• Popok, Vladimir N.
• Pedersen, Kristian Bonderup
• Kristensen, Peter Kjær
• Brincker, Mads

Abstract

Degradation of Al metallization on Si-based semiconductor<br/>chips under operation is a reliability problem known<br/>for many years but the mechanisms of this phenomenon are not<br/>fully understood. To quantify contributions of different possible<br/>effects, a passive thermal cycling setup has been developed<br/>allowing for accelerated tests by varying the device temperature<br/>on a short time scale without applying electrical power. The<br/>setup is also capable of testing devices in different atmospheres.<br/>The results obtained by the thermal tests of diode chips are<br/>compared to those from power cycled diodes with focus on<br/>degradation of the top metallization layer. The data on structural<br/>and electrical characterization of the samples show that the<br/>passive thermal cycling induces metallization degradation very<br/>similar to that found for the power cycled devices. Thus, it can be<br/>concluded that the thermal-induced stresses are the dominating<br/>mechanisms for the metallization fatigue and following failure.<br/>The role of oxidation and corrosion effects is also studied<br/>in the experiments on passive thermal cycling using different<br/>environmental conditions. It is suggested that the formation<br/>of self-passivating aluminum oxide under ordinary atmospheric<br/>conditions can play a positive role in limiting the structural, and<br/>electrical degradation of the metallization layers. The obtained<br/>results represent a considerable contribution into understanding<br/>of major failure mechanisms related to metallization fatigue and<br/>reconstruction.

Topics

• impedance spectroscopy
• corrosion
• experiment
• aluminum oxide
• aluminium
• semiconductor
• fatigue