The Material Properties of Silicon Nitride Formed by Low Energy Ion Implantation

Abstract

This paper reports on silicon nitride formation by low energy implantation of nitrogen or ammonia into silicon. Extensive material investigation on nitrogen‐implanted films using various analytical methods, including ellipsometry, chemical etching, transmission electron microscopy (TEM), x‐ray photoelectron microscopy (XPS), infrared transmission spectroscopy (IR), and Rutherford backscattering spectroscopy (RBS) is discussed. A new technique to derive the film thickness, density, refractive index, and dielectric constant is developed. This method employs a combination of ellipsometry, capacitance measurement, and nitrogen areal density obtained by RBS. A major finding indicates that the implanted nitride films have a low density compared to CVD nitride. Other material properties are also summarized.