1.1 This test method covers the measurement of the resistivity of a silicon substrate of known orientation and type, or of a uniform silicon epitaxial layer of known orientation and type that is deposited on a substrate of the same or opposite type. Resistivity of the epitaxial films can be evaluated without the necessity of thin film correction factors provided that the ratio of layer thickness to effective probe contact radius is greater than 20.
1.2 This test method is comparative in that the resistivity of an unknown specimen is determined by comparing its measured spreading resistance with that of calibration standards of known resistivity. These calibration standards must have the same surface finish, conductivity type, and orientation as the unknown specimen.
1.3 This test method is intended for use on silicon substrates and epitaxial layers. Within-laboratory precision has been determined through a multilaboratory experiment on substrates having resistivities from 0.01 to 200 Ω·cm.
1.3.1 The principles of this test method can be extended to lower and higher specimen resistivity values, but the precision of the test method has not been evaluated for values other than those in the range given in 1.3.
1.4 This test method is nondestructive in the sense that the specimen is not totally destroyed in making the measurements, the specimen need not be cut into a special shape, and no destructive processing need be done on the specimen. However, the probe can produce mechanical damage that may be detrimental to a device fabricated in the probed area.
1.5 The volume of semiconductor material sampled is proportional to the third power of the effective electrical contact radius of the probe. For an effective electrical contact radius of 2 μm, the volume sampled by a single probe is approximately 10−11 cm−3.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.