JPH089168Y2 - Infrared intensive heating single crystal manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an apparatus for growing a single crystal of a substance such as a high melting point oxide such as an oxide magnetic material or an oxide dielectric material by a floating zone method of an infrared concentrated heating system.

2. Description of the Related Art For example, in the production of a high melting point oxide single crystal, a floating zone type single crystal production apparatus by infrared heating using an infrared lamp such as a halogen lamp as a heating source is used.

A typical example of an infrared heating single crystal manufacturing apparatus using the above infrared lamp is a spheroidal surface, as introduced in Nippon Electric Technical Report 1974 No. 112, P13-P18, and Applied Physics Volume 47, 1978, P1166-P1169. An infrared lamp such as a halogen lamp is arranged as a heat source at one focal point of the mirror, and a heated material such as a raw material rod or a crystal rod is disposed at the other focal point, and infrared rays emitted from the infrared lamp are spheroidal mirrors. A device for reflecting and condensing on a heated object to perform concentrated heating. In this device, the spheroidal mirror has one spheroidal shape, or two spheroidal mirrors each substantially equal to a half body, A bi-elliptical type in which opposing couplings are arranged so that the respective focal points coincide with each other is common.

Therefore, a specific example of a bi-elliptical infrared heating single crystal manufacturing apparatus will be described with reference to FIG. In the figure,
Reference numerals 24 and 25 are two symmetrical ellipsoidal spheroidal mirrors, which are faced to each other so that the focal points F ₀ and F _{0 of one of} them coincide with each other. 26,
Reference numeral 27 denotes two photothermal sources fixedly arranged at the other first and second focal points F ₁ and F ₂ of the spheroidal mirrors 24 and 25, for example, infrared lamps such as halogen lamps. 33 is each spheroid mirror 2
In the heated portion arranged at the focal point F ₀ of 4,25, which coincides with the raw material rod 23 extending vertically downward from above and the crystal rod 29 extending vertically downward from above, that is, single crystal growth is performed. A melting zone (floating zone) is formed. Reference numeral 22 is a transparent quartz tube that surrounds the raw material rod 23 and the crystal rod 29, and an atmosphere gas suitable for crystal growth is passed through the quartz tube 22.

In single crystal growth by infrared heating using the above device,
The infrared rays emitted from the infrared lamps 26 and 27 arranged at the first and second focal points F ₁ and F ₂ of the spheroidal mirrors 24 and 25 are reflected by the spheroidal mirrors 24 and 25, Concentrated heating is performed by focusing on the heated portion 33 arranged at the focal point F ₀ .

The heated portion 33 is melted by the radiant energy due to the infrared irradiation, and the raw material rod 23 and the crystal rod 29 are rotated and lowered in the vertical direction while performing sufficient stirring, so that single crystal growth is performed.

Note that FIG. 5 is a partial cross-sectional side view showing the positional relationship when the quartz tube 22 is attached and detached.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above infrared concentrated heating single crystal manufacturing apparatus, the feed amount becomes longer as the raw material rod 23 and the crystal rod 29 become longer, and the upper spindle 20 and the lower spindle 30 are inevitably long. In addition, with the lengthening of the raw material rod 23 and the crystal rod 29, the main shaft bearings 21,3
Position 1 is to prevent the main shafts 20 and 30 from coming off from the main shaft bearings 21 and 31 when moving the upper and lower main shafts 20 and 30 upward and downward respectively to attach and detach the quartz tube for sealing the crystal growth atmosphere. It tends to move away from the center of the heating part. Therefore, the lengthening of the main shaft and the mounting position of the bearing part away from the center of the heating part cause mechanical precision problems such as non-smooth main shaft rotation, non-smooth main spindle feed, and vertical spindle misalignment. However, there was a problem of lengthening the entire device due to the lengthening of.

Means for Solving the Problems The present invention has been proposed in view of the above problems, and a technical means for solving the problems is to provide an upper and lower rotating main shaft holding a rotating main spindle. The main shaft bearing guarantees the stroke of the upper and lower main shafts during single crystal growth and is fixed at a position close to the center of the heating part.However, during preparatory operations such as when attaching and detaching the quartz tube, the main shaft bearings are linked to the upper and lower main shafts respectively. To move.

Action By using the above-mentioned means, the spindle bearing can be brought closer to the center of the heating part, that is, the crystal growth point during crystal growth, and the spindle length must previously satisfy the growth stroke plus the preparatory movement stroke plus the spindle bearing length. However, it only requires a training stroke plus spindle bearings. As a result, it is possible to reduce the ratio of the distance between the main shaft bearing and the fixed end of the main shaft to the distance between the main shaft bearing and the center of the heating section. It is easy to obtain mutual concentricity. Further, the height of the entire apparatus can be suppressed by the movement of the main shaft bearing position and the minimum required main shaft length.

EXAMPLE A bi-elliptical type infrared heating single crystal production apparatus which is an example of the present invention will be described with reference to FIGS. 1, 2 and 3. In Fig. 1 showing the state at the start of crystal growth
Numerals 6 and 7 are two symmetrical elliptical spheroidal mirrors, which are opposed to each other so that the focal points F ₀ and F _{0 of one of} them coincide with each other to form a heating furnace. Incidentally, the inner surface of the spheroidal mirrors 6, 7, that is, the reflecting surface,
Gold-plated to reflect infrared rays with high reflectance. 8 and 9 are the other first and second of the spheroidal mirrors 6 and 7, respectively.
It is a halogen lamp which is an infrared lamp fixedly arranged in the vicinity of the focal points F ₁ and F ₂ . Reference numeral 10 denotes a heated portion located at the focal point F ₀ of each spheroidal mirror 6, 7, which coincides with each other. The raw material rod 4 fixed to the lower end of an upper main spindle 2 extending vertically downward from above and a lower main spindle extending vertically upward from below. A crystal rod 11 fixed to the upper end of 12 is butted. Reference numeral 5 is a transparent quartz tube that forms a sample chamber 15 by partitioning a space 15 in which the raw material rod 4 and the crystal rod 11 are arranged and a space 16 in which a halogen lamp is arranged. The chamber 15 is filled with an atmosphere gas suitable for crystal growth. 3 and 13 are main shaft bearings that support the rotational sliding of the upper and lower main shafts 2 and 12, and 1,14 are the upper and lower main shafts 2 and 12.
It is a fixed end that transmits the movement and rotation of the. Main shaft bearing 3,
Reference numeral 13 denotes fitting portions 3a and 13a that are airtightly fitted to both ends of the quartz tube 5.
And lids 3b and 13b which are respectively fixed to the fixed ends 1 and 14 and can be airtightly joined and separated from the fitting portions 3a and 13a, respectively.

Next, FIG. 2 shows the starting material rod 4 and the crystal rod 11 at the start of crystal growth.
FIG. 3 is a side view, partly in cross section, in a state in which is installed. During crystal growth, the main shaft bearings 3, 13 remain fixed at the positions shown, and the main shaft fixed ends 1, 14 and the main shaft 2, attached to the main shaft fixed ends,
Only 12 moves up and down. Reference numerals 16 and 17 denote rails to which a fixed end of the main shaft and a main shaft bearing are attached and which can move in the vertical direction.

Next, FIG. 3 is a similar partial cross-sectional side view showing a state before and after starting crystal growth when the quartz tube is attached and detached. When attaching and detaching the quartz tube, it is necessary that the lower end of the raw material rod 4 rises above the upper end of the quartz tube 5 on the upper spindle 2 side, and the upper end of the crystal rod 11 falls below the lower end of the quartz tube 5 on the lower spindle side 12. However, if the main shaft bearing remains in the position at the time of crystal growth, the main shaft will come off from the main shaft bearing, so the main shaft bearing is interlocked with the quartz tube attachment / detachment operation of the main shaft, and the fitting parts 3a and 13a remain fitted. The lid portions 3b and 13b move apart and move following the fixed ends 1 and 14.

Effects of the invention As described above, the spindle bearing is fixed near the center of the heating furnace during crystal growth, and it is possible to shorten the spindle length by interlocking with the spindle fixed end during preparatory operation. Combined with the positional relationship with the bearing, the runout of the main shaft, the smoothness of rotation and movement are improved, and the workability of assembly and adjustment of the device is also improved. In addition, as the main shaft bearing position moves,
With the minimum required length of the spindle, the height of the device was suppressed and the size of each component of the device was shortened.

[Brief description of drawings]

FIG. 1 is a front sectional view of an infrared concentrated heating single crystal manufacturing apparatus showing the start of crystal growth in one embodiment of the present invention, FIG. 2 is a partial sectional side view of the apparatus shown in FIG. 1, and FIG. FIG. 4 is a partial cross-sectional side view showing the positional relationship when the quartz tube is attached and detached in one embodiment of the present invention, and FIG. 4 is a front cross-sectional view showing the start of crystal growth in a conventional infrared concentrated heating single crystal production apparatus. FIG. 5 is a partial cross-sectional side view showing the positional relationship when the quartz tube is attached and detached in the conventional single crystal manufacturing apparatus. 2 …… Upper spindle, 3,13 …… Spindle bearing, 3a, 13a …… Fit part,
3b, 13b ... Lid part, 4 ... Raw material rod, 5 ... Quartz tube, 6,7 ...
… Spheroidal mirror, 8,9 …… Infrared lamp, 11 …… Crystal rod, 12 …… Lower main axis.

Claims (1)

[Scope of utility model registration request] 1. An infrared concentrated heating single crystal manufacturing apparatus for heating an object to be heated between a raw material rod and a crystal rod using a spheroidal mirror for reflecting infrared rays from an infrared lamp, and connecting the raw material rod and the crystal rod. An infrared concentrated heating single crystal manufacturing apparatus characterized in that the bearings that hold the rotating and sliding upper and lower spindles respectively have a structure that moves in synchronization with the vertical movement of the spindle during the preparatory operation.