JPS62280367A - Cooling type vapor phase reactor - Google Patents

Abstract

PURPOSE:To effectively apply an unwelded part which is not conventionally utilized and to enhance cooling effect by providing a cooling means on an outer wall surface and covering the cooling means by a high-thermal conductive material. CONSTITUTION:A coil 20a made of a copper pipe constituting a cooling means is provided on the outer wall surface of the conical cover 3 of a CVD thin film forming device 1 and also the coil 20b made of the copper pipe is provided on the outer wall surface of an intermediate ring 5. High-thermal conductive materials 30 are filled between pipes to cover all surfaces of pipes. As the high-thermal conductive material, metallic powder of copper or aluminum or the like and a thermal conductive adhesive are used. As the thermal conductive adhesive, two-pack epoxy-compounded resin blended with i.e. the powder of copper or aluminum is used.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a cooled gas phase reactor. More specifically,
The present invention relates to a cooling type CVD thin film forming apparatus that prevents the formation and adhesion of foreign particle flakes such as SiO or 5i02 on the inner wall surface of a reactor.

[Prior Art] One of the methods widely used in the semiconductor industry for forming thin films is the vapor deposition method (CVD).
:Chemical Vapor Depos i
t 1on). CVD refers to turning a gaseous substance into a solid substance through a chemical reaction and depositing it on a substrate.

The characteristics of CV I) are that various thin films can be obtained at a deposition temperature considerably lower than the melting point of the thin film to be grown, and that the purity of the grown thin films is high. Because of its stable electrical properties even when grown, it is widely used as a passivation film on the surface of semiconductors.

Thin film formation by CVD is, for example, approximately 400°C-500°C.
A reactive gas (for example, Si
Hq+021 or S i Hq+PH3+02
). The reaction gas described in -1- is in a reactor (
5i02 or phosphorus silicate glass (PS) is blown onto the wafer surface.
6) Form a thin film. Also, 5i02 and PSG 2
Phase deposition may also be performed.

In the S1Hq-02-based CVD method, since SiH4 reacts explosively with 02 at room temperature, it is necessary to dilute it with an inert gas. For example, if the SiH4 concentration in the reaction gas is at least 0.8% in a mixed gas of SiH4-02-N2, no reaction will occur even at room temperature, and 140
The reaction starts when heated to -270°C.

With conventional CV I) Does the reaction start in the entire reactor, not just the wafer mounting table, in a thin film forming apparatus? The atmosphere was hotter than the actual temperature. Therefore, the reaction gas fed into the reactor is passed through a conical cover and buffer inside the reactor.

Near nozzle exit L1, the reactant gas flows through the reactor while contacting walls such as the large nozzle and the intermediate ring.
In some cases, a film formation reaction occurred not only on the wafer surface on the wafer mounting table but also on the wall surface in the reactor. As a result, flakes of oxide particles such as SiO or 5i02 are formed and attached to the wall surface.

Such flakes may peel off due to slight vibration or wind pressure, and may fall and adhere to the wafer surface.

Further, there is a possibility that the flakes are rolled up and blown off by the reaction gas, float in the furnace, and fall and adhere to the wafer surface. If these flakes (foreign substances) adhere to the wafer, they may cause pinholes in the deposited film, resulting in a significant decrease in the manufacturing yield of conductor elements.

Another problem is that the reactant gas reacts on the inner wall surface 1- of the reactor, so the reactant gas fed into the reactor is wasted and the effective utilization rate of the gas is reduced. This resulted in a decrease in the growth rate of the thin film.

[Problems to be Solved by the Invention] In order to prevent the reaction gas from reacting near the wall surface, an attempt was made to weld a cooling coil to the outer wall, as shown in FIG.

However, in conventional devices, the cooling coil was simply fixedly attached to the outside wall of the device by spot welding, and moreover, the entire coil was exposed to the air. Therefore, the coil is only in point or line contact with the wall surface, and the non-contact portion occupies a larger area than the contact portion. Also, depending on the welding location, the coil was lifted off the wall surface [--and there were some parts where it was not in contact at all.

As a result, even if cooling water or compressed refrigerant were allowed to flow through the coil, the cooling efficiency was poor and the wall surface could not be sufficiently cooled. Historically, the temperatures at welded and non-welded areas were different, making it impossible to cool the wall surface uniformly. Therefore, the intended purpose of suppressing the generation of foreign matter on the inner wall surface 1-1 could not be sufficiently achieved.

Therefore, the first object of the present invention is to provide a gas phase reactor having a cooling means with high cooling efficiency on the outer wall surface.

[Means for Solving the Problems] As a means for solving the problems described in mI and achieving the above object at the same time, the present invention provides a method for disposing a cooling means on the outer wall surface and heating the cooling means at high temperature. A gas phase reactor is provided, characterized in that it is encapsulated with a conductive material.

[Operations] As described above, in the cooling type gas phase reaction apparatus of the present invention, the cooling means disposed on the outer wall surface 11 is covered with a highly thermally conductive material.

As a result, the non-welded parts, which were not involved in cooling at all or were not used in the past, can be effectively utilized, so that the cooling efficiency is dramatically improved.

Furthermore, since the space between the removal means and the cooling means is filled with a thermally conductive material, the temperature distribution on the wall surface becomes more uniform than in the case of conventional spot welding.

By improving the cooling efficiency and making the temperature distribution uniform, the surface temperature of the inner wall surface of the reactor of a gas phase reactor such as a CVD apparatus can be maintained at a temperature lower than the film-forming reaction start temperature.

The cause is not clear at present, but it may be that the H20 vapor in the reactor condenses on the cooling wall and adheres to the wall, suppressing the growth of these into flakes. I don't think so.

Furthermore, since the wall surface temperature is lower than the reaction start temperature, reaction gas hardly reacts on the interior surface of the reactor.

As a result, the formation and adhesion of flakes of oxide particles such as SiO or 5i02 on the interior surface is effectively prevented. Therefore, these flakes (foreign substances) can fall and adhere to the wafer surface and cause pinholes in the evaporated film of sea urchin/).
Therefore, the manufacturing yield of f-conductor elements can be improved.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial schematic diagram showing one embodiment of the arrangement of the cooling means on the outer wall surface of the gas phase reactor of the present invention, and FIG. 2 is a partial schematic diagram showing another embodiment of the arrangement. be.

The gas phase reactor shown in FIG. 1 is a CVD thin film forming apparatus.

In FIG. 1, 1 is a CVD thin film forming apparatus, 3 is a conical cover, 5 is an intermediate ring, 7 is a reactor main body, 9 a and 9 b are reaction gas injection nozzles, 11 is a conical buffer,
13 indicates one wafer iJIRg.

As shown in FIG. 1, a copper pipe 26a constituting a cooling means is disposed on the outer wall surface of the conical cover 3.

Similarly, a coiled copper pipe 2 is also placed on the outer wall surface of the intermediate ring 5.
Allocate 0b. The flexible pipes 20a and 20b can be welded onto each outer wall surface by spot welding, or
It is also possible to just place it on the outer wall surface without any fixing process such as welding.

A liquid refrigerant (for example, cooling water) or a compressed gaseous refrigerant (for example, Freon) is circulated inside the copper pipe corrugation. Copper pipes can be used not only in a serpentine shape but also in a coil shape.

A high thermal conductive material 30 is filled between the pipes,
Covers the entire surface of the pipe. As shown in Figure 1,
If a highly thermally conductive material 30 is filled in the gap and the upper surface is covered with a heat insulating cover 40, the cooling efficiency will be further increased. Alternatively, as shown in FIG. It can also be implemented in such a manner that valleys are formed between the peaks simply by covering with the flexible material 30.

Highly thermally conductive materials that can be used in the present invention are, for example, metal powders such as copper or aluminum or thermally conductive adhesives. The thermally conductive adhesive is, for example, a two-component epoxy resin blended with copper powder or aluminum powder. Other thermally conductive space-filling materials can be used as well.

Such materials are well known to those skilled in the art.

The surface temperature of portions not directly required for heating the wafer, such as the conical cover and the intermediate ring, is cooled by the cooling means to a temperature lower than the film forming reaction starting temperature, for example, 90° C. or lower. One or more surface thermometers may be installed in each part to measure whether the surface temperature in each part is maintained below a predetermined set value.

In this way, the reactive gas reacts in areas that are not directly necessary for heating the wafer, such as the conical cover and the intermediate ring, forming and depositing flakes of oxide particles on these areas.
In addition, there is no inconvenient I that lowers the effective utilization rate of gas.
The occurrence of n is effectively prevented by 11.

Although 1-1 the present invention has been described with respect to a CVD thin film forming apparatus, the present invention can be practiced on any gas phase reaction apparatus that requires cooling.

[Effects of the Invention] As explained above, in the cooling type gas phase reaction apparatus of the present invention, the cooling means disposed on the outer wall surface is covered with a highly thermally conductive material.

As a result, the non-welded parts, which were not involved in cooling at all or were not used in the past, are effectively utilized, resulting in a dramatic improvement in cooling efficiency.

Furthermore, since the space between the cooling means is filled with a thermally conductive material, the temperature distribution on the wall surface becomes more uniform than in the case of conventional spot welding.

By improving the cooling efficiency and making the temperature distribution uniform, the surface temperature of the inner wall surface of the reactor of a gas phase reactor such as a CVD apparatus is maintained at a temperature lower than the film-forming reaction start temperature.

The cause is not clear at present, but the H20 vapor inside the reactor has condensed on the walls and adhered to them5.
It seems that by covering the iO2 particles with surface tension, their growth into flakes is suppressed.

Historically, since the wall surface temperature is lower than the reaction initiation temperature, reaction gases hardly react on the inner wall surface of the reactor.

As a result, the formation and adhesion of flakes of fine oxide particles such as SiO or 5i02 on the inner wall surface can be effectively prevented. Therefore, the occurrence of an inconvenient situation such as the occurrence of pinholes in the vapor deposited film of the wafer due to these flakes (5F4 particles) falling and adhering to the wafer surface is also prevented, and the manufacturing yield of semiconductor devices can be improved. .

Furthermore, not only will the reaction gas fed into the reactor be used extremely effectively, but the growth rate of the CVD film will also be improved.
1-, the manufacturing cost of semiconductor elements can be reduced.

4. Drawing no [? 11- Explanation FIG. 1 is a partial schematic diagram showing an embodiment of the arrangement of the cooling means on the outer wall surface-1 of the gas phase reactor of the present invention, and FIG. 2 is a partial schematic diagram showing another embodiment of the arrangement. FIG. 3 is a schematic erroneous diagram showing a conventional arrangement of cooling stages.

DESCRIPTION OF SYMBOLS 1... Reactor, 3... Conical cover, 5... Intermediate ring, 7... Reactor main body, 9a and 9b... Reaction gas insertion nozzle, 11... Buffer, 13...・Wafer mounting table, 20a and 20b...Copper pipe cooling means, 30...High thermal conductive material, 40a and 40b・
・・Insulating cover

Claims (7)

[Claims] (1) A gas phase reaction apparatus characterized in that a cooling means is disposed on an outer wall surface, and the cooling means is covered with a highly thermally conductive material. (2) The gas phase reactor according to claim 1, wherein the highly thermally conductive material is aluminum or copper powder. (3) The gas phase reactor according to claim 1, wherein the highly thermally conductive material is a thermally conductive adhesive. (4) The gas phase reactor according to claim 3, wherein the thermally conductive adhesive is a two-component epoxy compound resin mixed with metal powder. (5) The gas phase reactor according to claim 4, wherein the metal powder is aluminum or copper powder. (6) The cooling means is a coil or coil of a cooling pipe in which a liquid refrigerant or a compressed gas refrigerant is circulated. gas phase reactor. (7) Claims 1 to 6 which are CVD equipment
The gas phase reactor according to any one of paragraphs.