The purpose of this Test Method is to specify methods for the contactless measurement of the resistivity of semi-insulating samples and wafers.

This Test Method covers the determination of the electrical resistivity of semi-insulating semiconductors, including GaAs, InP, CdTe, Cd(Zn)Te, SiC, GaN, and AlN, within the resistivity range 1E5 to 1E12 Ω·cm. It may also be used to characterize other materials exhibiting resistivity in this range, including in particular high resistivity silicon.

The procedures described in this Standard measure the time constant t of a network consisting of the resistive sample and the series capacitance of the sample and the capacitive sensor. Alternatively, a plate sensor (PS) or ring sensor (RS) may be used. The evaluation is based on the observation of the time-dependent charge transfer after application of a voltage step (time domain [TD] evaluation described in Appendix 1) or on measuring the frequency response of the network (frequency domain [FD] evaluation described in Appendix 2).

Commercially available measurement system configurations offer the PS combined with TD evaluation and the RS combined with FD and TD evaluation. Topographic evaluation of the sample area is available as well as temperature dependent resistivity measurement to evaluate the activation energy ∆E, needed to normalize measured data to a reference temperature.

This Test Method follows the roadmap laid out by SEMI M54 (GaAs) and SEMI M55 (SiC), identifying resistivity as an essential material parameter.

Referenced SEMI Standards (purchase separately)

SEMI M54 — Guide for Semi-Insulating (SI) GaAs Material Parameters

SEMI M55 — Specification for Polished Monocrystalline Silicon Carbide Wafers

Revision History

SEMI M87-0422 (technical revision)

SEMI M87-0116 (first published)