SEMI C10-0299 GUIDE FOR DETERMINATION OF METHOD DETECTION LIMITS

SEMI C10-0299 © SEMI 1998, 19991 SEMI C10-0299 GUIDE FOR DETERMINATION OF METHOD DETECTION LIMITS NOTE: The document that was previously designated as SEMI C10 (Guide for Determination of Method Detection Limits for Trace Metal Analysis by Plasma Spectroscopy) has been redesignated as SEMI C10.1. Because the Guide for Determination of Method Detection Limits is the parent document, it has been designated as SEMI C10. 1. Purpose 1.1 To provide a minimal set of guidelines for the quantitative determination of a method detection limit (MDL) from data supporting a SEMI Process Chemicals or Gases specification. 2. Scope 2.1 Thisguideappliestotracecontaminants specified in SEMI Process Chemicals or Gases standards and guidelines. All relevant trace con- taminants should have an MDL determined from a regression analysis of a calibration curve that is equal to, or less than, their specifications. This guide is intendedforuseinbothestablishingnew specifications within SEMI as well as verification of performance to SEMI specifications. 3. Referenced Documents 3.1 SEMI Standard SEMI C16 — Guide for Precision Reporting/Data Traceability 3.2 Other Document1 Applied Regression Analysis, 2nd Edition, Norman Draper and Harry Smith, John Wiley and Sons, © 1981 4. Terminology None. 5. Boundary Conditions NOTE: A series of boundary conditions is required of the data from which the MDL is to be determined from. 5.1 Data should be collected on at least two standardsatdifferentconcentrationlevels,not including the blank. 5.2 Theconcentrationlevelsinvestigatedmust either span the relevant specification or include it as a level. For this purpose, the calibration range can be 1 John Wiley consequently, the manufacturer's manual should be followed. 6.2.2 Standard and Sample Preparation — With certainmethods,theachievableMDLcanbe improvedbypre-concentration.Somemethods require matrix dilution to run some analyses and may also affect the MDL. 6.2.3 Calibration — Calibrate the instrument for all specified trace contaminants using measurement and preparation protocols identical to those used in samplepreparationandmeasurement,wherever appropriate. The calibration data structure used to determine the MDL should be as close to identical as possible to the data structure normally used for calibrationinthelaboratory.Minimumdata requirements should be determinations at, at least, twoconcentrationlevels(standards),each independentlysampled3times.Thelowest concentration standard should be at, or below, the specification and give a measurable signal. The blank may be used in the calculation of the MDL if its variability is judged to be representative of that of a very low-level standard. All instrument response data used in the analysis should be measurable. The calibration range can be adjusted for instrument sensitivity by pre-concentration or dilution to match with how the samples are analyzed. Use the data collected to calculate the MDL using the formulas in the next section. 6.3