EFFECT OF H2O PARTIAL-PRESSURE AND TEMPERATURE DURING TI SPUTTERING ON TEXTURE AND ELECTROMIGRATION IN ALSICU TI/TIN/TI METALLIZATION/

The effect of residual gas constituents and substrate temperature duri ng Ti sputtering on the texture of TiN/Ti films deposited on SiO2/Si s ubstrates has been investigated. The Ti (002) and TiN (111) preferred texture of the films deposited at 350 degrees C was found to be improv ed drastically by increasing the H2O partial pressure from 1X10(-9) to 3x10(-8) Ton. Both the Ti (002) and TiN (111) texture showed a simila r H2O partial pressure and substrate temperature dependence because of the epitaxial transfer between these planes. The improved Ti (002) te xture was attributed to the self-assembly of Ti atoms on the SiO2 surf ace, which had a low surface free energy due to the formation of surfa ce OH groups. The A1SiCu/Ti/TiN/Ti layered film fabricated with the hi ghly textured TiN/Ti film showed a strong Al (111) texture and had a s mooth surface. Moreover, interconnects from this improved film had lon ger electromigration lifetimes. It was also confirmed that the increas ed H2O partial pressure (3X10(-8) Torr) does not affect the contact re sistance and junction leakage current of the AlSiCu/Ti/TiN/Ti/(n(+)Si or p(+)Si) contact system. (C) 1998 American Vacuum Society.[S0734-211 X(98)06005-3].