Imported Aluminum Ingot

Silicon Ingot Characterization by Quasi-Steady-State Photoconductance

The detailed knowledge of the distributions of carrier lifetimes, impurities and crystal defects in silicon ingots is key for understanding and improving wafer quality as well as solar cell processing steps. In this work, we have applied a quasi-steady-state photoconductance tester developed for the use on ingots to the measurement of lifetimes and dissolved iron concentrations along a p-type m...

Development of Multi-wire Edm Slicing Method for Silicon Ingot

INSTRUCTIONS The diameter of silicon wafer becomes larger in order to increase the number of chips per one wafer. For such a larger diameter silicon ingot is mainly sliced by using multi-wire method, in which a long thin wire is used with slurry. In this method, several hundreds of wafers could be sliced at the same time. However there are still problems remained, such as large cracks, slurry t...

Imported Antitrust

Transition-metal profiles in a multicrystalline silicon ingot

The concentrations of transition-metal impurities in a photovoltaic-grade multicrystalline silicon ingot have been measured by neutron activation analysis. The results show that the concentrations of Fe, Co, and Cu are determined by segregation from the liquid-to-solid phase in the central regions of the ingot. This produces high concentrations near the top of the ingot, which subsequently diff...

Study of Ac/rf Properties of Srf Ingot Niobium

In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typica...