Metrology methods comparison for 2D structures on binary and embedded attenuated phase-shift masks

Matthew Lassiter; Benjamin George Eynon Jr.

doi:10.1117/12.476969

1 August 2002 Metrology methods comparison for 2D structures on binary and embedded attenuated phase-shift masks

Matthew Lassiter, Benjamin George Eynon Jr.

Author Affiliations +

Proceedings Volume 4754, Photomask and Next-Generation Lithography Mask Technology IX; (2002) https://doi.org/10.1117/12.476969
Event: Photomask and Next Generation Lithography Mask Technology IX, 2002, Yokohama, Japan

Abstract

There are several different methods for printing contact holes on wafers using optical lithography. A preferred resolution enhancement technique for improved contact hole lithography performance is the embedded attenuated phase shift mask (EAPSM). The EAPSM comes in many flavors and forms, but the current preferred form is a film transmission of 6 percent and a phase shift of 180 degrees relative to the clear fused silica areas. It is important to note that the phase shift and transmission values for the phase shift mask are at the actinic exposure wavelength of the wafer stepper/scanner. That is the mask is designed to have a transmission of 6 percent and phase shift of 180-degrees at 248nm or 193nm, depending on the wafer stepper. The resulting transmission of the phase shift mask at the inspection tool wavelength of 365nm is much higher, and the phase shift of the 365nm radiation is significantly less than at the shorter actinic wavelength. The gray-scaled aerial images that are collected by the mask inspection tool could vary significantly for the same size 2-D feature in the binary mask, the 248nm EAPSM, and the 193nm EAPSM. This is also compounded by the fact that the inspection tool calibrates the background transmission of the phase shift material as 0 percent transmission and calibrates the transmission of the fused silica as 100 percent transmission. When these gray-scaled images are used in an energy flux algorithm for contact area measurement, they can be potentially different for each of the three types of masks used to print contact holes. This paper explores the issues involved in using an off-actinic aerial image as the basis for the AVI method of contact sizing.

Citation Download Citation

Matthew Lassiter and Benjamin George Eynon Jr. "Metrology methods comparison for 2D structures on binary and embedded attenuated phase-shift masks", Proc. SPIE 4754, Photomask and Next-Generation Lithography Mask Technology IX, (1 August 2002); https://doi.org/10.1117/12.476969

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
6 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Photomasks

Phase shifts

Inspection

Binary data

Calibration

Semiconducting wafers

CCD cameras

Show All Keywords

Keywords/Phrases

Search In:

Publication Years