The chemistry screening for ultra low-k dielectrics plasma etching

A. Zotovich; M. Krishtab; F. Lazzarino; M. R. Baklanov

doi:10.1117/12.2181010

18 December 2014 The chemistry screening for ultra low-k dielectrics plasma etching

A. Zotovich, M. Krishtab, F. Lazzarino, M. R. Baklanov

Proceedings Volume 9440, International Conference on Micro- and Nano-Electronics 2014; 944002 (2014) https://doi.org/10.1117/12.2181010
Event: The International Conference on Micro- and Nano-Electronics 2014, 2014, Zvenigorod, Russian Federation

Abstract

Nowadays, some of the important problems in microelectronics technological node scaling down are related to interconnect delay, dynamic power consumption and crosstalk. This compels introduction and integration of new materials with low dielectric permittivity (low-k materials) as insulator in interconnects. One of such materials under consideration for sub 10 nm technology node is a spin-coated organosilicate glass layer with ordered porosity (37-40%) and a k-value of 2.2 (OSG 2.2). High porosity leads to significant challenges during the integration and one of them is a material degradation during the plasma etching. The low-k samples have been etched in a CCP double frequency plasma chamber from TEL. Standard recipes developed for microporous materials with k<2.5 and based on mixture of C4F8 and CF4 with N2, O2 and Ar were found significantly damaging for high-porous ULK materials. The standard etch recipe was compared with oxygen free etch chemistries based on mixture CF4 with CH2F2 and Ar assuming that the presence of oxygen in the first recipe will have significant negative impact in high porous ULK materials. The film damage has been analyzed using FTIR spectroscopy and the k-value has been extracted by capacitance CV-measurements. There was indirectly shown that vacuum ultraviolet photons cause the main damage of low-k, whereas radicals and ions are not so harmful. Trench structures have been etched in low-k film and cross-SEM analysis with and without HF dipping has been performed to reveal patterning capability and visualize the sidewall damage and. The bottom roughness was analyzed by AFM.

Citation Download Citation

A. Zotovich, M. Krishtab, F. Lazzarino, and M. R. Baklanov "The chemistry screening for ultra low-k dielectrics plasma etching", Proc. SPIE 9440, International Conference on Micro- and Nano-Electronics 2014, 944002 (18 December 2014); https://doi.org/10.1117/12.2181010

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