Copper Hillock Induced Copper Diffusion and Corrosion Behavior in a Dual Damascene Process

Abstract

A copper hillock induced interconnect failure mechanism is presented. The copper hillock is frequently generated during a copper dual damascene process and hillock formation is found to degrade the interconnect integrity by affecting the following process steps. The copper hillock appears to damage the SiN capping layer and results in copper corrosion during via etch. The corrosion generates copper particles inside via holes and the defects are found to make the following metal depositions incomplete during via formation. Based on the observations, a copper hillock induced defect model is proposed and a new copper process is suggested to reduce copper hillocks.

Nanometer-thin pure boron CVD layers as material barrier to Au or Cu metallization of Si

“…In addition, stress from changes in the metal morphology during annealing and associated cool down can play a role. Al and Cu layers are notorious for pushing up hillocks to relieve stress during anneal-induced grain formation [35,36]. However, the present metal layers are quite thin, so grain formation is more likely to be associated with the creation of voids between the grains.…”

Decomposition and Dewetting of Super-Saturated Cu-15 at. % Cosolid Solution Film

“…The importance of thin films in different technologies, from microelectronics with conductors and interconnects [1][2][3][4][5][6] to sensors [7] and magnetic recording media [8], has increased by daily emerging innovations in nanotechnology. By decreasing the size of devices, the thermal and mechanical stability of their components becomes more important.…”

Stress Relaxation and Grain Growth Behaviors of (111)-Preferred Nanotwinned Copper during Annealing

“…Under a high temperature, severe compressive and/or tensile stresses are induced in Cu lines. The self-diffusion of Cu atoms can form hillocks on the Cu surfaces as subjected to EM stressing [ 45 , 46 , 47 , 48 ]. Previous studies have shown that voids are likely to form as tensile stress is significant [ 47 , 49 , 50 ].…”