Title :
Copper dual damascene interconnects with low-K (K/sub eff/<3.0) dielectrics using FLARE/sup TM/ and an organo-silicate hard mask
Author :
Hasegawa, T. ; Ikeda, K. ; Tokunaga, K. ; Yamamura, I. ; Fukasawa, K. ; Kito, H. ; Miyata, K. ; Komai, N. ; Taguchi, M. ; Hirano, S. ; Tatsumi, T. ; Kadomura, S.
Author_Institution :
Sony Corp., Kanagawa, Japan
Abstract :
Reliable Cu dual damascene (D.D.) interconnects with low-K (K/sub eff/<3.0) that use organic material (FLARE/sup TM/; K=2.8) and methyl-silsesquioxane (MSQ; K=2.7) film have been developed. We successfully substituted the MSQ for the SiO/sub 2/ as inorganic dielectrics. The MSQ acts as a hard mask for etching the FLARE/sup TM/, an etch stop layer for forming a trench and a Cu CMP buffer layer. The substitution does not cause any damage or degradation to the interconnect system. The effect of reducing the effective dielectric constant is demonstrated by using a ring oscillator to measure stage delay time. It is improved by 33% in comparison with the Al/SiO/sub 2/ system.
Keywords :
CMOS logic circuits; copper; delays; dielectric thin films; etching; integrated circuit interconnections; masks; organic compounds; permittivity; CMOS integration; Cu; Cu CMP buffer layer; Cu dual damascene interconnects; FLARE; effective dielectric constant reduction; etch stop layer; etching; low-K dielectrics; methyl-silsesquioxane; organic material; organo-silicate hard mask; ring oscillator; stage delay time; trench formation; Buffer layers; Copper; Degradation; Dielectric constant; Dielectric measurements; Etching; Materials reliability; Organic materials; Ring oscillators; Time measurement;
Conference_Titel :
Electron Devices Meeting, 1999. IEDM '99. Technical Digest. International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-5410-9
DOI :
10.1109/IEDM.1999.824230
