JPH02290013A - Temperature processing method - Google Patents

Abstract

PURPOSE:To prevent the contamination of a body to be treated, and improve rising characteristics of temperature processing time, by arranging many protrusions and recesses on the surface side of a temperature processing plate, retaining the body to be treated by the protrusions, and performing direct tem perature control on the protrusions and radiation temperature control on the recesses. CONSTITUTION:After a wafer 24 is retained at three points on a hot plate 10 by protruding pins 12, said pins 12 are made to descend and the wafer is mounted on the plate 10. Thereby the wafer 24 is retained in the manner of line contact by mountain top points of protruding parts 16 of the plate 10 whose temperature is controlled, and baking is started. As a result, processing provided with both merits of direct temperature control system and proximity temperature control system is enabled, so that the contamination of a body to be treated can be prevented and rising characteristics of temperature processing time can be improved.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a temperature treatment method such as heating, cooling, hot air, etc.

(Prior Art) In the photoresist processing step of the semiconductor manufacturing process, temperature treatment, such as baking treatment, is performed in order to dehydrate the water on the wafer surface or to remove the solvent in the resist applied to the wafer surface. Alternatively, a cooling temperature control process is performed to improve the accuracy of the coating film thickness.

Baking methods include the direct hot plate method, batch hot air heating method, and microwave method, but these methods are more compact and efficient. Direct hot plate methods have become mainstream due to demands for shorter cycle times and improved reproducibility.

However, in the hot plate method, the wafer is attracted to the hot plate and the entire surface is brought into contact with the wafer to directly heat the wafer, so the degree of close contact between the hot plate and the wafer greatly affects the uniformity of heat. Furthermore, since the hot plate is generally made of metal such as AI, problems such as heavy metal contamination of the wafer and adhesion of particles to the back surface of the wafer have occurred. In particular, it has been found that a large number of particles adhere to the plate during the baking process after applying the resist. If particles adhere to the back surface of the wafer, there is a high probability that defects will occur due to defocus at each position during the subsequent exposure process.

In order to eliminate this problem, we have developed a proximity technique in which baking is performed without directly touching the wafer to the pot 1 or plate 1 using three-point support, so that there is a slight gap between the hot plate and the wafer. There is a vector method.

(Problem to be Solved by the Invention) However, although the above method uniformly controls the temperature in areas other than the three-point support section using, for example, ceramic pins, it has the disadvantage that a temperature gradient is formed at the three-point support section. there were.

Furthermore, the rise and fall of heat conduction to the wafer is delayed, and temperature control is difficult.

Such problems are the same whether the object to be processed is heated or cooled.

Therefore, the present invention was developed to solve the problems of both the conventional direct temperature control method and the proximity temperature control method. The object of the present invention is to provide a temperature treatment method that can easily control the temperature and obtain a uniform temperature distribution.

[Structure of the Invention] (Means for Solving the Problems) The temperature treatment method of the present invention includes providing a large number of concave and convex portions on the surface side of a temperature treatment plate, supporting the object to be treated on the convex portions, and supporting the object to be treated by the convex portions. The object to be treated is temperature-treated by direct temperature control in one part and radiation temperature control in four parts.

(Function) In the present invention, the object to be processed is supported by the convex portions among the many concavo-convex portions formed on the temperature treatment plate 1. Therefore, compared to the case of contacting the entire surface as in the direct temperature control method, the contact area is significantly reduced due to the gap formed between the recess and the amount of particles adhering to the object to be processed is reduced. , yield can be improved.

Furthermore, since support is achieved at multiple points by the convex portions, uniform temperature control can be ensured without causing poor adhesion unlike full-surface contact, and heat uniformity over the entire surface of the object to be processed can be improved.

In addition, unlike the conventional proximity temperature control method, in addition to radiation from four parts, direct temperature control can be achieved by contacting many convex parts, which greatly improves the rise characteristics until the predetermined processing temperature is reached. This improves processing throughput.

(Example) Hereinafter, an example in which the present invention is applied to a baking method as a temperature treatment of a wafer will be specifically described with reference to the drawings.

As shown in FIG. 1, the hot plate 1-10, which is an example of the temperature treatment plate 1, is made of a metal plate such as AI203. Three push-up pins 12 for pushing up the wafer 24 from the surface of the pot plates 1 and 10 are arranged to be movable up and down.

The operation of loading and unloading the wafer 24 into and out of the hop 1, play 1, and 10 is carried out by means of transport tweezers 1 to 10 (not shown) having cutouts to prevent interference with the three push-up pins 1-2.

This hot play 1 10 has a built-in heater (not shown), and the temperature is controlled according to the purpose of use. In other words, if it is a dehydration bake, it will be 200'C.
~300'C, approximately 100'C for pre-baking
For cooling, the temperature controller I is set to room temperature.
- Rolled.

As a characteristic structure of the above-mentioned hot plate 10, an uneven portion consisting of, for example, a concentric recess 14 and a convex portion 16 is formed on the surface side of the hot plate 10 facing the wafer 24. ing. The depth of the four parts 14 is, for example, such that the wafer 24 is 0.5 m below the bottom surface of the four parts 14.
It is set to levitate by about m.

The four portions 14 and the convex portion]-6 are each formed of, for example, acute triangular peaks and valleys, as shown in FIG. 2, which shows a cross section thereof. Therefore, the wafer 24 placed on the hot plate 10 is supported by the apexes of the acute-angled convex portions 16 in line contact with a plurality of concentric circles.

Further, the groove depth of the four portions 14 and the gap d set on the back side of the wafer 24 are set to a value that allows desired radiant heat transfer characteristics to be obtained.

Next, the effect will be explained.

The wafer 24 supported by transport tweezers (not shown) is transported to above the hot plate 10 and is supported at three points by the push-up pins 12 of the hot plates 1 and 10 in a UPL state. After that, push up this pin 12 to D
By turning on the wafer 24 and placing the wafer 24 on the hot plate 10, baking of the wafer 24 on the temperature-controlled hot plate 10 is started.

Here, the wafer 24 is attached to the convex portion 1 of the hot plate}10.
It will be supported by concentric line contact only by the peak apex as 6. Therefore, the portion other than this portion does not come into contact with the back surface of the wafer 24, and a gap d is formed.

By realizing such support for the wafer 24,
It is possible to eliminate the drawbacks of the conventional direct temperature control method and proximity temperature control method, and to achieve temperature control processing that has the advantages of both methods.

That is, according to the direct temperature control method, since the entire surface of the wafer 24 is in contact, there is a very high possibility that impurities on the temperature control plate 1 side will adhere to the back surface of the wafer 24, but in the case of this embodiment, Since a large number of four parts 14 that do not contact the wafer 24 are formed on the hot plate 10, the contact area is greatly reduced, the amount of attached particles can be reduced, and the yield can be improved. Furthermore, in the direct temperature control method, if poor adhesion occurs due to the presence of impurities on the temperature control plate, it becomes difficult to control the temperature uniformly over the entire surface, but in this embodiment, by dropping impurities into the four parts 14, horizontal support can be achieved without compromising uniform heating.

On the other hand, when compared with the conventional proximity temperature control method, the gap d between the wafer 24 and the hot plate 10 is achieved by forming uneven parts on the hot plate 10. By machining this uneven portion, the gap distance can be set as desired as a distance suitable for efficient radiant heating, and compared to securing the gap with a pin etc., this process is performed on the surface of the hot plate 10 itself. It also has excellent strength.

As for the heating method in this embodiment, direct heating can be performed using the convex portion 16 that is in direct contact with the back surface of the wafer 24, and baking can be achieved using radiant heat in the concave portions 14 that are arranged facing each other through a gap. . In particular, when compared with the conventional proximity temperature control method, due to the contribution of direct heating at the convex portion 16, the rise characteristics during heating until the predetermined heating temperature is reached can be greatly improved, and the heat treatment can be improved. Throughput can be improved.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible within the scope of the invention.

In the above embodiments, an example of baking was explained as the temperature treatment, but any temperature treatment may be used, including cooling, low temperature (below room temperature), and constant temperature.

In the above embodiment, the wafer 24 was placed on the uneven portion of the temperature control plate 10 and subjected to temperature treatment. It is also possible to make it even better. That is, as shown in FIG. 3, a vacuum tube part 18 is provided inside the temperature control plate 10, and by forming an opening hole 18a communicating with the recessed part 14, the wafer 24 is moved to the convex part 16. vacuum adsorption becomes possible.

In addition, various cross-sectional and planar shapes can be adopted as the shape of the uneven portion. For example, in order to enhance the direct temperature control effect,
It is sufficient to arrange the convex portions 16 in contact with each other on four sides. Alternatively, point contact at multiple locations may be used.

Its planar configuration is not limited to concentric circles or spiral configurations, but may also include a large number of small-area protrusions.

Furthermore, the object to be processed is not limited to wafers, but also TPT.
It may also be applied to temperature treatment of a liquid crystal substrate on which a transistor circuit is formed.

[Effects of the Invention] As explained above, according to the present invention, a large number of uneven portions are formed on the surface of the temperature processing plate, the object to be processed is supported at multiple locations by the projecting portions, and the four portions are used to support the wafer. Since a gap can be formed between the two, it is possible to secure the advantages of both the conventional direct temperature control method and proximity temperature control method, reduce particle adhesion, and increase yield through uniform heating temperature control. By improving the start-up characteristics during processing, the throughput of temperature processing can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing an example of a pop-up plate on which the method of the present invention is carried out, Fig. 2 is an enlarged sectional view of section A in Fig. 1, and Fig. 3 is a pop-up plate with a vacuum suction function added. FIG. 3 is a schematic cross-sectional view for explaining a modification of Hot 1-Breto. DESCRIPTION OF SYMBOLS 10... Temperature control play 1., 12... Ejection pin, 14... Recessed part, 16... Convex part, 18... Vacuuming pipe part, 18a... Opening hole, 24...
・Wafer.

Claims (1)

[Claims] (1) Provide a large number of uneven parts on the surface side of the temperature treatment plate,
A temperature treatment method characterized in that the object to be treated is supported by the convex portion and the object to be treated is subjected to temperature treatment by direct temperature control in the convex portion and radial temperature control in the concave portion.