Guidelines for Two-Dimensional Dopant Profiling Using Scanning Capacitance Microscopy

2000 ◽  
Author(s):  
Axel Born ◽  
R. Wiesendanger
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Edge Effects ◽  
Two Dimensional ◽  
Stray Capacitance ◽  
Scanning Capacitance Microscopy ◽  
Dopant Profiling ◽  
3D Geometry ◽  
Cv Measurements ◽  
Preparation Techniques

Abstract This paper provides guidance and insights on the use of scanning capacitance microscopy (SCM) in semiconductor failure analysis. It explains why SCM systems are constrained by rigid performance tradeoffs and how CV measurements are affected by large stray capacitance and as well as edge effects associated with the 3D geometry of the sample and probe. It also explains how samples should be prepared and how proper sample preparation techniques combined with optimally selected voltages make it possible to accurately determine doping concentrations, even in p-n junctions.

Novel Failure Analysis Sample Preparation Techniques for PoP Packaging

2012 ◽  
Author(s):  
Ng Sea Chooi ◽  
Chor Theam Hock ◽  
Ma Choo Thye ◽  
Khoo Poh Tshin ◽  
Dan Bockelman
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Failure Mechanisms ◽  
Preparation Process ◽  
Space Saving ◽  
Optical Probing ◽  
Preparation Techniques

Abstract Trends in the packaging of semiconductors are towards miniaturization and high functionality. The package-on-package(PoP) with increasing demands is beneficial in cost and space saving. The main failure mechanisms associated with PoP technology, including open joints and warpage, have created a lot of challenges for Assembly and Failure Analysis (FA). This paper outlines the sample preparation process steps to overcome the challenges to enable successful failure analysis and optical probing.

Sample Preparation Challenges In WLCSP Epoxy Underfill Coating Removal

2012 ◽  
Author(s):  
Jason H. Lagar ◽  
Rudolf A. Sia
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Vital Role ◽  
Fault Isolation ◽  
Wafer Level ◽  
Chip Scale Package ◽  
Coating Removal ◽  
Customer Returns ◽  
Preparation Techniques ◽  
Mechanical Defect

Abstract Most Wafer Level Chip Scale Package (WLCSP) units returned by customers for failure analysis are mounted on PCB modules with an epoxy underfill coating. The biggest challenge in failure analysis is the sample preparation to remove the WLCSP device from the PCB without inducing any mechanical defect. This includes the removal of the underfill material to enable further electrical verification and fault isolation analysis. This paper discusses the evaluations conducted in establishing the WLCSP demounting process and removal of the epoxy underfill coating. Combinations of different sample preparation techniques and physical failure analysis steps were evaluated. The established process enabled the electrical verification, fault isolation and further destructive analysis of WLCSP customer returns mounted on PCB and with an epoxy underfill coating material. This paper will also showcase some actual full failure analysis of WLCSP customer returns where the established process played a vital role in finding the failure mechanism.

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.

The Challenge and Methods of TEM Cross-Sectioning of < 0.25 Micron Plugs

1998 ◽  
Vol 523 ◽  
Author(s):  
C. Amy Hunt ◽  
Yuhong Zhang ◽  
David Su
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Failure Analysis ◽  
Cross Section ◽  
Adhesion Layer ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Sectional Plane ◽  
Preparation Techniques

AbstractTransmission electron microscopy (TEM) is a useful tool in process evaluation and failure analysis for semiconductor industries. A common focus of semiconductor TEM analyses is metalization vias (plugs) and it is often desirable to cross-section through a particular one. If the cross-sectional plane deviates away from the center of the plug, then the thin adhesion layer around the plug will be blurred by surrounding materials such as the inter-layer dielectric and the plug material. The importance of these constraints, along with the difficulty of precision sample preparation, has risen sharply as feature sizes have fallen to 0.25 μm and below. The suitability of common sample preparation techniques for these samples is evaluated.

scholarly journals Two-dimensional dopant Profiling on Operating MOSFET by Scanning Capacitance Microscopy

Hyomen Kagaku ◽  
2007 ◽  
Vol 28 (2) ◽  
pp. 84-90
Author(s):  
Koji USUDA ◽  
Kenjiro KIMURA ◽  
Kei KOBAYASHI ◽  
Hirofumi YAMADA
Keyword(s):  
Two Dimensional ◽  
Scanning Capacitance Microscopy ◽  
Dopant Profiling

A Novel Sample Preparation Approach for Dopant Profiling of 14 nm FinFET Devices with Scanning Capacitance Microscopy

2020 ◽  
Author(s):  
Nirmal Adhikari ◽  
Phil Kaszuba ◽  
Gaitan Mathieu ◽  
Erik McCullen ◽  
Thom Hartswick ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Low Voltage ◽  
Negative Impact ◽  
Electrical Contact ◽  
Process Models ◽  
Ion Milling ◽  
Cross Sectional ◽  
Scanning Capacitance Microscopy ◽  
Dopant Profiling ◽  
Profile Control

Abstract Three-dimensional device (FinFET) doping requirements are challenging due to fin sidewall doping, crystallinity control, junction profile control, and leakage control in the fin. In addition, physical failure analyses of FinFETs can frequently reach a “dead end” with a No Defect Found (NDF) result when channel doping issues are the suspected culprit (e.g., high Vt, low Vt, low gain, sub-threshold leakage, etc.). In new technology development, the lack of empirical dopant profile data to support device and process models and engineering has had, and continues to have, a profound negative impact on these emerging technologies. Therefore, there exists a critical need for dopant profiling in the industry to support the latest technologies that use FinFETs as their fundamental building block [1]. Here, we discuss a novel sample preparation method for cross-sectional dopant profiling of FinFET devices. Our results show that the combination of low voltage (&lt;500eV), shallow angle (~10 degree) ion milling, dry etching, and mechanical polishing provides an adequately smooth surface (Rq&lt;5Å) and minimizes surface amorphization, thereby allowing a strong Scanning Capacitance Microscopy (SCM) signal representative of local active dopant (carrier) concentration. The strength of the dopant signal was found to be dependent upon mill rate, electrical contact quality, amorphous layer presence and SCM probe quality. This paper focuses on a procedure to overcome critical issues during sample preparation for dopant profiling in FinFETs.

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