Paper
27 March 2017 Development of a robust reverse tone pattern transfer process
Niyaz Khusnatdinov, Gary Doyle, Douglas J. Resnick, Zhengmao Ye, Dwayne LaBrake, Brennan Milligan, Fred Alokozai, Jerry Chen
Author Affiliations +
Abstract
Pattern transfer is critical to any lithographic technology, and plays a significant role in defining the critical features in a device layer. As both the memory and logic roadmaps continue to advance, greater importance is placed on the scheme used to do the etching. For many critical layers, a need has developed which requires a multilayer stack to be defined in order to perform the pattern transfer. There are many cases however, where this standard approach does not provide the best results in terms of critical dimension (CD) fidelity and CD uniformity. As an example, when defining a contact pattern, it may be advantageous to apply a bright field mask (in order to maximize the normalized inverse log slope (NILS)) over the more conventional dark field mask. The result of applying the bright field mask in combination with positive imaging resist is to define an array of pillar patterns, which then must be converted back to holes before etching the underlying dielectric material. There have been several publications on tone reversal that is introduced in the resist process itself, but often an etch transfer process is applied to reverse the pattern tone. The purpose of this paper is to describe the use of a three layer reverse tone process (RTP) that is capable of reversing the tone of every printed feature type. The process utilizes a resist pattern, a hardmask layer and an additional protection layer. The three layer approach overcomes issues encountered when using a single masking layer. Successful tone reversal was demonstrated both on 300mm wafers and imprint masks, including the largest features in the pattern, with dimensions as great as 60 microns. Initial in-field CD uniformity is promising. CDs shifted by about 2.6nm and no change was observed in either LER or LWR. Follow-up work is required to statistically qualify in-field CDU and also understand both across wafer uniformity and feature linearity.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Niyaz Khusnatdinov, Gary Doyle, Douglas J. Resnick, Zhengmao Ye, Dwayne LaBrake, Brennan Milligan, Fred Alokozai, and Jerry Chen "Development of a robust reverse tone pattern transfer process", Proc. SPIE 10146, Advances in Patterning Materials and Processes XXXIV, 101461A (27 March 2017); https://doi.org/10.1117/12.2260455
Lens.org Logo
CITATIONS
Cited by 2 scholarly publications and 1 patent.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Etching

Photomasks

Photoresist processing

Atomic layer deposition

Oxides

Semiconducting wafers

System on a chip

Back to Top