Method for producing straightly-pulled heavily-doped ultralow-resistivity silicon monocrystal

Abstract

The invention provides a method for producing a straightly-pulled heavily-doped ultralow-resistivity silicon monocrystal. The method includes combining heavily-doped monocrystal head tailings (with certain resistivity) with protogenic polycrystal materials according to a certain ratio; performing doping according to normal doping quantity after mixing, switching blast furnace pressure parameters for baking during doping to enable dopants to be fused into melts quickly, starting crystal pulling after normal furnace pressure is stable, injecting argon mixed gas during crystal growth, and increasing partial pressure of the dopants in a furnace; when the monocrystal is kept and grows stably, increasing the furnace pressure gradually to further reduce volatilization of the dopants and resistivity. The method has the advantages that monocrystal cost is reduced through the heavily-doped monocrystal head tailings, head total resistivity can be reduced by 5-25% without addition of first doping amount, monocrystal silicon resistivity is reduced obviously without influence on monocrystal forming rate, resistivity reflex action is suppressed and axial uniformity of the resistivity is improved.

Description

technical field [0001] The invention relates to a production method of silicon single crystal, in particular to a method for producing Czochralski heavy doped silicon single crystal with extremely low resistivity. Background technique [0002] Heavily doped monocrystalline silicon is mainly used in power semiconductor devices. With the development of "4C industries" such as communication, computer, consumer electronics and automobiles, the application range of power semiconductor devices is becoming wider and wider, and has become the foundation of the major pillar industries of the national economy. . [0003] Since power semiconductor devices usually work under high current conditions, and the current flows vertically through the device, the silicon chip as the substrate will consume part of the power when the device is in the on state. In order to reduce this part of power to the greatest extent, it is required to reduce the resistivity of the silicon substrate to reduc...

AI Technical Summary

Problems solved by technology

[0004] A doping method disclosed in Chinese patent CN1556255A, its main feature is only that the doping efficiency is improved through funnel doping, but the resistivity of the single crystal after doping does not involve

However, the disadvantages of existing heavy-doped low-resistance single crystals are: first, heavy doping is easy to volatilize, and the volatilization of dopants during the growth of single crystals makes the re-doped resistivity reverse, and it is not easy to obtain extremely low-resistance heavy-doped single crystals. ; Second, by increasing the doping to reduce the resistivity of the head, the crystal formation will be greatly affected; third, the axial resistivity of silicon single crystal decays faster