JP2000040666A - Semiconductor heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor heat treatment device with which the temperature of heat treatment can be constantly maintained both in heightwise direction and horizontal direction of a reaction tube. SOLUTION: A quartz jig 70, where a plurality of wafers are mounted, is provided inside a reaction tube 10, the inside of the reaction tube is heated up by a heater device 20 containing a plurality of heaters arranged on the circumference of the reaction tube. A temperature control part feeds power through heater terminals 21 to 25 corresponding to heaters having different mounting heights. The circumferential part 20a of the heater terminals of each heater is separated from other part 20b, and power can be fed individually to each part of the separated heater. The temperature control part feeds power individually to each part of the separated heaters, and the above-mentioned power can be controlled in such a manner that the temperature inside the reaction tube becomes constant in heightwise direction and horizontal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical reaction tube in which a quartz jig on which a large number of wafers are mounted is installed through a lower opening for heat treatment of the wafer, and a periphery of the reaction tube. Heater devices each having a heater at a different height for heating the inside of the reaction tube, and a plurality of heater devices connected to each heater of the heater device for supplying power independently to each heater. The present invention relates to a semiconductor heat treatment apparatus having a heater terminal and a temperature control unit that supplies desired power to each heater via the plurality of heater terminals to control the temperature inside the reaction tube to be constant.

[0002]

2. Description of the Related Art FIG. 4A is a schematic view showing a main part of a conventional vertical semiconductor heat treatment apparatus, and FIG.
4A is a front view, and FIG. 4C is a cross-sectional view as viewed from the right side of FIG. A cylindrical reaction tube 50 is arranged inside, and a heater device 60 for heating the inside of the reaction tube 50 is arranged around the reaction tube 50. In this example, the upper part of the reaction tube 50 is sealed, and the lower part is an opening. From the lower opening of the reaction tube 50, a quartz jig (a so-called boat) on which a large number of wafers are mounted is set up for heat treatment of the wafers. FIG.
In the case of (1), if the temperature for the heat treatment of the wafer is different depending on the location of the reaction tube 50, there is a disadvantage that the film is thickened at a high temperature and thinned at a low temperature. Such non-uniformity of film formation on a wafer is a factor that causes an important problem of lowering the yield in producing semiconductor devices.

Therefore, in the heater device 60, a plurality of heaters surrounding the reaction tube 50 are arranged at different heights, and the heater devices 60 corresponding to the respective heights are arranged.
The heater terminals 61, 62,... The reason why the plurality of heaters are arranged at different heights is to prevent the temperature inside the reaction tube 50 from being different depending on the height. That is,
A heater connected to the heater terminal 61;
, The CU zone between the heater terminals 62 and 63, the CL zone between the heater terminals 63 and 64, and the heater terminals 64 and
The temperature is controlled so as to be divided into 65 zones as L zones.
Therefore, in general, the temperature of the upper part of the reaction tube 50 tends to be higher than that of the lower part. However, this tendency can be eliminated by the configuration shown in FIG. .

[0004]

In the conventional vertical semiconductor heat treatment apparatus described above, the heater device 60 has a plurality of heaters arranged at different heights, and the heaters of each height are connected to the heater terminals 61 and. Since the temperature is controlled independently through 62, 65, and 65, the temperature inside the reaction tube hardly causes a difference depending on the height. However, when observing the same plane (the same substrate to be processed) at a predetermined height, there is a problem that the temperature differs depending on the location. The cause of this temperature difference is that the heater terminals 61 and
It was found that the main factors were the heat conduction from 62, 65, and 65 to the outside and the temperature decrease due to the heat conduction from the wafer holding portion of the quartz jig.

That is, the cause of the temperature drop will be described with reference to FIG. Each of the large number of wafers 90 is horizontally mounted on a quartz jig 70, and the quartz jig 70
The outer edges thereof are held by the holding portions 71, 72, 73, 74. The quartz jig 70 on which a large number of wafers are mounted is inserted from the lower opening of the reaction tube 50 for heat treatment of the wafer, and is internally inserted through the lower opening of the reaction tube 50 as shown in FIG. And heat treatment is performed. At this time, heat escapes through the heater terminals 61, 62,..., 65 and the holding portions 71, 72, 73, 74 of the quartz jig 70, and a portion near the wafer 90, particularly the heater terminals 61, 62, The temperature in the rear region of the reaction tube 50 close to 65 is reduced. Therefore, there is a problem in that the film located on the front region of the reaction tube 50 becomes thick while the film located on the rear region becomes thin.

In view of the above problems, an object of the present invention is to provide a semiconductor heat treatment apparatus capable of maintaining a constant heat treatment temperature in both the height direction and the horizontal direction in a reaction tube.

[0007]

In order to solve the above-mentioned problems, the present invention provides a tube in which a quartz jig on which a number of wafers are mounted is installed through a lower opening for heat treatment of wafers. -Shaped reaction tube, a heater device arranged around the reaction tube and having heaters at different heights for heating the inside of the reaction tube, and connected to each heater of the heater device, A plurality of heater terminals for independently supplying electric power, and a desired electric power is supplied to each heater via the plurality of heater terminals to control the temperature inside the reaction tube to be constant. In a semiconductor heat treatment apparatus having a temperature control unit, each of the heaters includes:
At least a peripheral portion of a heater terminal connected to the heater is separated from other portions, and the heater terminal is configured to be able to individually supply power to each separated portion,
The temperature control means individually supplies power to each of the separated heaters via the heater terminal capable of individually supplying power to each of the separated heaters, and performs the reaction. The power supply is controlled so that the temperature inside the tube is constant both in the height direction and in the horizontal direction.

[0008] With this configuration, the temperature control section heats the peripheral portion of the heater terminal of the separated heater to a higher temperature than the other portions, thereby transferring heat from the heater terminal to the outside. Thereby, the temperature drop near the heater terminal inside the reaction tube, which normally tends to be low, is compensated, and the temperature inside the reaction tube is controlled so as to be constant in both the height direction and the horizontal direction.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1A is a schematic view showing a main part of a semiconductor heat treatment apparatus according to a first embodiment of the present invention, and FIG. 1B is a front view of the semiconductor heat treatment apparatus of FIG. 1 (c) is a cross-sectional view of the semiconductor heat treatment apparatus of FIG. 1 (a) viewed from the right side, and FIG. 2 shows that a wafer mounted on a quartz jig is inserted through an opening below a reaction tube of FIG. 1 (a). It is an expanded sectional view which shows the place installed in. In the vertical semiconductor heat treatment apparatus shown in FIG.
A cylindrical reaction tube 10 in which a quartz jig on which a number of wafers are mounted is installed through a lower opening for heat treatment of the wafer is disposed, and around the reaction tube 10, the inside of the reaction tube 10 is disposed. A heater device 20 for heating the heater is disposed. In this example, the upper part of the reaction tube 10 is sealed and the lower part is an opening, and a quartz jig (a so-called boat) on which a large number of wafers are mounted is opened at the lower part of the reaction tube 10. From the inside of the reaction tube 10.

In the heater device 20, a plurality of heaters surrounding the reaction tube 10 are arranged at different heights, and heater terminals 21 and 22 are respectively provided at the rear of the heater device 20 in correspondence with the heaters of each height. , To 25 are arranged. Each heater is divided into a first portion 20a, which is a peripheral portion of the heater terminals 21, 22, to 25, and a second portion 20b, which is another portion, with a separation line 27 as a boundary. Also, the heater terminals 21, 22, to 25
Are separated so that power can be separately supplied to these first and second portions 20a and 20b.

The reason why the plurality of heaters are arranged at different heights and the inside of the reaction tube 10 is divided into a U zone, a CU zone, a CL zone, and an L zone in the height direction to control the temperature is as follows. The temperature control unit (not shown) controls the temperature inside the reaction tube 10 so as not to cause a difference depending on the height as in the prior art, and the same heater is used for the first and second portions 20a, 20a. The reason why the power can be separately supplied to the power supply section 20b is that the temperature control section controls so as to reduce the temperature difference in the horizontal direction. That is, FIG.
As shown in FIG.
The quartz jig 70 held by 73 and 74 is
When installed and heat-treated from the opening below the
In the height direction, there is no difference in temperature because the temperature is controlled by being divided into a plurality of zones.
The temperature decreases in the rear region of the reaction tube 10 near 1, 22, to 25.

The reason is that, in the case of FIG.
Heat is released by the holding portions 71, 72, 73, 74 in addition to the heat being released by the holding terminals 71, 72, 73, 74, so that the heater terminals 21, 22,.
The rear part close to 5 has a lower temperature than the other front parts. Therefore, the temperature control unit is, for example, the heater terminal 21
In, the portion corresponding to the first portion 20a is heated to a higher temperature than the portion corresponding to the second portion 20b,
The temperature is balanced so that the rear area in the reaction tube 10 does not have a lower temperature than the front area.

As described above, by keeping the temperature in the reaction tube 10 in equilibrium, the temperature with respect to the wafer 90 becomes constant over the entirety, and the film is formed with a constant thickness. The yield of manufacturing semiconductor devices using wafers will be improved. The results of the comparison by experiment are as shown in the following table (TOP is the upper part in the reaction tube 10, CTR is the central part, BTM is the lower part).

(1) In case of POLY Si 3000Å: Uniformity of film thickness in wafer (%) TOP CTR BTM Conventional ± 1.0 ± 0.8 ± 2.5 Present invention ± 0.8 ± 0.7 ± 1.3 (2) In the case of wet oxidation of 30 °: uniformity of the film thickness in the wafer σ (Å) TOP CTR BTM Conventional 0.3 0.4 0.5 Present invention 0.2 0.3 0.3

FIG. 3 is an enlarged sectional view showing a main part of a second embodiment of the semiconductor heat treatment apparatus according to the present invention, in which a wafer mounted on a quartz jig is inserted through an opening below a reaction tube. Shows where it was installed. In the semiconductor heat treatment apparatus of FIG. 3, the heater device 20 and the heater terminals 21, 22,.
, The heater device 30 and the heater terminals 31, 3
2, to 35 are provided. In the semiconductor heat treatment apparatus of FIG. 3, each heater of the heater device 30 is a peripheral portion of the heater terminals 31, 32, to 35, a first portion 30 a sandwiched between two separation lines 37, and a quartz. The second portion 30b, which faces the holding portions 71, 74 of the jig 70 and is interposed between the separation lines 37 and 38, and the third portion 30c which is interposed between the separation lines 37 and 39, and the separation lines 38 and 39 It is divided into the other fourth portion 30d sandwiched therebetween.

The above-mentioned heater terminals 31, 32,.
35 is separated so that power can be separately supplied to the first, second, third, and fourth portions 30a, 30b, 30c, and 30d of these heaters. Therefore, for example, the temperature control unit may control the fourth portion 3 in the heater terminal 31.
0d, the second and third portions 30b,
The portion corresponding to 30c is heated to a higher temperature, and the second and third portions are heated.
By heating the portion corresponding to the first portion 30a to a higher temperature than the portions corresponding to the portions 30b and 30c, the temperature of the entire region in the reaction tube 10 is kept in equilibrium. Thus, the semiconductor heat treatment apparatus of FIG. 3 can finely control the temperature distribution inside the reaction tube 10 and can set the temperature distribution more uniformly than the semiconductor heat treatment apparatus of FIG. 2, and can form a film with a more uniform thickness. Can be run,
As a result, the yield of manufacturing semiconductor devices using the wafer can be further improved.

[0016]

As described in detail above, the semiconductor heat treatment apparatus according to the present invention has a cylindrical jig in which a large number of wafers are mounted. -Shaped reaction tube, a heater device arranged around the reaction tube and having heaters at different heights for heating the inside of the reaction tube, and connected to each heater of the heater device, A plurality of heater terminals for independently supplying electric power, and a desired electric power is supplied to each heater via the plurality of heater terminals to control the temperature inside the reaction tube to be constant. In the semiconductor heat treatment apparatus having temperature control means, at least each heater has a peripheral portion of a heater terminal connected to the heater separated from other portions, and the heater terminal is connected to each of the separated portions. Each of the separated heaters can be individually supplied with electric power, and the temperature control means can be individually supplied with electric power to each of the separated heaters via the heater terminals. The temperature controller controls the supply power so that the temperature inside the reaction tube is constant both in the height direction and in the horizontal direction. By heating the peripheral part of the heater terminal to a higher temperature than the other parts, the temperature drop near the heater terminal inside the reaction tube, where the temperature tends to be lower due to the conduction of heat from the heater terminal to the outside, is usually reduced. Compensation can be performed to control the temperature inside the reaction tube to be constant both in the height direction and in the horizontal direction, and the film formation of the wafer in the reaction tube is also performed at a constant thickness. Half used There is an effect that it is possible to improve the yield of production of the body device.

[Brief description of the drawings]

FIG. 1A is a schematic view showing a main part of a first embodiment of a semiconductor heat treatment apparatus according to the present invention.
(B) is a front view of the semiconductor heat treatment apparatus of (a).
FIG. 3C is a cross-sectional view of the semiconductor heat treatment apparatus of FIG.

FIG. 2 is an enlarged cross-sectional view showing a state where a wafer mounted on a quartz jig is installed inside an opening below a reaction tube in FIG. 1A.

FIG. 3 is an enlarged cross-sectional view showing a state where a wafer mounted on a quartz jig is installed inside an opening below a reaction tube of a semiconductor heat treatment apparatus according to a second embodiment.

FIG. 4 is a diagram showing a conventional example of a semiconductor heat treatment apparatus.

5 is an enlarged cross-sectional view showing a state where a wafer mounted on a quartz jig is installed inside the reaction tube of FIG. 4 from an opening below the reaction tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reaction tube 20, 30 Heater device 21, 22, ..., 25 Heater terminal 20a, 30a First part 20b, 30b Second part 27, 37, 38, 39 Separation line 30c Third part 30d Fourth part 70 Quartz Jig 71, 72, 73, 74 Holder 90 Wafer

Claims (1)

[Claims] A quartz jig on which a number of wafers are mounted is provided with a tubular reaction tube installed therein through a lower opening for heat treatment of the wafer, and a quartz jig is disposed around the reaction tube. A heater device having heaters for heating the inside at different heights, a plurality of heater terminals connected to each heater of the heater device for supplying power independently to each heater; Through the heater terminals
A temperature control means for supplying desired electric power to each heater to control the temperature inside the reaction tube to be constant, wherein each of the heaters is at least a heater connected to the heater. A peripheral portion of the terminal is separated from other portions; the heater terminal is configured to be able to individually supply power to each of the separated portions; and the temperature control unit is configured to control each of the separated portions of the heater. Power is individually supplied to each portion of the separated heater via the heater terminal which can be individually supplied with power, so that the temperature inside the reaction tube is increased both in the height direction and in the horizontal direction. A semiconductor heat treatment apparatus, wherein the supply power is controlled so as to be constant.