High resolution 3D subsurface mapping using a towed transient electromagnetic system ‐ tTEM: case studies

2020 ◽  
Vol 18 (3) ◽  
pp. 249-259 ◽  
Author(s):  
Pradip Kumar Maurya ◽  
Anders Vest Christiansen ◽  
Jesper Pedersen ◽  
Esben Auken
Keyword(s):  
High Resolution ◽  
Case Studies ◽  
Electromagnetic System ◽  
Transient Electromagnetic ◽  
Subsurface Mapping

tTEM — A towed transient electromagnetic system for detailed 3D imaging of the top 70 m of the subsurface

Geophysics ◽  
2019 ◽  
Vol 84 (1) ◽  
pp. E13-E22 ◽  
Author(s):  
Esben Auken ◽  
Nikolaj Foged ◽  
Jakob Juul Larsen ◽  
Knud Valdemar Trøllund Lassen ◽  
Pradip Kumar Maurya ◽  
...  
Keyword(s):  
High Resolution ◽  
Raw Materials ◽  
Geophysical Methods ◽  
Central Valley ◽  
Aquifer Vulnerability ◽  
Late Time ◽  
Electromagnetic System ◽  
Aquifer Storage ◽  
Transient Electromagnetic ◽  
Subsurface Layers

There is a growing need for detailed investigation of the top 30–50 m of the subsurface, which is critical for infrastructure, water supply, aquifer storage and recovery, farming, waste deposits, and construction. Existing geophysical methods are capable of imaging this zone; however, they have limited efficiency when it comes to creating full 3D images with high resolution over dozens to hundreds of hectares. We have developed a new and highly efficient towed transient electromagnetic (tTEM) system, which is capable of imaging the subsurface up to depth of 70 m at a high resolution, horizontally and vertically. Towed by an all-terrain vehicle, the system uses a [Formula: see text] transmitter coil and has a [Formula: see text]-component receiver placed at 9 m offset from the transmitter. The tTEM uses dual transmitter moment (low and high moment) measurement sequence to obtain the early and late time gates corresponding to shallow and deep information about the subsurface layers. The first bias-free gate is as early as [Formula: see text] from beginning of the ramp ([Formula: see text] after end of ramp). Data are processed and inverted using methods directly adopted from airborne electromagnetics. The system has been successfully used in Denmark for various purposes, e.g., mapping raw materials, investigating contaminated sites, and assessing aquifer vulnerability. We have also used the tTEM system in the Central Valley of California (United States) for locating artificial recharge sites and in the Mississippi Delta region, to map complex subsurface geology in great detail for building hydrogeologic models.

SEM-Based Nanoprobing on 40, 32 and 28 nm CMOS Devices Challenges for Semiconductor Failure Analysis

2013 ◽  
Author(s):  
Erik Paul ◽  
Holger Herzog ◽  
Sören Jansen ◽  
Christian Hobert ◽  
Eckhard Langer
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
Case Studies ◽  
State Of The Art ◽  
Root Cause ◽  
Highly Efficient ◽  
Technology Nodes ◽  
Scanning Electron

Abstract This paper presents an effective device-level failure analysis (FA) method which uses a high-resolution low-kV Scanning Electron Microscope (SEM) in combination with an integrated state-of-the-art nanomanipulator to locate and characterize single defects in failing CMOS devices. The presented case studies utilize several FA-techniques in combination with SEM-based nanoprobing for nanometer node technologies and demonstrate how these methods are used to investigate the root cause of IC device failures. The methodology represents a highly-efficient physical failure analysis flow for 28nm and larger technology nodes.

Sign in / Sign up

Export Citation Format

Share Document