JPH0325918A - Heater - Google Patents

Abstract

PURPOSE:To prevent the rubbing of a pin and a through-hole and the generation of particles due to the rubbing, and to attain high-degree cleaning by installing a member guiding the pin for supporting a body to be treated into the through- hole of a hot plate, on which the body to be treated is placed, in a heater for a semiconductor manufacturing process. CONSTITUTION:Three through-holes 2a are formed in a hot plate 2 in response to three pins 7, and guide members 9 supporting the pins 7 are buried into the underside of the hot plate 2. Holes having approximately the same diameters as the diameters of the pins 7 are shaped to the guide members 9, the pins 7 are supported slidably, relative displacement to the hot plate 2 of the pins 7 is guided when the hot plate 2 is moved, and the swing of the hot plate 2 is prevented. Holes 3a are shaped to a plate 3, on which the hot plate 2 is fixed, in response to the through-holes 2a, and the plate 3 is fastened to guide shafts 10 and the driving section of a driving means 4. A block 5 is slid by the guide shafts 10, thus allowing the stable driving of the hot plate 2. On the other hand, the pins 7 are fixed to a unit base 1 by frames 6, the diameters of sections 7b in the guide block 5 are made large than sections (small diameter sections 7b) above the sections 7b, and strength is kept.

Description

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

[Conventional technology] Conventionally, in the semiconductor manufacturing process, before and after resist coating,
Alternatively, after development or the like, the wafer is placed on a heating device using a hot plate, a so-called hot plate, and heat treatment such as dehydration bake, prebake, boss 1 bake, etc. is performed. Such a heating process is usually performed in a line system together with processing steps before and after it, and the wafer is transported between each unit by a suitable transport system.

Cleanliness is one of the most important issues in such systems, and for this reason, the transport system is shifting from conventional belt transport to arm transport, which reduces contamination of the wafer surface. There is a shift from a method in which the wafer is placed on a hot plate and vacuum adsorbed to a proximity method in which the wafer is supported with pins and baked with a small gap between the wafer and the hot plate.

The heating equipment used in such conventional semiconductor manufacturing processes is
As shown in FIGS. 4 and 5, a hot plate 20 made of AQ, etc.
Three to four through-holes 20a are provided in the through-holes 20a, and the wafer 80 is supported by pins 70 that move up and down the through-holes 20a.

During baking, the tips of the pins 70 are located within the hot plate 20 or at a position that slightly protrudes from the surface of the hot plate 20, but when the wafer is transferred, the hot plate 20 is lowered by a sliding part provided below the hot plate 20, and the pins 70 are exposed to the heat. It protrudes from the surface of the board. As a result, the wafer 80 placed on the hot plate 2o is supported by the pins 70, so the wafer 80 after baking is transported to the next process by an arm (not shown), and the wafer before baking is transported from the previous process. It becomes possible to do so.

[Problems to be Solved by the Invention] Incidentally, in such a conventional heating device, there is some play between the pin 70 and the through hole 20a.
A push 22 for guiding the pin 70 is provided on the hot plate fixing plate 21 so that the pin 70 does not move when the hot plate 20 moves up and down. However, since the relative movement distance between the hot plate 20 and the pin 70, that is, the thickness of the hot plate 20 is quite large (30-/30III+1), the pin 70 during this period
In order to prevent zero deviation, the gap between the pin 70 and the through hole 20 must be as small as possible, and the pin 70 must also have a certain thickness. For example, by using a bottle with a diameter of 3+am for a through hole with a diameter of 4.5+nm, the pin 70 is prevented from wobbling.

However, in such conventional heating devices,
Although the shake of the bottle 70 is prevented, since there is little play between the through hole 20a and the pin 70, the aluminum of the hot plate and the pin (for example, SUS) rub against each other, which generates particles and contaminates the backside of the wafer. There was a problem. Especially metal particles generated from AM and SUS! It has a big impact on the quality of q products. On the other hand, if the diameter of the through hole is increased to increase the free movement between the bottle and the through hole, the temperature uniformity on the hot plate surface cannot be maintained. In addition, if the pins are simply made thinner, the heat plate itself is quite thick, so there is a risk of the pins wobbling between them, causing breakage and generation of particles due to rubbing. [Object of the Invention] The present invention has been made to solve such conventional problems, and provides a heating device including a hot plate and a pin that relatively moves through holes in the hot plate. The purpose of this invention is to provide a highly clean heating device that is free from rubbing between pins and through-holes and the generation of particles as a result of the movement of bottles. A further object of the present invention is to provide a heating device that allows smooth relative movement between the hot plate and the pins without impairing the thermal properties of the hot plate. [Means for Solving the Problems] A heating device of the present invention that achieves the above object includes a hot plate on which an object to be processed is placed, and a heating device that penetrates through the hot plate and is relatively to the hot plate. The heating device includes a movable pin for supporting the object to be processed, in which a member for guiding the pin is provided in a through hole of the hot plate. Here, the position of the guide member is a position that does not impair the uniformity of heat on the surface of the hot plate, for example, preferably on the lower side of the center of the hot plate in the thickness direction.

[Function] Since a member is provided to guide the pin inside the hot plate,
It is possible to use a pin with a smaller diameter than in the past, and this allows for a larger clearance between the through hole and the pin, so that when the hot plate or the pin moves, the pin will not rub against the through hole.

Furthermore, since the free end of the bottle (from the guide member to the tip) is short, there is less wobbling during movement, and the reliability of operation is high.

[Example] Hereinafter, an example in which the heating device of the present invention is applied to a heating device in semiconductor manufacturing equipment will be described with reference to the drawings.

The heating device shown in Fig. 1 consists of a heating plate 2 that is placed on a unit base 1 and has a heat source inside, a fixing plate 3 that fixes the heat exhaust 2, and a heating plate 2 that is placed under the unit base 1 and that moves the heating plate 2 up and down. A displacement means 4 such as a liquid cylinder or an air cylinder for movement, a block 5 and a guide shaft 10 for guiding the moving part of the displacement means 4, and a block 5 and a guide shaft 10 fixed to the unit base 1 by a piece 6 and attached to the hot plate 2. It is composed of a plurality of pins, for example, three pins 7 passing through the provided through hole 2a.

A wafer 8, which is an object to be processed, is placed on the top surface of the hot plate 2, either directly or through pins 7, with a small gap between them.In order to improve the uniformity of heat on the top surface, a material with a large heat capacity such as AQ is used. A heat source (not shown) such as an electric heater is built in near the bottom surface.

In addition, the hot plate 2 has three through holes 2a corresponding to the three pins 7.
The diameter of this through hole 2a varies depending on the heating device, but is usually about 4.5 mm. As shown in FIG. 2, a guide member 9 that supports the pin 7 is embedded in the lower surface of the hot plate 2 corresponding to each through hole 2a. The pin 7 is slidably supported by the hole, and when the hot plate 2 is moved, the relative movement of the pin 7 with respect to the hot plate 2 is guided to prevent the pin 7 from wobbling. As the material for the guide member 9, wear-resistant and heat-resistant resins such as fluororesin (Teflon (trade name)), polyacetal resin (Delrin (trade name)), silicone resin, etc. are used.

The guide member 9 may be provided so as to be embedded in the lower surface of the hot plate 2 as shown in FIG. 2, but it may also be provided near the axial center of the through hole 2a as shown in FIG.

However, if the position of the guide member 9 approaches the upper surface of the hot plate 2, it will affect the heat distribution on the upper surface, so it is necessary to provide it at a position that does not impair heat uniformity.

Next, a plate 3 for fixing the hot plate 2 is made of a heat insulating material such as ceramic, and has holes 3 corresponding to the through holes 2a.
a is provided, and is fixed to the guide shaft 10 and the opening portion of the movable means 4.

Therefore, when the cylinder of the driving means 4 rises, the plate 3 and the hot plate 2 move upward as one. At this time, by sliding the guide shaft 10 on the block 5, stable movement of the hot plate 2 is possible.

On the other hand, the pin 7 is fixed to the unit base 1 by a piece 6, and a part of the pin 7 is inside the guide block 5. This pin 7
The part 7b in the guide block 5 is the part above it (
It has a larger diameter than the narrow diameter portion 7b) and is constructed to maintain strength. For example, if the diameter of the tribute hole 2a is 4.5 mm, the large diameter part 7b is 3III11, and the small diameter part 7b is 21Im.
Let it be l. The narrow diameter portion 7b of the pin is connected to the through hole 2 of the hot plate described above.
For example, in the case of proximity baking, the tip of the pin 7 is at a position slightly protruding from the surface of the hot plate 2 during baking, and supports the wafer 8 at this tip. If the proximity method is not used, the tip will be located below the surface of the hot plate 2, and the wafer 8 will be placed directly on the surface of the hot plate. The operation of the heating device of this embodiment in the above structure will be explained.

First, during wafer transfer, the hot plate 2 is in the lowered position shown by the solid line in FIG. 1, and the pins 7 protrude from the surface of the hot plate 2. In this state, the wafer 8 coated with resist in the previous processing step, for example, a resist coating step, is transported by a transport means such as a robot arm (not shown) and placed on the tips of the pins 7 .

Next, when the hot plate 2 is raised by the cylinder of the moving means 4 being raised, the wafer 8 is placed on the hot plate 2. The hot plate 2 performs a stable upward movement as the guide shaft 10 slides on the block 5, and at the same time the pin 7
This will result in a relative decline. At this time, since the pin 7 moves while being guided by the guide member 9 embedded in the hot plate 2, the pin 7 is prevented from wobbling. In addition, since the pin 7 has a small diameter at the portion that moves within the through hole 2a, the play in the through hole 2a is larger than that of the conventional one, so that the wall surface of the through hole 2a and the pin 7 are Relative movement takes place without any contact. Therefore, generation of particles due to friction between the through hole 2 and the pin 7 can be prevented.

After the wafer 8 placed on the hot plate 2 is baked for a predetermined time by raising the hot plate 2, the hot plate 2 is lowered by the moving means 4 from now on. Thereby, the wafer after baking is supported by the tip of the pin 7 protruding from the hot plate 2, and is transported to the next processing step, for example, an exposure step, by the above-mentioned transport means.

In this case, the lowering operation of the hot plate 2 is performed in a completely non-contact state between the pin 7 and the through hole 2a of the hot plate 2, and no vibration or particles are generated, similar to the above-described upward movement.

In the above embodiment, a structure in which the hot plate 2 is moved up and down has been described, but it goes without saying that the hot plate 2 may be fixed to the unit base 1 and the pin 7 moved up and down.

[Effects of the Invention] As is clear from the above description, according to the heating device of the present invention, there is no friction between the hot plate and the support pin when the hot plate or the support pin for the object to be processed is operated, and the generation of particles is prevented. It can be completely prevented, and especially when applied to semiconductor manufacturing processes, a high degree of dust-free can be achieved.

[Brief explanation of drawings]

Fig. 1 is an overall view of a heating apparatus in a semiconductor manufacturing process to which the heating apparatus of the present invention is applied, Fig. 2 is a cross-sectional view showing the upper part of the heating apparatus, and Fig. 3 is another embodiment of the heating apparatus. A sectional view showing an example, FIG. 4 and FIG. 5 are views showing a conventional heating device and its main parts, respectively. 9...Guide member

Claims (1)

[Claims] In a heating device comprising a hot plate on which an object to be processed is placed, and a pin for supporting the object to be processed that passes through the hot plate and moves relative to the hot plate, in a through hole of the hot plate. A heating device comprising: a member for guiding the pin.