XRF and SIMS/SNMS analyses of BaxSr1−xTiO3 dielectrics

Abstract

The development of analytical tools and procedures for process control is a prerequisite for the integration of high permittivity and/or ferroelectric materials in CMOS devices. The thickness and composition of perovskite oxide films were determined by wavelength dispersive X-ray fluorescence analysis (XRF) with special emphasis on the ratio of the group-II elements to the Ti content, and a precision of 0.5% was achieved for a typical film thickness of 20-30 nm. Secondary ion mass spectrometry (SIMS) and sputtered neutrals mass spectrometry (SNMS) was used for depth profiling to determine film homogeneity and elemental interdiffusion at hetero-interfaces. Examples are given for Ba(x)Sr(1-x)TiO(3) and SrTiO(x) thin films which were grown in a prototype MOCVD production tool. No interdiffusion was observed for films grown at 600 degrees C on Pt electrodes in contrast to films grown directly on Si.

Metal-organic chemical-vapor deposition of (Ba,Sr)TiO3: Nucleation and growth on Pt-(111)

“…17 CSD-deposited films of similar com-position were used as calibration standards. Generally, we used Pt/ TiO 2 / SiO x / Si substrates with a platinum thickness of 100 nm.…”

Quantitative X-ray fluorescence analysis of samples of less than ‘infinite thickness’: Difficulties and possibilities

“…Thus, the matrix effects are compensated and matrix correction (mainly absorption effects) is not required. The same situation can be observed in the analysis of the samples of very small thickness when matrix effects can be neglected [9][10][11][12].…”

Atomic spectrometry update. Atomic mass spectrometry

“…Electroceramics, such as perovskite, offer a wide potential for novel nanoscale devices such as multi-GBit memories, transistors and nano-actuators. Breuer et al 217 exploited the combination of SNMS and SIMS for the depth profiling of Ba x Sr 12x TiO 3 dielectric films on multistack layers of Pt/TiO 2 / SiO 2 /Si or Pt/ZrO 2 /SiO 2 /Si, where TiO 2 or ZrO 2 served as an adhesion layer. Use of Cs 1 sputtering and EI gave depth profiling measurements of interfacial reactions in the virtual absence of matrix effects.…”