SEMI PV88 - Test Method for Determination of Hydrogen in Photovoltaic (PV) Polysilicon by Inert Gas Fusion Infrared Absorption Method
This Standard was technically approved by the Photovoltaic – Materials Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on July 6, 2018. Available at www.semiviews.org and www.semi.org in October 2018.
The purpose of this Test Method is to standardize analytical protocols for the determination of hydrogen content in photovoltaic (PV) polysilicon which may affect the safety of casting process for polycrystalline silicon ingot and the quality of polysilicon ingot relating to the subsequent properties and performances of PV solar products. This will facilitate comparison of test results among worldwide laboratories used for monitoring or qualifying PV polysilicon and other PV silicon materials.
This Test Method can be used to analyze hydrogen content in polysilicon for PV applications, involving all types of PV polysilicon; for example, granular polycrystalline silicon produced by fluidized bed process or PV polysilicon wafers and slugs, etc.
Based on the same matrix and instruments, the test method may also be used for determining hydrogen content in other silicon materials covering PV monosilicon, semiconductor monosilicon and semiconductor polysilicon, silicon raw materials including metal silicon and silicon powder, etc.
This Test Method is for use with commercially available hydrogen analyzers which are based on the inert gas fusion principle and use infrared detector as the measuring technique.
The detection range of the method described will depend upon the detection range of individual hydrogen analyzers. For the one hydrogen analyzer, the detection range when expressed as a mass percentage (%, m/m) could be changed by different weight of sample. For example, three of commercially available hydrogen analyzers, the detection range of the First is between 0.0001 mg hydrogen and 2.5 mg hydrogen (i.e., between 0.00001% (m/m) and 0.2500% (m/m) for 1 g sample or between 0.00007% (m/m) and 1.666% (m/m) for 0.15 g sample), the Second is between 0.0001 mg hydrogen and 1.0 mg hydrogen (i.e., between 0.00001% (m/m) and 0.1000% (m/m) for 1 g sample or between 0.00007% (m/m) and 0.666% (m/m) for 0.15 g sample), while the Third is between 0.00008 mg hydrogen and 2.5 mg hydrogen (i.e., between 0.000008% (m/m) and 0.2500% (m/m) for 1 g sample or between 0.00006% (m/m) and 1.666% (m/m) for 0.15 g sample).
Silicon samples in a range of physical forms can be used, including polysilicon powders, granules, chunks, single and multicrystalline wafers and slugs.
The hydrogen determinations described in this test method can be used irrespective of all dopant species and concentrations.
Referenced SEMI Standards
SEMI PV17 — Specification for Virgin Silicon Feedstock Materials for Photovoltaic Applications
SEMI PV22 — Specification for Silicon Wafers for Use in Photovoltaic Solar Cells
SEMI PV43 — Test Method for the Measurement of Oxygen Concentration in PV Silicon Materials for Silicon Solar Cells by Inert Gas Fusion Infrared Detection Method