Pellicle films supporting the ramp to HVM with EUV

Abstract

EUV pellicles are needed to support EUV lithography in high volume manufacturing. We demonstrate progress in cap layer design for increased EUV transmission and infrared emission of the Polysilicon-film. In our research lab we obtained EUV transmission of 90% and good emissivity for a fully capped pSi film. We also discuss results on next generation EUV pellicle films. These include metal-silicides and graphite. Next-gen film performance is compared to the current generation pSi film. These films are expected to be stable at higher operating temperature than pSi. Metal-silicides have the advantage of sharing a similar process flow as that of pSi, while graphite shows ultimate high temperature performance at the expense of a more complicated manufacturing flow. Capping layers are needed here as well and capping strategies are discussed for these film generations.

Low temperature pure boron layer deposition for Si diode and micromachining applications

“…Boron has also been studied as a material for capping EUV pellicles for EUV lithography systems [45]. These pellicles are preferably made of polysilicon due to the high transmissivity and mechanical strength.…”

“…For high-volume EUV exposure, the infrared emission needed for preventing overheating of the pellicle requires capping of the poly-Si with layers of suitable emissivity. Capping layers incorporating boron were found to have both good transmissivity [47] and emissivity [45]. To extend this to using pure B-membranes for pellicles, high demands on the mechanical strength and stiffness need to be met.…”

“…Also, for application as membranes, an important advantage with respect to graphene is that B thin films are highly manufacturable [18,43,44]. The XUV group at University of Twente was also devoting some time to studying boron as a material for capping EUV pellicles for EUV lithography systems [45]. These pellicles are preferably made of polysilicon due to the high transmissivity and mechanical strength.…”

Impact of thermal expansion coefficient on the local tilt angle of extreme ultraviolet pellicle

“…( 2)]. 2,15,16 The material properties of the EUV pellicle and the exposure conditions for numerical analysis were considered to be independent of the temperature and were approximated by rounding to the fourth decimal place (Table 1): 2,17,18 E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 2 ; 1 1 6 ; 1 7 4…”

Fracture Toughness of Free-Standing ZrSix Thin Films Measured Using Crack-on-a-Chip Method

“…Characterization and improvement of fracture toughness are essential for designing mechanically strong and reliable free-standing thin film components, including EUV pellicles. Despite this, however, the literature shows no reports on the characterization of the fracture toughness of metal silicide thin films, which are considered to be promising candidate materials for the next generation EUV pellicles thanks to their high thermal stability, yield strength, and EUV transmission [3].…”