Title :
Ti-Si-N diffusion barriers between silicon and copper
Author :
Reid, J.S. ; Sun, X. ; Kolawa, E. ; Nicolet, M.A.
Author_Institution :
California Inst. of Technol., Pasadena, CA, USA
Abstract :
Thin films of Ti-Si-N, reactively spattered from a Ti/sub 5/Si/sub 3/ target, are assessed as diffusion barriers between silicon substrates and copper overlayers. By tests on shallow-junction diodes, a 100 nm Ti/sub 34/Si/sub 23/N/sub 43/ barrier is able to prevent copper from reaching the silicon substrate during a 850/spl deg/C/30 min anneal in vacuum. A 10 nm film prevents diffusion up to 650/spl deg/C/30 min. By high-resolution transmission electron microscopy, Ti/sub 34/Si/sub 23/N/sub 43/ predominantly consists of nanophase TiN grains roughly 2 nm in size.<>
Keywords :
VLSI; chemical interdiffusion; diffusion in solids; metallisation; nitrogen; silicon; sputter deposition; titanium; transmission electron microscope examination of materials; 10 nm; 100 nm; 30 min; 850 C; Ti-Si-N; Ti-Si-N diffusion barriers; Ti/sub 34/Si/sub 23/N/sub 43/; Ti/sub 34/Si/sub 23/N/sub 43/ barrier; Ti/sub 5/Si/sub 3/; Ti/sub 5/Si/sub 3/ target; TiN; anneal; copper; copper overlayers; diffusion; diffusion barriers; high-resolution transmission electron microscopy; in vacuum; nanophase TiN grains; reactively spattered; shallow-junction diodes; silicon; silicon substrates; thin films; Aluminum; Annealing; Copper; Diodes; Nitrogen; Silicon; Sputtering; Substrates; Testing; Tin;
Journal_Title :
Electron Device Letters, IEEE
