Abstract

Disclosed is a preparation method for a polycrystalline silicon ingot. The preparation method comprises: arranging a non-silicon material nucleation source layer at the bottom of a crucible, and filling a silicon material above the non-silicon material nucleation source layer; heating to make the silicon material melt, and regulating a thermal field in the crucible to make the molten silicon material start to grow crystals based on the non-silicon material nucleation source layer; and after the crystallization is completed thoroughly, obtaining a polycrystalline silicon ingot through annealing and cooling. The preparation method can be applied to enable a polycrystalline silicon ingot to obtain favourable initial nucleation, and reduce the dislocation propagation of a polycrystalline silicon ingot in a growing process. Also disclosed at the same time are a polycrystalline silicon ingot obtained through the preparation method, and a polycrystalline silicon chip made of same.

IPC Classes  ?

• C30B 28/06 - Production of homogeneous polycrystalline material with defined structure from liquids by normal freezing or freezing under temperature gradient
• C30B 29/06 - Silicon

Abstract

Disclosed is a preparation method of a polycrystalline silicon ingot. The preparation method comprises: providing a silicon nucleation layer at the bottom of a crucible, and filling a silicon material above the silicon nucleation layer; heating the silicon material to melt same, adjusting the thermal field inside the crucible to make the melted silicon material to start crystallization on the basis of the silicon nucleation layer; and when the crystallization is finished, performing annealing and cooling to obtain a polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot. Further disclosed are a polycrystalline silicon ingot obtained through the preparation method and a polycrystalline silicon wafer made using the polycrystalline silicon ingot as a raw material.

IPC Classes  ?

• C30B 28/06 - Production of homogeneous polycrystalline material with defined structure from liquids by normal freezing or freezing under temperature gradient
• C30B 29/06 - Silicon

Abstract

A sorting method of residue silicon material mixed with foreign substance is characterized in that: the residue silicon material mixed with foreign substance is put into a carbonate solution; the gas generated by the reaction of the carbonate solution and the silicon material drives the rest silicon material floating upwardly; the silicon material floated upwardly is taken out, and the separation of the foreign substance and silicon material is achieved; the sorting of residue silicon material mixed with foreign substances is accomplished. Said sorting method is a sorting method of residue fine crushing silicon material mixed with foreign substance. The sorted silicon material is mainly used in the reign of semiconductor and solar energy photovoltaic. The present invention employs carbonate solution to sort silicon material，and the sorting method is efficient. It is suitable for large scale sorting, and can substitute traditional manual sorting work completely.

IPC Classes  ?

• B03D 1/002 - Inorganic compounds

Abstract

The present invention discloses a use of high-purity polycrystalline silicon rod as feed rod in monocrystalline silicon zone melting process and its manufacturing method. The high-purity silicon rod is pressed into silicon rod with a diameter of 20mm-30mm by isostatic pressing method using silicon powder with purity of 99.9999%-99.9999999999%. Silicon powder used for the feedstock silicon rod has a diameter of 0.1mm-100mm.The density of the feedstock rod is 1.60-2.29g/cm3, anti-pressure parameter thereof is 0.1-50MPa and the purity thereof is 99.9999%-99.9999999999%. The feedstock rod has uniform density, which manifests in that an amplitude of density difference is 0-18% between any two points on any cross section of the silicon bulk. The high-purity polycrystalline silicon rod is of excellent anti-pressure performance and can be directly used as monocrystallinel silicon feedstock rod in zone melting process.

IPC Classes  ?

• C30B 13/00 - Single-crystal growth by zone-meltingRefining by zone-melting
• C30B 28/02 - Production of homogeneous polycrystalline material with defined structure directly from the solid state
• C30B 29/06 - Silicon
• C01B 33/037 - Purification

Abstract

A method of employing silicon powder and silicon ingots of raw material in a single-crystal furnace or a polycrystalline furnace comprises: compressing silicon powder of diameter between 0.1-100 micrometers into silicon ingots of 0.2-2000000 grams, by cold isostatic pressing or hot isostatic pressing; feeding the silicon ingots into the single-crystal furnace or polycrystalline furnace. Wherein, the pressure for cold isostatic pressing is in the range of 10-800 Mpa; the pressure for hot isostatic pressing is in the range of 10-800 Mpa, and the temperature is between 30-1400℃. The silicon ingots are used as raw material for silicon crystal growth in manufacturing of solar cells, which have a good performance against oxidation and compression.

IPC Classes  ?

• H01L 31/18 - Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• B22F 3/02 - Compacting only