SOLID-STATE REACTIONS OF THE AG-CU-TI THIN-FILM AL2O3 SUBSTRATE SYSTEM

A new interpretation of the reaction mechanism between active metal th in-film filler and ceramic substrate is proposed. The authors predict the possibility of prebonding reactions, prior to melting of the fille r, at the interface of the system described above. To prove this, soli d-state reactions of Ag-Cu-Ti thin films on sapphire substrates have b een studied with Auger electron spectroscopy (AES) and x-ray diffracti on (XRD). Reaction process and products have been clarified at the tem perature just below the melting point of the filler. It is evident tha t Cu3Ti3O (diamond structure of Fd3m) is formed by the reaction betwee n Cu3Ti and 0 which results from the reduction of sapphire. It seems t hat Cu3Ti3O contributes to bonding between metals and sapphire as an i ntermediate phase.