Loading patent…
AssigneeLeybold Aktiengesellschaft
InventorsBurkhard Alterkruger, Joachim Aufreiter, Dieter Bruss, Klaus Kalkowski
Estimating the term…
In a process and a device for the controlled feeding of a melting crucible (13) with doped particles (2, 2a) during the drawing of a crystal (16) by the Czochralski method by the control of a flow of particles (2, 2a) from a source (1) to the melting crucible (13), the source (1) is equipped with a conveying device (4) for discharging the particles (2, 2a) at adjustable rates per unit time. A crystal (16), formed from the particles, is withdrawn from the melting crucible (13) at a predetermined rate per unit time. So that the control process can be conducted smoothly over prolonged periods of time with precise doping, the particles (2, 2a) are separated into individuals on their way to the melting crucible (13) and counted by at least one sensor (21, 22). The sequence of count pulses is sent to a counter (25) and compared there with a corresponding sequence of reference input pulses. The comparison signal formed from the count pulses and the reference input pulses is used, in accordance with its sign, as a control signal for adjusting the amount of particles being discharged per unit time from source (1) to correspond to the reference value.
Process for the controlled feeding of a melting crucible (13) with particles during the drawing of a crystal (16) by the Czochralski method by regulation of the flow rate of particles (2, 2a) from a source (1) to the melting crucible (13), where the source (1) is equipped with a conveying device (4) for discharging particles at an adjustable rate per unit time, and where a crystal (16) with a constant diameter and a uniform dopant concentration, formed from the particles, is drawn from the melting crucible (13), wherein the doped particles (2, 2a) are separated into a single file of individual particles on their way to the melting crucible (13) and counted by at least one sensor (21, 22) to generate a sequence of count pulses which is sent to a counter (25) and compared therein with a corresponding sequence of reference input pulses to produce a comparison signal;
Process for the controlled feeding of a melting crucible with particles during the drawing of a crystal by the Czochralski method, said process comprising
Dependencies are inferred from the claim text.