How to improve intra-field CDU of contact hole patterns in both X-Y directions with CDC technology

Yilei Zeng; Xiuxuan Zhang; Levi Tang; Yingjie Wang; Pei Su; Adam Liu; Claire Zhang

doi:10.1117/12.2685350

21 November 2023 How to improve intra-field CDU of contact hole patterns in both X-Y directions with CDC technology

Yilei Zeng, Xiuxuan Zhang, Levi Tang, Yingjie Wang, Pei Su, Adam Liu, Claire Zhang

Proceedings Volume 12751, Photomask Technology 2023; 1275112 (2023) https://doi.org/10.1117/12.2685350
Event: SPIE Photomask Technology + EUV Lithography, 2023, Monterey, California, United States

Conference Poster

Abstract

In Dynamic Random Access Memory (DRAM) manufacturing process, contact hole (CH) patterns are critical and challenging array layers. Compared to line/space patterns, CH patterns generally tend to have a higher Mask Error Enhancement Factor (MEEF), therefore it will bring big challenges to wafer Global Critical Dimension Uniformity (GCDU) control, and it is also obvious to observe that the intra-field CDU error contributes mainly to the wafer GCDU variations compared with inter-field error. To improve CH patterns’ intra-field CDU, lithography process generally uses ASML scanner dose mapper (DOMA) solution. Here we introduce a new intra-field CDU improvement technology called CD Correction (CDC) by mask tuning, which is developed by Carl Zeiss and can obtain local illumination transmittance control with higher space resolution than DOMA. In our CDC application cases of contact hole (aka 2D pattern) layers, CDU in both X-Y directions is crucial for process, but different improvement results are found. When CDU in one direction is fully improved by CDC, improvement in the other direction is often insufficient or excessive and hard to achieve a win-win effect. By further experiments and analysis, the key factor we figure out is CDCR (CDC ratio), which is different in X-Y directions. In our work, first, we present a CDC implementation approach that trades off both X-Y directions of improvement. Second, the principle of different CDCR in X-Y directions is explored, it provides a theoretical interpretation for different CDCR and can predict CDCR in future applications.

(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Yilei Zeng, Xiuxuan Zhang, Levi Tang, Yingjie Wang, Pei Su, Adam Liu, and Claire Zhang "How to improve intra-field CDU of contact hole patterns in both X-Y directions with CDC technology", Proc. SPIE 12751, Photomask Technology 2023, 1275112 (21 November 2023); https://doi.org/10.1117/12.2685350

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