L. Tielemans

High-resolution in-situ of gold electromigration: test time reduction

Mat Res Inst, B-3590 Diepenbeek, Belgium. Xpeqt, B-3980 Tessenderlo, Belgium. Philips Semicond, NL-6539 AE Nijmegen, Netherlands.Croes, K, Mat Res Inst, Wetenschapspk 1, B-3590 Diepenbeek, Belgium.

Bimodal failure behaviour of metal film resistors

The ageing behaviour of metal film resistors was studied using high-resolution in-situ resistance measurements. A temperature storage experiment was performed at five different temperature levels. At each condition, the ageing behaviour of 128 resistors was monitored. It turned out that the failure behaviour of the samples is rather complicated. One remarkable fact is that measurements coming from two different production lots led to completely different results. One production lot displayed monomodal failure behaviour, while for the other lot bimodality was observed. Serious errors in the calculation of the FTTF (first time to failure) can be expected when this fact is not properly taken into consideration. This paper also discusses some important aspects of the analysis of failure time data, such as (i) the choice of the underlying failure distribution, (ii) the number of samples to be tested and (iii) the failure criterion to be used.

The Arrhenius relation for electronics in extreme temperature conditions

In the field of high temperature electronics some doubts have been expressed about the validity of the Arrhenius relation. In this paper the in-situ electrical measurement technique is presented to investigate the temperature dependence of failure mechanisms and conduction mechanisms of several material systems in a broad temperature region. Measurement results will be presented showing single-activation energy and multiple-activation energy behaviour of a.o. electrical conduction, degradation of resistances, electromigration and time dependent dielectric breakdown at high temperature conditions.

Electrical characterization and reliability evaluation of capacitors by means of in situ leakage current measurements

The in situ leakage current measurement technique is presented for the high-resolution observation of the electrical behaviour of dielectric material systems, e.g. capacitors, at high temperatures. This technique is useful for the electrical characterization of dielectrics during linear heating experiments and/or isothermal steps. Applied to a population of test structures, the in situ leakage current measurement technique is a rapid and powerful tool to assess the reliability and quality of dielectric components and assemblies. Results obtained on populations of film capacitors and ceramic capacitors are presented.

Thermal Degradation of Power Modules

One of the main problems in power devices is the increase of the junction temperature due to internal heat dissipation. Different packaging technologies have different thermal management. This management changes during the life time of the device due to thermal mechanical stresses. The degradation of the thermal resistance is one of the main limitations in life time of power devices. In this study different substrate technologies have been compared on their degradation during reliability testing. Thermal shock (liq. to liq.), thermal cycling (air to air) and power cycling test were applied. For power cycling test, the degradation of the devices is measured as a change in thermal resistance (Rth). For the DCB substrate technology, this change is measured at different power dissipation levels to study the influence of temperature difference between junction and case on the degradation behaviour.

How reliable are reliability tests

Chiron Pte Ltd, Singapore 757720, Singapore. ESE bvba, B-2260 Westerlo, Belgium. Philips, NL-6534 AE Nijmegen, Netherlands. LUC IMO, B-3590 Diepenbeek, Belgium.Tielemans, L, Chiron Pte Ltd, 21 Woodlands Ind Pk E1 02-06, Singapore 757720, Singapore.

High resolution electromigration measurements for reduction of the test time

This paper presents a faster method to assess the electromigration performance of metal tracks. The method is based on high accuracy measurements (in the PPM range) which allow monitoring of resistance variations in NIST metal tracks. It is shown that, due to the high accuracy, differences in degradation can be observed after a relatively short stress time and the failure criterion for time-to-failure (TTF) can be decreased. By decreasing the failure criterion for resistance changes from the typical range of 20 to 30% to a range of 1 to 5%, electromigration test time can be reduced by a factor of four. It was also shown that reducing the failure criterion has no impact on the determined values of thermal activation energy E, and current acceleration factor n. Finally, a new strategy is proposed: by using a 1% failure criterion for determination of E/sub a/ and n (at 3 temperatures and 3 current densities) and a 30% failure criterion for determination of the cumulative failure curve (1 temperature and 1 current density), the total test time duration can be reduced by a factor of four and provides the same information than a conventional electromigration test.

Evaluation on a two‐day time scale of high‐reliability electronic assemblies by in‐situ electrical and opto‐mechanical test techniques

We present the results of SHORTEST, a BRITE EURAM II project for the introduction in industry of an advanced approach to the reliability evaluation of electronic assemblies. The achievements so far are the development and validation of seven in-situ test techniques. Five of the test techniques demonstrate the capability of detecting failure mechanisms at 48 hours with moderate stress conditions, and half of the in-situ test results obtained at 48 hours on 10 subtechnologies correlate with conventional tests. All correlation results are presented. The application of the method for quality assurance and building-in reliability is discussed. The final aim of SHORTEST is to look for the exploitation of the developed in-situ techniques. The marketing study that will define the industrial needs of European companies is presented. In parallel, the insertion in the CECC specification of recommendations based on the SHORTEST principle is foreseen.

Ageing and Lifetime of Electronic Components Studies By Means of a High-Resolution In-Situ Measurement Technique

Since the invention of the integrated circuit (IC) in 1959, there has been an enormous growth in performance and complexity of electronic systems by drastically reducing the basic building blocks and increasing the circuit density. Due to this ongoing miniaturization of microelectronics, new physical mechanisms can be triggered or known physical mechanisms can be enhanced inducing ageing and failure of the electronic material systems. The time evolution of these ageing mechanisms has to be understood in order to guarantee the lifetime of several years required for products such as personal computers, automobiles, home appliances etc. The study of failure mechanisms in electronic components requires a combination of advanced electrical, analytical and statistical tools.

The kinetics of the early stages of electromigration and concurrent temperature induced processes in thin film metallisations studied by means of an in-situ high resolution resistometric technique

Abstract Compared with traditional test techniques, the in-situ high resolution resistometric technique allows a sensitive monitoring of thin film metallisations submitted to ’realistic’ current stress levels and reveals the occurrence of distinct reversible and irreversible processes. A review is provided of the processes observed in metallisations submitted to three regions of current stress: no current stress, low current density stress ( j MA/cm 2 ) and ‘high’ current density stress ( j>0.5 MA/cm 2 ). Discarding the contributions of the concurrent, temperature induced, masking mechanisms results in an accurate observation of the kinetics of the early stages of electromigration, revealing fundamental features such as incubation time, subsequent linear resistance increase and current and temperature dependence.