	US 11,720,025 B2
	Extreme ultraviolet lithography method, extreme ultraviolet mask and formation method thereof
Chih-Tsung Shih, Hsinchu (TW); Yu-Hsun Wu, New Taipei (TW); Bo-Tsun Liu, Taipei (TW); and Tsung-Chuan Lee, Taipei (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed on Jun. 23, 2022, as Appl. No. 17/848,139.
Application 17/848,139 is a division of application No. 16/900,384, filed on Jun. 12, 2020, granted, now 11,392,022.
Prior Publication US 2022/0326598 A1, Oct. 13, 2022
Int. Cl. G03F 7/20 (2006.01); G03F 1/24 (2012.01)

CPC G03F 7/2004 (2013.01) [G03F 1/24 (2013.01)]

20 Claims

1. An extreme ultraviolet lithography (EUVL) method, comprising:

turning on a droplet generator to eject a metal droplet toward a zone of excitation in front of a collector;

turning on a laser source to emit a laser toward the zone of excitation, such that the metal droplet is heated by the laser to generate EUV radiation;

guiding the EUV radiation, by using one or more first optics, toward a reflective mask in an exposure device, the reflective mask comprising a capping layer having a ruthenium complex with a ligand, the ligand having a halogen element, a pentavalent element, a hexavalent element or combinations thereof; and

guiding the EUV radiation, by using one or more second optics, reflected from the reflective mask toward a photoresist coated substrate in the exposure device.