SEMI MF1451 - Test Method for Measuring Sori on Silicon Wafers by Automated Noncontact Scanning -

Sori can significantly affect the yield of semiconductor device processing.

Knowledge of this characteristic can help the producer and consumer determine if the dimensional characteristics of a specimen wafer satisfy given geometrical requirements.

Changes in wafer sori during processing can adversely affect subsequent handling and processing steps. These changes can also provide an important process monitoring function.

This Test Method is suitable for measuring the sori of wafers used in semiconductor device processing in the as-sliced, lapped, etched, polished, epitaxial or other layer condition and for monitoring thermal and mechanical effects on the sori of wafers during device processing.

This Test Method covers a noncontacting, nondestructive procedure to determine the sori of clean, dry semiconductor wafers.

This Test Method employs a two-probe system that examines both external surfaces of the wafer simultaneously.

The Test Method is applicable to wafers 50 mm or larger in diameter, and approximately 100 µm and larger in thickness, independent of thickness variation and surface finish, and of gravitationally induced wafer distortion.

This Test Method is not intended to measure the flatness of either exposed silicon surface. Sori is a measure of the distortion of the front surface of the wafer.

This Test Method measures sori of a wafer corrected for mechanical forces applied during the test. Therefore, the procedure described gives the unconstrained value of sori.

This Test Method includes several methods for canceling gravity-induced deflection which could otherwise alter the shape of the wafer.

Referenced SEMI Standards (purchase separately)

SEMI M1 — Specification for Polished Single Crystal Silicon Wafers

SEMI M59 — Terminology for Silicon Technology

SEMI MF1530 — Test Method for Measuring Flatness, Thickness, and Thickness Variation on Silicon Wafers by Automated Noncontact Scanning

Revision History

SEMI MF1451-0707 (Reapproved 0421)

SEMI MF1451-0707 (Reapproved 0319)

SEMI MF1451-0707 (Reapproved 0512)

SEMI MF1451-0707 (technical revision)

SEMI MF1451-1104 (technical revision)

SEMI MF1451-0704 (technical revision)

SEMI MF1451-92 (Reapproved 1999) (first SEMI publication)