Andreas Rummel

3D failure analysis in depth profiles of sequentially made FIB cuts

A new method of investigating structures below a surface in a dual beam microscope is presented. It comprises electrical measurements in depth profiles of sequential focused ion beam (FIB) cuts by the use of two or more nanomanipulators with plugged in probe needles. The sample is oriented such that the structures are observed with the electron beam while they are cut free with the FIB. The nanomanipulators are moved to contact the structures for examination. The FIB cut is extended step by step, and after each cut the nanomanipulators are repositioned and measurements of the new structures that appear in the FIB cut are made. The measurement series provide a three dimensional electrical characterization of the examined sample volume.

Physical fault isolation of complex BEOL defects in advanced microprocessors using EBAC technique in nano-prober

Electron beam absorbed current (EBAC) has been used to isolate defects in BEOL metal stacks. With the increasing layout complexity, metal signal lines often run over 100um area and over multiple metal stacks. This makes SEM inspections during polishing tedious, time consuming and easy to overlook the defect. With the EBAC technique, it often shows the entire routing of the signal line with additional or absence that can pinpoint or narrow the location of the defects. In this paper, we will show how the Kleindiek system is used to perform the EBAC technique and locate the BEOL defect.

Towards the Understanding of Resistive Contrast Imaging in in-situ Dielectric Breakdown Studies Using a Nanoprober Setup

This work aims at attaining a more complete understanding of the principles governing resistive contrast imaging (RCI) of copper/low- k interconnects used for dielectric breakdown studies in a nanoprober scanning electron microscope (SEM) system. RCI is employed in such in situ dielectric breakdown studies to facilitate the localization of interconnect defect sites related to various stages in the degradation process of the low- k dielectric material. This work shows that RCI is suitable for detecting high-resistance sites, like opens, in copper/low- k interconnects. Moreover, RCI demonstrates potential in locating defects that lie deep in the test structure and are, thus, not detectable by SEM. A model is also proposed to explain the formation of RCI images of specific interconnect test structures with complex layout.

Achieving Fast and Reliable TEM-Sample Lift-out and Transfer Using Novel Materials and Novel in-situ Tools

quently, a patch of tungsten or platinum metal is deposited, fixing the needle to the previously cut lamella. Then the lamella is lifted away from the substrate and attached to a TEM-grid for further processing [1, 2]. The first improvement on the established method is to replace this step with a simple, cleaner and more reliable one. Using tungsten probes which are precisely aligned and mounted to a piezo driving Received: October 30, 2008 Accepted: December 4, 2008

In Situ Nanoprobing Tools for Fault Localization and Defect Characterization

As the semiconductor devices that power our modern world continue to shrink, more and more of the research & development process is moving into Scanning Electron Microscope (SEM) and Focussed Ion Beam (FIB) tools. The SEM is most commonly used for visualizing the devices under test, however there are a number of additional ways to employ the electron beam for fault localization and failure analysis.

Combining current imaging, EBIC/EBAC, and electrical probing for fast and reliable in situ electrical fault isolation

Using a compact nanoprobing setup comprising eight probe tips attached to piezo-driven micromanipulators, various techniques for fault isolation are performed on 28 nm samples inside an SEM. The recently implemented Current Imaging technique is used to quickly image large arrays of contacts providing a means of locating faults.

Correlating SEM and SPM for nanoprobing in failure analysis

A compact nanoprober suitable for SEM/FIB is presented. Each of the eight probes can be biased and scanned over the sample surface, allowing for the acquisition of current flow images (CI) with sub-pA resolution. The correlation of SEM and CI is used to locate leakages in 22 nm SRAM devices.

Electrical Probing and Current Imaging for Failure Analysis in the SEM/FIB

As the transistors and other circuits in semiconductor devices shrink to smaller and smaller sizes, failure analysis on these devices is becoming more and more challenging. There is a large need for highly precise nano-probers to quickly and reliably address contacts in the range of few tens of nanometers. Using piezo-driven micromanipulators, individual nano-scale components on semiconductor devices can be tested inside a SEM or FIB system.