JPH01209722A - Heat treating method - Google Patents

Abstract

PURPOSE:To obtain a countermeasure for excessive baking with a simple constitution and to omit a buffer device, by separating a body under heat treatment from a heater and a cover after heat treatment of the body under heat treatment is finished, supporting the body with rod shaped bodies, and making it possible to support the body for a specified time. CONSTITUTION:After heat treatment is finished, a cover 17 and pins 16 are fixed. A hot plate 13 is lowered with a lift mechanism 14. At this time, a semiconductor wafer 12 is mounted on the tip parts of the pins 16 that are positioned in a protruding mode higher than the mounting surface of the hot plate 13. The wafer 12 is lifted from the hot plate 13. Since the cover 17 and the hot plate 13 are separated, a gap 20 is formed. Therefore, the semiconductor wafer 12 is cooled. Namely, even if the semiconductor wafer 12 after the heat treatment cannot be carried out, countermeasure for excessive baking can be performed and the function of a buffer can be performed under the state wherein the semiconductor wafer 12 can be kept in the chamber 11 for a specified time.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a heat treatment method.

(Prior Art) In a semiconductor manufacturing process, such as a photolithography process, after applying a resist to an object to be processed, such as a semiconductor wafer, or before and after a resist phenomenon treatment, the semiconductor wafer is heat-treated for the purpose of stabilizing the resist, etc. This is commonly done.

As shown in FIG. 3, a semiconductor wafer (2), which is an object to be processed, is placed on a hot plate (2) of a heat treatment apparatus (2) and heated, and heat treatment is performed for a predetermined period of time.

When this heat treatment is completed and the semiconductor wafer (3) is transferred to the next step W (a), if there is no semiconductor wafer (3) in the next step (a), the semiconductor wafer (3) is transferred immediately.

However, for example, if the processing time of the next step (a) is longer than the above heat treatment time, or if a trouble occurs and there is a waiting time after the above heat treatment is completed, overbake to avoid excessive heating of the semiconductor wafer Countermeasures are necessary. As an example of this, it is common to provide a buffer device 0 for subsequently storing the semiconductor wafer (2) between the heat treatment device (4) and the next step device (4).

(Problem to be Solved by the Invention) However, when a plurality of heat treatment apparatuses (G) are arranged and a plurality of semiconductor wafers 0 are simultaneously processed in parallel, if the above-mentioned waiting time becomes long, the plurality of semiconductor wafers 0
This requires a buffer device that can store the storage capacity, which may increase manufacturing costs.

The present invention has been made in response to the above-mentioned conventional situation, and provides a countermeasure against overbaking with a simple configuration.

The present invention aims to provide a heat treatment method that does not require buffer mounting.

[Structure of the invention]

(Means for Solving Problem M1) That is, the present invention provides a heating element for placing an object to be processed and heat-treating it, a cover for sealing the object to be processed placed on the heating element, and a heating element for heat-treating the object to be processed. and a rod-shaped body that moves up and down through the rod-shaped body and supports the object to be processed when the tip thereof is located above the object to be processed surface.

After the heat treatment of the object to be treated is completed, the heating element, the cover, and the rod-shaped body are moved relatively, and the object to be treated is separated from the heating element and the cover, and the object is heated by the rod-shaped body. It is characterized by being able to be supported and held for a certain period of time.

(Function) According to the heat treatment method of the present invention, there is provided a heating element on which an object to be treated is placed and heat-treated, a cover that seals the object to be treated placed on the heating element, and a cover that penetrates the heating element. and a rod-shaped body that supports the object to be processed when the tip thereof is moved up and down by the object to be processed, and the rod-shaped body supports the object to be processed when the tip thereof is located above the mounting surface of the object to be processed. and the rod-shaped body, the object to be treated is separated from the heating element and the cover and supported by the rod-shaped body, and can be held for a certain period of time. By allowing air to flow outside through the space, the object to be processed can be cooled, and the object to be processed after the heat treatment can be kept on standby for a certain period of time.

(Example) Hereinafter, an example of the heat treatment method of the present invention will be described with reference to the drawings.

Inside the chamber (11) is a temperature control mechanism (not shown).
A heating element, for example, a disk-shaped hot plate ( 13) is arranged, and this hot plate (13) is configured to be able to be raised and lowered by a lifting mechanism (14) attached to the chamber (11).

Further, the hot plate (13) is provided with a plurality of holes (15) passing through it vertically, and is configured such that four rod-shaped bodies, for example, pins (16), which will be described later, can pass through it and move up and down. There is.

Next, above the hot plate (13), a side surface is formed in a cylindrical shape, and when the hot plate (13) rises, the lower end portion of the side surface and the peripheral portion of the top surface of the hot plate (13) come into contact. A heat insulating cover (17) configured to hermetically seal the semiconductor wafer (12) on the hot plate (13) is placed inside the chamber (
11).

Below the hot plate (13), a plurality of rod-shaped bodies, such as pins (16), which pass through holes (15) provided in the hot plate (13) and are movable up and down, are attached to the chamber (11). Ori,
When the hot plate (13) is at its highest point, the tip of the pin (16) is below the top surface of the hot plate (13), and when the hot plate is at its lowest point, the tip of the pin (16) is at the top of the hot plate (13). The semiconductor wafer (12) is protruded further and is configured to be lifted and supported from the hot plate (13).

In addition, an exhaust port (18) is provided on the bottom of the chamber (11), and an outside air inlet (19) is provided on the side, and an exhaust mechanism (not shown) is connected to the exhaust port (18) by piping. ), the inside of the chamber (11) can be evacuated, and outside air can be introduced through an outside air inlet (19). In addition, the transport mechanism (
(not shown) so that semiconductor wafers (12) can be carried in and carried out.

The hot plate (13) has a purge gas inlet (not shown) such as nitrogen (N2) gas, and a purge gas exhaust port (not shown).
is provided, and is configured to seal the top surface of the hot plate (13) so that gas such as resist solvent generated during heat treatment of the semiconductor wafer (12) can be discharged as necessary.

Next, a heat treatment method will be explained.

First, the hot plate (13) is lowered by the lifting mechanism (14).

A gap is provided between the hot plate (13) and the lower end of the cover (17), and the unprocessed semiconductor wafer (12) is transferred to the chamber (11) by a transport mechanism (not shown) through the outside air inlet (19).
) and place the semiconductor wafer (
12).

Next, the heating plate (13) is raised by the lifting mechanism (14), and the semiconductor wafer (1) placed on the tip of the pin (16) is raised.
2) on the hot plate (13), and connect the hot plate (13) and the cover (
17) to keep the upper surface of the hot plate (13) containing the semiconductor wafer (12) in a sealed state. By doing so, even if there is an air current in the chamber (11), the ambient temperature of the processing surface of the semiconductor wafer (12) is less affected and it becomes easier to maintain the temperature at a constant temperature.

Then, heat treatment is performed by heating the semiconductor wafer (12) at a predetermined temperature for a predetermined time using a hot plate (13). At this time,
Introduce purge gas into the upper closed atmosphere as necessary,
Further, gas generated by heat treatment is exhausted.

After the above heat treatment is completed, the above heat plate (13) and the cover
(17) and the pin (16) are moved relatively, for example, the cover (17) and the pin (16) are fixed and the hot plate (1
3) is moved or lowered by the lifting mechanism (14).

At this time, as shown in FIG. 2, the semiconductor wafer (12) rests on the tip of the pin (16) that protrudes above the mounting surface of the hot plate (13), and the hot plate (13) The cover (17) and hot plate (
13) is separated, creating a gap (20).

Therefore, since the semiconductor wafer (12) is supported by the pins (16) at a distance from the hot plate (13) and the cover (13), heat transfer from the hot plate (13) is reduced, and the semiconductor wafer (12) is By moving away from the hot plate (13), the influence of radiant heat from the hot plate (13) can be reduced, and since outside air (21) is introduced through the gap (20), the semiconductor wafer (12) can be cooled. You can keep it.

In addition, as a means for promoting the cooling effect of the semiconductor wafer (12), a gas such as air, N2 gas, etc. is supplied to the surface of the semiconductor wafer (12) while the cover (17) and the hot plate (13) are separated. Cooling may be performed by providing a mechanism (not shown) for forcibly cooling by ejecting water.

That is, even if the semiconductor wafer (12) remains in the next process and cannot be immediately carried out after the heat treatment, the semiconductor wafer (12) is kept in the chamber (11) for a certain period of time. Since it can be held, it becomes possible to take measures against overbaking and to function as a buffer device.

Then, when the semiconductor wafer (12) is ready for reception in the next step, the heat-treated semiconductor wafer (12) is transported by a transport mechanism (not shown) through the outside air inlet (19).

In addition, in the above embodiment, the hot plate (13) and the cover (17
) and the pin (16), the cover (17) and the pin (16) are fixed and the hot plate (
13) has been described; however, the present invention is not limited to the above embodiments;
) may be fixed and the cover (17) and pin (16) may be movable, and the same effect can be obtained. Also, a hot plate (13), cover (17), pin (16)
) may be configured to be movable independently to perform the above operations.

Furthermore, according to the heat treatment method of the present invention, as can be understood from the above explanation, it can also function as a buffer, so it goes without saying that there is no need to specifically provide a buffer device, and the heat treatment device is arranged in multiple stages in series. , parallel arrangement, and setting of the heat treatment process for each heat treatment apparatus is easily possible.

Further, the heat treatment method of the present invention is optimally applied to, for example, hydrophobic heat treatment, prebake treatment, resist curing process, etc., in addition to the heat treatment described above.

〔Effect of the invention〕

As described above, according to the heat treatment method of the present invention, overbake countermeasures can be taken with a simple configuration, and a conventional buffer device is not required, making it possible to downsize the entire device and reduce manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram for explaining an embodiment of the heat treatment apparatus of the present invention, and FIG. 2 is an explanatory diagram of the operation of FIG. 1. FIG. 3 is an explanatory diagram of a conventional example. DESCRIPTION OF SYMBOLS 11... Chamber, 12... Semiconductor wafer, 13... Hot plate, 14... Lifting mechanism, 16... Pin, 17... Cover.

Claims (1)

[Claims] a heating element for placing and heat-treating the object to be processed; a cover for sealing the object to be processed placed on the heating element; and a cover that passes through the heating element and moves up and down to place the object to be processed. a rod-shaped body that supports the object to be treated when positioned above the surface, and after the heat treatment of the object to be treated is completed, the heating element;
A heat treatment method characterized in that the cover and the rod-shaped body are moved relatively to separate the object to be treated from the heating element and the cover and supported by the rod-shaped body so that the object can be held for a certain period of time. .