects. Isolated storage cells can be electrically characterized by depositing small probe pads, using FIB for contact hole milling and probe-pad deposition. To localize trench capacitors with a leakage path to the surrounding substrate, the trenches are isolated by mechanical polishing and probeless voltage contrast in the FIB tool. Failing trench capacitors can be marked in the FIB tool. Physical isolation of leaking trench capacitors can be achieved by recessing the adjacent trench capacitors, with the FIB used for milling and a subsequent wet chemical removal added for the remaining substrate material. Alternatively, trench capacitors can be inspected from the backside when stabilized by a quartz deposition on top, followed by mechanical polishing from the side and a wet chemical etching of the remaining substrate material. In both cases, the dielectric of the node trench capacitors can be inspected by high resolution SEMs and the defect areas precisely analyzed.

The Novel Dopant Profile Inspection Methodology by FIB

2010 ◽  
Author(s):  
Po Fu Chou ◽  
Li Ming Lu
Keyword(s):  
High Resolution ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Real Sample ◽  
Physical Analysis ◽  
The Novel ◽  
High Contrast ◽  
Dopant Profile ◽  
P Type

Abstract Dopant profile inspection is one of the focused ion beam (FIB) physical analysis applications. This paper presents a technique for characterizing P-V dopant regions in silicon by using a FIB methodology. This technique builds on published work for backside FIB navigation, in which n-well contrast is observed. The paper demonstrates that the technique can distinguish both n- and p-type dopant regions. The capability for imaging real sample dopant regions on current fabricated devices is also demonstrated. SEM DC and FIB DC are complementary methodologies for the inspection of dopants. The advantage of the SEM DC method is high resolution and the advantage of FIB DC methodology is high contrast, especially evident in a deep N-well region.

Solving the Voltage Contrast on Floating Substrate with Standard FA Toolset

2016 ◽  
Author(s):  
Julien Goxe ◽  
Béatrice Vanhuffel ◽  
Marie Castignolles ◽  
Thomas Zirilli
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sample Preparation ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Silicon On Insulator ◽  
Mixed Signal ◽  
Voltage Contrast ◽  
Scanning Electron

Abstract Passive Voltage Contrast (PVC) in a Scanning Electron Microscope (SEM) or a Focused Ion Beam (FIB) is a key Failure Analysis (FA) technique to highlight a leaky gate. The introduction of Silicon On Insulator (SOI) substrate in our recent automotive analog mixed-signal technology highlighted a new challenge: the Bottom Oxide (BOX) layer, by isolating the Silicon Active Area from the bulk made PVC technique less effective in finding leaky MOSFET gates. A solution involving sample preparation performed with standard FA toolset is proposed to enhance PVC on SOI substrate.

Failure Modes, Reliability Analysis and Case Studies on the Integration of Copper and Low-K Technology

2004 ◽  
Author(s):  
Huixian Wu ◽  
James Cargo ◽  
Huixian Wu ◽  
Marvin White
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Cross Section ◽  
Focused Ion Beam ◽  
Failure Modes ◽  
Ion Beam ◽  
Copper Interconnects ◽  
Wet Chemical ◽  
Low K ◽  
Section Analysis

Abstract The integration of copper interconnects and low-K dielectrics will present novel failure modes and reliability issues to failure analysts. This paper discusses failure modes related to Cu/low-K technology. Here, physical failure analysis (FA) techniques including deprocessing and cross-section analysis have been developed. The deprocessing techniques include wet chemical etching, reactive ion etching, chemical mechanical polishing and a combination of these techniques. Case studies on different failure modes related to Cu/low k technology are discussed: copper voiding, copper extrusion; electromigration stress failure; dielectric cracks; delamination-interface adhesion; and FA on circuit-under-pad. For the cross-section analysis of copper/low-K samples, focused ion beam techniques have been developed. Scanning electron microscopy, EDX, and TEM analytical analysis have been used for failure analysis for Cu/low-K technology. Various failure modes and reliability issues have also been addressed.

Comparison of Precision XTEM Specimen Preparation Techniques for Semiconductor Failure Analysis

1997 ◽  
Vol 3 (S2) ◽  
pp. 357-358
Author(s):  
C. Amy Hunt
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Mechanical Polishing ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Tem Analysis ◽  
The Past ◽  
Preparation Techniques

The demand for TEM analysis in semiconductor failure analysis is rising sharply due to the shrinking size of devices. A well-prepared sample is a necessity for getting meaningful results. In the past decades, a significant amount of effort has been invested in improving sample preparation techniques for TEM specimens, especially precision cross-sectioning techniques. The most common methods of preparation are mechanical dimpling & ion milling, focused ion beam milling (FIBXTEM), and wedge mechanical polishing. Each precision XTEM technique has important advantages and limitations that must be considered for each sample.The concept for both dimpling & ion milling and wedge specimen preparation techniques is similar. Both techniques utilize mechanical polishing to remove the majority of the unwanted material, followed by ion milling to assist in final polishing or cleaning. Dimpling & ion milling produces the highest quality samples and is a relatively easy technique to master.

A Study on a Low Cost Thin Film Antireflection Coating Solution for Failure Analysis Applications

2016 ◽  
Author(s):  
Fritz Christian Awitan ◽  
Camille Joyce Garcia ◽  
Dirk Andrew Doyle ◽  
Lawrence Benedict
Keyword(s):  
Failure Analysis ◽  
Focused Ion Beam ◽  
Spray Pyrolysis Technique ◽  
Low Cost ◽  
Ion Beam ◽  
Antireflection Coating ◽  
Hot Plate ◽  
Coating Solution ◽  
Set Up ◽  
Voltage Contrast

Abstract An ARC solution that can be used to improve backside imaging for backside photoemission microscopy applications is presented in this paper. Zinc Oxide (ZnO) -based thin films used as ARCs are deposited at the backside of the failing units through a simple and low cost spray pyrolysis technique. An improvised set-up, composed of an atomizer and a hot plate, is used in the experiment. The paper provides evidence of acceptable process repeatability and demonstrates that the technique and the material have important applications in the field of failure analysis. Furthermore, it shows that the application of ARC resulted in better defect localization. The location of the defect is easily been determined upon doing frontside inspection - to - backside image comparison on the deposited unit. By using high kV ion beam passive voltage contrast (PVC) and angled cut focused ion beam (FIB) cross section, we are able to isolate further and show the nature of the defect at the failing block.

A Simple FIB Method for Constructing Electrically Isolated Microprobe Pads for the Electrical Analysis of Failing 0.12μm Technology SRAM Bit Cells

2004 ◽  
Author(s):  
Randal Mulder
Keyword(s):  
Failure Analysis ◽  
Success Rate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Success Rate ◽  
Minimal Amount ◽  
Physical Analysis ◽  
Simple Method ◽  
Defect Type ◽  
Electrical Analysis

Abstract This paper provides failure analysis engineers a simple method for constructing probe pads on failing 0.12um SRAM bit cells using the FEI 820 Focused Ion Beam (FIB) tool. This method allows for the easy location of the failing bit cell, results in good electrical isolation, and only takes a minimal amount of FIB time (2 hours for 6 pads). The method is effective for all technologies 0.12um or greater with a high success rate once the analyst is proficient in its use. Once probe pads have been constructed, it is then relatively easy for an analyst to perform electrical analysis to identify the defect type and location causing the bit cell failure before the physical analysis is performed.

Failure Analysis of Tungsten Stud Defect from the CMP Process

2000 ◽  
Author(s):  
K. Takagi ◽  
Y. Kohno ◽  
S. Nukii
Keyword(s):  
Electron Microscopy ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Electrical Characterization ◽  
Open Circuit ◽  
Physical Analysis ◽  
Metal Line ◽  
Cross Sectional ◽  
Defect Isolation

Abstract This paper describes a failure analysis that effectively combined multiple analytic techniques to find the cause of I/O leakage in a flawed chip produced for an OEM (Original Equipment Manufacturer) product. Internal probing was initially used for defect isolation and a Tungsten (W) stud open circuit flaw was isolated by electrical characterization with internal probing. SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy, and FE-AES (Field Emission Auger Electron Spectroscopy) analysis with FIB (Focused Ion Beam) preparation were used for physical analysis. Cross-sectional SEM and TEM observations showed a gap with foreign material (FM) between the bottom of the metal line and the top of the W stud, possibly from the W CMP (chemical mechanical polish) process. FE-AES is effective for the analysis of light materials and their chemical composition, so a flat milling FIB process was used to prepare a cross-section for FE-AES analysis of the FM and the interfaces of the open defect. The spectra showed that the FM was traceable to the W CMP process. From these analytical results and problem reproduction experiments in the W CMP process on the manufacturing line, the failure mechanism was identified.

Voltage Contrast Application on 1M SRAM Single Bit Failure Analysis

1997 ◽  
Author(s):  
D. Luo ◽  
X. Song
Keyword(s):  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Random Access ◽  
Access Memory ◽  
Operating Life ◽  
New Techniques ◽  
Analysis Techniques ◽  
Temperature Operating ◽  
Voltage Contrast

Abstract A single bit failure is the most common and the most difficult failure mode to analyze in a Static Random Access Memory (SRAM). As chip feature sizes decrease, the difficulties compound. Traditional failure analysis techniques are often ineffective, particularly for high temperature operating life (HTOL) failures, because HTOL failures are most often caused by subtle physical defects. A new analysis approach, using Focused Ion Beam (FIB) cross-sectioning combined with Fffi passive voltage contrast (PVC), greatly enhances the analysis success rate. In this paper, we outline the use of these new techniques and apply them to a technologically important problem.

Failure Analysis Using Voltage Contrast and Ebic

1998 ◽  
Vol 523 ◽  
Author(s):  
Larry Rice ◽  
Wei Chen
Keyword(s):  
Electron Microscopy ◽  
Failure Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Sem Analysis ◽  
Silicon On Insulator ◽  
Traditional Use ◽  
Critical Dimensions ◽  
Voltage Contrast ◽  
Microscopy Techniques

AbstractAs ULSI device critical dimensions continue to shrink to submicron sizes, electron microscopy techniques such as electron beam induced current (EBIC) and voltage contrast are finding more applications towards pinpointing failure sites for subsequent cross sectioning or deprocessing. In addition to the traditional use of EBIC for junction delineation, EBIC has been applied to locate leakage sites in capacitor structures and silicon-on-insulator (SOI) devices as well. Similarly, voltage contrast has been applied to identify single or multiple opens in via chains which consist of thousands of vias. In addition to a brief revisit of the basic principles of EBIC and voltage contrast, focus will be placed on the application of EBIC and voltage contrast in failure analysis of semiconductor devices. Examples of using voltage contrast combined with precision cross section focused ion beam (XFIB) for identifying the failure mechanism of 0.8μm vias will be presented. Also, the use of EBIC for identifying leakage sites in SOI and bipolar devices and subsequent FIB/scanning electron microscopy (SEM) analysis will be presented.

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