JPS6218032Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a boat loader that inserts and pulls out objects to be processed, such as wafers and substrates, into and out of a heat treatment furnace that performs operations such as diffusion and vapor phase growth.

Conventionally, this type of boat loader is installed on the back of the heat treatment furnace or on a clean bench placed in series with the heat treatment furnace, and moves forward and backward by driving a boat made of quartz or the like that holds the object to be treated by the boat loader body. In most cases, the boat's stopping position, moving speed, stopping time, etc. are automatically controlled according to a program. has been done.

On the other hand, heat treatment furnaces use temperature control,
Gas system control, etc. is automated individually or comprehensively. Furthermore, recently, auto-profiles have been developed that detect the temperature inside the furnace core tube and feed it back to the auto-profile amplifier to maintain the soaking temperature and soaking zone (heat-soaking length) inside the furnace core tube at the required values. By adopting this system, temperature control within the furnace core tube of the heat treatment furnace has been significantly streamlined.

However, in order to use this auto-profile system, it is necessary to place three or more pairs of thermocouples for temperature detection inside the heat treatment furnace according to the required soaking zone, and to connect these to the auto-profile system. becomes. For this purpose, the following various means have been conventionally employed.

(1) As shown in Fig. 1, a thermocouple protection tube 6 housing thermocouples 3, 4, and 5 for temperature measurement at each part is inserted into the inlet 2 of the furnace core tube 1, and each thermocouple is The measured data is stored in the auto profile system, and temperature control is performed based on this stored data. In the figure, 7 is a gas introduction part.

(2) As shown in Figure 2, the furnace core tube 11 and heater 1
2 (if using soaking tube 13, heat soaking tube 1
A thermocouple protection tube 15 housing three pairs of thermocouples 14 is disposed in a portion close to the furnace core tube 11 (between 3 and 3).

(3) As shown in FIG. 3, a thermocouple protection tube 25 housing three pairs of thermocouples 22, 23, and 24 is arranged close to the inner wall of the furnace core tube 21, and the thermocouple protection tube 25 is attached to the furnace core tube 21 via a ball joint 26 (in some cases, it may be directly fixed without using a ball joint). In the figure, 27 is a gas introduction part.

(4) A thermocouple is placed on the boat driven by the boat loader main body, and after the workpiece held on the boat is positioned at the heated position in the furnace core tube, the thermocouple is connected to the autoprofile amplifier. Connect the compensation lead.

However, each of these had the following drawbacks.

In the case of (1), only one state can be stored for a single temperature point, and the autoprofile system's response to changes in gas flow rate, heat capacity changes due to the inserted boat, workpiece holder, and amount of workpiece, etc. Sexuality is impaired.

In the case of (2), the difference between the actual temperature inside the furnace core tube and the temperature detected by the thermocouple becomes so large that it cannot be ignored in practical terms, resulting in extremely poor responsiveness as an autoprofile system.

In the case of (3), since the core tube is equipped with a thermocouple protection tube, the structure is complicated and expensive, and there is a high possibility of breakage. In addition, it is impossible to rotate the furnace core tube at appropriate times to prevent deformation because the thermocouple protection tube interferes with the object to be treated and the boat, which inevitably shortens the life of the core tube. Furthermore, since the thermocouple protection tube protrudes into the furnace core tube, the usable furnace core tube joint area is reduced, and in order to process the same size of workpiece, the furnace core tube is larger than the conventional furnace core tube. A cross-sectional one is required, which is not preferable.

In the case of (4), the thermocouple and compensation conductor must be connected and disconnected each time heat treatment is performed, which is time-consuming. Furthermore, temperature changes at the connection point between the thermocouple and the compensation conductor lead to a large temperature detection error, resulting in deterioration of the accuracy of the auto profile system. For this reason,
The above-mentioned connection points require heat insulation treatment to prevent heat radiation from the inlet of the furnace core tube, but it is quite troublesome to connect and disconnect the connection points that have been subjected to such heat insulation treatment.

The purpose of this invention is to solve the various problems mentioned above, and to provide an easy-to-operate boat loader that can extend the life of the furnace core tube and control the temperature inside the furnace core tube with high precision. The purpose is

Next, an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a perspective view showing an embodiment of the boat loader according to the present invention, and FIG. 5 is a schematic diagram of an autoprofile system that controls the temperature in the furnace core tube that processes the workpiece operated by this boat loader. in,
In the figure, 31 is the boat loader main body, 32 is a boat,
33 is a furnace core tube, 34 is a soaking tube, 35, 36, 37
38 is a heater, 38 is a power supply control unit, and 39 is an auto profile amplifier (detection member).

The boat loader main body 31 includes a frame 40, a feed screw 41 rotatably supported by the frame 40, and an arm 42 that is screwed onto the feed screw 41 and is movable in the axial direction of the feed screw 41. It consists of a drive source (not shown) that rotates the feed screw 41.

The boat 32 includes a quartz tube 43 and a boat support section 44 and a workpiece support member 45 fixed to the quartz tube 43, respectively.
is fixed to the tip of the arm 42. Quartz tube 4
Three pairs of thermocouples 46 are inserted within the thermocouple.

The workpiece 60 is held on the workpiece support member 45 and is driven via the arm 42 by rotating the feed screw 41 to move forward in the direction of arrow A and to be inserted into the furnace core tube 33. 32, it is positioned at a predetermined position on the furnace core tube 33, and in that state, it is heated by the heaters 35, 36, and 37 via the soaking tube 34 and the furnace core tube 33, and processes such as diffusion are performed.
The processed object 60 is taken out by rotating the feed screw 41 in the opposite direction to that described above and pulling out the boat 32 in the direction of arrow A'.

On the other hand, the soaking tube 34 and each heater 35, 36, 37
Thermocouples 47, 48, and 49 are arranged between them, and these are connected to the auto profile amplifier 39.
It is connected to connection parts 50, 51, and 52 of.

In the processing object processing apparatus having such a configuration,
In the present invention, a first junction box 53 is attached to the boat 32 in the vicinity of the connection with the arm 42, and a second junction box 54 is attached to the boat loader main body 31. Each junction box 53, 54 is connected to the furnace core tube 3.
3. It has a function of removing the influence of heat radiation from the heat treatment furnace consisting of the soaking tube 34 and heaters 35, 36, and 37. A mechanism for detecting radiant heat and correcting it may be built into the box. The thermocouple 46 is connected to the junction box 53, the connections 55, 56, 57 of the auto profile amplifier 39 are connected to the junction box 54, and the junction boxes 53, 54 are connected to the three pairs of compensation conductors 5.
8. The compensating conductor 58 is coil-shaped and is guided by a guide member 59 provided on the boat loader main body 31 so that it can expand and contract in the directions of arrows A and A' when the boat 32 moves forward and backward, and can move together with the boat 32. .

The auto profile amplifier 39 receives the set value in the temperature setting section 39A of the auto profile amplifier 39, the measured value of the thermocouple 46, and the thermocouples 47, 4.
8 and 49, and set the output section 39B so that the actual temperature inside the furnace core tube 33 becomes equal to the set value.
The power supply control section 38 is controlled by sending a signal from the power supply control section 38.

As described above, according to the present invention, it is possible to achieve various effects as described below.

1 A thermocouple that measures the temperature inside the furnace core tube is installed on the boat, and since there are no obstacles inside the furnace core tube, the furnace core tube can be rotated by a predetermined amount at appropriate times to extend the life of the furnace core tube. It is possible to reduce the amount of heat used in the furnace, and it is also possible to effectively use the inside of the furnace core tube.

2. Easy operation because there is no need to connect and disconnect the thermocouple that measures the temperature inside the furnace core tube and the compensating lead each time during heat treatment (because the compensating lead is flexible and can be moved with the boat) be converted into

3. Because the temperature inside the furnace core tube can be directly measured and each junction box has the function of removing the influence of radiant heat from the heat treatment furnace, it is possible to control the temperature inside the furnace core tube with high precision. .

In the above description, an example has been described in which an auto-profile system is applied to a heat treatment furnace, but the present invention can also be applied to record processing temperatures in a heat-treatment furnace that does not have an auto-profile system.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of various arrangement examples of thermocouples for measuring heat treatment temperature, Figure 4 is a perspective view showing an embodiment of a boat loader according to the present invention, and Figure 5 is an illustration of the boat loader operated by the boat loader. This is a schematic diagram of an auto-profile system of a heat treatment furnace that heats a workpiece. In the figure, 31 is a boat loader main body, 32 is a boat, 33 is a furnace core tube, 35, 36, 37 are heaters,
38 is a power supply control unit, 39 is an auto profile amplifier (detection means), 46 is a thermocouple (temperature detection element), 53 and 54 are junction boxes, 5
8 is a compensation conducting wire (relay conducting wire), and 60 is an object to be processed.

Claims (1)

[Scope of utility model registration request] A boat is fixedly supported by a boat support section through the tube, the boat being composed of a tube and a workpiece support member fixed to the pipe, and the workpiece is held on the workpiece support member to support the boat. The boat is inserted into and pulled out of the heat treatment furnace by being driven forward and backward by the drive device of the boat loader main body, and the temperature inside the heat treatment furnace is detected and the temperature information is sent to the temperature measurement circuit. In a boat loader in which a plurality of temperature detection elements to be sent out are provided at different positions within the tube, first and second junction boxes having a function of removing the influence of heat radiation from the heat treatment furnace are installed in the boat support section. Temperature detection elements are attached to the boat loader main body and near the joint with the arm to which the tube is fixed, and are provided at different positions within the tube, and are connected to the first junction box, and both junction boxes are connected to the first junction box. is connected to each of the plurality of flexible temperature detection elements by corresponding compensation conductive wires, and the temperature measurement circuit is further connected to the second junction box.