Chemical Analysis of Surface by Fluorescent X-Ray Spectroscopy Using RHEED-SSD Method

Abstract

A new RHEED apparatus combined with a Si(Li) solid-state detector has been constructed, and spectroscopy of fluorescent X-rays emitted during RHEED observation has been carried out using the detector. Preliminary measurements have revealed the usefulness of this apparatus both for chemical analysis of surfaces and for investigating the behaviour of incident electrons in surface layers. When Ag thin films evaporated on a clean Si(111) surface were studied, the smallest detectable amount was about 0.02 Å in mean thickness. The penetration depth of the primary electron beam in the Ag film at an accelerating voltage of 20 kV was estimated to be 33.0 Å from analysis of the intensity of AgLα and AgLβ lines with increasing thickness of the Ag films.

Spectroscopies combined with reflection high-energy electron diffraction (RHEED) for real-time in situ surface monitoring of thin film growth

“…The full width half maximum (FWHM) of the distribution is known to be the energy resolution of the detector and deconvolution of multiple, overlapping lines is therefore accurate and reliable (Hashimoto et al, 2009). The surface sensitivity of EDS-XRF was tested by Ino et al (1980) for the deposition of thin Ag layers on Si(111) surface. The detection limit is very good, less than 1% of a monolayer.…”

Atomic depth distribution analysis and growth dynamics of metals on metal-covered Si(111) surfaces studied by incident-angle-dependent RHEED-TRAXS (total-reflection-angle x-ray spectroscopy)

“…However, it becomes surface-sensitive by placing the x-ray take-off angle (θ t ) at a grazing angle close to the critical angle for total reflection [20][21][22][23][24][25][26] as shown in Fig. 1, a technique known as total reflection angle x-ray spectroscopy (RHEED-TRAXS) [25].…”

MBE Growth of High Tc Superconductors

“…Two emerging in-situ composition analysis techniques which make use of the RHEED beam, and are thus quite compatible with the standard MBE geometry, are total-reflection-angle x-ray spectroscopy in RHEED (RHEED-TRAXS) [ 425] and reflection-electron energy loss spectroscopy (REELS). [ 426] Both are highly surface sensitive and give chemical information on the region of the sample upon which the RHEED beam is incident.…”