Jürgen Frosien

Breakthrough in internal failure analysis of integrated circuits

Abstract The application of the multisampling technique in conjunction with a digital control loop enables the E-BEAM PROBE STATION 8000 to be extremely suitable for fast internal measurements of signals with repetition rates down to a few Hz. Failure analysis of passivated ICs can therefore be performed within some seconds while the device is running its original user program.

High performance electron beam tester for voltage measurement on unpassivated and passivated devices

An electron-beam tester designated for precise and damage-free voltage measurement and for diagnostics in the interior of highly integrated circuits has been developed. Its specifications meet the requirements necessary for testing present and future generations of integrated circuits with line patterns down to 0.5 mu m. The electron optical column has been optimized for low-energy operation, providing an electron beam of 0.1 mu m diameter with 2 nA current at 1 keV electron energy. The variable extraction voltage system incorporated in the tester not only enables accurate voltage measurements on unpassivated devices, but also offers the possibility of detailed failure analysis on passivated devices. On passivated devices, however, limitations may arise when the passivation layer thickness and the line separation distance reach the same order.<<ETX>>

State of the art e-beam probing

Abstract Electron beam testing is an effective tool for internal IC diagnosis. Modern ICs are characterised by higher densities and smaller structures down to 0.5 μm. More complex hierarchy requires up to 6 wiring layers. While operated at clock frequencies of several 100 MHz supply voltages and internal signal levels are decreased to reduce power consumption. E-Beam Probe Stations developed at ICT offer the means for design verification and defect analysis of these modern ICs by high frequency sampling operation and by using field emission technology for optimised spatial and voltage resolution. Access to signals on deeper and passivated wiring layers becomes possible by a charge compensation method; if these signals are to be measured with highest accuracy an integrated etching tool can be activated at any time to open windows through the passivation for direct probing on deeper lines. In addition a field correction tool provides a stable probing position even on smallest lines.