JPH1192941A - Thin coating forming device and formation of thin coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of foreign matters (particles) and to facilitate the maintenance of a thin coating forming device. SOLUTION: This thin coating forming device has a chamber 1 housing a substrate W at the inside and to be introduced with a gas for the formation of thin coating and a heating element 6 generating heat which heats the substrate and is furthermore provided with a heating member which holds the substrate to the upper part and a supporting stand which supports the heating member, and the heating member is arranged on the supporting stand at prescribed intervals, and feed ports 21 and 22 for primary non-raw material gases different from the gas for the formation of thin coating in order to form a flow from prescribed intervals to the outside thereof are arranged at the intervals between the heating member and the supporting stand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin film forming apparatus and a thin film forming method for forming a thin film on a surface of a substrate such as a glass substrate, a semiconductor wafer, and a plastic sheet.

[0002]

2. Description of the Related Art With the development of electronic devices, the necessity of forming a thin film on a glass substrate, a semiconductor wafer, a plastic sheet or the like is increasing. The thin film to be formed is spread over everything such as an insulator, a conductor, and a semiconductor. In particular, in manufacturing a semiconductor device, the performance required for a thin film is becoming strict. In addition, such a thin film does not mean that a good quality film can be formed even with time, but must be formed in a short time with good reproducibility. In addition, the surface shape of the substrate on which a thin film is to be formed is not necessarily flat, but may be various such as a concave surface, a convex surface, and a curved surface. In particular, ultra-fine semiconductor devices and multilayer wiring have been developed, and accordingly, a thin film must be formed uniformly on a surface having fine holes such as 0.25 μm or less on one side and 1.0 μm or more in depth. In some cases, a thin film formation method by selective deposition in which a thin film must be formed (deposited) only in this hole and not deposited elsewhere may be desired.

The present inventors have disclosed a method disclosed in Japanese Patent Application Laid-Open No. H03-183768.
No. 5,179,042, European Patent No. 04
Japanese Patent Publication No. 25084 and the like have proposed a thin film forming method and a thin film forming apparatus in which a high-quality fine thin film is deposited in a hole. This method is a method of depositing a thin film on a semiconductor or a conductive surface by utilizing a chemical reaction (thermal CVD method) between hydrogen and an alkyl aluminum hydride represented by dimethyl aluminum hydride.

[0004] However, the thin film forming apparatus described in the above-mentioned patent document is not necessarily appropriate when mass-producing semiconductor devices by processing a substrate having a large processing area such as a 12-inch wafer. And further improvements must be made.

FIG. 1 is a schematic longitudinal sectional view of a conventional thin film forming apparatus.

In a chamber 1, a substrate W as an object to be subjected to a thin film forming process, a heater 2 having a built-in heating element 6, and a support 3 are arranged in close contact with each other. Is transmitted to both the workpiece W and the support 3 by heat conduction. In this case, the heater 2 itself is a support for the substrate W. The thin film forming gas is supplied from the supply port 4,
Air is exhausted from the exhaust port 5. A current flows from the power supply 7 to the heating element 2 through the wiring 8. 9 is an insulator.

In such a conventional apparatus, the surface of the heater 2 itself, which is a support for repeatedly forming a thin film, becomes dirty, the heating element inside the heater 2 deteriorates, and the heater itself needs to be replaced. . In the case of a mass production machine, it is not preferable that such replacement of parts takes a long time because the operation rate of the device is lowered.

[0008]

Therefore, the present inventors first improved the apparatus of FIG. 1 to an apparatus as shown in FIG. 2 as described later so that the time required for replacing the heater could be shortened. .

However, when thin films were repeatedly formed using the apparatus shown in FIG. 2, more foreign substances (particles) were generated than before, and the number of times of maintenance of the apparatus was increased.

A first object of the present invention is to provide a thin film forming apparatus and a thin film forming method in which generation of foreign matter (particles) is suppressed.

A second object of the present invention is to provide a thin film forming apparatus and a thin film forming method which can easily maintain the apparatus.

[0012]

According to the present invention, there is provided a thin film forming apparatus having a chamber in which a substrate is accommodated and a gas for forming a thin film is introduced, and a heating element for generating heat for heating the substrate. A thin film forming apparatus comprising a heating member for holding the substrate thereon and a support base for supporting the heating member, wherein the heating member is disposed at a predetermined interval on the support base. The first non-source gas, which is arranged and different from the thin film forming gas, is formed from the predetermined interval to the outside thereof so as to form a first non-source gas.
Wherein the supply port of the non-source gas is disposed at a distance between the heating member and the support.

Here, the substrate is disposed with a predetermined gap between a back surface of the substrate and an upper surface of the heating member,
In order to form a flow of a second non-source gas different from the thin-film forming gas flowing from the gap to the outside, a supply port of the second non-source gas is provided in a gap between the back surface of the substrate and the heating member. Preferably, it is arranged and the heating member is preferably replaceable.

Preferably, the heating member is made of one of a metal, aluminum nitride, and silicon carbide,
The support is made of metal.

It is preferable that the wiring of the heating element can be separated into a heating member side and a support base side by a connector portion, and further, it is preferable that a cooling means for cooling the support base is provided.

The thin film forming method according to the present invention comprises a chamber for accommodating a substrate therein and into which a thin film forming gas is introduced, and a heating element for generating heat for heating the substrate, and the substrate is provided thereon. A heating member for holding the heating member, and a support table for supporting the heating member, using a thin film forming apparatus, the heating member is disposed at a predetermined interval on the support table, the thin film A thin film is formed on the substrate surface while supplying a forming gas to the surface of the substrate and flowing a first non-source gas different from the thin film forming gas to the outside from the predetermined interval. And

Further, preferably, a second non-source gas different from the thin film forming gas flows to the outside through a gap provided between a back surface of the substrate and an upper surface of the heating member. A thin film is formed on a substrate surface.

Preferably, the gas for forming a thin film is an organic metal gas, and the organic metal is aluminum,
It is an organic compound of any of tungsten, molybdenum, copper and titanium, and more preferably, the organic metal is an alkyl aluminum hydride. The first non-source gas and the second non-source gas may be equal.

Further, based on the supply amount of the thin film forming gas,
It is preferable that the supply amounts of the first and second non-source gases are small.

[0020]

FIG. 3 is a schematic longitudinal sectional view for explaining a thin film forming apparatus according to a preferred embodiment of the present invention. The apparatus shown in FIG. 3 has a chamber 1 in which a substrate W is accommodated and a gas for forming a thin film is introduced, a heating element 6 for generating heat for heating the substrate, and a substrate W A heater 2 as a heating member for holding the heating member, and a support base 3 for supporting the heating member 2,
It has. The heating member 2 is placed on the support 3 at a predetermined interval 2.
0, and a non-source gas supply port 21 is provided between the heating member 2 and the support base 3 so as to form a flow of the non-source gas different from the thin film forming gas from a predetermined interval 20 to the outside thereof.
Are arranged at an interval 20.

In order to explain the reason for adopting such a configuration, first, an apparatus which the present inventors have tried to improve first will be described. The present inventors first improved the conventional apparatus shown in FIG. 1 into an apparatus as shown in FIG. The point of improvement is that the heater 2 is floated from the support base 3 by using a plurality of support rods 11 so that the wiring 8 of the heating element 6 can be separated at the connector section 10 so that the heater 2 together with the heating element 6 can be supported by the support base 3. Is that it can be easily removed. As a result, the replacement time of the heater could be shortened. However, as described above, when a thin film was repeatedly formed using this apparatus, the generation of foreign substances (particles) in the apparatus, particularly near the heater 2, increased.

As a result of analyzing the reason, it is considered that the amount of foreign substances (particles) on the entire back surface of the heater 2 was increased by the amount of foreign substances (particles) generated. A gap 20 is provided between the back surface of the heater 2 and the upper surface of the support base 3 by the support rod 11.
Was formed, so that the thin film forming gas, that is, the raw material gas, also flowed into this gap. As a result, the source gas is decomposed and deposited on the back surface of the heater at a high temperature, and it seems that the source gas is peeled off to form foreign matter (particles). Gap 2
The sealing may be performed at the peripheral end of the support base 3 so that the raw material gas does not flow into the base plate 0, but this does not make it possible to easily replace the heater 2 and shorten the maintenance time of the apparatus.

Therefore, as shown in FIG. 3, a non-source gas different from the source gas is discharged from the supply port 21 into the gap 20 through the supply pipe 13 and the non-source gas flows from the gap 20 to the outside. Was formed. by this,
The partition member 17 and the plurality of openings 1 are supplied from the supply port 4.
The source gas supplied into the chamber 1 through the shower plate 18 in which the holes 9 are formed becomes difficult to flow into the gap 20. Therefore, it was possible to prevent the source gas from decomposing on the back surface of the heater 2 to generate particulate foreign matter or to generate an unnecessary film.

As the non-source gas different from the source gas,
Hydrogen, argon, nitrogen, helium, neon, or the like can be appropriately selected and used. The flow rate of the non-source gas flowing through the gap 20 is 5 SCCM to 100 SCCM, and the size of the gap 20 is preferably 2 mm or more.

Further, if necessary, the substrate W
Is disposed with a predetermined gap 16 between the back surface of the heater 2 and the upper surface of the heater 2, and the second non-source gas is supplied through the supply pipe 14.
The gas supply port 22 may be disposed in the gap 16 so that the gas is discharged from the supply port 22 into the gap 16 and flows out of the gap 16 from the gap 24 between the heater 2 and the substrate holder 23. In this case, the same gas as the above-mentioned non-source gas can be used as the second non-source gas. Gap 1
The flow rate of the non-source gas flowing through 6 is 5 SCCM to 100 SCCM, and the dimension of the gap 16 is preferably 1 mm or less. As shown in the figure, the gap 16 forms a dish-shaped depression on the upper surface of the heater 2 while leaving a flat ring-shaped portion at the peripheral edge, and radial grooves 15 are formed on the inclined portion of the depression and the flat ring-shaped portion. By forming, it can be easily formed. The supply amount of the non-source gas is smaller than the supply amount of the source gas, and even if a very small portion of the non-source gas goes to the substrate surface side, there is no effect.

FIG. 4 shows an example of the substrate holder 23. The substrate holder 23 is a ring-shaped part 23A for holding the substrate.
, A cylindrical side wall 23B, and fixed legs 23C for fixing the substrate holder 23 to the heater. The fixed legs 23 are fitted into holes or ring-shaped grooves provided in the heater 2. ing. The inner diameter of the side wall portion 23B is slightly larger than the outer diameter of the heater 2 so as to form the gap 24 described above. The vertical movable rod 25 shown in FIG. 3 is provided as necessary,
Thus, the substrate holder 23 may be vertically movable. Thus, the substrate holder 23 holds the substrate W and forms a non-source gas flow path. Further, instead of the above-described fixed legs, a fixed frame that is in contact with the outer surface of the heater 2 may be used.

The heater 2 as a heating member used in the present invention can be formed from a metal such as aluminum or stainless steel, or a heat conductive material such as aluminum nitride or silicon carbide. Aluminum and stainless steel are inexpensive and easy to process, and aluminum nitride is excellent in corrosion resistance.

The support 3 can be made of a metal such as aluminum or stainless steel.

The wiring 8 of the heating element 6 can be separated into the heater 2 side and the support base 3 side by the connector section 10. Reference numeral 9 denotes an insulator provided as needed to electrically separate the wiring 8 and the support 3 from each other.

Further, although not shown, it is also preferable to provide a mechanism (cooling means) for flowing the refrigerant to the back side of the support 3 in order to cool the support 3.

According to the above-described embodiment of the present invention, by flowing a non-source gas different from the source gas into the gap 20, it is possible to prevent the source gas from flowing to the back side of the heater, and the heat of the source gas on the back side of the heater is prevented. Generation of foreign matter due to decomposition can be suppressed.

Further, a gap 16 is also formed between the back surface of the substrate and the top surface of the heater, and a non-source gas is flown here, so that the substrate W can be uniformly distributed by utilizing the heat conduction of the non-source gas. , And can be efficiently heated. this is,
This is particularly effective when a thin film is formed under a reduced pressure of 133 Pa or less during the thin film forming process in the reaction chamber.

The thin film forming apparatus of the present invention comprises a silicon thin film,
For forming semiconductor thin films such as gallium arsenide and indium phosphide, metal thin films such as aluminum, copper, tungsten, molybdenum, and titanium, and insulating or conductive compound thin films such as silicon oxide, silicon nitride, aluminum nitride, and titanium nitride. It is preferably used.

As a raw material gas for forming a thin film, silane,
Disilane, silicon tetrafluoride, silicon tetrachloride, tetraethoxysilane, trimethylgallium, trimethylindium,
Examples include trimethylaluminum, triisobutylaluminum, dimethylaluminum hydride, diethylaluminum hydride, diisobutylaluminum hydride, tungsten hexafluoride, and titanium tetrachloride.

The method for forming a thin film according to the present invention will be described.

The substrate W is placed on the heater 2 in the chamber 1, and the periphery of the substrate W is covered with the substrate holder 23. By driving a vacuum pump (not shown), the exhaust port 5
Exhaust from The non-source gas is supplied from the supply port 21 and the supply port 22 to the gaps 20 and 16, respectively, to form a flow of the non-source gas on the back surface and the top surface of the heater 2. Heater 2
An electric current is supplied from the power supply 7 to the heating element 6 to generate heat.

The source gas is supplied into the chamber 1 from the source gas supply port 4. The supplied source gas is supplied to the shower plate 1 having the partition member 17 and the plurality of openings 19 formed therein.
8 and uniformly supplied to the surface of the substrate W,
It is exhausted to the side. In this state, when the amount of electricity supplied to the heating element is adjusted to a value determined from data on the amount of electricity applied to the substrate surface temperature, which has been measured in advance, deposition of the raw material by thermal CVD occurs on the substrate surface, and the thin film is formed. It is formed.

[0038]

EXAMPLE 1 An example in which an aluminum thin film is formed using an alkyl aluminum hydride will be described.

The heater 2 made of aluminum nitride and having a built-in heating element was mounted on the support 3 via a support bar 11, and the heating element 6 and the wiring 8 were connected at the connector section 10. An 8-inch silicon wafer was mounted on the heater 2 as the substrate W.

The heating element 6 was energized and the inside of the chamber was evacuated, and hydrogen gas as a non-source gas was supplied from supply ports 21 and 22 at 5 to 10 SCCM, respectively.

A mixed gas of dimethyl aluminum hydride (DMAH) as a source gas and hydrogen as a reaction gas was introduced into the chamber 1 from the source gas supply port 4 at 500 SCCM (of which DMAH was 100 SCCM). The chamber pressure at this time is 1.33 Pa.

The amount of electricity supplied to the heating element 6 was adjusted so that the temperature of the substrate surface became 200 ° C.

Thus, an aluminum thin film having a thickness of 1 μm was formed on the substrate surface, and the uniformity of the film thickness was measured to be ± 1%.

On the other hand, the non-source gas is supplied to the supply port 21,
As a result of forming a thin film without flowing from any of the samples 22, it was confirmed that aluminum was slightly deposited on the back surface of the heater 2. The uniformity of the aluminum thin film formed on the substrate was also ± 10%.

Embodiment 2 In this embodiment, the supply of the non-source gas from the supply port 22 to the gap 16 between the back surface of the substrate and the upper surface of the heater is stopped.
Otherwise, a thin film was formed under the same conditions as in Example 1.

No aluminum was deposited on the back surface of the heater.

Embodiment 3 Instead of the substrate used in Embodiment 1 described above, in this embodiment, a silicon oxide film is formed on the surface of a silicon wafer by thermal oxidation to a thickness of about 1 μm, and reactive ion etching is performed on one side. A substrate formed such that 0.25 μm contact holes were uniformly distributed on a wafer was used. Other conditions are almost the same as in the first embodiment.

It was confirmed that aluminum was deposited in all the contact holes.

[0049]

As described above, according to the present invention,
By providing a gap between the back of the heater and the top of the support,
By flowing the non-source gas there, the thermal decomposition and deposition of the source gas on the back surface of the heater are suppressed, the generation of foreign matter in the chamber is suppressed, and the number of maintenance of the apparatus can be reduced.

Furthermore, the above-mentioned gap facilitates replacement of the heater and shortens the time required for one maintenance.

Thus, according to the present invention, a thin film forming apparatus and a thin film forming method suitable for mass production can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a conventional thin film forming apparatus.

FIG. 2 is a schematic longitudinal sectional view of a substrate holding mechanism of the improved thin film forming apparatus.

FIG. 3 is a schematic longitudinal sectional view of one embodiment of a thin film forming apparatus according to the present invention.

FIG. 4 is a perspective view showing an example of a substrate holder.

[Explanation of symbols]

 W Substrate 1 Chamber 2 Heater 3 Support 4 Material gas supply port 5 Exhaust port 6 Heating element 7 Power supply 8 Wiring 9 Insulator 10 Connector section 11 Support rod 12 Heater back surface 13, 14 Non-material gas supply pipe 15 Groove 16 Substrate back surface Gap between heater 17 Partition member 18 Shower plate 19 Opening 20 Gap between backside of heater and support base 21, 22 Non-source gas supply port 23 Substrate restraint

Claims (14)

[Claims] 1. A heating chamber for housing a substrate therein and introducing a gas for forming a thin film, and a heating element for generating heat for heating the substrate and holding the substrate on the heating element. In a thin film forming apparatus, comprising: a member and a support for supporting the heating member, wherein the heating member is disposed at a predetermined interval on the support, and is different from the thin film forming gas. A supply port for the first non-source gas is arranged at an interval between the heating member and the support so as to form a flow of the first non-source gas to the outside from the predetermined interval. Thin film forming apparatus. 2. A second substrate, wherein the substrate is disposed with a predetermined gap between a back surface of the substrate and an upper surface of the heating member, and the second gas is different from the thin film forming gas flowing from the gap to the outside. 2. The thin film forming apparatus according to claim 1, wherein a supply port of the second non-source gas is arranged in a gap between the back surface of the substrate and a heating member to form a flow of the non-source gas. 3. The heating member is replaceable.
2. The thin film forming apparatus according to 1. 4. The thin film forming apparatus according to claim 1, wherein said heating member is made of one of metal, aluminum nitride, and silicon carbide. 5. The thin film forming apparatus according to claim 1, wherein the support is made of metal. 6. The thin film forming apparatus according to claim 1, wherein the wiring of the heating element is separable into a heating member side and a support base side by a connector portion. 7. The thin film forming apparatus according to claim 1, further comprising cooling means for cooling the support. 8. A chamber for accommodating a substrate therein and introducing a gas for forming a thin film, a heating element for generating heat for heating the substrate, and a heating unit for holding the substrate above the heating element. Using a thin film forming apparatus including a member and a support for supporting the heating member, disposing the heating member at predetermined intervals on the support, and supplying the thin film forming gas to the substrate. Forming a thin film on the surface of the substrate while supplying a first non-source gas different from the thin film forming gas to the outside from the predetermined interval, while supplying the gas to the surface of the substrate. 9. The substrate surface while flowing a second non-source gas different from the thin film forming gas to the outside through a gap provided between the back surface of the substrate and the upper surface of the heating member. 9. The method for forming a thin film according to claim 8, wherein a thin film is formed on the thin film. 10. The method according to claim 8, wherein the gas for forming a thin film is an organic metal gas. 11. The method according to claim 10, wherein the organic metal is any one of aluminum, tungsten, molybdenum, copper and titanium. 12. The method according to claim 10, wherein the organic metal is an alkyl aluminum hydride. 13. The method according to claim 8, wherein the first non-source gas is equal to the second non-source gas. 14. The thin film forming method according to claim 8, wherein the supply amounts of the first and second non-source gases are smaller than the supply amount of the thin film forming gas.