SEMI PV17 - Specification for Virgin Silicon Feedstock Materials for Photovoltaic Applications
Silicon is one of the key materials in the growing photovoltaic (PV) industry. Solar cells made of silicon will be manufactured for many years to come. New parties supplying or purchasing Si feedstock materials are entering this industry.
The need for higher volumes and more cost efficient feedstock Si triggered development of metallurgical refining methods. In addition new methods modifying the original Siemens process were investigated and were introduced in high volume manufacturing. In parallel to the development of refining methods a wide variety of crystallization techniques and solar cell designs, each requiring specific material properties, were investigated by industry and research organizations. A multidimensional parameter space would be necessary to describe all the relations between feedstock material quality, single and multicrystalline ingots and finally solar cell performance. These would result in a multitude of interface problems, inhibiting the relations between suppliers and their customers, that is not appropriate for a high volume and fast growing industry.
Standardized specifications for Si feedstock materials are expected to reduce these interface problems and to enable a common understanding of material properties and terms, allowing reliable manufacturing of ingots of solar cells and benefiting all parties.
This Specification covers virgin silicon feedstock materials produced by CVD processes, metallurgical refining processes or other processes. CVD processes include the so-called Siemens process, fluidized bed processes, powder processes and other processes using distilled silane or halosilane compounds.
These specified materials are intended for growing of single crystalline ingots and casting or other methods of growing multicrystalline Si, used for producing Si wafers for solar cells.
This Specification is not intended for material used for manufacturing thin film solar products such as amorphous or micromorphous Si products, but it may be used if it is appropriate for the specific application.
This Specification only applies to virgin silicon feedstock and not to scrap or waste material coming from the semiconductor industry.
This Specification is also not intended for specifying material blends, although it may be used as a guideline for melts from blended materials.
Referenced SEMI Standards
SEMI M44 –– Guide to Conversion Factors for Interstitial Oxygen in Silicon
SEMI MF28 –– Test Method for Minority Carrier Lifetime in Bulk Germanium and Silicon by Measurement of Photoconductivity Decay
SEMI MF84 –– Test Method for Measuring Resistivity of Silicon Wafers with an In-Line Four-Point Probe
SEMI MF391 –– Test Method for Minority Carrier Diffusion Length in Extrinsic Semiconductors by Measurement of Steady-State Surface Photovoltage
SEMI MF397 –– Test Method for Resistivity of Silicon Bars Using a Two-Point Probe
SEMI MF723 –– Practice for Conversion between Resistivity and Dopant or Carrier Density for Boron-Doped, Phosphorous-Doped, and Arsenic-Doped Silicon
SEMI MF1188 –– Test Method for Interstitial Oxygen Content of Silicon by Infrared Absorption with Short Baseline
SEMI MF1389 –– Test Method for Photoluminescence Analysis of Single Crystal Silicon for III-V Impurities
SEMI MF1391 –– Test Method for Substitutional Atomic Carbon Content of Silicon by Infrared Absorption
SEMI MF1528 — Test Method for Measuring Boron Contamination in Heavily Doped n-Type Silicon Substrates by Secondary Ion Mass Spectrometry
SEMI MF1535 –– Test Method for Carrier Recombination Lifetime in Silicon Wafers by Noncontact Measurement of Photoconductivity Decay by Microwave Reflectance
SEMI MF1630 –– Test Method for Low Temperature FTIR Analysis of Single Crystal Silicon for III-V Impurities
SEMI MF1708 –– Practice for Evaluation of Granular Polysilicon by Melter-zoner Spectroscopies
SEMI MF1723 –– Practice for Evaluation of Polycrystalline Silicon Rods by Float-zone Crystal Growth and Spectroscopy
SEMI PV1 — Test Method for Measuring Trace Elements in Silicon Feedstock for Silicon Solar Cells by High-Mass Resolution Glow Discharge Mass Spectrometry
SEMI PV10 — Test Method for Instrumental Neutron Activation Analysis (INAA) of Silicon
SEMI PV25 — Test Method for Simultaneously Measuring Oxygen, Carbon, Boron and Phosphorous in Solar Silicon Wafers and Feedstock by Secondary Ion Mass Spectrometry