Process for production of silicon single crystal, and highly doped n-type semiconductor substrate

Abstract

After adding phosphorus (P) and germanium (Ge) into a silicon melt or adding phosphorus into a silicon/germanium melt, a silicon monocrystal is grown from the silicon melt by a Czochralski method, where a phosphorus concentration [P](atoms/cm) in the silicon melt, a Ge concentration in the silicon monocrystal, an average temperature gradient G(K/mm) and a pull speed V (mm/min) are controlled to satisfy a formula (1) as follows, the phosphorus concentration [P] (atoms/cm) in the silicon monocrystal is 4.84×10atoms/cmor more and 8.49×10atoms/cmor less, and the phosphorus concentration [P] (atoms/cm) and the Ge concentration [Ge] (atoms/cm) in the silicon monocrystal satisfy a relationship according to a formula (2) as follows while growing the silicon monocrystal.[P]+(0.3151×[Ge]+3.806×10)/1.5<0.5×(G/V+43)×10  (1)[Ge]←6.95×[P]+5.90×10  (2).