Effect of Pulsed Photon Processing in a Nitrogen Ambient on the Reliability of Gate Silicon Oxide Obtained by Pyrogenic Oxidation

Abstract

Reliability of a gate dielectric is a key factor in its application for modern electronic devices’ electronic component base. Silicon oxide layers’ operating free-running time depends on defects’ density due to presence of hydroxyl groups and hydrogen in its volume, and broken silicon bonds at the interface with the oxide. Purpose of this work was to study effect of pulsed photon processing in a nitrogen ambient on the reliability of gate silicon oxide obtained by pyrogenic oxidation. Silicon oxide layers with a thickness of 17.7 nm were obtained by pyrogenic oxidation of single crystal silicon substrates doped with boron having resistivity of 12 Ω×cm, diameter of 100 mm, with an orientation of (100) at a temperature of 850 ℃ for 40 min. Pulsed photon processing was performed by heating in a nitrogen ambient upto 1150 ℃ in 7 s under an incoherent radiation flux from quartz halogen lamps directed at the non-working side of the substrate. The dielectric layers’ failure time was determined by accelerated testing using test MOSFET capacitors. It was shown that pulsed photon treatment of pyrogenic oxide in a nitrogen ambient lead to a 2.45–fold increase in operating free-running time due to densification of silicon dioxide and formation of Si-N bonds, which was 29.8 % longer than after processing in natural atmospheric conditions.