公开(公告)号：US20220208785A1

公开(公告)日：2022-06-30

申请号：US17136471

申请日：2020-12-29

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Monica TITUS ,  Senaka KANAKAMEDALA ,  Rahul SHARANGPANI ,  Raghuveer S. MAKALA ,  Yao-Sheng LEE

IPC: H01L27/11582 ,  H01L27/11556 ,  H01L27/11565 ,  H01L27/11519

Abstract: An alternating stack of first material layers and second material layers is formed over a substrate. A hard mask layer is formed over the alternating stack. Optionally, an additional hard mask layer can be formed over the hard mask layer. A photoresist layer is applied and patterned, and cavities are formed in the hard mask layer by performing a first anisotropic etch process that transfers a pattern of the openings in the photoresist layer through the hard mask layer. Via openings are formed through an upper portion of the alternating stack by performing a second anisotropic etch process. A cladding liner can be optionally formed on sidewalls of the cavities in the hard mask layer. The via openings can be vertically extend through all layers within the alternating stack by performing a third anisotropic etch process.

公开(公告)号：US20220208600A1

公开(公告)日：2022-06-30

申请号：US17508036

申请日：2021-10-22

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Roshan Jayakhar TIRUKKONDA ,  Senaka KANAKAMEDALA ,  Raghuveer S. MAKALA ,  Rahul SHARANGPANI ,  Monica TITUS ,  Adarsh RAJASHEKHAR

IPC: H01L21/768 ,  H01L21/306 ,  H01L21/308

Abstract: A source-level semiconductor layer and an alternating stack of first material layers and second material layers is formed above a substrate. A hard mask layer is formed over the alternating stack, and is subsequently patterned to provide a pattern of cavities therethrough. Via openings are formed through the alternating stack by performing an anisotropic etch process. A cladding liner is formed on sidewalls of the cavities in the hard mask layer and on a top surface of the hard mask layer. The via openings are vertically extended at least through the source-level semiconductor layer by performing a second anisotropic etch process employing a combination of the cladding liner and the hard mask layer as an etch mask.