US 9,812,325 B2
Method for modifying spacer profile
Nihar Mohanty, Clifton Park, NY (US); and Akiteru Ko, Schenectady, NY (US)
Filed by Tokyo Electron Limited, Minato-ku, Tokyo (JP)
Filed on Sep. 2, 2016, as Appl. No. 15/255,863.
Claims priority of provisional application 62/213,873, filed on Sep. 3, 2015.
Prior Publication US 2017/0069495 A1, Mar. 9, 2017
Int. Cl. H01L 21/033 (2006.01); B81C 1/00 (2006.01); H01L 21/3065 (2006.01); H01L 21/308 (2006.01); H01L 21/306 (2006.01)
CPC H01L 21/0337 (2013.01) [B81C 1/00404 (2013.01); H01L 21/3065 (2013.01); H01L 21/3086 (2013.01); H01L 21/30604 (2013.01); Y10S 438/947 (2013.01)] 12 Claims
OG exemplary drawing
1. A method for processing a substrate, the method comprising:
receiving a substrate having spacers positioned on an underlying layer, the spacers defining a relief pattern, each spacer having a first sidewall and a second sidewall on opposing sides of each spacer, the first sidewall and the second sidewall being normal to the underlying layer, the first sidewall being greater in height as compared to the second sidewall;
depositing a filler material on the substrate, the filler material filling spaces between the spacers, the filler material planarizing the substrate such that the spacers are buried;
executing a first etch step that etches a first portion of the filler material until uncovering a top portion of the spacers such that a top of the first sidewall and a top of the second sidewall are both uncovered;
executing a second etch step that isotropically etches the substrate until the top of the first side wall and the top of the second sidewall are approximately equal in height as measured from the underlying layer, the second etch step using a plasma etch chemistry that etches the spacers at an etch rate that is greater than at least five times an etch rate of the filler material; and
removing the filler material from the substrate such that the spacers remain on the substrate.