Highly reliable molecular-pore-stacking (MPS)/Cu interconnects using novel post-etching treatment (PET) for 28 nm-node and beyond

Oshida, Daisuke; Kume, I.; Kunishima, H.; Tsuchiya, Hiroyuki; Katsuyama, Hirokazu; Ueki, Makoto; Iguchi, Manabu; Yokogawa, Shinji; Inoue, N.; Oda, Noriaki; Sakurai, Michio

doi:10.1109/iitc.2011.5940341

Cited by 1 publication

(2 citation statements)

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“…However, porous ultra low-k materials are easily damaged during BEOL process, such as reactive ion etching, wet cleaning, barrier layer deposition, and chemical mechanical polishing (CMP) processes. The main damage mechanism is the plasmas induced process that can remove the carboncontaining hydrophobic groups and convert to hydrophilic ones for the ultra low-k film [1][2][3]. The moisture absorption by hydrophilic porous ultra low-k film can lead to kvalue increase and TDDB degradation.…”

Section: Introductionmentioning

confidence: 99%

“…The moisture absorption by hydrophilic porous ultra low-k film can lead to kvalue increase and TDDB degradation. In these years, post etch treatment and post CMP process optimization have been the focus of study for the porous ultra low-k film damage recover [3][4][5]. However, the integrative research on low-k damage recover has not been fully understood.…”

Section: Introductionmentioning

confidence: 99%

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Ultra Low-k Damage Control and k Recovery for 28nm RC Improvement

et al. 2013

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To improve resistance-capacitance delay, porous ultra low-k dielectric materials are used in advanced copper damascene integration. However, the BEOL processes often lead to low-k film damage by removing the hydrophobic groups Si-CH3, and convert partially low-k materials surface from hydrophobic to hydrophilic one. During the wet related processes, the hydrophilic porous low-k film surface is easy to absorb moisture and potentially increase k-value. In this work, we developed the processes that can maintain ultra low-k film k-value either by repairing low-k damage or by removing moistrue. Dry etch plasma process is one of the main steps to result in low-k film damage. Post etch treatment (PET) was optimized to repair porous low-k film surface due to the etch damage. This improved process with less low-k damage can significantly reduced the moisture absorption in the following wet process and improve the capacitance by about 10%. Various thermal treatments post wet and post CMP processes were studied, including temperature, gases and pressures. From our results, post wet clean heat treatment can improve capacitance by about 5% and post CMP heat treatment can improve capacitance by about 10%. To decrease moisture absorption from atmosphere after the wafers were processed thru CMP, queue time from CMP to NDC deposition also was studied and the safe specification was also defined.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%