US 12,256,565 B2
Method for preparing recessed gate structure with protection layer
Kuo-Hui Su, Taipei (TW)
Assigned to NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed by NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed on Apr. 16, 2024, as Appl. No. 18/636,545.
Application 18/636,545 is a division of application No. 17/672,138, filed on Feb. 15, 2022, granted, now 12,211,905.
Prior Publication US 2024/0258381 A1, Aug. 1, 2024
Int. Cl. H10D 64/01 (2025.01); H01L 21/768 (2006.01); H01L 23/528 (2006.01); H01L 23/532 (2006.01); H10D 64/27 (2025.01); H10D 64/68 (2025.01)
CPC H10D 64/01 (2025.01) [H01L 21/76846 (2013.01); H01L 21/76858 (2013.01); H01L 21/76867 (2013.01); H01L 23/5283 (2013.01); H01L 23/53238 (2013.01); H10D 64/513 (2025.01); H10D 64/685 (2025.01); H10D 64/693 (2025.01)] 16 Claims
OG exemplary drawing
 
1. A method for preparing a recessed gate structure, comprising:
forming a recessed structure, wherein the recessed structure comprises a substrate with the recess extending into the substrate from a topmost surface of the substrate;
forming a first functional layer to at least cover a sidewall of a recess of the recessed structure;
forming a second functional layer to cover the first functional layer;
performing a rapid thermal treatment to form an interfacial layer extending along an interface between the first functional layer and the second functional layer; and
forming a conductive feature to fill up the recess;
wherein oxygen in the first functional layer diffuses into a thin portion of the second functional layer in contact with the first functional layer during the rapid thermal treatment, and the thin portion of the second functional layer is oxidized to form the interfacial layer;
wherein formation of the first functional layer comprises:
forming an initial functional layer globally and conformally covering the recessed structure; and
removing a portion of the initial functional layer above the recessed structure and another portion of the initial functional layer extending along a bottom surface of the recess, wherein a portion of the initial functional layer remained in the recess and extending along a sidewall of the recess form the first functional layer.