Direct measurement of trace elements on wafer surfaces by TXRF is quick and nondestructive. SR-TXRF has similar features to TXRF, but much better detection limits mainly due to the high flux. VPD-TXRF and VPD-SR-TXRF improve the detection capability to various degrees. However, some elements (e.g. Cu) may have recovery problems at certain concentrations. VPD-ICP-MS is a destructive technique because of dissolving native oxide, but it can analyze most of elements in the periodic table and especially well for low Z elements. By using NIST standards for calibration, quantification can be verified relatively easily. All of these techniques can be complementary to each other and provide comprehensive analyses for the semiconductor industry. Read more