Novel process to pattern selectively dual dielectric capping layers using soft-mask only

We are reporting for the first time on the use of simple resist-based selective high-k dielectric capping removal processes of La
₂
O
₃
, Dy
₂
O
₃
and Al
₂
O
₃
on both HfSiO(N) and SiO
₂
to fabricate functional HK/MG CMOS ring oscillators with 40% fewer process steps compared to our previous report [1]. Both selective high-k removal (using wet chemistries) and resist strip processes (using NMP and APM) have been characterized physically and electrically indicating no major impact on Vt, EOT, Jg, mobility and gate dielectric integrity (PBTI, TDDB and charge pumping).