Failure Analysis

Failure Analysis

FA-1 Dynamic Avalanche in Charge-Compensation MOSFETs Analyzed with the Novel Single Pulse EMMI-TLP Method

T. Chirila, T. Reimann*, M. Rüb, University of Applied Science Jena, *Technische Universität Ilmenau

As a main switch in a broad range of applications, the Charge-Compensation MOS Transistor must be able to withstand the avalanche multiplication regime. Using the classical rating method for avalanche robustness, two destruction limits have been identified – thermal and current limit. However, up to date there is no complete understanding of current induced failure mechanisms. In this paper we combine single transmission line pulses with emission microscopy in order to bring more insight into these kinds of destruction modes. We identify three different avalanche regimes and observe the occurrence of current filaments. We provide an interpretation for filament formation.

FA-2 Fast 3D Electro-Optical Frequency Mapping and Probing in Frequency Domain

K. Melendez*, K. Sanchez*, P. Perdu*, K. Melendez, D. Lewis, Bordeaux University, *CNES

The main goal of this paper is to show the capability of extracting several frequencies at one electro-optical scanning
in order to reconstruct few 512 by 5 12 pixels images. With these 3D data (X and Y are pixels and Z is the frequency locked), it is possible to study several frequencies in one time and to reconstruct the original signal waveform at each pixel.

FA-3 Direct Photo Emission Monitoring for High Power IGBT during Avalanche Operation

T. Matsudai, K. Endo, T. Ogura, T. Matsumoto*, K. Uchiyama*, K. Koshikawa*, Toshiba Corporation, *Hamamatsu Photonics K.K.

IGBTs have been developed extensively to improve trade-off relation between on state losses and switching losses. Therefore the reliability enhancement of IGBTs is very important technology. For the past failure analyses, only the final destruction point have been observed under testing. With this way, it is difficult to perform physical analysis,
because the process of the destruction phenomenon is unknown. In this work, our target is investigating the avalanche phenomenon of IGBTs, directly. During avalanche operation, it is well known that the formation of current filament appears and visible light is emitted in the device. For the first time, we have succeeded observing the photo emission directly from avalanche phenomena under UIS (Unclamped Inductive Switching) condition of IGBTs using the streak camera. We have also measured moving the emission region in edge termination area.