Production equipment"Waterfall"can also be used for research purposes that are geared to creation and development of new technologies of oxide single crystal growth.

Background Art The prototype of the production equipment for single crystal growth "Waterfall"was a production unit"Omega 3"designed and built by a Lugansk production company"Zavod Donets"in 1986 to serve as the base model for subsequent developments. A resistive heating unit"Omega 3"was designed for bulk single crystal growth of leucosapphire by the Czochralski and Kyropoulus methods in the vacuum with the maximum output diameter of Similar equipment to the production equipment"Waterfall"is"Astra"of a Lugansk company"Zavod Donets"and a production unit"Oxypuller"of Cyberstar.

Disclosure of Invention Resistive heating production equipment"Waterfall"equipped with a high precision string weight sensor has been designed for automated crystal growth processes of bulk leucosapphire in the vacuum environment and by the Czochralski and Kyropoulus methods.

The maximum diameter of single crystals that can be grown on the given equipment is 150 mm. The system of control equipped with a string weight sensor allows for the growth of single crystals with preset geometric parameters and weight by means of high precision control of these parameters in the process of growth.

This equipment allows for the growth of a range of other oxide single crystals in the vacuum environment, than single crystals of sapphire.

See production equipment"Waterfall"in Fig. 1 This production equipment consists of the following parts and sections: a Load Bearing Frame (1), a Vacuum Chamber (2) with water-cooled walls, a Heat Unit (3) with a resistive heater, a Rack of Drives (4), a Standard and Accelerated Displacement Drive (5), a Manual Control Unit (6), a Manual Lifting Drive for the Top Lid (7), Current Leads (8), Viewing Windows (9), Horizontal Displacement Unit for X and Y (10), Rod Rotation Drives (11), a Sylphon Unit (12), a Hollow water-cooled Rod (13), a String Weight Sensor (14) with an Electronic Section (15), a Power Cabinet (16), a Control Rack (17), an Industrial Workstation (18), a Control Unit (19), a Control Unit for the Vacuum Set (21).

The principle units of the equipment are mounted on the Load Bearing Frame (1).

The Vacuum Chamber (2) with the Heat Unit (3) is the workspace for conducting of technological processes of bulk leucosapphire single crystal growth.

The Rack of Drives (4) that is mounted up on the top slab of the Load Bearing Frame comprises displacement drives and rod rotation drives (5 and 11), respectively, the Manual Control Unit (6), the Manual Lifting Drive for the Top Lid (7).

Vertical Standard and Accelerated Displacement, as well as rotation of the Hollow water-cooled Rod (13) is executed by the Displacement Drive (5) and the Rod Rotation Drive (11) according to the preset diagram of the technological process in the automated and manual modes of control.

The Manual Control Unit (6) is used for performing tasks for adjusting of the rod rotation at the preparatory stage of the process of growth.

Manual Lifting Drive for the Top Lid (7) is used for the purposes of loading and unloading of the Vacuum Chamber (2).

Current Leads (8) are mounted up on the Vacuum Chamber (2) serve the purpose of fixation of the heater and securing of power supply from the Power Cabinet.

Viewing Windows placed on the lid of the Vacuum Chamber (2) are used for observation purposes of the alignment of the geometric axes of the seed crystal and the crucible with a charge inside, as well as before the beginning of the technological process of growth, as well as for the purposes of visual control of the process of insertion of the seed crystal and overgrowth of the crystal.

Alignment of the axis of the seed crystal with the axis of the crucible or the melt is conducted by means of the precision angle of the horizontal displacement of the rod along the axes of X and Y (10).

The Sylphon unit (12) contains a vacuum rod seal that serves the purpose of a compensator when horizontal displacements occur.

The Hollow water-cooled Rod (13) serves the purpose of a moving feed- through in the Vacuum Chamber (2) and consists of a pull and a seed crystal that are mounted up to the weight sensor.

The String Weight Sensor (14) with the Electronic Section (15) mounted on the top of the Hollow Rod (13) provides for the automated control of the geometric sizes and weight of the growing crystal by means of periodic weighing and calculation of the weight increment at a time unit.

The Power Cabinet (16) has been designed for voltage transformation of the three-phase power grid into the voltage required to power a resistive heating crucible and other sections of the equipment.

The Control Rack (17) that is located on the left-hand side of the Load Bearing Unit (1) and contains the Industrial PC-based Workstation (18), the Control Unit (19) and the Control Unit for the Vacuum Set (20).

All the principle units of the equipment interact through the system of control.

The system of control, according to the preset parameters that are fed to the computer, controls the equipment in accordance with the initially set parameters, and performs further control of the process flow by means of the sensors. If necessary, the system of control makes a decision concerning changes of the preset parameters.

The Control Unit (19) installed into the Control Rack (17) is the executive section of the system of control of the equipment. The Control Unit for the Vacuum Set (20) that is installed into the Control Rack (17) controls the Vacuum Set (21) in the automated and manual modes.

The Vacuum Set (21) serves the purpose of creation of high vacuum in the Vacuum Chamber (2).

The system of control is equipped with a feedback function that detects the weight increment of the growing crystal. A signal generated by the string weight sensor is transmitted to the PC-based system of control and is processed there by the control software. With the change of weight increment for a time unit, the system of control changes the rate of crystal growth and the power going into the resistive heating crucible.

Brief Description of Drawings The production equipment"Waterfall"has been designed for the growth of bulk oxide single crystals with the diameter of up to 150 mm by the Kyropoulus and Czokhralski methods.

This production equipment consists of the following parts and sections: a Load Bearing Frame (1), a Vacuum Chamber (2) with water-cooled walls, a Heat Unit (3) with a resistive heater, a Rack of Drives (4), a Standard and Accelerated Displacement Drive (5), a Manual Control Unit (6), a Manual Lifting Drive for Top Lid (7), Current Leads (8), Viewing Windows (9), Horizontal Displacement Unit for X and Y (10), Rod Rotation Drives (11), a Sylphon Unit (12), a Hollow water cooled Rod (13), a String Weight Sensor (14) with an Electronic Section (15), a Power Cabinet (16), a Control Rack (17), an Industrial Workstation (18), a Control Unit (19), a Control Unit for the Vacuum Set (20) and a Vacuum Set (21).

Best Mode for Carrying Out the Invention This equipment has been designed to be utilized indoors at the air temperature of 20-25°C (68-77 °F) and the relative humidity rate of 5010%.

The premises should be equipped with combined extract and input ventilation.

Power to this equipment is supplied from a four-wire power grid of three phase AC current (with a neutral wire) with the voltage of 380 V and the frequency of 50 Hz.

General Lighting. Illumination level of the work place should exceed 300 luxes.

It is preferable that the quality of the water supplied to the equipment in use be close to that of potable water with the solid residual not exceeding 1gr per liter, and the bacteria level not exceeding 100 pcs. per m3 and the pressure of 25050 KPa. Average water consumption is 3 M3 per hr. The incoming water temperature should not exceed 30°C with the maintenance accuracy not lower than +2 °C.

This equipment should be connected to the following : water-main with gravity water supply with the diameter of the nominal carrying capacity not less than 70 mm; gaseous pure argon of best quality under the pressure of 63 kPa (. 63 kgf. per cm2) from the water-main or a separate canister; grounding mat for production areas; exhaust branch pipe of the mechanical roughing-down pump is supposed to be hooked to the system of centralized cleansing of exhaust fumes from the roughing-down pumps.

Industrial Applicability Production equipment"Waterfall"can be utilized in the semiconductor, electronics and medical industries, as well as in the instrument-making industry with the application to bulk single crystal growth of leucosapphire with preset geometric parameters. In addition, this equipment has a capacity for growth of a range of other oxide single crystals in the vacuum for industrial and research purposes.

Specifications List 1. Load Bearing Frame 2. Chamber 3. Heat Unit 4. Rack of Drives 5. Standard and Accelerated Displacement Drive 6. Manual Control Unit 7. Manual Lifting Drive for Top Lid 8. Current Lead 9. Viewing Windows 10. Horizontal Displacement Unit for X and Y 11. Rod Rotation Drive 12. Sylphon Unit 13. Hollow Rod 14. Weight Sensor 15. Electronic Section of Weight Sensor 16. Power Cabinet 17. Control Rack 18. Industrial Workstation 19. Control Unit 20. Control Unit for Vacuum Set 21. Vacuum Set