The purpose of this document is to test substitutional atomic carbon concentration in GaAs by Fourier Transform Infrared Absorption Spectroscopy (FT-IR). This referee test method covers the determination of substitutional carbon concentration in single crystal GaAs. The useful range of carbon concentration measurable at room temperature by this test method is from the maximum amount of substitutional carbon soluble in GaAs to 1 × 1015 cm-3. The detection limit depends on the equipment and measurement conditions. It is expected that many users of this test method can reduce the detection limit to 1014 cm-3 level. 77K measurement is effective to reduce the detection limit. The test method utilizes the relationship between carbon concentration and absorption coefficient at 580 cm-1 for room temperature measurement (around 582 cm-1) for 77K measurement), the infrared absorption band is associated with substitutional carbon in GaAs. These specific absorption bands in GaAs have been associated with the local vibration mode of Cas. Slices can be any crystallographic orientation and should be polished or lapped and etched on both surfaces.

This test method is intended to be used with FT-IR spectrometers that are equipped to operate in the region including the wave number range from 700 to 500 cm-1. This standard may involve hazardous materials, operation, and equipment.

Referenced SEMI Standards
None.

Revision History
SEMI M30-0997 (first published)