In-SituMeasurements of Charged Nanoparticles Generated During Hot Wire Chemical Vapor Deposition of Silicon Using Particle Beam Mass Spectrometer

Abstract

It has been experimentally confirmed in many chemical vapor deposition (CVD) processes that charged nanoparticles tend to be generated in the gas phase. In an effort to confirm and measure charged gas phase nuclei, that might be generated during the deposition of Si thin films by hot wire CVD, we performed an in-situ measurement using particle beam mass spectrometer (PBMS), which can measure a size distribution of nanoparticles at low pressure. The size distribution of positively and negatively charged Si gas phase nuclei generated during hot wire CVD under 1.5 torr could be firstly measured. The particle diameter at the peak of the size distribution is about 10 ∼ 13 nm. At a wire temperature of 1800°C, the number concentration of negatively charged Si nanoparticles was higher than that of positively charged ones. The size and number concentration of charged nanoparticles decreased with increasing wire temperature from 1800 to 2000°C and increased with increasing SiH4 concentration from 3 to 6%. Copyright 2013 American Association for Aerosol Research