SEM Analysis of Transistors Damaged by Microwave Energy

Abstract

In this paper we discuss the importance of visual microscopic data as it pertains to recognizing the characteristic traits of semiconductor microwave failures. Failure modes associated with a current and voltage overstress have been identified. However, characteristic traits of transistor failures during high microwave irradiation are at present undetermined. The analysis is focused on a thorough microscopic inspection of the surface topography of the microelectronic device after being opened. The temperature of the chip during RF irradiation is the significant key to determining the cause of semiconductor failures. The approximate temperature variations which occur during RF irradiation can be estimated after a microscopic investigation of damaged areas. The SEM was used for the analysis because of its large depth of field (Figure 1). In addition, the specimen-current amplifier in the SEM was used to amplify the electrical current which flows through a specimen when the electron probe strikes its surface. The specimen current amplifier method of obtaining a signal is especially valuable to transistor investigations where a bias is applied and the conduction current collected (Figure 2}