SEMI M58 - Test Method for Evaluating DMA Based Particle Deposition Systems and Processes
SEMI M52 requires the use of certified reference materials (CRMs) for calibration of scanning surface inspection systems (SSISs). The calibration method is defined in SEMI M53. This Test Method provides the procedure to determine whether a specific particle deposition system, using a differential mobility analyzer (DMA), can produce the required CRMs.
Both organizations producing depositions internally for in-house use and companies manufacturing depositions for sale can apply this Test Method to ensure that their particle deposition systems provide depositions that meet the requirements of SEMI M52.
This Test Method covers determination of the deposition peak diameter and the associated expanded relative combined peak diameter uncertainty produced by a particle deposition system and its associated deposition procedures for comparison to the 3% requirement of SEMI M52.
This Test Method also covers determination of the ability of the deposition system to produce depositions with diameter distributions that are less than 5% full width at half maximum (FWHM) as required by SEMI M52 even when using a particle source with a much wider distribution.
These tests require that the deposition system employ a DMA (or an equivalent programmable filtering system) to accomplish both peak diameter determination and narrowing of particle source distributions (see Related Information 1).
This Test Method covers determination of repeatability over a period of one week. Tests can be repeated periodically to determine long term stability. Long term stability of most DMA-based particle deposition systems is believed to be on the order of a year or more, but it is recommended that the tests be repeated on an annual basis or whenever the instrument appears to be out of control.
This Test Method requires the use of three different kinds of particle distributions with specified characteristics and wafers that have surface characteristics adequate to allow detection of the smallest particles utilized with a capture rate of greater than 95%.
Referenced SEMI Standards
SEMI M50 — Test Method for Determining Capture Rate and False Count Rate for Surface Scanning Inspection Systems by the Overlay Method
SEMI M52 — Guide for Specifying Scanning Surface Inspection Systems for Silicon Wafers for the 130 nm to 11 nm Technology Generations
SEMI M53 — Practice for Calibrating Scanning Surface Inspection Systems Using Certified Depositions of Monodisperse Reference Spheres on Unpatterned Semiconductor Wafer Surfaces
SEMI M59 — Terminology for Silicon Technology
SEMI ME1392 — Guide for Angle Resolved Optical Scatter Measurements on Specular or Diffuse Surfaces
SEMI MF1811 — Guide for Estimating the Power Spectral Density Function and Related Finish Parameters from Surface Profile Data