Development of B‐doped Si multiple delta‐layer reference materials for SIMS profiling

Abstract

B-doped Si multiple delta-layers (MDL) were developed as certified reference materials (CRM) for secondary ion mass spectrometry (SIMS) depth profiling analysis. Two CRMs with different delta-layer spacing were grown by ion beam sputter deposition (IBSD). The nominal spacing of the MDL for shallow junction analysis is 10 nm and that for high energy SIMS is 50 nm. The total thickness of the film was certified by high resolution transmission electron microscopy (HR-TEM). The B-doped Si MDLs can be used to evaluate SIMS depth resolution and to calibrate the depth scale. A consistency check of the calibration of stylus profilometers for measurement of sputter depth is another possible application. The crater depths measured by a stylus profilometer showed a good linear relationship with the thickness measured from SIMS profiling using the calibrated film thickness for depth scale calibration. The sputtering rate of the amorphous Si thin film grown by sputter deposition was found to be the same as that of the crystalline Si substrate, which means that the sputtering rate measured with these CRMs can be applied to a real analysis of crystalline Si.

Quantitative depth profiling of an alternating Pt/Co multilayer and a Pt–Co alloy multilayer by SIMS using a Buckminsterfullerene (C60) source

“…In this system, the target material is sputtered by a 1 keV Ar + ion beam produced by a Kaufmanntype DC ion gun and deposited on a Si(1 0 0) wafer at room temperature. The deposition chamber is connected to a surface analysis system and therefore the original chemical state and composition can be analyzed by in situ X-ray photoelectron spectroscopy (XPS) [15]. The composition of alloy thin films is controlled by varying the relative sputtering areas of two adjacent target materials using a movable target holder.…”

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

“…The standard materials were developed for the calibration of the depth analysis, and the shallowly arsenicimplanted CRMs with a density of 3×10 15 [9] and 6×10 14 atoms/cm 2 [10] were supplied. With these reference materials, all the sputtered arsenic atoms can be calibrated by sputtering-out the entire arsenic-implanted region.…”

“…Another type of the standard material has a multilayer structure that has delta-doped layers considerably thinner than the other layers [7,[11][12][13][14][15][16][17][18]. The advantage of this structure is that an almost constant sputtering rate can be obtained during the sputtering of the multilayer, and the delta layer can be a depth scale, if the distance between the delta-layers is measured accurately.…”

Nonlinearities in depth profiling nanometer layers

“…In the work of Kim et al, 19 using B delta layers in Si, the offsets observed assuming a linear sputtering rate depended on the way the delta function position was defined, although, unfortunately, the data were at such large depths and the precision was too poor to make very precise statements concerning the absolute changes in the sputtering rate. If the shape of the delta function remains constant, it is easy to define the constancy of the sputtering rate after the first delta layer, but between the original flat surface and the profile for the first delta layer, some assumptions are required in order to establish a sputtering rate.…”