Ultimate-low-k SiOCH film (k=3D1.3) with sufficient modulus (>5 GPa) and ultra-high thermal stability formed by low-temperature pulse-time-modulated neutral-beam-enhanced CVD

Abstract

We investigated a pulse-time-modulated neutral-beam-enhanced CVD at a low substrate temperature of -70 o C with dimethoxy-tetramethyl-disiloxane to form low-k SiOCH film. This method provided an ultimate low-k SiOCH film with a k-value of 1.3, a sufficient modulus of more than 5 GPa, and ultra-high thermal stability (no desorption of CH 3 and H 2 O by 400 o C annealing). This result is explained by the extremely high polymerization due to a drastic increase in absorption probability of the precursor combined with the pulse-time-modulated neutral beam irradiation and low substrate temperature of -70 o C.