Bulk silicon-germanium (SiGe) alloys and two SiGe thick films (4 and 5 μm) on Si wafers were tested with the electron probe microanalyzer (EPMA) using wavelength dispersive spectrometers (WDS) for heterogeneity and composition for use as reference materials needed by the microelectronics industry. One alloy with a nominal composition of Si0.86Ge0.14 and the two thick films with nominal compositions of Si0.90Ge0.10 and Si0.75Ge0.25 on Si, evaluated for micro- and macroheterogeneity, will make good microanalysis reference materials with an overall expanded heterogeneity uncertainty of 1.1% relative or less for Ge. The bulk Ge composition in the Si0.86Ge0.14 alloy was determined to be 30.228% mass fraction Ge with an expanded uncertainty of the mean of 0.195% mass fraction. The thick films were quantified with WDS-EPMA using both the Si0.86Ge0.14 alloy and element wafers as reference materials. The Ge concentration was determined to be 22.80% mass fraction with an expanded uncertainty of the mean of 0.12% mass fraction for the Si0.90Ge0.10 wafer and 43.66% mass fraction for the Si0.75Ge0.25 wafer with an expanded uncertainty of the mean of 0.25% mass fraction. The two thick SiGe films will be issued as National Institute of Standards and Technology Reference Materials (RM 8905).

Electron microprobe testing and evaluation procedures to determine the extent of within- and between-specimen heterogeneity of reference materials and the experimental uncertainty are described. These procedures have been developed and used at NIST in the certification of several NIST Standard Reference Materials (SRMs). In this article, they have been simplified and updated for general use. Suggestions for experimental testing of specimens are described and a detailed description of the statistical evaluation process is included with an example of a data spreadsheet and instructions for its preparation.

Despite the great potential of fluorescence microscopy, its application to date has largely been in the study of biological specimens. It will be shown that conventional fluorescence microscopy provides an invaluable tool with which to study the photophysics of polymer-supported luminescence-based oxygen sensors. The design of the imaging system, the measurement methods, and the data analysis used in the investigation of sensor systems are described. Fluorescence microscopic images of sensor films in which microheterogeneous regions exhibiting enhanced luminescence intensity and poorer oxygen quenching relative to the bulk response are shown. This is the first direct evidence that sensor molecules in various domains of the polymer support can exhibit different oxygen quenching properties. It will be shown that μ- and nano-crystallization of the sensor molecule are the probable source of both the observed heterogeneous microscopic responses and the microscopic and macroscopic nonlinear Stern-Volmer plots. The implications of these results in the rational design of luminescence-based oxygen sensors are discussed.