Characteristics of Electomigration & Surface Hardness about Tungsten-Carbon-Nitrogen(W-C-N) Related Diffusion Barrier

Copper is known as a replacement for aluminum wire which is used for semiconductor. Because specific resistance of Cu (-cm) is lower than that of Al (-cm), Cu reduce RC delay time. Although melting point of Cu() is higher than melting point of Al, Cu have characteristic to easily react with Silicon(Si) in low temperature, and it isn`t good at adhesive strength with Si. For above these reason, research of diffusion barrier to prevent reaction between Cu and Si and to raise adhesive strength is steadily advanced. Our study group have researched on W-C-N (tungsten-carbon-nitrogen) Diffusion barrier for preventing diffusion of Cu through semiconductor. By recent studies, It`s reported that W-C-N diffusion barrier can even precent Cu and Si diffusing effectively at high temperature. In this treatise, we vaporized different proportion of N into diffusion barrier to research Cu`s Electromigration based on the results and studied surface hardness in the heat process using nano scale indentation system. We gain that diffusion barrier containing nitrogen is more stable for Cu`s electromigration and has stronger surface hardness in heat treatment process.