公开(公告)号：US20210183660A1

公开(公告)日：2021-06-17

申请号：US17115313

申请日：2020-12-08

Applicant: SEMES CO., LTD.

Inventor： Jung Suk GOH ,  Jae Seong LEE ,  Do Youn LIM ,  Kuk Saeng KIM ,  Young Dae CHUNG ,  Tae Shin KIM ,  Jee Young LEE ,  Won Geun KIM ,  Ji Hoon JEONG ,  Kwang Sup KIM ,  Pil Kyun HEO ,  Yoon Ki SA ,  Ye Rim YEON ,  Hyun YOON ,  Do Yeon KIM ,  Yong Jun SEO ,  Byeong Geun KIM ,  Young Je UM

IPC: H01L21/311 ,  H01L21/66 ,  H01L21/67

Abstract: Method and apparatus for etching a thin layer including silicon nitride formed on a substrate are disclosed. Etchant including phosphoric acid and water is supplied on the substrate so that a liquid layer is formed on the substrate. The thin layer is etched by reaction between the thin layer and the etchant. Thickness of the liquid layer is measured to detect variation in the thickness of the liquid layer while etching the thin layer. Variation in the concentration of the phosphoric acid and the water is calculated based on the variation in the thickness of the liquid layer. Water is supplied on the substrate based on the variation in the concentration of the phosphoric acid and the water so that the concentration of the phosphoric acid and the water becomes a predetermined value.