Title :
Selective oxide trench etch for dual damascene process in a transformer coupled plasma system
Author :
Woo Sung Chu ; Yoon, Kuk Han ; Yoon, Han Sik ; Koh, Wook Hyun ; Kim, Dong Seok ; Park, Jae Hyun ; Ha, Jae Hee
Author_Institution :
Res. Center, Hyundai MicroElectron. Co. Ltd., Cheongju, South Korea
Abstract :
The characteristics of oxide trench etch in a dual damascene process were studied in a transformer coupled plasma etcher using C4F8/CH2F2/CO mixed plasmas. It was found that the selectivity of oxide with respect to nitride is inversely proportional to the DC bias voltage measured in the C4 F8 plasma system. However adding CO gas to C4F8 plasma caused an increase in the selectivity with increasing DC bias voltage, which possibly resulted from the reduction of ion densities by the reaction of CO with fluorine ions in the plasma. Under the optimized trench etch conditions with low DC bias voltage, a dual damascene structure of 0.18 μm design rule was successfully constructed
Keywords :
CMOS integrated circuits; integrated circuit interconnections; plasma chemistry; plasma density; sputter etching; 0.18 mum; C4F8 plasma; C4F8/CH2F2/CO mixed plasmas; CMOS interconnection fabrication; CO; CO gas; CO/F- ion reaction; DC bias voltage; difluoromethane; dual damascene process; ion density reduction; octafluorobutane; oxide etch selectivity; selective oxide trench etch; transformer coupled plasma system; Electrostatics; Etching; Plasma applications; Plasma chemistry; Plasma density; Plasma measurements; Plasma properties; Plasma sources; Plasma temperature; Voltage measurement;
Conference_Titel :
VLSI and CAD, 1999. ICVC '99. 6th International Conference on
Conference_Location :
Seoul
Print_ISBN :
0-7803-5727-2
DOI :
10.1109/ICVC.1999.820854
