CPC H01L 21/76205 (2013.01) [H01L 21/041 (2013.01); H01L 21/042 (2013.01); H01L 21/311 (2013.01)] | 7 Claims |
1. A method of manufacturing a semiconductor structure, comprising:
providing a base;
forming, in the base, a plurality of first trenches arranged in parallel at intervals and extending along a first direction, and an initial active region between two adjacent ones of the plurality of first trenches, wherein the initial active region comprises a first initial source-drain region close to a bottom of a first trench of the plurality of first trenches, a second initial source-drain region away from the bottom of the first trench of the plurality of first trenches, and an initial channel region located between the first initial source-drain region and the second initial source-drain region;
forming a filling dielectric layer in the first trench of the plurality of first trenches, wherein the filling dielectric layer covers a sidewall of the first initial source-drain region, and exposes a sidewall of the second initial source-drain region and a sidewall of the initial channel region;
forming a protective dielectric layer, wherein the protective dielectric layer covers the sidewall of the second initial source-drain region and the sidewall of the initial channel region;
thinning the first initial source-drain region; and
depositing a conductive material layer at two opposite sides of the first initial source-drain region, to form bit line structures, wherein the bit line structures extend along the first direction, wherein
the forming a protective dielectric layer comprises:
depositing a protective dielectric material layer, wherein the protective dielectric material layer covers an upper surface of the filling dielectric layer, the sidewall of the initial channel region, and the sidewall and a top surface of the second initial source-drain region; and
removing the protective dielectric material layer on the upper surface of the filling dielectric layer and on the top surface of the second initial source-drain region, and forming the protective dielectric layer; and
the thinning the first initial source-drain region comprises:
partially removing the filling dielectric layer, to expose the sidewall of the first initial source-drain region;
oxidizing the first initial source-drain region, to form a sidewall oxide layer on the sidewall of the first initial source-drain region; and
removing the sidewall oxide layer.
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