GB/T 6616-2023Test method for resistivity of semiconductor wafers and sheet resistance of semiconductor films—Noncontact eddy-current gauge (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document replaces GB/T 6616-2009 "Non-contact eddy current method for testing resistivity of semiconductor silicon wafers and sheet resistance of silicon films".

Compared with GB/T 6616-2009, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) Changed the scope (see Chapter 1, Chapter 1 of the 2009 edition);

b) Interference factors have been changed (see Chapter 5, Chapter 5 of the 2009 edition);

c) The test conditions have been changed (see Chapter 6, 6.1 of the 2009 edition);

d) Changed the requirements for standard films and reference films (see 8.1, 8.2, 8.3, 4.2 of the 2009 edition);

e) Added sample requirements (see 8.4, 8.5, 8.6);

f) The test procedures have been changed (see Chapter 9, Chapter 6 of the 2009 edition);

g) Changed the precision (see Chapter 10, Chapter 7 of the 2009 edition);

h) Increased temperature coefficient of resistivity of silicon single crystal (see Appendix A).

1 Scope

This document describes the non-contact eddy current method for testing the resistivity of semiconductor wafers and the sheet resistance of semiconductor films.

This document is suitable for testing silicon, conductive gallium arsenide, and conductive gallium arsenide with a diameter or side length of not less than 25.0mm and a thickness of 0.1mm~1.0mm.

The resistivity of the electric silicon carbide single crystal wafer, and the resistance of the thin film layer prepared on the substrate with a resistance not less than 1000 times the thin film resistance. one The testing range of wafer resistivity is 0.001ohm·cm~200ohm·cm, and the testing range of film sheet resistance is 2.0 x 10^3ohm/-~ 3.0 x 10^3ohm/-. This method can also be extended to other semiconductor materials, but it is not suitable for determining the radial resistivity change of the wafer.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 14264 Semiconductor material terminology

GB/T 25915.1-2021 Clean rooms and related controlled environments Part 1: Classification of air cleanliness levels according to particle concentration

3 Terms and definitions

The terms and definitions defined in GB/T 14264 apply to this document.

4 Principles

Insert the chip flat into the fixed gap between a pair of coaxial eddy current probes (eddy current sensors), and the two eddy current probes connected to the oscillation circuit The alternating magnetic field between the probes induces eddy currents on the chip, and the change in the excitation current is a function of the conductance of the chip. Excitation current by test The change in the conductivity of the wafer can be measured. The sheet resistance (Rs) of the wafer is calculated according to formula (1). deltat (1) In the formula.

Rs---Sheet resistance of the chip, unit is ohms per square (ohm/-);

rho ---Resistivity of the wafer, unit is ohm centimeter (ohm·cm); t ---Thickness at the center of the wafer (when measuring the film, the thickness is 0.0508cm as the effective thickness), in centimeters (cm);

G ---Thin layer conductance of the wafer, the unit is Siemens (S);

delta ---The conductivity of the wafer, the unit is Siemens per centimeter (S/cm).

5 Interference factors

5.1 The surface of the wafer is contaminated or damaged, which will introduce errors in the test results.