JPH0319315A - Heating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a heating device.

[Prior art and problems to be solved by the invention] Conventionally, in the manufacturing of semiconductor integrated circuits, it has been necessary to remove moisture after cleaning before coating in the photoresist coating process of semiconductor wafers, to remove solvent after coating, or to remove solvents after coating photoresist on semiconductor wafers. In the film exposure process, there is a baking process in which heat treatment is performed to improve the shape of the pattern after exposure, or in the development process to remove the cleaning solution after development. The heat treatment equipment shown in Figure 6 is used in this baking process. This heat treatment apparatus heats a semiconductor wafer W placed on the heat-generating plate 1 by enclosing a flat resistance wire 2 such as a nichrome wire in a circular heat-generating plate 1. However, in the heat treatment apparatus as described above, an uneven temperature distribution occurs depending on the arrangement of the resistance wire 2.

In order to uniformly heat the semiconductor wafer W, the heating plate 1 is made to have a very large heat capacity to make uneven temperature distribution uniform. However, in a heating device equipped with a heat generating plate 1 having a large heat capacity, on the other hand, the power consumption was large and it took a long time to heat the heat generating plate 1 to reach a predetermined temperature after power was turned on. Moreover, if you want to increase the heating temperature for processing, even if you change the power supply to the resistance wire 2, it will not respond instantly and it will take time, and if you want to lower the processing temperature, it will take a very long time to cool down. There was a drawback that uniform heating and quick response of temperature control were at odds with each other, and it was impossible to hope for a solution that would satisfy both.

In addition, the heat generating plate 1 with a large heat capacity is inevitably thick and heavy, for example, about 50 to 70 mm, making it difficult to apply to a multi-stage baking device, and from the standpoint of installation area, it is cost-effective. There was an economic disadvantage. The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a compact heating device that performs uniform heat treatment on objects to be treated, has excellent temperature control responsiveness, and is compact. ．． [Means for Solving the Problems] The heating device of the present invention cancels out the temperature distribution of the plurality of circular thin film resistance heating element layers having a temperature distribution, and maintains a uniform heat generation temperature. A laminate is provided in which resistive heating element layers are stacked with mutual phase angles and an insulating layer is sandwiched between them. [Operation] The heating device of the present invention has a conductive thin film resistance heating element formed in a circular shape, two electrodes are provided in the circle, and when electricity is applied, the current passes through the shortest distance in the thin film resistance heating element, so the current There is a difference in the height of the density. Alternatively, when a linear thin-film resistance heating element is mounted on a circular substrate, the linear distribution of the thin-film resistance heating element causes an uneven distribution of heat generation. In order to offset this, second, third, etc. thin film resistance heating elements are placed on the first circular thin film resistance heating element layer or the linearly formed thin film resistance heating element layer via a 1fA edge layer. The body layers are sequentially laminated with phase angles, so that the entire surface of the heating device has a uniform temperature distribution. Since a thin film resistance heating element is used, the thickness of the entire device is extremely thin, and even heating can be achieved without using a heating plate.The heat capacity of the entire device is small, and by changing the power supplied to the thin film resistance heating element, The temperature changes instantly to the desired temperature. [Example] An example in which the heating device of the present invention is applied to a heating device after resist coating for semiconductor integrated circuit IB construction will be described with reference to the drawings. As shown in the configuration diagram in Figure 1, the heating device is a circular flat plate-shaped electrical insulator with electrodes arranged around the circumference on a base 3 made of heat insulating material.
A thin film resistance heating element layer 5-1 to which -1 is attached is laminated, and a thin film resistance heating element layer 5-2 to which an electrode 4-2 is attached via an insulator layer 6-1 is provided thereon, Furthermore, the insulator layer 6-
A semiconductor wafer W, which is an object to be processed, is stacked with 1! Power is supplied from the source device if7, and the thin film resistance heating element layer 5
-1 and 5-2 heat up. Furthermore, the top layer that comes into direct contact with the object to be processed is $! The III body layer 6-2 is equipped with a temperature sensor 8, and this temperature sensor 8
The temperature control device 9 sends a control signal according to the detected temperature,
By controlling the power supply unit H7, each thin film resistance heating element layer 5-
Let *a be the power supplied to 1 and 5-2. The heating device is also equipped with a transport mechanism (not shown) for the semiconductor wafer W. For example, when the semiconductor wafer W is transported by a beam or a beam for transporting the semiconductor wafer W from the pre-processing device to the post-processing device in a square motion, Alternatively, when unloading, the semiconductor wafer W is moved up and down by penetrating the base 3, the thin film resistance heating element layers 5-1, 5-2, and the insulating layer 6-1, 6-2, and supporting the semiconductor wafer W by suction or the like. At least three bottles or the like are provided to be placed or raised on the device.

Here, each layer that forms the heating device will be explained. The thin film resistance heating element layer is made of metals such as chromium, nickel, platinum, tantalum, tungsten, tin, iron, lead, alumel, beryllium, antimony, indium, chromel, cobalt, strontium, rhodium 5 palladium, magnesium, molybdenum, lithium, rubicium, etc. In addition to carbon-based simple substances such as carbon black and graphite, conductive materials include alloys such as nichrome, stainless steel SOS, bronze and brass, polymer-based composite materials such as polymer-grafted carbon, and composite ceramic materials such as molybdenum silicide. Any material that can become a resistance heating element when energized can be suitably used.

As shown in Figure 2, the thin film resistance heating element M5 is made of ceramic such as alumina by thermal spraying or detonation of the above material.
The electrode 40 may be attached by forming a film uniformly over the entire surface of the body layer 8a, or the resistive heating element layer formed on the base material 10 or the insulating layer may be exposed and developed as shown in FIG. The desired linear resistance heating element Jil50 may be formed by using the following method. The film thickness of these thin film resistance heating element layers is, for example, 0. ↓ to 100 μm, preferably 1 to 10 μm.

The insulating layer provided through the thin-film resistance heating layer can be made of any material that has excellent electrical insulation and good thermal conductivity, that is, it easily emits far infrared rays, such as alumina, zirconia, etc. , silicon carbide, diamond, and other ceramics, as well as heat-resistant plastics such as Teflon, can also be used. The film thickness varies depending on the power used, but it is 10
10 to 100 when using a commercial power supply of 0 to 20 ov
0 μm is applied.

In addition, a base made of Teflon or the like and serving as a heat insulating material is provided at the bottom layer where these thin film resistance heating element layers and super edge body layers are provided, so that the heat generated from the thin film resistance heating element layer is diffused downward. It is used to heat the object to be processed. A method for achieving uniform heating in a heating device with such a structure will be explained. In the thin film resistance heating layer 5 shown in FIG.
0, the current passes through the shortest distance in the thin-film resistance heating layer 5, so the current density is high in the region 1 where the distance between the electrodes is short, and the current density is high in the center part 12 of the thin-film resistance heating layer 5. Region 11 where the current density is low and therefore the amount of heat generated is high.
The current density is high in the central part 12 where the current density is low, and the current density is low in the central part 12 where the current density is low. Therefore, as shown in FIG. 4, the attached electrode 40 of the second thin film resistance heating element layer 5 is located at a position rotated by 90' with respect to the position of the attached electrode 40 of the first thin film resistance heating element layer 5. By stacking the layers, uneven temperature distribution is canceled out and a uniform temperature distribution is achieved. Furthermore, in the case of a device having a linear wi film resistance heating element layer as shown in FIG. 3, non-uniform temperature distribution occurs in a linear manner. Non-uniformity in temperature distribution can be alleviated by stacking and providing the attached electrode 4l at a position rotated 90a relative to the electrode 41 of the second thin film resistance heating element layer 50.

In this case, 21 thin film resistance heating element layers were provided. When stacking three or four layers in sequence, the electrodes should be placed at equal phase angles so that the electrode positions are point symmetrical. Although the insulator layer is omitted in the above description, the thin film resistance heating element layers are laminated with an insulator layer in between.

The thin film resistance heating element layer formed in this way has a thickness of 0.1 to 1. O Oμm Insulator layer also 10-100μm
Even if it is a laminate of several layers, the thickness of the heating portion of the device itself is several III1.

Further, if necessary, a cooling device or the like may be provided below the heating device for cooling the device by jetting out gas or liquid fluid.

The operation of the heating device configured as above after resist coating will be explained. First, before placing the 'f-conductor wafer W on the uppermost insulator layer 6-2, the thin film resistance heating element layers 5-1, 5-2 are
Power is supplied from the power supply device 7 to generate heat so that the temperature reaches the desired heat treatment temperature. Then, the pins are made to protrude from the heating device, and after supporting the semiconductor wafer W transported by a beam or the like by suction or the like, the pins are lowered and the suction is released when the semiconductor wafer W is placed on the insulator M3. Thin film resistance heating element layer 5-1
, 5-2 at a predetermined temperature for a predetermined time (for example, 80°C initially).
15 seconds, then 100°C for 15 seconds, then 120°C for 15 seconds) to increase the supplied current from the power supply 7 to heat continuously. Next, if you want to lower the temperature to 100 degrees Celsius, for example, turn off the power supply, activate the cooling device, and quickly cool down. When the temperature sensor 8 detects 100 degrees Celsius, the power supply 7 will turn on the predetermined current again. It is sufficient to supply and heat at 100° C. IS seconds.

In heating performed in this way, the amount of heat from the thin film resistance heating element layer is very small because the thin film resistance heating element layer and the sewn edge layer are formed very thin, and the amount of heat escaping from the sides is very small. Since a heat insulating material is provided at the bottom of the layer as a base, almost all of the heat from the thin film resistance heating element layer is consumed for heating and is used efficiently. In addition, since the heat capacity of the heating device itself is extremely small, the time from when power is turned on to when the processing temperature is reached can be shortened. When cooling, it cools down immediately, so there is no delay in processing. Further, in a multi-stage device that performs multi-stage baking by layering heating devices as described above, heating devices can be placed in multiple layers. The above description is an example in which the heating device of the present invention is used as a heat treatment device after applying a resist, and the present invention is not limited to this, and the heating device is used for heat treatment after applying a developer, ashing, etching, CvD, etc. It can be applied to a process of heating a semiconductor substrate such as sputtering.

[Effects of the Invention] As is clear from the above description, the heating device of the present invention is uniform and has a very small heat capacity, so that it can be used for heat treatment that involves temperature changes or for heating after cooling down. It also enables responsive temperature control with very little waiting time for processing. In addition, a highly reliable, thin and compact heating device can be obtained.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the heating device of the present invention, Fig. 2 is a block diagram of an embodiment of the main part of the embodiment shown in Fig. 1, and Fig. 3 is shown in Fig. l. 4 is an explanatory diagram for explaining the embodiment shown in FIG. 2, and FIG. 5 is an explanatory diagram for explaining the embodiment shown in FIG. 3. figure,
FIG. 6 is a configuration diagram showing a conventional heating device.

Claims (1)

[Claims] The plurality of thin film resistance heating element layers are held at mutual phase angles and the insulating layer is sandwiched between the plurality of thin film resistance heating element layers so as to offset the temperature distribution of the plurality of circular thin film resistance heating element layers having a temperature distribution and maintain a uniform heat generation temperature. A heating device characterized in that it is provided with a laminate made of laminates.