Analyses of three-dimensional atomic arrangements of impurities doped in Si relating to electrical activity by spectro-photoelectron holography

Abstract

Electrical activation of dopants in semiconductors with high concentration is a significant requirement in device technology. However, the maximum concentration is actually limited depending on the materials and process conditions, and deactivated dopants are considered to form various cluster structures. Photoelectron holography is demonstrated to be useful for analyzing the three-dimensional (3D) atomic arrangements of such structures. Through experiments of As doped in Si, the usefulness of this method as well as the combination of first-principles calculation and simulation is discussed. As a result, the 3D atomic arrangements of individual substitutional As, which is electrically active, and AsnV (n = 2–4) clusters, which are electrically inactive, are revealed. Furthermore, co-doping of As and B is proposed as a new method to enhance the activation rate of As based on structural analyses and theoretical prediction.