The invention discloses a method for preparing vacuum
zone melting high resistant
silicon single crystal, comprising the two sequential major processes: polysilicon purification and
crystal forming of
silicon single crystal, wherein, the process of polysilicon purification comprises the steps of cleaning fire, charging, evacuating, preheating, melting materials heat sealing, growing narrow necks, shouldering, shoulder circuiting, equating
diameter, ending and repeating; the process of
crystal forming of
silicon single crystal comprises the steps of cleaning fire, charging, evacuating, preheating,
processing of chemicals,
crystal seeding, shouldering, shoulder circuiting, equating
diameter, ending and blowing out. With the method of the invention adopted to prepare silicon single crystal,
electric resistivity, ultra-high purity, resistivity profile, uniformity of cross-section
electric resistivity and minority
carrier lifetime are greatly improved; purity of the silicon single crystal is above 11N,
electric resistivity reaches 8000
omega / cm-30000
omega / cm, uniformity of cross-section electric resistivity is less than 15%, and minority
carrier lifetime is more than 600-1000Mus, thus greatly improving performance, stability and safety of the devices while realizing
mass production of vacuum
zone melting high resistant silicon single crystal.