CF3Br plasma cryo etching of low-k porous dielectric

3rd International School and Conference on Optoelectronics, Photonics, Engineering and Nanostructures (Saint Petersburg OPEN 2016)

Clemente, I.^1,2 ; Koehler, N.^3 ; Miakonkikh, A.^1,2 ; Zimmermann, S.^3,4 ; Schulz, S.E.^3,4 ; Rudenko, K.^1,2

Institute of Physics and Technology, Moscow

117218, Russia^1

Moscow Institute of Physics and Technology, Dolgoprudny

147001, Russia^2

Technische Universität Chemnitz, Center for Microtechnologies, Chemnitz

09126, Germany^3

Fraunhofer Institute for Electronic Nanosystems (ENAS), Chemnitz

09126, Germany^4

关键词: DC voltage;    Ellipsometric porosimetry;    Etch rates;    ICP plasmas;    Low pressures;    Porous dielectrics;    Sample temperature;    Spectral ellipsometry;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/741/1/012204/pdf
DOI  :  10.1088/1742-6596/741/1/012204

来源: IOP

【 摘 要 】

Process of plasma etching of CVD low-k dielectric was studied. We used CF3Br low pressure ICP plasma for etching at cryo temperatures (-20°C - -100°C), pressures (5-20 mTorr) and RF bias with effective DC voltage 80-140 V. Refractive index of film and its thickness were measured by spectral ellipsometry. Ellipsometric porosimetry was employed to compare pore size distribution before and after etching of films. Measurements show increasing of etch rate increase with decreasing sample temperature.