HDP-CVD STI gap-fill using the parallel resonance antenna

Summary form only given, as follows. Summary form only given. In sub-micron technologies, the HDP-CVD STI gap-fill process has progressed to sub-0.1 /spl mu/m technology. In this paper, we investigate the characteristics of the parallel resonance antenna as a high density plasma source for HDP-CVD STI gap-fill process at the sub-0.1 /spl mu/m level. The parallel resonance antenna generates a high density plasma. by inductive coupling of 13.56 MHz RF power and controls plasma uniformity by tuning the LC resonance circuit. With this plasma source, we have studied STI gap-fill capabilities and trends by changing gas flow rates, distance from the wafer on substrate to the plasma source and deposited RF power. The ion density and plasma uniformity were obtained with a commercial Langmuir probe and compared with sputter etch results on 8-inch wafers. Gap-fill was evaluated on the patterned wafer with a gap size of 90 nm and aspect ratio of 3:5:1, to confirm void-free gap-fill results using cross-section SEM. As the gap size shrinks below 0.1 /spl mu/m, the major effects for implementation of HDP-CVD STI gap-fill are reduced gas flow rate, reduced distance from the wafer to the plasma source and increased RF power resulting in higher ion to radical ratio.