JPH06158306A - Production of target for sputtering by ga-deposition method and device therefor - Google Patents

Abstract

PURPOSE:To easily form a target which has an uniform composition and a smooth surface on a target fixing plate by supplying superfine particles of raw material for forming a target to a target forming room from respective generating rooms by using gaseous Ar as a carrier gas. CONSTITUTION:A Ti superfine particle generating room 1, a Si superfine particle generating room 2 and the target forming room 4 are connected by a transporting pipe 3, respective rooms 1, 2, 4 are evacuated to vacuum and the internal pressure of the target forming room 4 is made lower than the internal pressures of the other rooms 1, 2. In the room 1, Ti material A in a water- cooled copper hearth 5 is heated and evaporated by an arc between W tips 6 and Ti superfine particles are taken off via transporting pipe 34 by using gaseous At from a bomb 16 as a carrier. Similarly, Si material B in the room 2 is heated and evaporated by a W heater 21 and Si superfine particles are taken off via a transporting pipe 35 by using gaseous Ar 30 as the carrier gas and they are sucked into the target forming room 4 having lower pressure via the transporting pipe 3 and thereby a TiSi2 target is formed on the target fixing plate 41 by a rection between Ti and Si.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sputtering target by a gas deposition method and an apparatus for producing the same. More specifically, the composition of the target is directly superposed on a target fixing plate used for sputtering. The present invention relates to a method of manufacturing a sputtering target for depositing fine particles and using the target as a target, and a manufacturing apparatus used in the manufacturing method.

[0002]

2. Description of the Related Art A method of manufacturing a target for AB sputtering, in which a target is most commonly used as a target manufacturing technology, is blended with a composition of elements A and B.

First, powders of elements A and B (the particle size of each of these powders is about 10 μm, which is practically used as relatively small particles), are weighed based on a predetermined mixing ratio, and placed in a mixing mixer. Stirring for about 2 hours to complete the mixing. Next, the powder mixture is molded into a flat plate,
It is put in a pressure mold made of graphite or heat-resistant steel and heated at high temperature in a vacuum or in an inert, non-oxidizing gas atmosphere by hot pressing and held for a predetermined time to complete sintering.

A taken out from the graphite pressure die
The surface of the element-B sintered body is ground to a level of about 3S and smoothed. After that, a brazing material is used to bond the water-cooled copper target fixing plate prepared in advance to form a shape that can be used in a sputtering apparatus. The manufacturing process is shown in the chart of FIG.

An example of producing a titanium silicide (TiSi ₂ ) target, which is at a high level as its manufacturing technique, will be described.

First, 1,100 g of titanium hydride (TiH ₂ ) powder having an average particle size of 13 μm and 670 g of silicon (Si) powder having an average particle size of 11 μm were placed in a titanium container of a V-type mixer for rotary mixing. Argon (Ar) gas is blown in to close the chamber. Next, a V-type mixer was set to 20γ. p.
m. The rotation is continued for 2 hours to complete the mixing. Next, made of carbon material, inner diameter 300 mm, depth 6
The mixed powder is put into a 0 mm pressure die, upper and lower pressing plates are set, and this is inserted into a hot press machine. The hot press machine has a 0.06 Pa (4.5 x 10
^{- 4} Torr) was evacuated to, 70 kPa (530
Argon gas is introduced up to Torr). Next, the pressure type upper push plate is brought into contact with the pressure piston of the hot press.

Then, the heater around the pressure die is heated to 450 ° C. in 2 hours. Upon completion of the temperature rise, the pressure piston is operated to apply a pressure of 300 kg / cm ^{2 to} the pressure type upper push plate. While maintaining the pressurized state, the temperature of 1300 ° C. is maintained for 1 hour, and the hot pressing is finished.

After cooling to near room temperature in the hot press machine, the pressure die is taken out, the upper and lower pressing plates are removed, and the titanium silicide sintered body is taken out.

The titanium silicide sintered body taken out was in the form of a disk having a diameter of 300 mm and a thickness of 8 mm, and had an apparent density of 9
The surface roughness was 4% (the true density was 3.33 g / cm ³ ), and the surface roughness was 10S. Then, one surface of the disk-shaped sintered body is ground by a grinder to a surface roughness of 3S to make the surface smooth and finished as a target.

Then, in order to mount the target in the sputtering apparatus, the surface of the target which is not cooled and is brazed to the surface of the water-cooled copper target fixing plate in the apparatus. The brazing material used is indium (In)
In the system, the brazing conditions are in an argon inert atmosphere heated to 200 ° C.

[0011]

In the above conventional manufacturing technique, the starting material for the target has an elemental particle size of 10 μm.
Since it starts with m or larger particles, the target after sintering at high temperature and hot pressing under pressure is a coarse particle sintered body containing many pores (holes). Therefore, there is a problem that the discharge becomes unstable due to the ion bombardment of the target surface during the scatter operation, which eventually leads to defective film formation.

Further, in the bonding between the target and the fixing plate, the target may be peeled off from the fixing plate because a heat cycle of heating-non-heating is applied to the target during use.

The present invention solves the above problems, and as a sputtering target, a plurality of elements composing the target, such as titanium and silicon, have a uniform composition in the submicron order, a submicron-sized dense structure, and a smooth surface. It has the excellent characteristics of a strong surface and a strong bond with the fixed plate, and the process of mixing, pressure sintering, surface grinding, and brazing can be omitted as a process. An object of the present invention is to provide a manufacturing apparatus used for the manufacturing method.

[0014]

The present invention forms an ultrafine particle mixed deposition film for homogenizing a composition in which main components of a target, for example, titanium and silicon are mixed in the order of submicron, and at the same time, forms a film. Densification of the internal structure, formation of a smooth surface with irregularities on the film surface of 1 μm or less (<1S), and further, strong bonding with the fixing plate without deposition by direct deposition on the fixing plate. I do. They are to generate ultrafine particles (here, titanium and silicon) and to directly form an ultrafine particle mixed film on a target fixing plate by carrying, mixing, and jetting an aerosol in which the ultrafine particles and a carrier gas are mixed.

More specifically, the present invention proposes a method for producing a sputtering target by the gas deposition method, which achieves the above-mentioned object. The target is a target used for sputtering, and the target is prepared by the gas deposition method. It is characterized in that ultrafine particles having the composition of the target are directly deposited on the fixed plate to form a target on the fixed plate that is dense inside the deposition portion, has a uniform composition ratio, and has a smooth surface.

Further, the present invention proposes a manufacturing apparatus for carrying out the above-mentioned manufacturing method, which comprises an evaporation source for heating and evaporating each of a plurality of elements constituting a sputtering target to generate ultrafine particles. Ultrafine particle generation chamber, target forming chamber for ejecting ultrafine particles onto a target fixing plate to form a target, and ultrafine particle generated in the ultrafine particle generation chamber disposed between the ultrafine particle generation chamber and the target formation chamber And a carrier gas for carrying the carrier gas to the target forming chamber, and a nozzle for injecting the ultrafine particles and the carrier gas provided on the tip side of the carrier pipe onto the target fixing plate.

[0017]

Function A plurality of elements forming the target in the ultrafine particle generation chamber are heated by respective evaporation sources to generate ultrafine particles.
The ultrafine particles are carried by the carrier gas through the carrier pipe to the target forming chamber, and are sprayed and deposited on the target fixing plate by the nozzle provided on the tip side of the carrier pipe. At that time, since the particle size of the ultrafine particles is on the order of submicrons, a target having a dense interior, a uniform composition ratio, and a smooth surface is directly formed on the fixed plate.

[0018]

Embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a manufacturing apparatus for carrying out the method of the present invention. In the figure, 1 is an ultrafine particle producing chamber (hereinafter referred to as a first producing chamber) for producing ultrafine particles of titanium, for example. 2 is, for example, an ultrafine particle generation chamber for generating ultrafine particles of silicon (hereinafter referred to as a second generation chamber), 3 is an ultrafine particle / gas mixture carrying pipe for carrying ultrafine particles of titanium and silicon together with a carrier gas, and 4 is a target. A target forming chamber (hereinafter, referred to as a film forming chamber) for forming a film is shown.

A water-cooled copper hearth 5 is installed in the first production chamber 1, and titanium (T
i) was filled. Further, a tungsten (W) tip 6 having a diameter of 3 mm is attached to the arc electrode holder 7 in a direction diagonally above the water-cooled copper hearth 5. Further, a DC arc power source 8 was installed adjacent to the first generation chamber 1, the water-cooled copper hearth 5 was connected to the + pole, and the arc electrode holder 7 of the tungsten tip was connected to the − pole. In addition, the vacuum pipe 9 and the vacuum valve 1 are provided in the first generation chamber 1.
0, a vacuum exhaust system 12 composed of a vacuum pump 11, a gas stop valve 13, a gas flow meter 14, a gas flow rate control valve 15,
A gas introduction system 17 composed of an argon (Ar) gas cylinder 16, a vacuum gauge 18 and a pressure gauge 19 were connected.

In the second generation chamber 2, a boron nitride (BN) crucible 20 and a tungsten cylindrical heater 21 are installed around the crucible 20. The crucible 20 is filled with silicon (Si) as an evaporation raw material B. It was to so. Also, the crucible 2
0 was connected to a resistance heating power source 22 installed outside the second generation chamber 2. In addition, the vacuum pipe 2 is provided in the second generation chamber 2.
3, a vacuum exhaust system 26 including a vacuum valve 24 and a vacuum pump 25, and a gas introduction system 31 including a gas stop valve 27, a gas flow meter 28, a gas flow rate adjusting valve 29, and an argon (Ar) gas bomb 30. A vacuum gauge 32 and a pressure gauge 33 were connected.

Furthermore, one end of a transfer pipe 34 having an inner diameter of 3 mm for transferring the ultrafine particles of the raw material A (here, titanium) to be heated and generated together with the carrier gas is airtightly inserted and connected above the first generation chamber 1, and Above the second generation chamber 2, one end of a carrier pipe 35 having an inner diameter of 3 mm for carrying the ultrafine particles of the raw material B (here, silicon) generated by heating together with the carrier gas was hermetically inserted and connected. Further, the respective leading end portions of the carrier pipe 34 and the carrier pipe 35 are connected to the carrier pipe 3, the leading end of the carrier pipe 3 is extended into the film forming chamber 4, and the nozzle mounting pipe 36 is installed in the film forming chamber 4. Connected to. A nozzle 37 having a length of 25 mm and a width of 0.1 mm and having a slit-shaped cross section is attached to the tip of the nozzle attachment pipe 36.

A target fixed plate moving carriage 38 is installed in the film forming chamber 4, and the fixed plate moving carriage 38 is moved in X and Y directions.
It was made possible to move in each direction by 200 mm. Further, a heating stage 39 is built in the fixed plate moving carriage 38,
The heating stage 39 was connected to a resistance heating power source 40 installed outside the film forming chamber 4 so that the maximum temperature could be raised to 500 ° C. Further, for example, a rectangular copper target fixing plate 41 having a size of 200 mm × 200 mm and a thickness of 20 mm can be placed on the fixed plate moving carriage 38. In addition, a vacuum pipe 42 and a vacuum valve 4 are provided in the film forming chamber 4.
3. A vacuum exhaust system 45 composed of a vacuum pump 44 and a vacuum gauge 46 were connected.

Next, using the manufacturing apparatus shown in FIG.
A specific example of creating a target on the target fixing plate will be described.

In this embodiment, titanium and B are used as evaporation raw materials A.
Using silicon as the material, an ultrafine particle deposition film of titanium silicide (TiSi ₂ ) having an area of 150 mm × 150 mm and a thickness of 5 mm is formed on a target fixing plate for sputtering (made of copper: 200 mm × 200 mm × 20 mmt) 41, that is, a target is prepared. Here is an example.

First, 410 g of titanium as the evaporation raw material A was filled in the water-cooled copper hearth 5 in the first production chamber 1, and 450 g of silicon as the evaporation raw material B was filled in the crucible 20 in the second production chamber 2. . Further, the tip of the nozzle 37 and the target fixing plate 40 were kept at 1 mm intervals.

Next, the vacuum pump 11 of the first generation chamber 1, the vacuum pump 25 of the second generation chamber 2, and the vacuum pump 44 of the film formation chamber 4 are each actuated, and the respective vacuum valves 10,
The valves 24 and 43 are opened to exhaust the interiors of the first production chamber 1, the second production chamber 2 and the film formation chamber 4. After confirming that the internal pressure of each of the first generation chamber 1, the second generation chamber 2 and the film formation chamber 4 has reached 2 Pa or less (<0.015 Torr), the vacuum valve 10 of the first generation chamber 1 and The vacuum valve 24 of the second generation chamber 2 is closed to stop the evacuation, but the film formation chamber 4 continues to evacuate.

Subsequently, the gas cylinder 1 is placed in the first production chamber 1.
Argon gas is introduced as a carrier gas from 6 and the pressure is maintained at 40 kPa (300 Torr). afterwards,
Argon gas is continuously supplied at a flow rate of 1.6 l / min by the gas flow rate control valve 13. In addition, a high frequency of 2 kHz is superposed between the water-cooled copper hearth 5 and the electrode holder 7 of the tungsten tip 6 by the DC arc power source 8 at 65 V.
DC current is applied. Immediately after that, an arc is generated between titanium of the evaporation raw material A in the water-cooled copper hearth 5 and the tungsten tip 6, and the titanium is heated and begins to melt. When the DC arc power source 8 is adjusted to maintain the applied current at 26V × 180A, the titanium in the water-cooled copper hearth 5 is entirely melted,
Titanium evaporates from the surface to produce ultrafine titanium particles.
Since there is a pressure difference of ≈40 kPa between the first generation chamber 1 and the film formation chamber 4, the titanium ultrafine particles that have been vaporized and generated are sucked into the carrier pipe 34 in a state of being suspended in the argon gas, thereby forming a film. It is transported to the chamber 4 side.

Similarly, a gas cylinder 3 is placed in the second generation chamber 2.
Argon gas is introduced as a carrier gas from 0, and the pressure is maintained at 40 kPa (300 Torr). afterwards,
Argon gas is continuously supplied at a flow rate of 1.6 l / min by the gas flow rate control valve 27. Further, the output of the resistance heating power source 22 is gradually increased to raise the temperature of the tungsten cylindrical heater 21 to heat the crucible 20 and the silicon of the evaporation raw material B. When the heating condition of the heater 21 is maintained at 2.6 V × 80 A, silicon atoms evaporate from the molten silicon surface in the crucible 20 and are cooled by the surrounding argon gas to generate ultrafine silicon particles, which are added to the argon gas. To float. Further, since there is also a pressure difference between the second generation chamber 2 and the film formation chamber 4, the ultrafine silicon particles suspended in the argon gas are sucked into the transfer pipe 35 and transferred to the film formation chamber 4 side. To be done.

Then, the argon gas mixed with the titanium ultrafine particles and the argon gas mixed with the silicon ultrafine particles are mixed through the carrier pipes 34 and 35 in the carrier pipe 3 for the ultrafine particle / gas mixture. The ultrafine particles in the argon gas are evenly mixed and transported into the film forming chamber 4, and the ultrafine particles mixed with titanium and silicon are supplied to the target together with the argon gas at a high speed from the nozzle 37 connected to the tip of the transport tube 3. It is ejected onto the fixed plate 41 and deposited to form a deposited film of ultrafine particles having a uniform composition of titanium and silicon, that is, a target T.

At this time, the target fixing plate 41 is heated to a temperature of about 250 ° C. by the output of 6.2 V × 35 A of the resistance heating power source 40 of the heating stage 39. Further, the fixed plate moving carriage 38 is 150 mm in the X direction at a speed of 6 mm / min.
It reciprocates over the length of. In addition, the nozzle 37
The mixed ultra-fine particles ejected from the tip of the slab are 25 mm wide and 5 m thick on the target fixing plate 41 in one reciprocation in the X direction.
A deposited film of m, that is, the target T is formed. The required time in the meantime is 50 min. When one reciprocation is completed, the fixed plate moving carriage 38 moves 25 mm in the Y direction and reciprocates 150 mm in the X direction at the same speed in the same manner as described above. This movement in the Y direction is performed six times in total, and the length in the Y direction is 150.
Deposition takes place over the mm. The total deposition time was 5 hours, during which the evaporation of titanium ultrafine particles and the evaporation of silicon ultrafine particles were performed under the same conditions. FIG. 2 shows the formation state of the target T by jetting and depositing the mixed ultrafine particles of titanium and silicon from the nozzle 37 onto the target fixing plate 41.

FIG. 3 shows a carrier gas circulation system disposed between the film forming chamber and the first and second generation chambers of the apparatus shown in FIG.

Differences between the manufacturing apparatus shown in FIG. 3 and the manufacturing apparatus shown in FIG. 1 will be described. In the figure, 51 is the first generation chamber 1
A gas circulation circuit for reusing the carrier gas discharged from the film forming chamber 4 arranged between the second generation chamber 2 and the film forming chamber 4 is shown. In the illustrated example, the starting end 51 a of the gas circulation circuit 51 is connected to the vacuum pump 44 of the film forming chamber 4, and a branch path 51 that is branched into two downstream of the gas circulation circuit 51.
b is provided, and one gas circulation circuit 5 from the branch path 51b is provided.
The terminal end 51c of No. 1 is connected to the gas introduction system 17 of the first generation chamber 1, and the other gas circulation circuit 51 from the branch path 51b is connected.
End 51d of was connected to the gas introduction system 31 of the second generation chamber 2.

A circulation valve 52 is arranged on the side of the starting end 51a of the gas circulation circuit 51, and a branch passage 54 having an exhaust valve 53 is provided on the upstream side of the circulation valve 52. Further, a low pressure reservoir 55, a filter 56, a compressor 5 are provided in the circulation circuit 51 on the downstream side of the circulation system valve 52.
7. A high pressure reservoir 58 was provided. In addition, the branch road 51b
A stop valve 59 is provided in the circulation circuit 51 on the first generation chamber 1 side.
Stop valves 60 are provided in the circulation circuit 51 on the second generation chamber 2 side from the branch path 51b.

Since the other reference numerals are the same as those of the apparatus shown in FIG. 1, the description thereof will be omitted.

The manufacturing apparatus having the carrier gas circulation system shown in FIG. 3 has the following advantages. In the manufacturing apparatus shown in FIG. 1, the carrier gas (argon gas) introduced into the first generation chamber 1 and the second generation chamber 2 is transported by the carrier tube 3 together with the ultrafine particles generated by evaporation in the respective generation chambers 1, 2.
Through the nozzle 38 attached to the tip of the nozzle 38 into the film forming chamber 4, and diffuses in the film forming chamber 4.
It is exhausted by the vacuum pump 44 and released into the atmosphere. Thus, when the carrier gas is simply released into the atmosphere after being used, not only is it costly to fractionate argon, which has a low content in the air, as the carrier gas from the air, but it is also time-consuming. Is a big problem. Therefore, as shown in FIG. 3, the carrier gas discharged by the vacuum pump 44 of the film forming chamber 4 is recovered by the carrier gas circulation circuit 51, and the low pressure reservoir 55, the filter 56, the compressor 57, and The carrier gas is purified and pressurized by each device of the high-pressure reservoir 58, and the purified carrier gas is supplied into the first generation chamber 1 and the second generation chamber 2.
Each of them can be introduced and reused, which can reduce the cost and the time loss.

In the above embodiment, the composition of the target formed on the target fixing plate is titanium silicide (TiS).
i ₂ ), the present invention uses the titanium silicide (Ti
It is not limited to Si ₂ ) and is difficult to produce by the conventional method of joining and fixing the target and the target fixing plate with a brazing material, and also for the production of a target of a composition whose quality is difficult to improve, for example, tungsten and silicon. It can be applied. Further, as a demand in the semiconductor industry in the future, spattering of a combination of new elements is expected, but the method of the present invention and the manufacturing apparatus therefor can meet such demand.

[0038]

According to the method for producing a sputtering target by the gas deposition method of the present invention, the conventional method is combined with the ultrafine particles constituting the target, the gas deposition and the uniform mixing method, and the deposition of a wide film. Excellent characteristics such as solving the technical problem that was a problem in the above, homogenizing the composition of mixed elements in the submicron order, submicron-sized dense structure, smooth surface, and strong bonding with the target fixing plate. There is an effect that it is possible to extremely easily form the target having the above directly on the target fixing plate.

When the apparatus for producing a sputtering target by the gas deposition method of the present invention is used, the target obtained by omitting the operations of mixing, pressure sintering, surface grinding and brazing in the production process is fixed to the target. There is an effect that it is possible to provide a manufacturing apparatus that can be formed on a plate directly and extremely easily.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a target manufacturing apparatus of the present invention,

FIG. 2 is an explanatory view of a formation state of ultrafine particle targets on a target fixing plate using the manufacturing apparatus of FIG.

FIG. 3 is an explanatory diagram of another embodiment of the target manufacturing apparatus of the present invention,

FIG. 4 is a manufacturing process diagram of a target for compound sputtering of A element-B element by a conventional method.

[Explanation of symbols]

1, 2, ultrafine particle generation chamber, 3, 34, 35 transfer pipe,
4 target forming chamber, 37 nozzles, 41
Target fixing plate, elements that compose A and B targets, and T target.

Claims (2)

[Claims] 1. A target used for a sputter, wherein ultrafine particles having the composition of the target are directly deposited on a target fixing plate by a gas deposition method, and the inside of the deposition portion is dense on the fixing plate, and the composition ratio is high. A method for producing a sputtering target by the gas deposition method, which comprises forming a target having a uniform surface and a smooth surface. 2. A target is formed by injecting ultrafine particles onto an ultrafine particle generating chamber provided with an evaporation source that heat-evaporates a plurality of elements constituting a sputter target to generate ultrafine particles, and the target fixing plate. A target formation chamber, a transfer pipe for transferring the ultrafine particles generated in the ultrafine particle generation chamber between the ultrafine particle generation chamber and the target formation chamber together with a carrier gas to the target formation chamber, and provided on the tip side of the transfer pipe A gas characterized by comprising a nozzle for injecting ultrafine particles and carrier gas onto a target fixing plate.
Equipment for manufacturing targets for sputtering by the deposition method.