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Low‐Temperature Deposition of Reactively Sputtered SiN x Films Applicable to TSV Process
Author(s) -
SATO MASARU,
TAKEYAMA MAYUMI B.,
KOBAYASHI YASUSHI,
NAKATA YOSHIHIRO,
NAKAMURA TOMOJI,
NOYA ATSUSHI
Publication year - 2016
Publication title -
electronics and communications in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.131
H-Index - 13
eISSN - 1942-9541
pISSN - 1942-9533
DOI - 10.1002/ecj.11865
Subject(s) - materials science , sputtering , annealing (glass) , fabrication , optoelectronics , silicon , deposition (geology) , diffusion barrier , thin film , substrate (aquarium) , electronic engineering , nanotechnology , composite material , layer (electronics) , engineering , biology , medicine , paleontology , oceanography , alternative medicine , pathology , sediment , geology
SUMMARY In the through silicon via (TSV) process, which is a key technology for a three‐dimensional large‐scale integration (LSI), particularly in the “via‐last process,” SiN x films of high density are urgently needed for fabrication at low deposition temperatures. However, it is generally known that a SiN x film prepared at low temperatures shows low film density, resulting in poor insulating barrier properties. As a solution to this issue, we propose the use of the SiN x films deposited by reactive sputtering. We can obtain sputtered SiN x films at high density (2.78 to 2.99 g/cm 3 ) in spite of deposition without substrate heating. The 20‐nm‐thick SiN x films passed an experimental check on barrier properties with respect to Cu diffusion upon annealing at 700 °C for 1 h. The films also show good step coverage for a TSV with an aspect ratio of 1.5. The SiN x films prepared by reactive sputtering are a candidate for a good insulating barrier applicable to the via‐last TSV process.