DE2056321A1 - Knstallziehofen - Google Patents

Description

BR. L. WESSELY

PATENT ADVOCATE

MONKS 19

MONTENSTRASSE 9Jl

ARTHUR D. LITTLE, Inc, Cambridge, Mass., USA

Kristallζiehofen

The invention relates to a crystal pulling furnace and more particularly to a device for pulling crystals under a set pressure of 10 Torr up to 100 atm and at temperatures up to 4,000 ^° C.

A device that is suitable for pulling very many different types of crystal must be able to enable many different set or controllable operating states. When pulling crystals of an IH-V intermetallic compound, it may be necessary to maintain very high pressure around the pulling crystal area in order to control the evaporation of a volatile component, such as arsenic or phosphorus in the production of an intermetallic arsenide or phosphides. With other crystal pulling processes it is necessary to apply a medium to high vacuum. A crystal pulling furnace which can be used in many ways for general processes should be able to be used ^ to extract crystals of oxides,

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To draw salts, metals and semiconductors, including phosphides, arsenides, tellurides, selenides and sulphides and whatever other inorganic elements, compounds or devices of these. In particular, such a furnace should be in the Be able to use one of several crystal pulling techniques, including the vertical pull technique or the Czochralski process, the teraperature gradient drawing technique or the Briägman-Stockbarger-Yerfahretis or according to the Pliesszonentechrtik.

It is therefore a principal object of the invention to provide a crystal pulling furnace, which can at and over a pressure range of from about 10 Torr up to about 100 to work at temperatures of 4000 ⁰ C. Another object of the invention is to provide a crystal pulling furnace of the character described which can be operated in accordance with one of several crystal pulling techniques, including the Czochralski technique, the Bridgman-Stockbarger technique and the fluidization technique. Another object of the invention is to create such an oven which can be operated by means of a remote control and remote monitoring and in which safety precautions have been taken that enable this oven to operate reliably under extremely high vacuum oaer Bruekbedinguugen and It is also an object of the invention to provide such a furnace which allows for rapid height adjustment of one or both of the pull rods before, during and after crystal pulling Other objects of the invention will in part be obvious and will in part be described hereinafter still become clear.

The invention accordingly comprises the features of the construction, the combinations of elements and the arrangements of parts to be set forth below.

The invention will now be explained with reference to the figures of the drawing. Εε show:

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1 shows a perspective view of the device according to the invention, in which the furnace in a side view is shown and iti which also shows the energy source and the control panel,

Fig. 2 is a front view of the furnace shown in Fig. 1, Fig. 3 is a plan view of the furnace shown in Fig. 1,

Figure 4-6 are front, side, and sectional views of the print seals Access opening,

7 is a sectional view of the furnace which operates according to the Czochralsky method,

Fig. 8 is a partially sectioned side view of the synchronous drive assembly for the rods, whereby this assembly enables controlled rotary and longitudinal movements,

9 is a perspective view of the rotary and longitudinal drive for the rods,

10 is a sectional view of the rotary and longitudinal movement drive, assigned to the lower bar,

Fig. 11 is a sectional view of the mechanism shown in Fig. 10 taken along line 11-11;

Figure 12 is a sectional view of the lower end of the lower Staff,

Figure 13 is a sectional view of the upper end of the lower Staff,

Figure 14 is a detailed view of the upper end of the upper rod, showing means for introducing and withdrawing of a coolant are shown,

15 is a schematic representation of the flow of a coolant around the furnace,

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Pig. 16 is a schematic view of the mechanism for continuous Display of the position of the bars,

Figure 17 is a schematic view of the temperature control system and

Figure 18 is a schematic view of the selection mechanism the bars to be moved and the speed at which they are to be moved.

The inventive crystal pulling device has a pressure-tight, water-cooled furnace, upper and lower rods that can be rotated and moved along their axes, with these Rods are operated inside the furnace and spread over the Oven extend out so that the drive mechanism associated with these rods are located outside of the oven can. This device also has a viewing window which is suitable for receiving a television camera for remote monitoring. The drive mechanism can be in a can be operated in a slow crystal pulling procedure or in a fast one, which is used for quick adjustment. There are also Means are provided to monitor the temperature of the crystal pulling area and means are also provided to to replace the heating devices and to cool the upper rod inside the furnace, and also devices, to precisely determine the position of each rod. A simple exchange of different parts carried by the bars and parts of the associated crystal pulling device enable a choice of the crystal pulling method. This shows the inventive device a large number of degrees of freedom with respect to the operation and also with respect to the Materials from which the crystals are drawn, and also in terms of atmospheres, pressures and temperatures, under what the crystals can be pulled, and the speed at which these crystals are formed and like that.

The overall situation is shown in perspective in FIG. 1.

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This system has a furnace assembly 10, an energy supply 11 and a control panel 12. The furnace is from the power supply system and separated from the control panel by a wall 13, for example. Although the furnace assembly is designed in this way is that it complies with Section VIII of the ASME Pressure Vessel Code, it is always desirable to have such To locate equipment that is under high pressure away from the operating personnel. From the following description it emerges that the device according to the invention can be controlled and monitored from a remote station. The general outline shape of the furnace assembly is shown in FIGS. Pig. 1 is a side view and FIG. 2 is a front view. The furnace assembly includes furnace 15, pressure tight access port 16, main viewing window 17 with a television camera 18 placed on a television stand 19 so that the operator can perform the crystal pulling process can view on a television screen 20, which is arranged on the control panel 12. Optionally, an additional Viewing window 21 may be provided.

The energy for heating the crystal pulling area is via a High-frequency line 25 fed to the furnace through a pressure sealing flange 26 is arranged pressure-tight. A high-frequency cable 27 passes through this flange 26 and runs through a cable line 28 and is connected to the power supply device 11 connected.

The pressure that is maintained within the furnace can be monitored by means of a pressure gauge or vacuum gauge 30 which is connected to the energy supply line 25 via a connection 31. For remote monitoring is a second pressure measuring device 29 is arranged on the desk 12. A connection between the interior of the furnace and a vacuum pump 32, for example an oil diffusion pump, takes place via a vacuum line 53 and a slider 34

The rods that are used in the furnace and the associated ones

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Actuators are shown very generally in FIGS. 1 and 2 and should be described in detail with reference to the Pig. 7 to 14 explained. The upper rod mechanism is indicated generally at 36 and the lower rod mechanism at 37 x the upper one Motor 38 for producing rotational movement of the upper rod and the lower motor 39 for generating a rotary movement of the lower rod, a drive synchronous motor 40 (Fig. 3) »a gear 41 j a motor 42 high speed, an upper housing 43 for . a flexible shaft and a "flexible shaft lower housing 44 are shown in Figures 1 and 2. As shown, For example, the furnace assembly may be mounted on any suitable support such as that shown in these figures mobile table 45

The line 33 is above the slide 34 a self-resetting pressure relief valve 57 and a solenoid operated Relief valve 58 assigned. A gas outlet line 59 'which is controlled by a slide 60 on the desk is connected to the Interior of the furnace via line 33 in connection.

Before describing the parts of the oven in detail, it is useful for orientation purposes to refer to FIG to take. Figure 3 is a top plan view of the furnace assembly. In this In the figure, the same parts are provided with the same reference numerals as in FIGS. 1 and 2. The drive synchronous motor 40 is used to the. To supply drive power for the translational movement of the two rods during crystal pulling, while using the high speed motor 42 to drive the bars at high speed at any desired time; this motor is especially used for quick adjustment. A speed control gear 41 is used to provide the required control of translational speed allow the rods to operate at low speed, and the synchronous motor 40 with Variable speed is via a gear 48, a clutch 49 »a shaft 50 and a clutch 51 with the main gear tied together. The transmission system 41 and the engine 42 with high

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Speed 1 can alternately be connected to the shaft 52, as will be explained in the following with reference to FIG shall be. A pulley drive 53 enables the necessary mechanical connection between the motor 42 higher Speed and the shaft 52. The shaft 52 is in turn connected via a coupling 54 to the drive mechanism, the general is denoted by 55. This drive mechanism 55 is designed such that a translational movement to the upper and lower rod mechanism is granted. The upper rod mechanism 36 is shown in Fig. 3 with this drive mechanism 55 connected via a flexible shaft 43, which in turn is connected to the upper rod via a coupling 56.

Figures 4, 5 and 6 show front, side and sectional views the access opening of the furnaceB, this access opening is closed by a hinged lock. The access opening 64 (Fig. 6) allows direct access for the operator so that the desired heating device, the desired crystal puller and starting material can be introduced into the interior of the furnace, specifically in the crystal pulling area. This access opening is locked, so that the space inside the furnace can be made pressure-tight by means of a hinged cover 65 The peripheral flange of this cover fits onto the peripheral flange of the access port housing 66. A sealing ring 67 is positioned between these two flanges. The cover 65 is through two struts '68 held, which are attached to a rod 69. This rod is rotatable about its axis and is mounted on the access opening housing 66 by means of brackets 70. A mechanical pressure between the hinged lid 65 and the access opening housing 66 is created by semicircular rings 72 and 73, which have internal grooves. The internal grooves of these semicircular rings are shaped to match the inclined surfaces the flanges of the hinged link 65 and the access port housing 66 correspond. A mt; _ anic burden that the Resisting internal pressure is achieved by a ^ · use of screw bolts 74 and 75 generated which pass through central bushings 76 and 77. When the upper and lower bolts 74

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and 75 are rotated at the same time, the grooved planes 72 and 73 are drawn together and toward the center of the hinged Cover "65. This causes the sealing ring 67 to form a seal between the flanges of the cover and the housing forms. The access port is with a pressure relief valve 79, which prevents the operator from opening the furnace before the pressure inside the Furnace is essentially atmospheric pressure.

The furnace is shown in longitudinal section in FIG. It is recognizable, that the furnace housing has an upper section 90, a middle section 91 and a lower section 92. Within these sections there is a space 93 and this is the working space of the furnace, the one shown in FIG The furnace and pulling head are used to pull crystals using the Czochralski method. In this embodiment the crucible, which contains the molten material from which the crystal is formed, remains stationary during the Crystal is pulled up and attached to the upper pulling head 94, which in turn is attached to the upper rod 95. With the upper rod 95, a lower rod 96 is comparable, which carries a graphite container 97, as well as a support ring 98, which is attached to is attached to the rod via a support collar 99. An inner quartz radiation screen 100 is supported on this support ring 98. The crucible 101, which contains the melt 102 that is used to produce the crystal 104, rests in the graphite container 97 · This crucible can be covered with a sealing material 103, through which the crystal 104 is pulled will.

In the exemplary embodiment of a method shown in FIG an outer Cuarz radiation screen 110 is arranged around the inner quartz radiation screen; this has the shape of a Cylinder and is supported on a faceplate 111. A socket 112 allows the lower rod 96 to pass through extends through the bottom of the outer radiation shield and upwards towards the support collar 99 and into the graphite container 97.

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a. Over the length of the lower rod 96, which is hollow and attached to his Is closed at the upper end, 'extends a thermocouple screen 114' through which thermocouple wires 115 extend and 116 (Fig. 13) having a thermocouple connection 117 which is used to monitor the temperature of the graphite vessel near the crucible. By the two radiation protection screens 110 and 100 extends a sapphire light pipe 120, which is connected to a radiation pyrometer can be connected, which is arranged outside the furnace chamber. This device forms a second temperature measuring device .

Heat is supplied to the crucible 101 by means of a high frequency coil 125 which is arranged around the outer radiation shield is, and this coil is connected via lines 126 and 127 to the terminals within a flange 128 • are arranged. The fitting flange 128 is connected via corresponding connections to the high-frequency cable 27, which extends through the power supply line 25 extends therethrough and out of the high frequency flange 26, this flange having a Has blind flange 129, which together form a pressure-tight closure with a matching flange 130 of the inlet line 25, this pressure-tight closure by means of an O-ring 131 and through the use of a number of screw bolts 132 is achieved. A pressure-tight closure must also be used be provided around the high-frequency cable 27 at the point at which it passes through the high-frequency flange 26, and this closure, as shown in FIG. 7, has a sealing body 133 and a Conax pressure stuffing box 134. The high frequency cable and the flange 128 are secured by an insulating collar 135 carried within the energy supply line 25. This training makes it possible that various high-frequency coils can be built into the crystal pulling room and that resistance heating can be used if desired. It is only necessary to connect the lines 126 and 127 from the flange 128 and use a different heating assembly in place of these lines. How

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has already been explained, a measuring device connection 31 enables a connection to a pressure gauge or to a vacuum gauge to monitor the pressure in the furnace · A foreign body trap 35 is arranged in the slide-controlled line 33, which leads to the vacuum pump shown in FIGS leads·

As already stated, the furnace shown in FIG. 7 is "intended to pull crystals according to the Czochralski process. However, it is clear to a person skilled in the art that the embodiment shown in FIG. 7 can easily be modified in order to do so the temperature gradient method (Bridgeman-Stockbarger) is used can be, namely in that the upper rod 95 is moved to its uppermost position and that a suitable Wise formed crucible is attached to the lower rod 96. This crucible is shaped in such a way that this forms a deep well that ends in a conical tip at the bottom, and this crucible is inside the high frequency coil arranged to melt the material forming the crystal. The crystallization then takes place in such a way that the lower rod and the crystal it carries is rotated and moved down under the end of the radio frequency coil.

It is also clear to a person skilled in the art that the flow zone technique can also be used in that a pressed Cylinders made of the material which is to be formed into a crystal are arranged between the upper and lower clamping jaws can attached to the upper and lower bars 95 and 96 are, and that ^ at the same time these rods are moved, to rotate the pressed cylinder and to slowly guide this pressed cylinder through the heating area.

The upper and lower bars extend through the interior of the furnace and are driven by mechanisms that are arranged outside the furnace chamber 93. Rods 95 and must have upper and lower socket assemblies 284 and 285, which are explained in detail with reference to FIG.

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the. Bb it should be noted that the two rods are separate or simultaneous can be moved slowly at a predetermined speed and at a predetermined translation speed or that these bars can be moved quickly for quick adjustment.

The main viewing window 17 is arranged and aligned in such a way that that this enables a relatively large overview of the crystal pulling space within the furnace space 93 - this The main viewing window consists of a main housing 136 which is welded to the central section 91 of the furnace housing and a window cap ring 137 which is attached to the main window housing by means of a number of screws one of which is shown at 138. The viewing opening 139 lies within the cap ring 137 · The window housing and the cap ring are designed so that between This includes an annular recess in which a tempered Pyrex window 140 is arranged. The waterproofing between the window surface and the main housing takes place by means of an O-ring 142. The internal pressure load on the Window 140 is made from an elastomeric washer 141 Transfer material to window cap ring 137. To protect the Pyrex window and its optical properties of the image transmitted through the window is between the window 140 and the crystal pulling room adjustable infrared reflecting window 143 used, which is used to adjust the axial temperature gradient at the window 140 to decrease. This window 143 is held in a mounting ring 144 which is inside the housing 136 by means of a Thread is rotatable. A polarizer 121 is rotatably mounted in frame 122 on cap ring 137. The purpose of this polarizer is to adjust the intensity or light intensity of the image transmitted through the window 140.

Gas to purge or pressurize the oven is introduced via a gas line 145 which is arranged so that the inflowing gas hits the exposed surface of the

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polarizing radiation shield 143 falls'. This enables that the window can be cleaned if necessary. The gas flow is controlled by means of a slide 146, the establishes a connection between the line 145 and the gas feed line 147, which leads to a gas source (not shown) leads.

The auxiliary viewing window 21, which is formed so as to that only a limited view of the crystal pulling space is made possible at a different angle is essential constructed in the same way. As the use of an auxiliary viewer window is free, an opening is made in the central portion 91 only when the auxiliary viewing window is desired, in which case an adapter 151 is provided which communicates with the space 93 in the oven. As shown in Fig. 7, the auxiliary viewing window is attached to this adapter. This help viewing window has a window housing 152 and a window housing cap 153. The tempered Pyrex window 156 is mounted in the same way like window 140, using a washer 157 made of an elastomeric material and an O-ring 158 made of an elastomeric material. This window assembly also includes an infrared reflective window 159 and an outer polarizer 123 rotatably mounted in frame 124. As in the case of the main viewing window, a gas conduit 160 is arranged to direct the gas onto the exposed surface of the radiation shield. The flow of the gas against the shield and into the system is controlled by a slide 161 which controls the connection between the line 160 and the gas feed line 162 produces. In addition to gate valves 146 and 161, gas flow into the furnace is also remotely controlled by a slide 148 on the desk 12 (Fig. 1).

Means are provided to cool the furnace assembly. The entire cooling device is shown schematically in FIG. In Fig. 7 a part of the cooling coil system is shown.

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in which a coolant such as water circulates The upper and lower sleeve assemblies 284 and 285 have annular channels 163 and 164. These channels can via connections 165 and 166 with a water feed line 167 (Fig. 15) are connected. Cooling coils are wound around the outer walls of the furnace parts for heat exchange. A cooling coil 169a is assigned to the upper housing section 90, a cooling coil 170 to the auxiliary viewing window 21, a cooling coil 171 of the high-frequency line 25, a cooling coil 169b, a cooling coil is attached to the middle housing section 911 172 of access port 16 (Fig. 5), a cooling coil 173 to the main viewing window 17 and a cooling coil 169c to the lower housing section 92. The Pig. 15 it can be seen that that the serpentines are two wires that are wound in parallel, as indicated by the solid and dashed lines is illustrated. These are connected to one another by means of a loop 174, the two slide-controlled connections 174a and 174 b. The coolant can be in one side of the parallel snakes, for example via a not shown Line, which is connected via connector 188, and the coolant can pass through the other side of the snakes are withdrawn, for example via a line, not shown, which is connected to the connection 189. Alternatively · a certain amount or all of the coolant can be used Coolant may be withdrawn through a conduit connected to port 174a and fresh coolant or additional Coolant can be supplied through a conduit connected to port 174b. This alternative embodiment allows flexibility in the manner in which the furnace assembly can be cooled.

The translational movements and the rotational movements of the two rods 95 and 96 are generated by mechanisms, which in detail is shown in Figs. 8-11. Reference is also made to FIG. 3. To one or both rods 95 and 96 slowly to drive for crystal pulling or fast for setting, it is necessary to provide a mechanism that is operated by a

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Drive type can be switched to the other, whereby it is ensured that when this switchover is carried out the unselected operating mode is automatically disengaged. The mechanism by which this is achieved is detailed shown in Fig. 8 and in plan view in Fig. 3.

In the illustration in FIG. 8, the time 50 and the associated Clutches that connect the transmission 48, which is assigned to the drive synchronous motor 40, with the transmission 41, omitted. These parts are shown in FIG. The "crystal pulling method" or the slow drive method is thereby allows the flexible drive shafts 43 and 44 associated with the lower and upper rods to be connected to the shaft 52 can be connected. The speed of this shaft is determined by the appropriate selection of the gears in the gearbox 41 and through the setting of the speed of the motor 40 is determined. The shaft 52 is connected to the flexible shafts 43 and 44 via a magnetic coupling treatment 175, which in turn is used to drive a shaft 176 when that clutch is engaged. These Shaft 176 is connected to a bevel gear 177, and this gear consists of worms 178, 179 and 180. The combination of worms 178 and 179 are used to drive the flexible shaft 43 that supports the upper rod and the combination of worms 178 and 180 is used to drive flexible shaft 44, which is used to drive the lower rod 96. The flexible one Shaft 4 3 is inserted into a flexible shaft adapter 181, namely through a spacer 182. By means of a coupling 183, a pin 184, a shaft collar and a Pressure disk 185, the shaft 43 is connected to the drive shaft 186, which is assigned to the worm 179. The connection between the worm 179 and the shaft 186 are controlled via a magnetic coupling 187. The flexible one is similar Shaft 44 in a flexible adapter I9I via a spacer 192 inserted and by means of a coupling 193, a pin 194, a collar and a thrust washer 195 are connected to the drive shaft 196, which is assigned to the worm 180. The connection between the screw J ^ C ^ and ^ of the shaft 196 is means

ORIGINAL INSPECTED

controlled by a magnetic coupling 197. The shafts 186 and 196 bind are aligned and supported by bearing systems 198 and 199, which are arranged in a drive housing ΪΟ5 and from this are carried, this drive housing preferably is formed integrally with the drive carrier 206 and has cover plates 207.

When it is desired to move the rods 95 and 96 at high speed, the high speed motor 42 is used to drive the pulley shaft 210 via the pulley 53 by means of a drive belt 211. As will be explained in connection with FIG. 17, when the motor 42 is turned on at high speed to perform the high speed operation, an electrical switch connected in parallel with the high speed motor operates the Magnetic clutch 175 to turn off the shaft yd and the drive mechanism for low speed drive. When the pulley shaft 210 is engaged to drive the shaft 178, the mechanism by which the flexible shafts are driven via the bevel gear is the same as in the slow drive or crystal pulling method. The pulley 210 rotates in a bearing 212 which is mounted in a bearing holder 213. The high speed motor 42 is mounted on a motor mount 214, precisely aligned to allow direct drive of the shafts 210 and 178 via the pulley 53.

Figures 9-11 show in detail the mechanism by which the lower rod 96 is imparted rotational movement and translational movement and the manner in which it is also shown. Mechanism with the flexible shaft 44 is connected. The mechanism that is illustrated in these figures, eating substantially the same, the ser in US patent application No. ₄ 653 478 of T4-7.67 is shown and described.

Reference is now made to FIG. Fig. 9 shows a urnee-

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Reverted view of the main elements that make up the translational and rotary drive system associated with the lower rod 96 and which is connected to the flexible shaft 44 (Pig x 8). The flexible shaft 44, which extends from the drive system shown in FIG. 8, is connected to a drive worm 220 via a coupling 221 and via a connection for the flexible shaft. The drive worm 220 in turn meshes with the translational drive system 223 - it can be seen that this system has a vertical drive spindle 224 which ends in a lower clamping device 225. The thermocouple wires 115 and 116, which extend upwardly through the lower rod (Figures 7 and 13), exit the underside of the chuck 225 (Figure 12) and are connected to associated electronic devices. As will be explained below, the vertical drive spindle itself does not rotate, but only performs a translational movement. This requires that rotation be generated by a spur gear 227 attached to the lower rod with a jig 228. This jig is mounted on the rod 96. The spur gear 227 is rotated by a drive motor 39 via a shaft 229 which carries a drive gear 230 at the end. This drive gear 230 meshes with the driven gear 231, which is mounted on the shaft 232. A rotating drive pinion shaft 233 is attached to this shaft.

The rod actuation assembly will be explained in detail with reference to Figs. The purpose of the lower Rod clamp assembly, indicated generally at 225 and shown in FIG 12, it is to connect the rod 96 to the drive spindle 240 such that the rod 96 can rotate within the drive spindle 240, which itself

It does not rotate, but only a translational movement on the rod 96 transmits. The lower clamping assembly 225 has a thrust bearing 241, which is in a thrust bearing housing 242 is held by means of a snap ring 243. A sleeve 244 is provided on the upper end of the drive spindle 240. The staff and

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the jigs are free to rotate in the sleeve 244 and in the drive screw which is only translational performs. Tranalation motion is imparted to rod 96 via the mechanism generally designated 223 (Pig. 10) is designated. As stated above, when the translational movement is performed, the drive spindle assembly rotates not. Instead, the threaded nut 245, which engages the thread of the vertical drive spindle 240, rotates, in the Hülee 239> and the mother turns on one shoulder 246 and is connected to a worm wheel 247, which is of the Screw 220 is driven. This pivot assembly is between an upper thrust washer 248 and a lower thrust washer 249, which is held by a push plate 250. Reference is now made to FIG. 11, in which it is shown that this thrust plate 250 is fastened by means of screws 251 to the cast body which the housing 252 which includes the drive mechanism. By In this way of fastening, tensile loads on the rod 96 are transmitted to the cast housing via the screws 251.

It was now back to Pig. 10 referred to. The upper end of the drive spindle 240 is attached to a non-rotatable plate 255, which in turn is attached to a non-rotatable arm 256 which rests against the non-rotatable shaft 257. At the upper end the drive spindle is a sleeve 258 in which the rod 96 rotates. The spur gear 227 for rotating the rod is attached to this by means of a clamping device 228 and by means of a pin 260 and a thrust bearing 261, which through a snap ring 262 is held.

The auger drive adapter assembly 263 for transient movement is in the cut in Pig. 11 shown. The worm 220 is attached to the worm shaft 264, which is in the housing 252 is mounted, through a front shaft bearing 265 and through a flanged sleeve 266 and through a rear V / ellenlagerung 267, which is attached to the rear plate 268 of the housing, and through a flanged bushing 269 · The shaft 264 is v / e

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a shoulder 222 which is intended for attachment to the flexible shaft 44 (Fig. 9), and the rear shaft bearing 267 has a threaded portion 270 to which the threaded portion 221 (Pig. 9) can be attached to a correct Establish connection with the housing of the flexible shaft.

The rotary drive is shown in detail in cross section in Pig. 11 shown. This rotary drive is generally designated 275. The drive bevel gear 230 is mounted on a shaft 276. This shaft 276 is arranged in a shaft holder 281 which is fastened to the plate 268 of the housing 252. One front end padded sleeve 277 and rear padded sleeve 278 are for the shaft 276 is provided. An adapter piece 279 is attached to the end of the shaft and is designed in such a way that with this adapter piece the shaft 276 can be connected to the shaft 229 (Pig. 9), which in turn is connected to the drive motor 39. It can be seen that, in addition to the rear panel 268, the housing has a removable front panel 280 that has the Housing closes.

The Pig. 7 and 10 show in detail how a pressure seal is formed around the rod 96 as it translates and rotates. That in Pig. 7th Bushing housing 285 shown has an adapter piece 286, in which a sleeve 287 is arranged, which allows the necessary alignment of the rod 96 when it is over the Top of the housing 252 extends beyond. The adapter piece 286 is designed such that this with the lower portion 92 of the furnace housing can be connected (Pig. 7) · For this purpose an annular groove 288 is provided, which has an O-ring 289 records.

The adapter piece 286 contains a gland seal 290-Di. ρ? .-: The stuffing box seal comprises a τι ■■ .-; ■■ housing section 291, a 0 ~ ring 29? _v r eggs against Oo e;.. '! : v. '; ■: e of the rod 96 rests, an O-Ririg 293, which the stuffing box housing against the adapter

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piece 290 seals, a felt wiper ring 294 and a metal wiper ring 295. The stuffing box is screwed into the adapter piece 286 and the wiper rings are held by a snap ring 296 held. A hexagon 297 is formed at the end of the stuffing box. When the pull head assembly is attached to the furnace 15 by means of Screws 298 (Fig. 7) is attached, a seal with the inner chamber 93 is made by the O-ring seals 289 and 293 scored. The rod needs to move naturally during this waterproofing is maintained with the oven, rotate and move, and the O-ring seal 293 makes this possible. The stuffing box is constructed in such a way that it can withstand the pressure of the frictional forces that must be overcome when the rod is moved. The gland is also designed to be easy and quick to clean or replace the O-rings can be expanded.

The rotary drive pinion 233 and the associated shaft 232 are held in the housing by means of a flanged sleeve 305 which is arranged in a section 306 of the housing cover. One Adjusting screw 307 with a fine thread and a grub screw 308 are provided to adjust the pinion shaft axially, so that a correct and precise bearing clearance is achieved. An opening, not shown, for electrical connection lines is provided in the housing to provide the necessary electrical lines for the microswitch limiting the movement stroke 315 to be provided. The microswitches 315 ', both the upper and the lower, are operated by the arm 257.

The lower portion of the lower rod 96 extends into a dust cap 322, which is attached to the housing 252 by means of a bundle and has an end plate 324.

The * .xdrive mechanism associated with the upper rod 95, corresponds to that of the lower rod 96 shown in FIGS. 9-11 is shown.

Fig. 7 shows the attachment of this upper drive mechanism

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mus on the stove. The top rod 95, however, is constructed sjo that this can be cooled, and this requires some modifications to the rod as well as means for supplying a coolant and "to derive, such as water.

The Pig. 14 shows the upper portion of the upper rod 95 in FIG Detail showing these modifications to the rod as well as the means for cooling the rod 95- A dust cap 325 is on the housing 252 (Pig- 7) attached, and this dust cap is through a metal cap 326 closed, which snapped on v / can earth. This forms a housing for the upper rod 95. In order to cool the rod 95, it is necessary to pass a coolant down through the rod and then return that coolant. There is a stuffing box for this corner 327 is provided, which surrounds the upper portion of the rod and opposite this by means of an upper O-ring 328, a weld 329 and a lower O-ring 330 sealed is. The stuffing box 327 is connected to the drive spindle 240 connected via a neck section 331 of this drive spindle. The rod itself consists of an outer tube 335 and an inner tube 336. This tube 336 has an inside inner coolant channel 337. The outer tube 335 and the inner tube 336 delimit an annular outer one between them Coolant channel 338. The channel 338 is closed at the end of the inner tube 336 by means of a plug 339. Above of the plug 339 and inside the outer tube 335 is a coolant inlet chamber 340, which is connected to an upper Annular groove 341 is in communication, which forms a channel and is connected to the chamber via a series of openings 342. The annular channel 34I in turn is provided with an inlet line 344 connected, which is connected via a coupling to a water supply pipe 345, which is in a quick coupling 346 ends.

Similarly, the outer tube 335 has openings 350, which establish a connection between the annular space 338 and a hanging groove which forms a channel 35I. This channel 35I

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stands via a water drain pipe 352 with a drain pipe 353 in connection, which is connected to a quick coupling 354 is. At the lower end of the cooled rod 95, a solid plug 355 is arranged, which both the inner coolant channel 337 as well as the outer coolant channel 338 closes off. A connection between these two channels takes place via openings 356.

In operation, water or other coolant is supplied through line 345 and that coolant passes over the Chamber 340 into the inner water channel formed by inner tube 336. At the end of the rod is the coolant passed through the openings 356 in the outer channel 338 and over this channel, the openings 350, the annular channel 351 and the Line 352 led into the outlet line 353. When the rod

95 is moved up and down, the inlet and outlet lines 344 and 352 move within the slot 357 in the dust cap 325

In operating the furnace, it is very desirable that the operator knows at all times the exact position of the rod or rods that are being used. A continuous one The rod position display system is therefore each of the rods 95 and 95

96 assigned. The display system associated with the lower rod 96 is shown in FIG. A same system is that upper rod 95 assigned. This display system is in that in Pig. 9 shown vertical drive system integrated.

A shaft 365 extends beyond the drive worm 220 and is attached to this drive worm and has a magnet 366 which is attached to the end of this shaft and along one side of this shaft. The shaft 365 and the magnet rotate in a switch system 367, which includes a magnetic leaf switch 368, which is disposed on one side of the shaft. The magnetic blade or reed switch is electrically connected to the center connection of section 369 of a disk switch, which has another section 370, and to a reversible electromagnetic counter,

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which is set in such a way that - it shows the route, traversed by the rod 96 from the lowest position in hundredths of an inch. The connections between the reversible counter and the DC motor controller 372 and dial switch 369 »370 are such that the rotations of shaft 365 are added and displayed when the Rod 96 moves up and that rotates shaft 365 can be subtracted as the rod 96 moves downward. In this way the counter always shows the exact position of the rod regardless of the direction in which the rod is moving. The exact setting is made possible by that the worm gear ratio and the thread pitch are such be chosen so that the rod 96 moves one inch, while the shaft rotates 365 hundred times.

It is within the scope of the invention, the sensitivity of the position indicator by increasing the number of magnets mounted on shaft 365. the The device can also be designed in such a way that it is displayed in metric units.

Precise temperature adjustment of the crystal melt in the crucible 97 is required during crystal pulling. This is done automatically by a mechanism which is shown schematically in FIG. The light pipe 120, which extends very close to the surface of the graphite receptacle 97 between the high-frequency coil, is connected to a radiation pyrometer 375, which in turn is connected to a temperature proportional control system yj6, such as the Leeds-Northrup HAZAR recorder or CAT Electric controller, this control system processes direct current signals received by it, and these signals are fed via a magnetic amplifier 377 in the form of an amplified signal to a pre-magnetizable coil 378, the core of this coil being saturable and this coil controlling the current which the induction heating supply source 379 is fed. By setting the temperature control

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systems 376 can be brought to the required temperature by the wholesalers Adjusted the energy delivered to the radio frequency coil 125, and thereby the temperature can be adjusted to the desired level Height can be maintained. A pyrometer 385 can be connected to a thermocouple 117, and thereby a direct Temperature display for the operating personnel.

FIG. 18 schematically shows the mechanism that controls the speeds and directions of rotational and translational movements of the rods 95 and 96. In the description of FIG. 18, reference is also made to FIG. 8, in which the synchronous drive assembly is shown. The DC motor controller 372 is used to control the direction and speed in which the rods 95 and 96 are moved, while the gear system 41 is used to control the speed of translation in the slow mode or crystal pulling. As set forth in the Tl cSchreibung of Fig. 8, clutches 187 and 197 provided around the rod to using v / ground select. It is of course possible to use both rods, such as in the zone melting crystal pulling process. The clutch 187 is engaged and disengaged by closing and opening the switch 385 that connects the clutch 187 to the associated voltage source 386. The voltage source is also connected to the upper and lower limit switches 315 (Fig. 10). Similarly, by closing and opening switch 388, clutch 197 is engaged and disengaged. The switch 388 connects the coupling 197 to the associated voltage supply 389. As with the rod 95, the end positions of the rod 96 are determined by limit switches 315.

To ensure that the rods are driven either slowly or quickly and that if the one operating mode is switched on is, the other is safely switched off, is a common animal power supply for both the motor 42 with high Speed as well as for the magnetic coupling 175. A switch system 390 blocks the possibility of electricity being

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BATH ORIGINAL

Timely the clutch 175 via the clutch DC connection 391 and the motor 42 is supplied. When the stove is in its slow operating mode works, that is, when crystals are pulled, is the one running at high speed Motor at rest.

The motors 38 and 39> which rotate the rods are over assigned motor controls 392 and 393, which determine both the direction of rotation and the speed

The device according to the invention is a completely integrated one System for pulling crystals or for corresponding processes in which pressure and temperature are precisely controlled or must be set. The procedures carried out in the furnace can be carried out by an operator and observed with the operator at a location remote from the furnace. Complete information The operator is constantly on hand with regard to the procedure, including the exact position of the bars and their loads to disposal. The rods can be driven in two ways, slow crystal pulling or quick to set, and facilities are provided to allow only one mode of operation at a time can be carried out.

It can be seen that the stated objectives, some of which are apparent from the foregoing description, are achieved v / ground, and design changes may be made which are within the scope of the invention.

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Claims (18)

- 25 claims 1. Pressure and temperature controlled device, especially for pulling crystals and the like, characterized by: a) a pressure-tight housing in which there is a working chamber, b) upper and lower bars, which are calibrated by pressure-tight bushings extend into the working chamber and are both rotatable and displaceable in the working chamber, c) upper and lower rod rotary and sliding drives, which are arranged outside the pressure-tight housing, wherein the displacement drive has devices to selectively move the rods slowly or quickly during crystal pulling to drive when adjusting, d) Position fixing devices for the rods that drive the displacement drive are assigned to continuously display the exact position of the bars within the working chamber, e) heaters positioned opposite the rods to remove a load from one or both of the rods Rods is carried to heat within the working chamber, and f) Viewing window for visual monitoring of the load. 2. Device according to claim 1, characterized in that the pressure-tight housing has a hinged access opening cover which is equipped with a pressure relief valve is. 3. Device according to claim 1, characterized in that the pressure-tight housing has an external cooling device in the form of of coils in which a coolant circulates. 1 09852/1649 - 4. Device according to claim 1, characterized in that the pressure tight housing has a self-resetting pressure relief valve and a solenoid operated relief valve up / down 5. The device according to claim 1, characterized in that the upper rod has medium channels in which a coolant can circulate. 6. Device according to claim 1, characterized in that theB the lower rod forms a housing for thermocouple wires and a thermocouple inside the rod at the top End is arranged. 7. Device according to claim 1, characterized in that the displacement drive assigned to each rod has the following parts: (1) a vertical drive spindle in which the rod rotates, (2) a worm gear drive to drive this drive spindle, (3) a flexible shaft connected to the worm gear drive " (4) a motor that has a gearbox, a first coupling, a bevel gear and a second coupling with the flexible Shaft is connected, (5) a high-speed motor connected to the flexible bevel gear and the second coupling Shaft is connected, (6) a first clutch apply device, the actuators having, which are connected to a power source, which also provides the current for the motor with high Speed supplies, and via a switch that does so 109852/1649 that power is set up to either the first clutch apply device or fed to the engine at high speed, but not both at the same time, and (7) a second clutch apply device. 8. Device according to claim 7 _}, characterized in that the rod position fixing device has the following parts: (1) a shaft extension on the drive worm, (2) a magnet attached along the side of this shaft extension, M (3) a magnetic reed switch that can be operated by this magnet, (4) a resettable electromagnetic counter, and (5) Switching devices that operate the reed switch and the Connect counters, these switching devices such are designed so that the counter is actuated to record rotations of the shaft extension in terms of the exact linear distance of the end of the rod from a fixed reference point. 9 · Device according to claim 1, characterized in that the heater is a high frequency coil. 10. The apparatus of claim 1, wherein the heating means is a high frequency coil and in which a temperature monitoring and control device is provided, characterized by; (1) a light pipe, (2) a radiation pyrometer which is connected to this light pipe and is constructed in such a way that it DC voltage signals generated that are proportional 109852/1649 - 28 are to the received light, (3) an induction heating power source for the high frequency coil, (4) a pre-magnetizable choke to control the current input for the supply source, and (5) Spanmmgssignalververarbeitungeinrichtung to the To amplify voltage signals in order to make them the premagnetizable Feed choke, so that it controls the temperature when controlling the current input, which of the high frequency coil is developed. 11. The device according to claim 1, characterized in that the viewing window assembly is a tempered Pyrex window on v / eist, which is protected within the housing by an infrared reflecting window and which an outer rotatably mounted polarizer to control the intensity of the image transmitted through the window will discontinue. 12. The device according to claim 1, characterized by valve-controlled Gas inlets which extend through the housing of the viewing window and which are arranged in such a way that that entering gas against the window system of the viewing window is directed, thereby providing means to clean this window system. 13. Device according to claim 1, characterized by a television camera, which is located next to one of the windows of the viewing system, and a television receiver, which is from this pressure-tight housing is arranged remotely. 14 · Pressure and temperature controlled device for pulling Crystals or the like, characterized by: a) a pressure-tight housing in which there is a working chamber and which has a hinged access opening 109852/1649 cover that with pressure relief valve devices Is provided, b) an external cooling device for this pressure-tight housing, in which a coolant can circulate, c) upper and lower rods which extend through pressure-tight bushings into and into the working chamber are both rotatable and slidable, d) upper and lower rod rotation and displacement drive devices, which are arranged outside the pressure-tight housing, the displacement drive the following Has parts: (1) a vertical drive spindle in which the rod rotates, (2) a worm drive to operate the drive spindle, (3) a flexible shaft connected to the worm drive, (4) a motor that has a gearbox, a first clutch, a bevel gear and a second clutch with the flexible shaft is connected, (5) a high speed motor connected to the flexible shaft via the bevel gear and the second coupling is, (6) a first clutch engaging device which is an energizing device which is connected to a power source that is also used for the high speed motor is provided, namely via a switch which is designed such that current either the first clutch apply device or the high speed engine, but not both at the same time, and (7) a second clutch engagement device, 109852/1649 '30-2055321 e) Devices for determining the bar position, which are assigned to the displacement drive and are designed in this way, that they continuously indicate the exact position of the rods within the working chamber, and that of the following Parts have: (1) a shaft extension on the worm drive of the Rod drive, (2) a magnet attached along the side of this shaft extension, (3) a reed switch that can be operated by this magnet, (4) a reversible electromagnetic counter, and (5) Switching devices that connect this reed switch and the counter, these switching devices are designed such that they operate the counter so that it rotates the shaft extension registered in terms of the exact linear distance of the end of the rod from a fixed reference point, f) a high frequency heating coil positioned opposite the rods so as to avoid a load generated by or from both rods is carried to heat within the working chamber, whereby a temperature monitoring and -Control device is provided, which is assigned to the high-frequency coil and which has the following parts: (1) a light pipe, (2) a radiation pyrometer, which is connected to this light pipe and is designed in such a way, that this pyrometer generates DC voltage signals proportional to the light received, (3) an induction heating voltage source for the high frequency coil, 109352/1649 (4) a pre-magnetizable choke to control the Currents for the source of supply, and (5) voltage signal processing devices that support these Amplify voltage signals in order to apply them to the pre-magnetizable To transmit the choke, so that the choke, by controlling the current input, controls the temperature developed by the high frequency coil, g) Viewing windows for observing the load, which have at least one coated Pyrex window, which is protected within the housing by an infrared-reflecting window, this Pyrex window having an outer rotatably mounted polarizer in order to adjust the intensity of the image which is transmitted through the viewing window , h) valve controlled gas inlets extending through the housing the viewing device extend therethrough and the are arranged so that incoming gas is directed against the window system, and i) valve-controlled evacuation devices to create a vacuum inside the working chamber zn. 15 · Device according to claim 14, characterized in that the upper rod has channels for circulating coolant therethrough. 16. The device according to claim 14, characterized in that the lower rod as a housing for thermocouple leads and a thermocouple is used, which is arranged inside the rod at the upper end. 17 · Device according to claim 14, characterized by a Television camera arranged to monitor the working chamber within the housing and a television receiver, which is located away from the camera. 109852/1649 18. The device according to claim 14, characterized by a self-resetting pressure relief valve and a solenoid-controlled relief valve on the pressure-tight Casing. 19 · Device according to claim 14 »characterized in that the controls for the rod drive, the locking device for the rod position, the supply source for the high-frequency coil, the control for the gas inlet and the valve-controlled evacuation devices from the pressure-tight Housings are remotely located so that all operation within the working chamber is controlled in one place and can be monitored by the print seals. casing away. 20- device according to claim H, characterized in that the viewing device a first viewing window and. has an auxiliary viewing window, and that each Window has a coated Fjrexschcibe and an infra-red reflectierencies Window and one. Polarizer. 109852/1649