In this photoelectric conversion element wherein group III-IV compound semiconductor single crystals containing zinc as an impurity are used as a substrate, the substrate is increased in size without lowering conversion efficiency. A heat-resistant crucible is filled with raw material and a sealant, and the raw material and sealant are heated, thereby melting the raw material into a melt, softening the encapsulant, and covering the melt from the top with the encapsulant. The temperature inside the crucible is controlled such that the temperature of the top of the encapsulant relative to the bottom of the encapsulant becomes higher in a range that not equal or exceed the temperature of bottom of the encapsulant, and seed crystal is dipped in the melt and pulled upward with respect to the melt, thereby growing single crystals from the seed crystal. Thus, a large compound semiconductor wafer that is at least two inches in diameter and has a low dislocation density of 5,000 cm.sup.−2 can be obtained, despite having a low average zinc concentration of 5×10.sup.17 cm.sup.−3 to 3×10.sup.18 cm.sup.−3, at which a crystal hardening effect does not manifest.

The present invention relates to a temperature control device for growing a single crystal ingot capable of accurately measuring a temperature of a silicon melt and quickly controlling to a target temperature during an ingot growing process, and a temperature control method applied thereto. The present invention provides a temperature control device for growing a single crystal ingot, which controls an operation of a heater for heating a crucible configured to accommodate a silicon melt, the device including: an input unit configured to measure a temperature of the silicon melt accommodated in the crucible and process the measured temperature of the silicon melt; a control unit configured to perform a proportional-integral-derivative (PID) calculation of one of the measured temperature T1 and the processing temperature T2 of the input unit and a set target temperature T0 and calculate as an output of the heater; and an output unit configured to input the output of the heater calculated in the control unit to the heater.

The present invention relates to a temperature control device for growing a single crystal ingot capable of accurately measuring a temperature of a silicon melt and quickly controlling to a target temperature during an ingot growing process, and a temperature control method applied thereto. The present invention provides a temperature control device for growing a single crystal ingot, which controls an operation of a heater for heating a crucible configured to accommodate a silicon melt, the device including: an input unit configured to measure a temperature of the silicon melt accommodated in the crucible and process the measured temperature of the silicon melt; a control unit configured to perform a proportional-integral-derivative (PID) calculation of one of the measured temperature T1 and the processing temperature T2 of the input unit and a set target temperature T0 and calculate as an output of the heater; and an output unit configured to input the output of the heater calculated in the control unit to the heater.

A crystal growth method and a crystal growth apparatus are disclosed in the present application. The crystal growth method comprises maintaining rotating of a crucible and meanwhile applying a horizontal magnetic field to silicon melt in the crucible during crystal growth. As and/or after changing magnetic field strength of the horizontal magnetic field, temperature fluctuation may easily occur at a solid-liquid interface of an ingot and the silicon melt. Through changing crucible rotating speed to change forced convection of the silicon melt, the temperature fluctuation at solid-liquid interface, caused by the changing of the magnetic field strength, may be rapidly reduced to stabilize diameter of the ingot.

Methods for producing single crystal silicon ingots by Continuous Czochralski (CCz) are disclosed. A batch of buffer members (e.g., quartz cullets) is added to an outer melt zone of the crucible assembly before the main body of the ingot is grown. In some embodiments, the ratio of the mass M of the batch of buffer members added to the melt to the time between adding the batch of buffer members to the melt and when the ingot main body begins to grow is controlled such that the ratio of M/T is greater than a threshold M/T.

Methods for producing single crystal silicon ingots by Continuous Czochralski (CCz) are disclosed. A batch of buffer members (e.g., quartz cullets) is added to an outer melt zone of the crucible assembly before the main body of the ingot is grown. In some embodiments, the ratio of the mass M of the batch of buffer members added to the melt to the time between adding the batch of buffer members to the melt and when the ingot main body begins to grow is controlled such that the ratio of M/T is greater than a threshold M/T.

Additive feed systems for feeding at least two different additives to silicon disposed within a crucible of an ingot puller apparatus are disclosed. The additive feed system may include first and second feed trays which are caused to vibrate to move first or second additive from a canister in which the additive is stored to another vessel in which the amount of first or second additive added to the vessel is sensed. The additive is discharged from the vessel into an additive feed tube through which the additive enters the crucible.

Additive feed systems for feeding at least two different additives to silicon disposed within a crucible of an ingot puller apparatus are disclosed. The additive feed system may include first and second feed trays which are caused to vibrate to move first or second additive from a canister in which the additive is stored to another vessel in which the amount of first or second additive added to the vessel is sensed. The additive is discharged from the vessel into an additive feed tube through which the additive enters the crucible.

Provided is a large diameter InP single crystal substrate having a diameter of 75 mm or more, which can achieve a high electrical activation rate of Zn over a main surface of the substrate even in a highly doped region having a Zn concentration of 5×10.sup.18 cm.sup.−3 or more; and a method for producing the same. An InP single crystal ingot is cooled such that a temperature difference of 200° C. is decreased for 2 to 7.5 minutes, while rotating the InP single crystal ingot at a rotation speed of 10 rpm or less, and the cooled InP single crystal ingot is cut into a thin plate, thereby allowing production of the InP single crystal substrate having an electrical activation rate of Zn of more than 85% over the main surface of the substrate even in a highly doped region having a Zn concentration of 5×10.sup.18 cm.sup.−3 or more.

An experimental method for validating a thermal history of a semiconductor ingot obtained by simulation of a crystallization process, includes a) measuring the concentration of interstitial oxygen in a portion of the semiconductor ingot; b) calculating a theoretical value of the concentration of thermal donors formed during the crystallization process, from the measurement of the concentration of interstitial oxygen and from the thermal history in the portion of the semiconductor ingot; c) measuring an experimental value of the concentration of thermal donors in the portion of the semiconductor ingot; and d) comparing the theoretical and experimental values of the concentration of thermal donors.