描述[文件摘要]

This practice covers calculation of the near-edge geometry metrics ESFQR, ESFQD and ESBIR.¹

The metrics calculated by this practice are based on a thickness data array. This array represents the front surface of the wafer when the back surface of the wafer is ideally flat, as when pulled down onto an ideally clean flat chuck. 

This practice is suitable for polished, epitaxial, SOI, or other layer condition.

The practice is applicable to notched 200 and 300 mm diameter wafers having dimensions in accordance with wafer categories 1.9.2, 1.9.3, 1.15, and 1.15.1 of SEMI M1.

This practice does not cover acquisition of the thickness data array. However, it gives the required characteristics of the thickness data array.

Other metrics analogous to flatness metrics can be calculated, but these are outside the scope of this practice.

NOTICE: This standard does not purport to address safety issues, if any, associated with its use. It is the responsibility of the users of this standard to establish appropriate safety and health practices and determine the applicability of regulatory or other limitations prior to use.

Purpose

Wafer near-edge geometry can significantly affect the yield of semiconductor device processing.

Knowledge of near-edge geometrical properties can help the producer and consumer determine if the dimensional characteristics of a wafer satisfy given geometrical requirements.

This practice is suitable for quantifying the flatness aspects of near-edge geometry of wafers used in semiconductor device processing. 

The ESFQR, ESFQD or ESBIR metric may be more suitable for quantifying the flatness aspects of near-edge geometry than traditional metrics such as SFQR, SFQD or SBIR. ESFQR, ESFQD and ESBIR quantify near-edge geometry fully and consistently at all angular positions on the wafer edge except at locations intentionally excluded. SFQR, SFQD and SBIR, on the other hand treat different angular positions differently and do not typically provide full coverage of the wafer edge.

NOTE 1: Acronyms beginning with E are analogous to those in Appendix 1 of SEMI M1 but relate to the near-edge region. The letter "S" in these acronyms refers to an edge Sector rather than to an exposure Site.

Consideration should be given to the use of near-edge geometry metrics as a process control tool rather than a material exchange specification.

There are other metrics for near-edge geometry, some of which quantify other aspects such as ZDD, ROA and PSFQR.

NOTE 2: ERO is frequently employed as a more general term for describing near-edge geometry, but as of the approval date of this standard there are no standardized conditions or test procedures for it. As such a general term, ERO is included in the keywords for this standard, even though it is outside the scope of the standard.

¹ The calculation of these metrics is the subject of U.S. Patent 7,324,917 owned by KLA-Tencor Corporation, One Technology Drive, Milpitas, CA 95035. KLA-Tencor has informed SEMI that, per SEMI regulations, it will license this patent on reasonable and customary terms.