The purpose of this Test Method is to determine the relative resistance to pitting corrosion of the wetted surfaces of components intended for use in corrosive gas distribution systems for semiconductor manufacturing. This Test Method is an adaptation of ASTM G61 and is intended to differentiate among manufacturing processes for stainless steel that can affect the performance of the wetted surfaces.
This Test Method describes a procedure, based on the electrochemical critical pitting voltage (CPV), which is used to rank the pitting corrosion resistance of wetted surfaces of tubing or test coupons of representative finished surfaces intended for use in corrosive gas systems. Pitting corrosion is believed to be a major corrosion failure mode in semiconductor gas delivery systems, particularly in components and tubing welded and exposed to corrosive gases and moisture.
This Test Method is an adaptation of ASTM G61. This adaptation describes a method for performing the test on wetted surface sections of finished fittings such as glands, elbows and blocks as well as tube welds to fittings. It is an aqueous immersion method.
The test method is reproducible and provides a metric (CPV) in addition to a qualitative (visual) evaluation of the location and extent of the pitting.
Referenced SEMI Standards (purchase separately)
SEMI F19 — Specification for the Surface Condition of the Wetted Surfaces of Stainless Steel Components
Revision History
SEMI F120-0922 (first published)
