Copper interconnection schemes: elimination of the need of diffusion barrier/adhesion promoter by the use of corrosion-resistant low-resistivity-doped copper

摘要: Copper is known to diffuse in dielectrics subjected high electrical bias at temperatures as low 100 degree(s)C. Also, it does not adhere the interlayer like SiO2 and polymers. In addition, copper corrodes readily corrosive environments. These properties of have inhibited early acceptance interconnection metal performance integrated electronic circuit/devices. We investigated use possible diffusion barrier (DB) adhesion promoter (AP) materials conventional layered structures which lead an increase total resistance negating advantages copper. since subquarter micron circuits necessitates need < 10 nm thick DBAP material, such are generally stable under processing, chip packaging, and/or actual conditions. this paper, we present results our study electrically corrosion resistant doped material. Al, Mg, Ta, all considerably higher free energy formation for their oxides compared that Cu or Si oxides, been added dopant concentration range 0.5 - atomic percent Resistivity, dielectric surfaces, effect annealing 800 degree(s)C on properties, air, I-V/C-V characteristics metal/SiO2/Si capacitors investigated. It found addition dopants provides necessary passivation. Doped films very smooth even after anneals They did lose adherence substrates demonstrated by adhesive tape-peel tests. Preliminary indications doping has reduced overall stress film. There a small resistivity copper, caused these dopants. For example, with Mg (less than 2 percent) remains below (mu) (Omega) cm. Al/Cu, Mg/Cu, Ti/Cu TiN/Cu show satisfy reliability requirements sacrifice manner similar Al containing amounts copper.© (1994) COPYRIGHT SPIE--The International Society Optical Engineering. Downloading abstract permitted personal only.