This standard was originally published by ASTM International as ASTM F399-74T. It was formally approved by ASTM balloting procedures and adhered to ASTM patent requirements. Though ownership of this standard has been transferred to SEMI, it has not been formally approved by SEMI balloting procedures and does not adhere to either SEMI Regulations dealing with patents, or SEMI Style Manual. Available at www.semi.org in June 2010. Originally published by ASTM International as ASTM F399-00a; previously published as SEMI MF399-00a.

NOTICE: This document was balloted and approved for withdrawal in 2010.

This test method covers the determination of thickness of silicon heteroepitaxial or polysilicon layers deposited under conditions such that the interface region between the deposited layer and the substrate is less than 20-nm thick. Interface regions 20 nm and thicker rarely occur, but are evidenced by a roughness in the originally smooth substrate which can be detected by a profilometer after the thickness measurement is completed and the layer has been etched away. This test method is applicable to layers having a thickness in the range from 0.1–20 m, inclusive. Other thicknesses may be measured by the same technique but the expected precisions have not been determined. This test method is applicable to silicon layers deposited on any substrate, such as silicon dioxide, sapphire, spinel, etc., that is not significantly attacked by the recommended etch.

SEMI C28 — Specifications for and Guidelines for Hyrodfluoric Acid
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