FST to launch full size EUV pellicle next year

Semiconductor exposure component maker FST will launch pellicles for use in extreme ultraviolet (EUV) process next year, the company said on Tuesday.

The company will launch a full size EUV pellicle based on silicon carbide (SiC), 30-nanometer (nm) thick and with 90% transmittance in the first quarter of 2021, said FST senior vice president Moon Seong-yong at SMC 2020 conference hosted by SEMI. FST will wrap up investment into new equipment for their production within the year, Moon said.

FST succeed in making it in 30x30㎟ size this year. Next year, they will be made with the company’s own membrane etching technology in full size.

The company previously wrapped up development of a polysilicon-based EUV pellicle with thickness of 50nm and transmittance of 83%. But the company likely thought silicon won’t be able to satisfy customers’ needs.

Moon stressed at the conference that SiC-based pellicles will last longer. SiC are better at resisting heat compared to SiC. EUV can raise temperatures of pellicles to over 600 degree Celsius.

FST’s customer is requiring the pellicle to survive 10,000 sheets but the company is aiming to have it survive over 20,000 sheets, Moon said.

Pellicles are used to protect masks from dusts. ArF exposure equipment shot the light top down but EUV equipment has the light reflected from a mirror to reach the wafer. The change weakens the strength of the light that requires pellicles to have high transmittance of over 90% from customers such as Samsung and TSMC.

Samsung and TSMC are pushing EUV without using pellicles despite the mask’s exposure to dusts __ if FST succeeds in developing such as pellicle it will help greatly with its sales.

FST was also developing a frame to fix the pellicles in place, Moon said. The goal is to develop the technology by 2023. The company will also launch pellicle mounting equipment and inspection equipment next year, he added.