GB/T 26068-2018 Active

This standard specifies the non-contact microwave reflectometry photoconductivity decay test method for determining the carrier recombination lifetime of monocrystalline and cast polycrystalline silicon wafers and ingots. This standard is applicable to the testing of the carrier recombination lifetime of silicon ingots and polished n-type or p-type silicon wafers (commonly referred to as silicon blocks when the wafer thickness exceeds 1 mm). Under the condition that the sensitivity of the conductivity detection system is sufficient, this standard can also be used to test the carrier recombination lifetime of cut or polished and etched silicon wafers. Generally, the lower limit of the room-temperature resistivity of the tested samples is between 0.05 Ω·cm and 10 Ω·cm, which is determined by the limit of the sensitivity of the detection system. The test range of the carrier recombination lifetime is greater than 0.1 μs. The shortest measurable lifetime value depends on the switching characteristics of the light source and the sampling frequency of the decay signal detector, while the longest measurable value depends on the geometric conditions of the sample and the degree of passivation on its surface.