GRAIN-GROWTH OF COPPER-FILMS PREPARED BY CHEMICAL-VAPOR-DEPOSITION

Copper films having thickness 600 nm were prepared on TiN using chemic al vapour deposition (CVD). The deposited films were annealed at vario us temperatures (350-550 degrees C) in Ar and H-2(10%)-Ar ambients. Th e changes in the grain size of the films upon annealing were investiga ted. Annealing in an H-2(10%)-Ar ambient produced normal grain growth; annealing in an Ar ambient caused grain growth to stop at 550 degrees C. The grain size followed a monomodal distribution and the mean size increased in proportion to the square root of the annealing time, ind icating the curvature of the grain is the main driving force for grain growth. Upon annealing at 450 degrees C for 30 min in an H-2(10%)-Ar ambient, the average grain size of the film increased from 122 nm to 2 19 nm, and the resistivity decreased from 2.35 mu Ohm cm to 2.12 mu Oh m cm at a film thickness of 600 nm.