SEMI International Standards
SEMI New Activity Report Form (SNARF)

Activity Number: 5106
SNARF for: New Standard: Guide for Extrapolating Particle Measurement Data for Liquid Chemicals

Originating Global Technical Committee: Liquid Chemicals
Originating Technical Committee Region: North America
Task Force in which work is to be carried out: Statistical Methods Task Force

1. Rationale: This is the second SNARF’s being presented around issues involving particle counters that the task force wishes to address. This SNARF concerns the following. Determine whether or not it is possible to predict particle size densities at sizes smaller than the lowest channel in the instrument. This is essentially an extrapolation problem. For many instruments the smallest channel size is 0.2 microns. Can the density be predicted at, say, 0.05 microns? If this proved to be possible then issue a guideline on how to do it.
Rate the Estimated Effect on the Industry
2: Major effect on an industry sector - identify the relevant sector

Rate the Estimated Technical Difficulty of the Activity
II: Some Difficulty - Disagreements on known requirements exist but developing consensus is possible

2. Scope:
a: Define the areas to be covered or addressed by this activity or document:
This activity will concern itself with the measurement of particle sizes in liquid chemicals produced for and used by the semi conductor industry. In particular the task force will focus on a method for cross calibrating between particle analyzers and extrapolating a measured particle size distribution to sizes smaller than the lowest channel reported.

b: Expected result of activity
New Standard

3. Projected Timetable for Completion:
a: General Milestones
a. Activity Start: 11/01/2010b. 1st Draft by: 08/30/2011
c. Preballot by: d. Technical Ballot by: 08/30/2011
e. Committee Approval By:04/01/2012

Safety Considerations:
The resulting document is expected NOT to be a Safety Guideline

Intellectual Property Considerations:
a. In complying with the standard or safety guideline to be developed, the use of patented technology or a copyrighted item(s) is NOT required
b. The body of the standard and any appendices or related information sections will NOT include copyrighted material

Comments, Special Circumstances: In order for this project to be successful at least some of the task force members will need to share data with each other and be willing to run round robin samples.

Approval: Activity approved by Committee/GCS on November 9, 2010