Browse Prior Art Database

Clean EUVL Mask Handling

IP.com Disclosure Number: IPCOM000124947D
Publication Date: 2005-May-13
Document File: 3 page(s) / 224K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a new mask carrier that modifies the mask corner to eliminate direct contact with the patterned side. Benefits include preventing particles from falling onto the mask during handling, shipping, storage, and loading.

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Clean EUVL Mask Handling

Disclosed is a method for a new mask carrier that modifies the mask corner to eliminate direct contact with the patterned side. Benefits include preventing particles from falling onto the mask during handling, shipping, storage, and loading.

Background

The current optical mask uses a pellicle, which is a thin organic membrane on a metal frame with a standoff distance of over 6mm. The pellicle is mounted on the clean optical mask to cover the patterned region. Any particle that falls onto the pellicle, in general, will not print (unless it is an extremely large particle) because of the pellicle frame standoff distance. The mask out of the shop is pelliclized, and therefore handling and particle protection after pelliclization is less critical.

Due to light absorption of all solid materials at EUV wavelength, there is no pellicle material that can be used for EUVL masks. As a result, the EUVL mask is handled and used with no pellicle. Some approaches include using a removable pellicle or a cover plate to protect the EUVL mask; however, these approaches add additional handling steps and contact the front side of the mask. In other words, these methods increase the potential for particle contamination.

General Description

Particles due to handling come primarily from robotic contact with the mask and the cleanliness of the mini-environment where the mask is handled. Particles due to shipping and storage by the current standard mask carriers come primarily from the contacts of the mask front side with the carrier, the un-tightened sealing of the box, and if the box is not clean during movement. The disclosed method shif...