Molecular and Atomic Hydrogen Diffusion Behavior by Reaction Kinetic Analysis in Projection Range of Hydrocarbon Molecular Ion for CMOS Image Sensors

Abstract

In this study, two types of hydrogen diffusion behavior in the projection range of a hydrocarbon molecular ion after high‐temperature heat treatment for the passivation of interface state defects at SiO2/Si interface of the CMOS image sensor is presented. The hydrogen peak concentration in the hydrocarbon ion projection range is observed by secondary ion mass spectrometry analysis after silicon epitaxial growth and the subsequent high‐temperature heat treatment. Moreover, the hydrogen peak concentration strongly depends on heat treatment time after epitaxial growth and the subsequent heat treatment. Two dissociation activation energies by reaction kinetic analysis using the results of the time dependence of hydrogen diffusion behavior are also determined. Assuming two dissociation reactions, the activation energy from the projection range of a hydrocarbon molecular ion is derived. The results of reaction kinetic analysis show that the dissociation activation energies are 0.79 eV for molecular hydrogen and 0.42 eV for atomic hydrogen. The dissociation activation energy of 0.79 eV indicates molecular hydrogen diffusion activation energy, whereas that of 0.42 eV indicates atomic hydrogen diffusion from the projection range of a hydrocarbon molecular ion. Therefore, it is believed that the molecular and atomic hydrogen diffusion behavior of the hydrocarbon molecular ion implanted silicon epitaxial wafers can contribute to the effective reduction in the density of interface state defects at the SiO2/Si interface.