JP2756444B2 - Heating equipment - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to a heating device.

(Prior Art) In general, a heating apparatus is used in a heat treatment process of an object to be processed, for example, a heat treatment process of a semiconductor wafer or the like in semiconductor device manufacturing. For example, when a fine circuit pattern is transferred to a semiconductor wafer, a photolithography technique is used. In this photolithography process, a heating device is used, for example, for heating a semiconductor wafer coated with a photoresist.

In such a heating device, for example, a heating device using a hot plate having a resistance heater as a heat source, in order to prevent the ambient temperature from rising due to heat from the heat source, a heat insulating member is provided so as to surround the hot plate periphery. In many cases, a housing is provided so as to cover the periphery of the heat insulating member.

(Problems to be Solved by the Invention) However, in the above-described conventional heating device, when the heating temperature is increased and the heat treatment is performed at a high temperature, for example, 250 to 350 ° C., the ambient temperature (the temperature of the outer cover) becomes, for example, 50 ℃
There is a problem that the temperature rises as described above, adversely affects the temperature control function of an adjacent device, and there is a risk of burns when an operator comes in contact with the device.

The present invention has been made in view of such a conventional situation. Even when the heating temperature is increased and the heat treatment is performed at a high temperature, an increase in the ambient temperature can be suppressed as compared with the related art. An object of the present invention is to provide a heating device capable of reducing the influence on the temperature control function of the device and improving safety.

[Means for Solving the Problems] That is, according to the present invention, a heat source for heating an object to be processed, a heat insulating member provided so as to surround the heat source, and a periphery of the heat insulating member are provided. In a heating device having a housing provided so as to cover, a low-temperature portion gas flow path mainly passing through a low-temperature portion between the outside of the heat insulating member and the housing, and a high temperature portion mainly near the heat source inside the heat insulating member. , And at least two gas passages of a high temperature part gas passage passing therethrough are provided.

Further, the invention according to claim 2 encloses a heating chamber for heating the object to be processed, a first discharge chamber provided above the heating chamber and discharging the atmosphere in the heating chamber, and surrounding the first discharge chamber. And a second discharge chamber passing through the first discharge chamber and a second discharge path passing through the second discharge chamber. It is characterized by being provided.

According to a third aspect of the present invention, in the heating device according to the second aspect, an exhaust direction from the heating chamber to the first exhaust chamber is upward, and the second exhaust chamber is the first exhaust chamber. It is characterized in that it is configured to take in outside air from above the chamber and exhaust it downward.

(Function) In the heating device of the present invention, a low-temperature portion between the outside of the heat insulating member and the housing can be cooled by the flow of a gas that is not heated by the high-temperature portion near the heat source, for example, the flow of clean air, thereby suppressing an increase in ambient temperature. can do.

(Embodiment) An embodiment in which the heating apparatus of the present invention is applied to a baking apparatus used for baking a semiconductor wafer coated with a photoresist will be described below with reference to the drawings.

As shown in FIG. 1, a housing 1 accommodates a semiconductor wafer 4 as an object to be processed by combining an upper unit 2 constituting an upper half and a lower unit 3 constituting a lower half. The airtight processing chamber 5 is formed. The upper unit 2 and the lower unit 3
Is configured to move relatively up and down by a lifting device (not shown) to form an opening through which the semiconductor wafer 4 can be loaded and unloaded.

In the lower unit 3, a hot plate 6 is provided, the surface of which is made of, for example, a substantially disk-shaped aluminum plate or the like which has been subjected to hard anodizing, and on which a semiconductor wafer 4 can be mounted. . The heating plate 6 is heated to a predetermined temperature, for example, 20 mm by a heating means (not shown) such as a resistance heater.
It is configured so that it can be set to a predetermined temperature of about 0 to 350 ° C.
The hot plate 6 is configured to be able to move up and down by a lifting device (not shown). By lowering the hot plate 6, a plurality of, for example, three pins 7 provided so as to penetrate the hot plate 6 are projected onto the hot plate 6, and the semiconductor wafer 4 can be supported by these pins 7. Have been.

A heat insulating material 8 is provided around the hot plate 6.
Outside the heat insulating material 8, a square pipe-shaped exhaust duct 9 connected to an exhaust device (not shown) is provided. A vent 10 is provided in the upper part of the exhaust duct 9 so as to form a communication part with the upper unit 2.
Further, a lower exhaust pipe 11 is provided at a location of the heat insulating material 8, and the lower exhaust pipe 11 is also provided with a connection port 12 so as to form a connection portion with the upper unit 2.

On the other hand, the upper unit 2 is provided with a lower plate 20 so as to face the semiconductor wafer 4. The lower plate 20 is provided with a plurality of exhaust ports 21, and the vapor or the like generated from the resist applied to the semiconductor wafer 4 is led out of these exhaust ports 21 to a space 22 formed above the lower plate 20. Is done. In the space 22, the connection port 12 described above is provided.
The upper exhaust pipe 23 connected to the lower exhaust pipe 11 of the lower unit 3 is connected through the lower exhaust pipe 11, and steam and the like drawn into the space 22 are exhausted from the upper exhaust pipe 23 through the lower exhaust pipe 11. It is configured as follows.

Above the space 22 of the upper unit 2, a heat insulating chamber 24 for shielding heat from the hot plate 5 is provided. Further, as forming a void 25 outside the heat insulating chamber 24,
An outer cover 26 is provided, and a plurality of air intakes 27 are provided on the upper surface of the outer cover 26.

The air gap 25 is connected to the exhaust duct 9 of the lower unit 3 through the above-described ventilation port 10, and the exhaust air is exhausted by an exhaust device (not shown), so that the clean air introduced from the air intake port 27 is filled with the air gap. 25, it is configured to circulate through the exhaust duct 9 and cool these parts.

 Next, the operation of the heating device having the above configuration will be described.

First, the hot plate 6 is set in advance to a predetermined temperature, for example, 200 to 350 ° C., and the upper unit 2 and the lower unit 3 are relatively separated to form an opening, and the hot plate 6 is lowered. The pins 7 are made to protrude above the hot plate 6, and the semiconductor wafer 4 is placed on the pins 7 by an automatic transfer mechanism or the like in this state.

Thereafter, the upper unit 2 and the lower unit 3 are brought close to each other to form an airtight processing chamber 5, and the hot plate 6 is raised to transfer the semiconductor wafer 4 from the pins 7 onto the hot plate 6. At this time, a pin having a minute height may be provided on the hot plate 6 and a minute gap (proximity gap) may be provided between the hot plate 6 and the semiconductor wafer 4.

Thereafter, the semiconductor wafer 4 is heated for a predetermined time while being placed on the hot plate 6. During the heat treatment, an inert gas, for example, a nitrogen gas is blown into the processing chamber 5 to put the semiconductor wafer 4 in an inert gas atmosphere.

At this time, exhaust is performed from the exhaust duct 9 and the lower exhaust pipe 11 by an exhaust device (not shown).

Therefore, due to the exhaust from the lower exhaust pipe 11, the vapor or extra nitrogen gas generated from the resist of the semiconductor wafer 4 during processing is discharged from the processing chamber 5 to the exhaust port 21, the space 22, the upper exhaust pipe 23, and the lower exhaust pipe. Exhausted through 11. Since the inside of the processing chamber 5 is at a high temperature due to heat from the heat plate 6 as a heat source, the gas discharged through the lower exhaust pipe 11 also has a considerably high temperature.

In addition, clean air is introduced from the air intake 27 by the exhaust air from the exhaust duct 9, and the clean air is supplied to the heat insulating chamber.
The air flows through a space 25 provided outside the heat insulating material 24 and an exhaust duct 9 provided outside the heat insulating material 8, and cools and exhausts these portions. The air gap 25 and the exhaust duct 9 are lower in temperature than the vicinity of the heat plate 6 which is a heat source due to the heat insulating effect of the heat insulating chamber 24 and the heat insulating material 8. Therefore, the clean air introduced from the air intake 27 passes through only these low-temperature portions (does not pass through the high-temperature portion near the heat source), and thus efficiently does not become hot due to the heat from the heat source. The part can be cooled. Therefore, for example, a rise in temperature outside the outer cover 26 or outside the exhaust duct 9 can be effectively prevented, and a rise in ambient temperature can be prevented.

Then, when the heating process for a predetermined time is completed, the semiconductor wafer 4 is carried out in a procedure reverse to the procedure at the time of carrying-in described above.

That is, in this embodiment, the gas flow passing through the high-temperature portion near the heat plate 6 serving as the heat source is separated from the gas flow passing through the low-temperature portion such as the air gap 25 and the exhaust duct 9.
For this reason, for example, the gas that has become hot through the high-temperature portion passes through the low-temperature portion, without causing the temperature of the low-temperature portion to rise,
For example, a rise in temperature outside the outer cover 26 or outside the exhaust duct 9 can be effectively prevented. Therefore, even when the heat treatment is performed at a high temperature of, for example, 250 to 350 ° C., the ambient temperature (the temperature of the outer cover) can be suppressed to, for example, about 50 ° C. or less, which adversely affects the temperature control function of an adjacent device. And there is no danger of injuring workers.

In the above embodiment, an example in which the present invention is applied to a semiconductor wafer baking apparatus has been described. However, the present invention is not limited to such an embodiment, and may be any apparatus that heats an object to be processed. Is also applicable.

[Effects of the Invention] As described above, according to the heating apparatus of the present invention, even when heat treatment is performed at a high temperature, an increase in the ambient temperature can be suppressed as compared with the related art, and the temperature of adjacent equipment can be reduced. The effect on the adjustment function can be reduced and the safety can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a baking apparatus according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Upper unit, 3 ... Lower unit, 4 ... Semiconductor wafer, 5 ... Processing chamber, 6 ... Hot plate,
7 ... pin, 8 ... insulation material, 9 ... exhaust duct, 10 ...
Vent port, 11… lower exhaust pipe, 12… connection port, 20… lower plate, 21… exhaust port, 22… space, 23… upper exhaust pipe, 24… insulation room, 25… void , 26 ... External cover, 27 ... Air intake.

Claims (3)

(57) [Claims] 1. A heating apparatus comprising: a heat source for heating an object to be processed; a heat insulating member provided to surround the heat source; and a housing provided to cover the heat insulating member. At least two types of gas flow paths, a low temperature part gas flow path passing through a low temperature part between the outside of the heat insulating member and the housing, and a high temperature part gas flow path mainly passing through a high temperature part near the heat source inside the heat insulating member. A heating device, comprising: 2. A heating chamber for heating an object to be processed; a first discharge chamber provided above the heating chamber for discharging an atmosphere in the heating chamber; and a discharge chamber surrounding the first discharge chamber and discharging the inside thereof. A second discharge chamber passing through the first discharge chamber and a second discharge path passing through the second discharge chamber. A heating device. 3. The heating device according to claim 2, wherein the exhaust direction from the heating chamber to the first exhaust chamber is upward, and the second exhaust chamber is outside air from above the first exhaust chamber. A heating device configured to take in air and exhaust the air downward.