US 12,007,684 B2
Mask blank, method of manufacturing imprint mold, method of manufacturing transfer mask, method of manufacturing reflective mask, and method of manufacturing semiconductor device
Osamu Nozawa, Tokyo (JP); Ryo Ohkubo, Tokyo (JP); and Hiroaki Shishido, Tokyo (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Filed by HOYA CORPORATION, Tokyo (JP)
Filed on Jul. 25, 2023, as Appl. No. 18/226,165.
Application 18/226,165 is a continuation of application No. 17/668,597, filed on Feb. 10, 2022, granted, now 11,762,279.
Application 17/668,597 is a continuation of application No. 16/488,901, granted, now 11,281,089, issued on Mar. 22, 2022, previously published as PCT/JP2018/002072, filed on Jan. 24, 2018.
Claims priority of application No. 2017-034706 (JP), filed on Feb. 27, 2017.
Prior Publication US 2023/0367196 A1, Nov. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G03F 1/24 (2012.01); H01L 21/033 (2006.01)
CPC G03F 1/24 (2013.01) [H01L 21/0332 (2013.01); H01L 21/0337 (2013.01)] 34 Claims
OG exemplary drawing
 
1. A mask blank comprising:
a substrate; and
a hard mask film formed on the substrate, wherein
the hard mask film is a single layer film having a composition gradient portion formed on a surface of the hard mask film that faces away from the substrate and in a region adjacent to the surface,
the hard mask film is made of a material containing chromium, oxygen, and carbon with a total content of chromium, oxygen, and carbon being 95 atomic % or more,
a part of the hard mask film excluding the composition gradient portion has a chromium content of 50 atomic % or more,
a ratio of a carbon content [atomic %] divided by a total content [atomic %] of chromium, carbon, and oxygen in the part of the hard mask film excluding the composition gradient portion is 0.1 or more,
a ratio of a carbon content [atomic %] divided by a total content [atomic %] of chromium and carbon in the part of the hard mask film excluding the composition gradient portion is 0.14 or more, and
a content of nitrogen in the hard mask film is equal to or less than a detection limit value in composition analysis of X-ray photoelectron spectroscopy.
 
15. A method of manufacturing a reflective mask using the mask blank according to claim 9, the method comprising:
performing a first dry etching to form a pattern on the hard mask film; and
performing a second dry etching to form a transfer pattern on the absorber film, wherein a mask used for the second dry etching is the hard mask film provided with the pattern.
 
17. A method of manufacturing a semiconductor device, comprising exposure-transferring a transfer pattern of a reflective mask onto a resist film on a semiconductor substrate, the reflective mask having been manufactured from the mask blank according to claim 9.