METHOD FOR MANUFACTURING SIGMA-SHAPED GROOVE

    公开(公告)号:US20240055263A1

    公开(公告)日:2024-02-15

    申请号:US18175092

    申请日:2023-02-27

    IPC分类号: H01L21/304 H01L21/8238

    摘要: A method for manufacturing a sigma-shaped groove in a semiconductor substrate includes: step 1: performing the first etching to form a U-shaped groove in a selected area of the substrate; step 2: performing a second etching configured to expand an opening width of the top sub-groove outward laterally, without changing an opening width of the bottom sub-groove and a depth of the groove; and step 3: performing the third etching which has different etching rates on different crystal surfaces of the semiconductor substrate to further expand the groove into a sigma-shaped groove with a sigma-shaped cross section. An increase of the opening width of the top sub-groove shifts the upper side surface towards an outer side of the sigma-shaped groove, resulting in an upward shift of the apex and reduces a vertical spacing between the apex and top surface of the semiconductor substrate, thereby improving the device performance.

    Method for Making Silicon Epitaxy of a FDSOI Device

    公开(公告)号:US20230130629A1

    公开(公告)日:2023-04-27

    申请号:US17951756

    申请日:2022-09-23

    IPC分类号: H01L21/762 H01L21/768

    摘要: The present application relates to a method for making silicon epitaxy of a FDSOI device, which includes the following steps: providing a semiconductor structure; sequentially forming a first etch stop layer and an etch reaction layer on a surface of the semiconductor structure; performing an etching operation to the etch reaction layer to form a sidewall structure respectively; filling a second etch stop layer in a space between the sidewall structures at the position of the trench; etching the sidewall structures and the first etch stop layer under the sidewall structures to form a groove structure; removing the second etch stop layer and the remaining first etch stop layer; enabling a silicon substrate at the positions of the trench and the groove structure to epitaxially grow upwards to form epitaxial silicon, the epitaxial silicon being in flush with a top silicon layer.