Method for Improving Minority Carrier Lifetime after Neutron Transmutation Doping or Stress Relief Silicon Single Crystal Annealing

Abstract

The invention provides a method for improving neutron transmutation doping or a minority carrier lifetime after distressing silicon single crystal annealing. The method for improving the neutron transmutation doping or the minority carrier lifetime after the distressing silicon single crystal annealing is characterized by comprising the following steps: (1) corrosion, washing and drying: using nitric acid and hydrofluoric acid to carry out corrosion on a silicon single crystal, using deionized water to wash the silicon single crystal, and drying the silicon single crystal; (2) soak: soaking the silicon single crystal in a phosphorus pentoxide solution; (3) airing: carrying out natural airing; (4) furnace entering: placing single crystal silicon obtained in the step (3) in a quartz boat, and entering a thermal treatment furnace to carry out processing; (5) ventilation: carrying out oxygen feeding on the interior of the thermal treatment furnace; and (6) annealing. The method for improving the neutron transmutation doping or the minority carrier lifetime after the distressing silicon single crystal annealing has the advantages of reducing contamination of a metal ion to a single crystal in the process of annealing, and improving the minority carrier lifetime of the single crystal.

Description

technical field [0001] The invention belongs to the field of semiconductor materials, and in particular relates to a method for increasing the minority carrier lifetime after neutron transmutation doping or stress relief silicon single crystal annealing. Background technique [0002] In the annealing process of the prior art, the main process condition is that the quartz tube is fed with nitrogen and hydrochloric acid gas during the annealing process. The purpose is to remove metal ions in the furnace tube and on the surface of the single crystal and improve the annealing life. This method is useful for improving the minority carrier life of the single crystal. It has a certain effect, but there are also disadvantages: the annealing process has high requirements on the environment, and the long-term introduction of HCL gas causes severe corrosion in many places of equipment and workshops, which causes great difficulties in equipment maintenance. Entering the furnace tube dur...

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Problems solved by technology

[0002] In the annealing process of the prior art, the main process condition is that the quartz tube is fed with nitrogen and hydrochloric acid gas during the annealing process. The purpose is to remove metal ions in the furnace tube and on the surface of the single crystal and improve the annealing life. This method is useful for improving the minority carrier life of the single crystal. It has a certain effect, but there are also disadvantages: the annealing process has high requirements on the environment, and the long-term introduction of HCL gas causes severe corrosion in many places of equipment and workshops, which causes great difficulties in equipment maintenance. Entering the furnace tube during the furnace will cause secondary contamination, and the lifetime of the single crystal minority carrier will be affected; in addition, long-term exposure to hydrochloric acid atmosphere will also greatly damage the health of operators