AVS 59th Annual International Symposium and Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS-ThP

Paper PS-ThP26
High K Metal Gate Etching towards sub 14 nm Features

Thursday, November 1, 2012, 6:00 pm, Room Central Hall

Session: Plasma Science and Technology Poster Session
Presenter: L. Desvoivres, CEA, LETI, MINATEC Campus, France
Authors: S. Barnola, CEA, LETI, MINATEC Campus, France
L. Desvoivres, CEA, LETI, MINATEC Campus, France
C. Vizioz, CEA, LETI, MINATEC Campus, France
C. Arvet, ST Microelectronics, Crolles, France
Correspondent: Click to Email
To progress towards the 11nm node, sub 14nm HK metal gates need to be patterned with a good CD control. Two lithography techniques were used at the same time on the wafer to achieve the same CD target for different goals : electron-Beam lithography with 30nm dense litho features for the circuit development and optical lithography with 80nm isolated features for single device optimization. A gate etching process has been developed at LETI starting from these two lithography options using different trimming strategies to achieve this aggressive CD target For this study, wafers were patterned with hybrid lithography. In the same die, E-beam and optical fields were realized separately using a common stack made of trilayer / hard masks/ HKMG. The optical side was first printed and patterned down to the Poly-si , then the ebeam side was printed with positive photoresist and etched to the Poly-Si as well. Finally the HKMG parts were etched at the same time on both fields.Metal Gate patterning has been performed in a 300mm industrial platform etcher: LAM VERSYS, Kiyo CX. Several conditions were tested to minimize added LWR for such small dimensions. We focused on several trimming conditions at different location on the stack to achieve our CD target : resist, ARC, SOC and hard mask. After optimization sub 14nm CD have been successfully achieved for FDSOI technology. Best results were achieved with hard mask trimming strategies for ebeam part and resist + hard mask trimming for optical part.