JP3128600B2 - Substrate heating method for film forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate heating method for an apparatus for forming a thin film by heating a substrate, and more particularly to a method for heating a relatively large substrate uniformly and at high speed.

[0002]

2. Description of the Related Art In a plasma CVD method or a sputtering method, it is necessary to heat a substrate to several hundred degrees in advance for film formation. There are various methods for heating the substrate.

For example, as shown in FIG. 4, a heating plate 42 having a sheath heater 41 embedded in a film forming chamber or a heating chamber 40 is opposed to a substrate 43, and the substrate 43 is heated by radiation from the heating plate 42.

Alternatively, as shown in FIG. 5, a substrate 43 is heated from both sides (or one side) by using a plurality of lamp light sources 50. Reference numeral 51 denotes a reflector of the lamp light source.

Alternatively, as shown in FIG. 6, a heat equalizing plate 70 is heated by a lamp light source 50, and the substrate 43 is heated by radiation from the heat equalizing plate 70.

[0006]

A hot plate as shown in FIG.
In the method of heating the substrate 43 using 42, it takes time to raise and lower the temperature of the heater (hot plate 42) before and after maintenance of the film forming apparatus.

In contrast to this method, if a method of heating from both sides (or one side) of the substrate 43 using a plurality of lamp light sources 50 as shown in FIG. The maintenance can be performed without applying any cost. In addition, generally higher-speed heating can be performed as compared with the substrate heating method using the hot plate 42. However, this method has a problem that the in-plane temperature uniformity is poor particularly when the substrate 43 is large.

In the method of heating the substrate 43 using a plurality of lamp light sources 50 as shown in FIG. 5, usually, all the lamp light sources 50 are arranged at regular intervals, and control of the power supplied to the lamp light sources 50 is performed. This is performed collectively using only one controller. In this case, a periodic temperature distribution appears on the surface of the substrate 43 corresponding to the arrangement of the lamp light sources 50 as shown in FIG. As a result, the temperature of the peripheral portion tends to be lower as a whole, and the substrate 43 cannot be heated uniformly.

As shown in FIG. 6, a method of heating the heat equalizing plate 70 by the lamp light source 50 and heating the substrate 43 by radiation from the heat equalizing plate 70 is generally employed. Since the heat capacity of the plate 70 is smaller than the heat capacity of the hot plate 42 in the method using the hot plate 42 in which the sheath heater 41 is embedded as shown in FIG. 4, it does not take much time to raise and lower the temperature of the heat equalizing plate 70. However, the time required for substrate heating is the same as the method using the hot plate 42 in which the sheath heater 41 is embedded as shown in FIG. 4, and cannot be said to be a heating method capable of high-speed heating.

An object of the present invention is to heat a substrate uniformly and at high speed using a lamp light source in view of the problems of the conventional method.

[0011]

According to the present invention, a plurality of lamp light sources are arranged on both sides of a substrate so as to face each other, and lamp light source groups corresponding to the front and back surfaces of the substrate are arranged so as to vertically cross each other. . Further, in each lamp light source, a portion of the filament corresponding to a point where the projected image of the lamp light source group corresponding to each of the front and back surfaces of the substrate on the substrate surface intersects is wound. Further, the control of the power supplied to each lamp light source is performed independently for each of several groups divided according to the distance from the substrate center.

[0012]

According to the present invention, the substrate can be heated at a high speed because the lamp light sources are arranged opposite to both surfaces of the substrate. In addition, the lamp light sources corresponding to the front and back surfaces of the substrate are disposed so as to vertically intersect with each other,
The periodic temperature distribution as shown in FIG. 7 is reduced. In each of the lamp light sources, a portion of the filament corresponding to a point where the projected image of the lamp light source group corresponding to each of the front and back surfaces of the substrate on the substrate surface intersects is wound. This avoids the concentration of radiant energy at this intersection on the substrate surface.

Further, the control of the power supplied to each lamp light source is performed independently for each of several groups according to the distance from the center of the substrate. Generally, a larger power is supplied to the lamp light source located at a position far from the center of the substrate. By performing such control, the temperature difference between the central portion and the peripheral portion of the substrate can be reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for heating a substrate in a heating chamber of a plasma CVD apparatus used for film formation of a large liquid crystal plate or the like will be described as an example.

FIG. 1 is a perspective view showing a first embodiment of the present invention. In a heating chamber, lamp light sources 11a and 11b are arranged so as to form an angle perpendicular to each other with a substrate 10 interposed therebetween. In addition, reflectors 121 and 122 are provided on each of the lamp light sources 11a and 11b. Each lamp light source 11a, 11
b is located 11 relatively close to the central surface 14a of the substrate 10.
a (hereinafter referred to as a first group) and a peripheral surface 11b (hereinafter referred to as a second group) located far away. The power supplied to the first group 11a is controlled using the surface temperature of the center surface 14a of the substrate 10 to be heated measured by the radiation thermometer 15a through the hole 13a formed in the center of the reflector 121. Similarly, the electric power supplied to the second group is determined by using the surface temperature of the peripheral surface 14b of the substrate 10 to be heated measured by the radiation thermometer 15b through a hole 13b formed in a portion near the outer periphery of the reflector 121. Controlled. The reflection plates 121 and 122 and the radiation thermometers 15a and 15b are provided with a water cooling mechanism for preventing heating.

Here, for the sake of simplicity, it is assumed that the substrate 10 is square and that the substrate 10 has an arbitrary heat transfer system in the vertical and horizontal directions. If this assumption does not hold, for example, if the substrate is not square or if there is no arbitrariness as a heat transfer system in the vertical and horizontal directions due to the structure of the heating chamber, the perspective view of the second embodiment in FIG. As shown in FIG.
Divided into three groups of 11c, and measured the temperature at three points on the board
Performed at 14a to 14c, the radiation thermometers 15a and 15 of the control system
Prepare three b and 15c. FIG. 3 is an enlarged perspective view of a part of the heating system of FIG. In this figure, the substrate 10
The filament around the point 32 corresponding to the point 31 where the projected image 33 of the group of the lamp light sources 11 corresponding to the front and back surfaces on the surface of the substrate 10 intersects is wound.

[0017]

As described above, in the substrate heating method of the film forming apparatus according to the present invention, the substrate can be heated at a high speed because the lamp light source is disposed opposite to both surfaces of the substrate. In addition, the lamp light source groups corresponding to the front and back surfaces of the substrate are arranged so as to vertically intersect with each other, and each lamp light source corresponds to the front and back surfaces of the substrate so that there is no portion where radiant energy is concentrated on the substrate. Since a portion of the filament corresponding to the point where the projected images of the lamp light source group on the substrate surface intersect is skipped and wound, the periodic temperature distribution on the substrate surface can be reduced.

Further, since the control of the power supplied to each lamp light source is performed independently for each of several groups according to the distance from the center of the substrate, the temperature of the central portion and the peripheral portion of the substrate is controlled. The difference can be reduced. This enables uniform and high-speed heating of the substrate.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is an enlarged perspective view of the heating system of FIG.

FIG. 4 is a view showing a conventional method of heating a substrate using a hot plate.

FIG. 5: Both sides of a substrate using a plurality of conventional lamp light sources
FIG. 3 is a diagram showing a method of heating from (or from one side).

FIG. 6 is a diagram showing a conventional method of heating a soaking plate by a lamp light source and heating a substrate by radiation from the soaking plate.

FIG. 7 is a diagram showing a temperature distribution generated in a substrate surface.

[Explanation of symbols]

10 ... substrate, 11a, 11b, 11c ... lamp light source, 121, 1
22: reflector, 13a, 13b, 13c: hole, 14a: substrate center surface, 14b: substrate peripheral surface, 15a, 15b, 15c ...
Radiation thermometer, 31… intersection, 32… corresponding point of intersection,
33 ... Projected image.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Ishio 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-63-181415 (JP, A) 30143 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/205

Claims (1)

(57) [Claims] 1. A substrate heating method of a film forming apparatus for heating a substrate by using a plurality of lamp light sources and forming a thin film on the substrate, wherein the lamp light sources are arranged opposite to both surfaces of the substrate. A lamp light source group corresponding to each of the front and back surfaces of the substrate is disposed so as to vertically intersect with each other. In each lamp light source, a point at which a projected image of the lamp light source group corresponding to each of the front and back surfaces of the substrate on the substrate surface crosses. That the filament corresponding to is skipped and that the control of the power applied to each lamp light source is performed independently for each group divided into several groups according to the distance from the center of the substrate. A substrate heating method for a film forming apparatus, which is characterized by the following.