Continuous liquid silicon recharging process in czochralski crucible pulling
AssigneeWacker-Chemitronic Gesellschaft fur Elektronik-Grundstoff mbH
InventorsHerbert Klingshirn, Reinhard Lang
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Abstract
In the Czochralski crucible pulling of crystal ingots, in particular those of silicon and having particularly large crystal diameters, the degree of filling of the crucible is kept approximately constant during the pulling process by continuously adding solid or liquid recharging material. According to the invention, the known disadvantages of thermal disturbances and the introduction of impurities and particles are overcome by a recharging system with a gas-tight seal, comprising additional crucible, stock container for semiconductor material and dopant having the appropriate feedlines and an exhaust gas line. In addition, the process makes possible a regulatable and separate recharging of dopant via the additional crucible.
Claims10
An apparatus for producing a high purity single crystal semiconductor ingot from a melt under protective gas, comprising
- a main crucible with a main heating element for the melt,
- a pulling means with a rotating suspension for the ingot;
- an additional crucible having a heating element for melting recharging materials and an outlet tube for discharging the recharging materials into the main crucible;
- a first stock container for holding solid recharging material and having a feed mechanism and a feedline to the additional crucible;
- a second stock container for holding dopant particles and having a feed mechanism and a feedline to the additional crucible;
- and
- means for separating the first stock container and feed mechanism, the second stock container and feed mechanism, and said additional crucible in a gas-tight and dust-tight manner from the surroundings, and from the main crucible.
Dependencies are inferred from the claim text.