Development of a Certified Reference Material with Delta-Doped Boron Nitride Layers for Surface Depth-Profile Analysis

Abstract

The certified reference material (NMIJ CRM 5206-a) is composed of a Si substrate with homogenously doped arsenic, and multiple alternately deposited boron nitride (BN) layers and Si layers. The designed thicknesses of the Si and BN layers were 8 nm and 0.05 nm, respectively. The thickness of each layer was measured using X-ray reflectometry (XRR), and the periodicity of the distance between the delta BN layers was determined to be 8.3 nm. The expanded uncertainty was 0.2 nm and was calculated using a coverage factor (k) of two that gives a level of confidence of approximately 95%. The concentration of the As atoms in the Si substrate, measured by instrumental neutron activation analysis (INAA) and inductively coupled plasma-mass spectrometry (ICP-MS), was determined to be 0.80 g/kg with an uncertainty of 0.04 g/kg (k = 2). For the calibration of the developed reference material, three institutes with two types of secondary ion mass spectrometry (SIMS) instruments derived the SIMS depth profiles of the implanted arsenic atoms. The results were compared, and it was observed that the relative standard deviation (RSD) of the profile parameters was approximately 10%.