Failure Analysis - Die Level

Chemical Unlayering

Deprocessing and Sample Preparation are important parts of the failure analysis process. Deprocessing is used to expose underlying layers for examination and characterization and viewing cross-sectioned surfaces. These courses provide information on how to deprocess circuits using chemical etches, plasma and reactive ion etches, and parallel polishing techniques. There is also a course discussing how to cross section circuits. Another course provides information on automated cross-sectioning techniques and TEM sample preparation. A final course provides information on chemical safety.

Certificate

Chemical Unlayering Certificate

Electron Beam Techniques

Electron Beam Techniques are a class of fault localization techniques that utilize a scanning electron microscope. These techniques rely on the interaction of the electron beam with the sample while monitoring an aspect of the electrical behavior of the circuit. These techniques include: charge-induced voltage alteration or CIVA, electron beam induced current or EBIC, resistive contrast imaging or RCI, and several variants of voltage contrast.

Certificate

Electron Beam Techniques Certificate

FIB

Introduction

The focused ion beam (FIB) system has become an indispensable tool for failure analysis, design debug, and circuit editing. The FIB allows one to make modifications to a circuit and test them before generating new masks for a chip design. This can save millions of dollars in mask and wafer processing costs. The FIB is also used for TEM sample preparation, cross-sectioning, and other types of micromachining activities.

Certificate

Focused Ion Beam Certificate

Inspection

Introduction

Die inspection is arguably one of the most important aspects of any failure analysis job. Die inspection is normally where one first generates an image of the defect, whether it be immediately after opening the sample or preparing the die for backside inspection, or after one or more layers have been removed. Die inspection is performed using three techniques: optical microscopy, infrared microscopy, and scanning electron microscopy. Optical microscopy is performed on the front side of semiconductor devices; infrared microscopy is performed from the backside, and scanning electron microscopy is performed on surface features.

Certificate

Inspection Certificate

Light Emission

Introduction

Light Emission Microscopy is a powerful technique for fault localization at the die level. Light Emission Microscopy uses an image intensifier or a cooled semiconductor array camera to detect light emanating from a semiconductor device. Many defects either emit light or cause emission in associated transistors. A variant of light emission called PICA can be used for inferring waveform information on an integrated circuit. Although the technique is quite powerful, interpretation of light emission data can be challenging. The analyst must possess a sound understanding of electrical circuit behavior as well as device recognition skills.

Certificate

Light Emission Certificate

Optical Beam Techniques

Introduction

Failure analysts now perform much of the fault localization work from the backside of the device. The complexity of the integrated circuits and the packaging has caused this transition. In order to penetrate the silicon, optical beam techniques are used. They are a class of techniques that rely on the interaction of an optical beam with the active devices or interconnect on the circuit. These include: electro-optical probing, light induced voltage alteration or LIVA, thermally induced voltage alteration or TIVA, optical beam induced current or OBIC, resistive interconnect localization and soft defect localization. The distinguishing feature of these techniques is that they require a scanning optical microscope system, and occasionally, complex stimulus, in the form of a properly chosen or designed vector set.

Certificate

Optical Beam Techniques Certificate

Scanned Probe Techniques

Introduction

The invention of the scanning tunneling microscope in 1981 has spawned a variety of instruments and techniques that fall under a category called Scanned Probe Techniques. Scanned Probe techniques involve micromachined tips that can be scanned with great precision over the surface of a device. These techniques can be used to look at the topography of a surface, and a variety of other phenomena such as electrical, magnetic, capacitive, thermal, and optical interactions.

Certificate

Scanned Probe Techniques Certificate

Thermal Detection Techniques

Introduction

Thermal Detection Techniques are a class of techniques used to detect heat-generating defects on semiconductor devices. They are also occasionally used to verify thermal models of semiconductor components. The most popular of the thermal detection techniques are Infrared Thermography, Liquid Crystal Thermography, and Fluorescent Microthermal Imaging. Infrared Thermography is a sensitive, non-contact technique, but it lacks the spatial resolution needed for fine localization on semiconductor dice. Liquid Crystal Thermography has better spatial resolution, but only delineates temperatures above or below a certain temperature. Fluorescent Microthermal Imaging has good spatial resolution and thermal mapping capabilities, but is somewhat more difficult to use.

Certificate

Thermal Detection Techniques Certificate