CN105256372B - GaN single crystal device - Google Patents

Abstract

The invention discloses GaN single crystal equipment, which comprises a reaction kettle, wherein a heater is arranged outside the reaction kettle, an air pipe with a valve is connected to the upper part of the reaction kettle, a crucible is arranged in the reaction kettle, and a seed crystal template is arranged in the reaction kettle. The invention controls the real-time growth position of the seed crystal template through the induction coil mechanism, and ensures that the seed crystal template is always in the optimal growth solution environment, thereby promoting the growth of GaN single crystals.

Description

A GaN single crystal device

technical field

The invention relates to the technical field of semiconductor production equipment, in particular to a GaN single crystal device.

Background technique

After more than ten years of research and development in the application of gallium nitride (GaN)-based semiconductor materials, breakthroughs have been made in blue LEDs, short-wavelength LDs, ultraviolet detectors, and white LED lighting. The manufacture of devices is restricted by the quality of the GaN substrate itself. As one of the methods for growing high-quality GaN single crystals, the NaFlux Method has made some progress, and GaN single crystal materials with a diameter greater than 2 inches and a thickness greater than 2 cm have been obtained.

The traditional equipment used to generate GaN single crystal is a reactor. The seed crystal template is placed in the growth solution in the reactor. The seed crystal template is generally in a static state. The seed crystal template in the reactor cannot realize real-time positioning of the growth position, and it cannot be guaranteed that the seed crystal template is always in the best growth solution. The environment is not conducive to the preparation of large-scale high-quality GaN single crystal materials.

Contents of the invention

The technical problem to be solved in the present invention is to provide a GaN single crystal device, which drives the seed crystal template to move through the coil induction mechanism, thereby controlling the real-time position of the seed crystal template to ensure that the seed crystal template is always in the best growth solution environment, GaN single crystal growth is thereby promoted.

In order to solve the above technical problems, the present invention takes the following technical solutions:

A GaN single crystal device, including a reactor, the reactor is equipped with a heater outside, a gas pipe with a valve is installed on the upper part of the reactor, a crucible is arranged inside the reactor, a seed crystal template is placed in the reactor, the device It also includes an induction coil mechanism, the induction coil mechanism includes an internal coil inside the reactor and an external coil outside the reactor, the external coil is connected to a power supply, a support rod is provided inside the reactor, and the internal coil is movable and sleeved on the reactor. On the supporting rod, one end of the internal coil is connected with the seed crystal template, and the external coil drives the internal coil to perform forced movement after being powered on, so that the internal coil moves on the supporting rod.

The support rod is installed on the top inner wall or the bottom inner wall of the reaction kettle along the axial direction of the reaction kettle, and the internal coil is set on the support rod parallel to the axial direction of the reaction kettle, and the internal coil drives the seed crystal template to move up and down.

The support rod is installed on the inner side wall of the reactor along the radial direction of the reactor, and the internal coil is set on the support rod to be equal to the radial direction of the reactor. The seed crystal template is connected, and the internal coil drives the seed crystal template to move horizontally.

The inner coil and outer coil are but not limited to single-layer coils, multi-layer coils or honeycomb coils.

The inner coil and the outer coil are but not limited to air core coils, ferrite coils, iron core coils or copper core coils.

The geometric central axes of the inner coil and the outer coil coincide or do not coincide.

The power supply is, but not limited to, a DC power supply, an AC power supply, or a power supply whose magnitude and direction of voltage and current change irregularly with time.

The external coil is arranged above the top of the reactor, or outside the side wall of the reactor.

The heater includes a lower heater arranged at the bottom of the reaction kettle, and a side heater arranged at the side wall of the reaction kettle.

The beneficial effects of the present invention are:

1. In the case of no mechanical damage to the reactor, the real-time control of the position of the seed crystal template is realized, which reduces the difficulty of equipment manufacturing and saves costs;

2. The real-time position control of the seed crystal template is conducive to the controllability of all aspects of crystal growth, ensuring that the seed crystal template is always in the best growth solution environment, thereby promoting the growth of GaN single crystal. .

Description of drawings

Accompanying drawing 1 is the cross-sectional structure schematic diagram of embodiment one of the present invention;

Accompanying drawing 2 is the schematic cross-sectional structure diagram of the second embodiment of the present invention.

Detailed ways

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, a GaN single crystal device includes a reactor 11, a heater is provided outside the reactor 11, a gas pipe 21 with a valve 22 is attached to the upper part of the reactor 11, and a crucible is arranged inside the reactor 11. 12. A seed crystal template 7 is placed in the reaction kettle 11, and an induction coil mechanism is also included. The induction coil mechanism includes an internal coil 42 arranged in the reaction kettle and an external coil 41 arranged outside the reaction kettle 11. The external coil 41 and Power supply connection, the reaction kettle 11 is provided with a support rod 5, the internal coil 42 is movably sleeved on the support rod 5, one end of the internal coil 42 is connected with the seed crystal template 7, and the external coil 42 drives the internal coil 41 to operate after the power supply 8 is connected. Forced to move, the inner coil 41 moves on the support rod 5 . The external coil is arranged correspondingly to the internal coil, so as to ensure that the magnetic field generated by the external coil can drive the internal coil to move after the external coil is powered on and the current is introduced. That is, after the current is passed into the external coil, the magnetic field in the external coil will change according to the current. If it is a periodic current, the magnetic field will change periodically accordingly, and the internal coil will be forced to move due to the action of the magnetic field. It will perform periodic motion with the change of the magnetic field. The heater includes a lower heater 32 arranged at the bottom of the reaction kettle, and a side heater 31 arranged at the side wall of the reaction kettle 11, and heaters can be arranged around each side wall of the reaction kettle. Introducing nitrogen gas into the reactor through the gas pipe, and filling the reactor with the growth solution are common knowledge, and will not be described in detail here.

The inner coil and the outer coil are but not limited to single-layer coils, multi-layer coils or honeycomb coils, or other coils. And the inner coil and the outer coil are but not limited to air core coils, ferrite coils, iron core coils or copper core coils. And when setting the specific positions of the external coil and the internal coil, the geometric central axes of the internal coil and the external coil coincide or do not coincide, which can be flexibly set according to the specific environmental space. A power supply is, but not limited to, a DC power supply, an AC power supply, or a power supply in which the magnitude and direction of voltage and current vary irregularly over time.

As for the specific installation manner of the internal coil, there are the following two preferred embodiments.

Embodiment 1, as shown in Figure 1, the support rod is installed on the top inner wall or bottom inner wall of the reactor along the axis direction of the reactor, and the internal coil is set on the support rod parallel to the axis direction of the reactor, and the internal coil Drive the seed crystal template to move up and down. The external coil is set above the top of the reactor. When the internal coil is forced to move by the external coil, the internal coil moves up and down along the support rod, thereby driving the seed crystal template to move up and down.

During the preparation period for crystal growth, adjust the power supply 8 so that the seed crystal template is in the upper part of the reactor 11, and does not contact the growth raw material; control the valve 22, the bottom heating device 32 and the side heating device 31, and increase the temperature and pressure to the preset Growth conditions, the growth raw material is melted into the growth solution 6; adjust the power supply 8 again so that the seed crystal template slowly drops below the liquid level of the growth solution 6, and the crystal formally grows; when the growth is completed, adjust the power supply 8 to raise the seed crystal template away from the growth solution 6. Lower the temperature and reduce the pressure to take out the crystals.

During the growth process, since a gallium nitride film is easily formed on the surface of the liquid, this film is suspended on the surface of the liquid gallium, which will prevent the mixing of nitrogen and liquid gallium. For this reason, a periodic current is passed through the external coil 41 to make the coil The magnetic field in the gallium changes periodically, and the internal coil 42 will also move up and down periodically due to the forced motion. This periodic motion will form a circle of ripples on the surface of the gallium source, and this ripple will cause the surface of the liquid gallium to vibrate. Gallium nitride films cannot be formed, and at the same time, this corrugation will accelerate the mixing of liquid gallium and nitrogen gas, further promoting the chemical reaction on the surface of the seed crystal, thereby improving the growth quality.

Embodiment 2, as shown in Figure 2, the support rod is installed on the inner wall of the reactor along the radial direction of the reactor, and the internal coil is set on the support rod to be equal to the radial direction of the reactor, and the internal coil The connecting rod arranged along the axis of the reactor is connected to the seed crystal template, and the internal coil drives the seed crystal template to move horizontally. The external coil is arranged outside the side wall of the reactor. When the internal coil is forced to move by the external coil, the internal coil moves left and right along the horizontal direction of the support rod, thereby driving the seed crystal template to move horizontally through the connecting rod.

Control the valve 22, the bottom heating device 32 and the side heating device 31, raise the temperature and pressurize to the preset growth condition, and the growth raw material melts into the growth solution 6; adjust the power supply 8 to make the seed crystal template slowly move horizontally in the growth solution 6 Move, thus, the vicinity of the seed crystal template is always in the supersaturated growth solution, which is conducive to crystal growth; after the growth is completed, the temperature is lowered and the pressure is reduced to take out the crystal.

When the external coil 41 passes a periodic current, a periodically changing magnetic field will be generated at the center of the excitation coil, and this periodic change will cause the internal coil 42 to perform forced motion, thereby producing a swing effect in the reactor. Swinging will effectively stir the liquid gallium source, and further promote the mixing of the liquid gallium source and nitrogen, while this swing also has the same effect as that of Embodiment 1, that is, avoiding the formation of a gallium nitride film on the surface of the liquid gallium source, which will further Promote the growth of materials.

In addition, different from Embodiment 1 and Embodiment 2, the internal coil 42 can also be separated from the seed crystal template, so that the internal coil can be placed in the reactor as an independent material growth auxiliary device, and can be independently Stirring the liquid gallium source inside the reactor will cause the gallium source to generate flow motion inside the reactor and form a flow field with a certain distribution state, which will also play an important role in the growth of the material.

It should be noted that the above description is not a limitation to the technical solution of the present invention, and any obvious replacements are within the protection scope of the present invention without departing from the inventive concept of the present invention.

Claims (9)

1. a kind of GaN single crystal grower, including reaction kettle, reaction kettle outside is equipped with heater, and the attaching of reaction kettle top has Tracheae with valve, reaction kettle is interior to be equipped with crucible, is placed with crystal seed template in reaction kettle, which is characterized in that described device is also wrapped Induction coil mechanism is included, which includes the Inside coil being located in reaction kettle and the outer lines that are located at outside reaction kettle Circle, the external coil are connect with power supply, and supporting rod is equipped in reaction kettle, and Inside coil movable set is internal on the supporting rod One end of coil is connect with crystal seed template, and external coil drives Inside coil to make diriven motion after powering on, and makes the inner wire Circle moves on supporting rod.

2. GaN single crystal grower according to claim 1, which is characterized in that the supporting rod is along reaction kettle axis side To the reaction kettle top inner wall or bottom inner wall is installed in, Inside coil is sleeved on the supporting rod flat with reaction kettle axis direction Row, the Inside coil drive crystal seed template to move up and down.

3. GaN single crystal grower according to claim 1, which is characterized in that the supporting rod is along reaction kettle radial direction side To the madial wall for being installed in the reaction kettle, Inside coil be sleeved on the supporting rod with reaction kettle radial direction equality, inside this Coil is connect by the connecting rod being arranged along reaction kettle axis direction with crystal seed template, which drives crystal seed template level to move It is dynamic.

4. GaN single crystal grower according to claim 1 or 2 or 3, which is characterized in that the Inside coil and outside Coil is single layer coil, lattice coil or honeycomb coil.

5. the GaN single crystal grower according to claim 4, which is characterized in that the Inside coil is with external coil Hollow coil, ferrite coil, iron-core coil or copper core coil.

6. the GaN single crystal grower according to claim 5, which is characterized in that the Inside coil and external coil The coincidence or misaligned of geometry central axes.

7. the GaN single crystal grower according to claim 6, which is characterized in that the power supply is AC power or voltage Irregular power supply is made in size of current and direction at any time.

8. according to claims 1 or 2 or the 3 GaN single crystal growers, which is characterized in that the external coil is located at reaction The over top of kettle, or be located at outside the side wall of reaction kettle.

9. according to claims 1 or 2 or the 3 GaN single crystal growers, which is characterized in that the heater includes being located at instead The lower heater in bottom portion is answered, and is located at the side heater of reaction kettle side wall.