Method for improving axial resistivity uniformity of single crystal with heavily doped Ar

Abstract

The invention relates to a method for improving axial resistivity uniformity of a single crystal with heavily doped Ar. The method comprises the following steps in sequence: (1) regulating furnace pressure along with the growth of a silicon single crystal: gradually decreasing the furnace pressure along with the growth of the single crystal from the maximum 70torr to the minimum 10torr; and (2) regulating Ar gas flow at the same time of executing the step (1): gradually increasing the Ar gas flow to the maximum 80slpm from the minimum 20slpm. The method has the advantages that the axial resistivity uniformity of the single crystal with heavily dope Ar is improved, wherein (rhomax-rhomin) / rhomin is smaller than 28%; the concentration of the doping agent Ar of a diffusion layer is reduced; the probability of the occurrence of a composition process is decreased; and the crystal forming rate is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor silicon single crystal production, in particular to a method for improving the axial resistivity uniformity of heavily doped arsenic single crystal. Background technique [0002] A certain amount of dopants are often added in the production of semiconductor silicon single crystal to meet the requirements of its electrical properties. Common dopants include: boron, phosphorus, arsenic and antimony. Due to the segregation phenomenon of dopants at the solid-liquid interface of silicon single crystal growth, due to the segregation coefficient k 0 =C s / C l <1 (C s is the concentration of dopant in the solid phase, C l is the concentration of the dopant in the liquid phase), that is, the solubility of the dopant in the solid phase is less than its solubility in the liquid phase, so a part of the dopant in the solid phase will be precipitated at the solid-liquid interface of crystal growth ...

AI Technical Summary

Problems solved by technology

[0003] The result of the above phenomenon is: due to the difference in the axial resistivity of single crystals, a single crystal will be partially out of gear, and only a part meets the production requirements, resulting in waste of materials

At the same time, due to the precipitation of dopants at the solid-liquid interface, the dopant concentration in the diffusion layer is higher than that in both the solid phase and the liquid phase. crystallization