Advanced Electron Energy Loss Spectroscopy investigation of microelectronic devices

Nowadays, the use of transmission electron microscopy in microelectronic field enables to address accurate physical and chemical characterization or even to determine the root cause of an electrical failure. Indeed, this instrument allows to perform several types of chemical analyses owing to different spectrometers fitted with. Among these associated technics fitted to this instrument, the Electron Energy Losses spectroscopy aims to provide elemental and chemical information. Focusing on an ionization edge of specific element allows to identify its chemical environment or oxidation state. In this present work, the study aimed to reveal the oxidation state of copper at Cu/SiO2 hybrid bonding interface. EELS investigations of the fine structure clearly revealed a self-formed Cu
2
O barrier for the Cu/SiO
2
hybrid bonding integration. Furthermore, combining the spatial resolution of TEM and the acquisition of EELS fine structure mapping, allows to precisely measure an ultrafine copper oxide layer of only a few nanometers thick.