Profiles of boron implantations in silicon measured by secondary ion mass spectrometry

Abstract

The concentration of boron implanted in silicon as a function of depth has been measured by using secondary ion mass spectrometry. In this method the silicon substrate is sputtered continuously by ion bombardment and the boron secondary ion current is measured as a function of time. The requirements that must be fulfilfed to ensure that this time-dependent current represents the true concentration profile are formulated and have been checked by a number of experiments. It has been found, that under certain precautions, this is a reliable and fast method for the measurement of boron profiles. A number of boron profiles in the energy range 30–75 keV have been measured and are discussed. Attention is paid to the range and range straggling as well as to the existence of a small tail on the profile.