| Title |
Electronic , Magnetic & Optical Materials / Effects of Current Wave Forms on the Copper Trench Filling during Damascene Plating |
| Authors |
이재봉(Jae Bong Lee),박영준(Young Joon Park),이유용(Yu Yong Lee),조병원(Byung Won Cho) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
The effect of current wave forms on the Cu filling behavior during damascene plating was investigated. Direct current(DC) and pulsed current were used with the variation of the current densities from 1 A/d㎡ to 7 A/d㎡. Straight trenches having 0.25, 0.4 and 0.8 ㎛ width were plated. The cross-sectional images of the electroplated trenches were observed by field emission scanning electron microscope(FE-SEM). Trenches were successfully filled without any void for Cu lines of 0.4 and 0.8 ㎛ width under optimized current densities which were different with respective current wave forms. In case the plating condition was not optimized two types of void were observed : center voids and side wall voids. The formation of center voids was attributed to the fast copper deposition rate at top corner of the trench for DC plating and the fast copper deposition rate at the side wall for pulse plating. Side wall void was formed due to the corrosion of Cu seed layer during the over immersion of the wafer before plating. |