LPCVD REXSIYNZ DIFFUSION-BARRIERS IN SI SIO2/CU METALLIZATIONS/

Low pressure chemical vapor deposition RexSiyNz thin films are investi gated as diffusion barriers between Cu overlayers and oxidized silicon substrates. Gaseous precursors are silane, in situ fabricated rhenium chloride, ammonia, hydrogen and argon. Thermodynamic simulation of th e Re-Si-N system is combined to the experimental study. The as-deposit ed RexSiyNz films are found to be amorphous or nanocrystalline. The [S i]/SiO2/RexSiyNz(200 nm)/Cu(100 nm) metallizations are tested up to 12 73 K by a 1 min RTP annealing in vacuum. The barrier performance is ch aracterized with SEM, RES and AES, for different RexSiyNz film composi tion and annealing temperature. RexSiyNz films properties are compared with Me-Si-N (where Me = Ta, W, Mo, Ti) films obtained by physical de position methods.