	US 12,463,048 B2
	Methods for forming semiconductor devices using metal hard masks
Alec Dorfner, Albany, NY (US); and Minjoon Park, Albany, NY (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Sep. 1, 2022, as Appl. No. 17/901,727.
Prior Publication US 2024/0079246 A1, Mar. 7, 2024
Int. Cl. H01L 21/308 (2006.01)

CPC H01L 21/3086 (2013.01) [H01L 21/3081 (2013.01)]

20 Claims

1. A method for forming a semiconductor device, comprising:

forming a first metal layer on top of an amorphous mask layer disposed over a substrate;

patterning the first metal layer and the amorphous mask layer using a metal etch hard mask layer to form an opening in the amorphous mask layer;

forming a second metal layer that extends along vertical sidewalls of the opening;

forming a first recess partially extending into the substrate using the first metal layer and the second metal layer as a first etch mask;

forming a third metal layer that extends along vertical sidewalls of the first recess; and

forming a second recess below the first recess using the first to third metal layers as a second etch mask.

12. A method for forming a semiconductor device, comprising:

forming a mask layer over a substrate;

forming a first metal layer comprising a first metal over the mask layer;

forming an opening in the first metal layer and the mask layer using a patterned metal etch hard mask layer;

forming a first portion of a metal spacer comprising a second metal along sidewalls of the opening;

etching the substrate to form a first recess using the first metal layer and the first portion of the metal spacer as a first etch mask;

forming a second portion of the metal spacer comprising a third metal along sidewalls of the first recess; and

etching the substrate to form a second recess below the first recess using the first metal layer and both of the first and second portions of the metal spacer as a second etch mask.

19. An apparatus, comprising:

a first chamber configured to house a substrate overlaid by a mask layer and perform deposition of a first metal layer over the mask layer;

a second chamber configured to form an opening through the first metal layer and the mask layer using a patterned metal etch hard mask layer;

a third chamber configured to perform deposition of a second metal layer to extend along vertical sidewalls of the opening;

a fourth chamber configured to etch a horizontal portion of the second metal layer;

a fifth chamber configured to form, based at least on a remaining vertical portion of the second metal layer, a first recess extending into the substrate;

a sixth chamber configured to perform deposition of a third metal layer to extend along vertical sidewalls of the first recess;

a seventh chamber configured to etch a horizontal portion of the third metal layer; and

an eighth chamber configured to form, based at least on a remaining vertical portion of the third metal layer, a second recess further extending into the substrate.