US 11,721,759 B2
Method for forming gate metal structure having portions with different heights
Yu-Ping Chen, New Taipei (TW); and Jhen-Yu Tsai, Kaohsiung (TW)
Assigned to NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed by NANYA TECHNOLOGY CORPORATION, New Taipei (TW)
Filed on Jul. 11, 2022, as Appl. No. 17/811,588.
Application 17/811,588 is a division of application No. 17/168,148, filed on Feb. 4, 2021, granted, now 11,424,360.
Prior Publication US 2022/0344507 A1, Oct. 27, 2022
Int. Cl. H01L 29/78 (2006.01); H01L 29/66 (2006.01); H01L 29/417 (2006.01); H01L 29/423 (2006.01)
CPC H01L 29/7827 (2013.01) [H01L 29/41741 (2013.01); H01L 29/4236 (2013.01); H01L 29/66666 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor device, comprising:
forming a first source region and a drain region in an active region of a substrate, wherein a trench is between the first source region and the drain region;
conformally forming a dielectric layer over the substrate and the trench;
forming a metal structure in the trench, wherein the dielectric layer surrounds the metal structure;
performing a first etching process to an edge of the metal structure, such that the metal structure has a first metal portion and a second metal portion which has a height greater than a height of the first metal portion, wherein the first metal portion is between the drain region and the second metal portion and the first and second metal portions are a continuous piece of a same material and both in direct contact with the dielectric layer; and
forming a first poly-metal structure electrically connected to the first source region and a second poly-metal structure electrically connected to the drain region.