JPH02197571A - Formation of thin film and device thereof and semiconductor device obtained thereby - Google Patents

Abstract

PURPOSE:To stably form a CVD film which is a few in impurities and has low resistance value even when a low-vapor pressure source is utilized by providing a conductance variable orifice between a source gas generating chamber and a reaction chamber of a CVD device utilized for production of a semiconductor. CONSTITUTION:A source gas generating chamber 1 is joined to a reaction chamber 2 via a plurality of conductance variable orifices 5. CVD source substance 13 housed in a vessel 14 is heated by a heater 7 and vaporized in the chamber 1. The inside of a reaction chamber 2 is exhausted and evacuated through an exhaust port 15 joined to an exhaust pump 12. A metallic pattern is formed by decomposition of source gas of organic metal having a complex structure on a base plate 6 heated by a heater 4. In this case, the low-pressure source gas can be stably introduced into the reaction chamber 2 without utilizing carrier gas 9 such as Ar by controlling the conductance variable orifices 5. It is prevented that purity of the metallic film is lowered and resistance value is raised by infiltration of carrier gas into the patternlike metallic film formed by CVD on the base plate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a four-layer forming technique, and more particularly to a CVD apparatus suitable for manufacturing semiconductor devices and a semiconductor device obtained thereby.

[Conventional technology]

Conventionally, a large number of mechanisms and 1M devices have been devised to improve C'VD devices. Among these mechanisms and devices, those closest to the present invention will be described here.

First, the gas generator of the CVD apparatus will be described.

Japanese Unexamined Patent Publication No. 60-46575 describes a method of keeping the amount of gas supplied constant by keeping the pressure inside the gas generator constant. However, in the above invention, since the extracted gas is transported through iM before being led out, the amount of gas that can be transported is too small to use a source with a low vapor pressure, which poses a problem. When using a source with low vapor pressure, it is possible to perform source gas formation and film formation in one reaction tube, as in the method described in "Gallium Arsenide" by Ikoma, Kawata, and Hase (Maruzen), pp. 60. preferable.

However, in the above method, the pressure of the entire reaction chamber is affected by the vapor pressure of the source gas, so the reaction chamber pressure, which has a large effect on the quality of the CVD film, is usually set independently of the source gas pressure. This becomes difficult.

Therefore, it is necessary to provide a source gas supply chamber loosely connected to the reaction chamber, as in the method described in Japanese Patent Application Laid-Open No. 58-206119. However, the above-mentioned prior art is merely intended to improve performance, and does not have a structure that takes into consideration the control of source gas pressure, the conductance of the introduction pipe when transporting the source gas, and the like.

Let's briefly talk about the gas exhaust mechanism.

In conventional CVD techniques, the invention regarding gas flow control was limited to the source gas, and no consideration was given to the decomposed gases produced as a result of tumor formation. Therefore, even in JP-A-60-9877, in which an inner chamber is further provided as a gas exhaust mechanism within the reaction chamber and a plurality of exhaust ports are provided, consideration is not given to the flow of cracked gas generated after the reaction.

Third, let's talk about the 1 exhaust trap.

Most source gases conventionally used have relatively high vapor pressures, and even when unreacted source gases are exhausted, they can reach the exhaust pump without solidifying or condensing. On the other hand, when using a source with low vapor pressure, the unreacted source cools to around room temperature in the exhaust meridian, where it solidifies or condenses, causing exhaust pump failure, vacuum loss, corrosion of the exhaust system, etc. Tonashi Ururu.

Therefore, a mechanism for removing unreacted source gas is required.

. The trap structure that has been devised so far is that of JP-A-61.
Examples include the powder removal device described in Japanese Patent Application Laid-open No. 69967, and the toxic substance removal trap described in Japanese Patent Application Laid-open No. 136570/1982. There is no comparison with the one that corresponds to this.

As a result, when forming W used for wiring in semiconductor devices from W(CO)-, which is a low vapor pressure source, in order to form a W hood with sufficiently low resistivity, T, glect
rochem, Soc, Vol, 117 pp-6
93-700 (1970), bifurcated/s
It can only be formed at a slow speed that is significantly different from the ec-level applicability.

Furthermore, until now, there are only a few known examples regarding CvD of alloys, including the method described in JP-A-55-114350. In this technology, WF or MoF6
is selected as one component of the source gas, which is different from the technology using W(CO) in the present invention. Until now, WF, in particular, has been used to multiply wt-* only on Si, S10
! It is attracting attention as a source for selective CVD in which no W is formed on the surface, and there are many related patents.

However, this is mostly W single or wsi.

Regarding CVD of alloys, there are almost no studies focusing on CVD of alloys. The technique of forming W by CVD using W(CO) is also known, but focusing on CVD of alloys, we actively use W(CO) in C'VD of W-containing alloys.
・There is no limitation.

[Problem to be solved by the invention]

One object of the present invention is to develop a CvD form acid formation technique using a low vapor pressure source, which has not been particularly considered heretofore.
An object of the present invention is to provide a VD device for forming an olfactory acid. In the above technology, the problems of the prior art must be corrected in three respects: the gas generator, the exhaust mechanism, and the trap device.

First, regarding a source gas generator, it is difficult to supply a source gas that can form a film at a practical speed because its vapor pressure is low at a sufficiently low temperature that the source gas does not cause a decomposition reaction.

Next, the exhaust mechanism will be explained. W to be put into practical use in the future
In CVD of metals such as , Cu, and Pt, the source gas is
W(Co)stcu(CsHnFsOs)m,
Pt(Co) means C45Pt(PFs)4sPt((4H
It becomes an organometallic compound with a complex structure such as yOt)z.

Therefore, when forming a fusuma, various organic gases having complicated structures are generated. When these gases are immersed in acid, the quality of the film formed deteriorates significantly. Therefore, an m structure is required to promptly exhaust this organic gas, but such consideration has not been taken in the past.

Third is the trap device. In conventional equipment, the source gas was just a gas under reduced pressure. However, in the case of a sauce with a low vapor pressure, it is necessary to heat or heat it to gasify it and transport the sauce. Therefore, when unreacted source gas flows into the exhaust path, it solidifies or condenses in a low temperature area and is not exhausted, which adversely affects subsequent film formation or the apparatus itself.

On the other hand, AA I! is currently suitable for semiconductor devices. Il! An alloy film containing W, represented by TiW, is attracting attention as a barrier material for wires.

Here, the barrier and barrier performance in semiconductor wiring will be explained. The semiconductor wiring is mainly made of At alloy and is in contact with 81 semiconductor elements. Then, from this A2 alloy wiring/S1 interface, 81 is solid-dissolved into the At alloy during the annealing step, which is essential in the process, and conversely, during the cooling step, Sl in At is precipitated at the interface. As a result, the At//31 interface with the At
Defects and the like occur due to destruction of the S1 semiconductor element due to the solid solution of Sl inside.

To prevent this, a barrier layer is introduced at the AA wiring/81 interface to block mass transfer and ensure only electrical conduction. Currently, alloy films such as TIW are used as a barrier, but TiW is still not sufficient as a barrier because it has weak reactivity with Sl and consumes Sl. This alloy film is currently formed by sputtering, but from the viewpoint of step coverage and the like, it is desirable to form the film by CVDK. Further, as mentioned above, the barrier properties of alloys such as TlW are not sufficient, and improvement thereof is desired.

Here, regarding film formation by CVD method, conventional CVD method using WF- as a W source has been considered;
This technique has a problem in that when horse is used as the reducing agent, HF is generated and corrodes the 81 surface. Generally, when a substance having a metal-fluorine bond is used as a source and is reduced with H, there is a problem in that HF is always generated.

On the other hand, there is a method using 5iH4 as a reduction method that does not generate HP. However, in this case, there are problems such as a considerable amount of 81 being contained in the alloy, an increase in the specific resistance of the film, and a decrease in barrier properties. When alloying elements other than W tend to form silicides more easily than W, that is, Ti, M
o, V, Zr, Ta, Nb, Ni, C.

etc., silicides of these elements are formed during the 8iH4 reduction of W, which poses a big problem.

Therefore, another purpose of the present invention is to improve the barrier performance of an alloy film typified by TiW.
Another object of the present invention is to provide a CVD method that does not cause corrosion to the substrate and does not contain a large amount of 81 in the alloy, and to make it possible to manufacture highly reliable semiconductor devices using the CVD method.

[Means to solve the problem]

Among the above purposes, CVD [formation technology involves gasifying a solid or liquid metal compound at room temperature in a reaction vessel and reducing or decomposing the gas on a substrate heated by a heating mechanism. In the formation method, a variable conductance orifice is provided between the source gas generation section and the thin film formation section in the reaction vessel, the amount of source gas generation and the degree of vacuum in the thin film formation section are independently controlled, and the source gas is formed with low conductance. By supplying gas and forming four high-purity metal patterns at high speed, the system also consists of a source gas generator, a reaction vessel, a reaction vessel heater, a film forming substrate, a substrate heater, an exhaust pipe, and an exhaust pump. In the CVD equipment,
The above object is achieved by having the source gas generator integrated with the reaction vessel and providing a variable conductance orifice between the two.

Another objective of the above is to improve the barrier performance of the alloy film and to create a highly reliable semiconductor device, which has the line pattern 1 on the semiconductor element, and at least a part of this wiring film is made of W and W. In addition, Ti, Mo, and 7% Zr.

In a semiconductor device that is an alloy containing at least one element among Ta, Nb%N1, and Co, C1N is included in the alloy.
, O1B%P as the total concentration of one or more types of (L
By containing O1vt% or more and 5vt% or less, W and Ti, MOLV, and Zr other than W can also be contained.

This was achieved by using the CVD method to form an alloy containing at least one element among Ta%Nb%Ni and Co, in which the formation reaction of W is W(Co) and -W+6CO.

Next, the present invention will be explained in detail. Regarding the source gas generator of the CVD apparatus, 1. The gas generator is integrated with the reaction chamber to eliminate reduction in conductance due to an intermediate introduction pipe.

2. The gas generator and reactor are connected through one or more orifices with variable opening areas.

The source gas 1 flowing out from the gas generator per second is 1/1 of the saturated source amount that can exist as gas in the gas generator.
10 or less.

Regarding the exhaust mechanism, an inner wall having an exhaust port is further provided inside the reaction chamber, and the film is formed inside the inner wall, and the gas is exhausted through the exhaust port provided on the inner wall, and then through a meridian to the outside of the exhaust port and then to the outside of the reaction chamber. At this time, three or more exhaust ports are provided on the inner wall on the sides of the substrate on which the film is to be formed, concentrically from the center of the substrate. Furthermore, it may be provided above the substrate.

Regarding the exhaust tube, at least a part of the exhaust pipe connecting the exhaust port of the reaction chamber and the exhaust pump has a heater in the exhaust pipe, and the temperature of the heater is set to be higher than the decomposition temperature of source 7.

[Effect]

CVD Formed Acid Forming Technology Regarding the source gas generator of the CVD apparatus, the conductance of the source gas flow was increased by eliminating the introduction pipe in the middle. Conventional gas generators have low conductance and weak connection to the reaction vessel due to the presence of piping between the gas generator and the reaction vessel.

Therefore, the state inside the gas generator is hardly affected by changes in conditions such as the pressure inside the reaction vessel. On the other hand, according to the present invention, since the gas generator and the reaction vessel are closely connected, it is necessary to take into consideration the effect that the condition inside the reaction vessel has on the gas generator, which is different from the conventional technique.

To deal with this, the amount of source gas flowing out from the gas generator is kept sufficiently small compared to the amount of gaseous source gas, thereby keeping the source gas pressure inside the gas generator at a constant pressure, that is, the saturated gas pressure, and reducing the amount of gas. Flow rate can be stabilized. Thereby, a practically sufficient amount of source gas can be supplied with good reproducibility.

In this case, in order to increase the amount of gas supplied, it is important to increase the size of the entire gas generator and its internal volume.

Regarding the exhaust mechanism, since the decomposed gas generated on the substrate first spreads to the upper half of the substrate, it is preferable that the exhaust port be located on the upper half of the substrate, and also to prevent it from accumulating in a part of the reaction vessel without being exhausted. Therefore, it is necessary to exhaust the entire reaction chamber. Therefore, the above-mentioned means of providing a sufficient number of exhaust ports on the sides of the substrate is effective.

Regarding the exhaust trap, all unreacted source gas is decomposed on the heater in the trap part, forms a film on the heater, and the rest is mixed with the gas and exhausted.

Therefore, the exhaust pump will not be damaged due to solidification or condensation of a part of the exhaust system.

i9. Regarding semiconductor devices with improved barrier performance,
C%N% or 0 added to the alloy exists in the alloy crystals and forms impurity sites.

As a result, the crystal (strain) is generated, and the diffusion rate of Sl, which has a large value in a perfect crystal, is suppressed to a small value. Therefore, the 81 absorption rate of the alloy is 1/1 of that in the case without impurities.
10, the barrier performance is improved. In this case, C
If the amount of ,N%0 is too large, the film will be hard and brittle, and the specific resistance of the film itself will also be large, causing the problem of υ.
The total concentration of %N and O is desirably 5 yt% or less.

On the other hand, in the CVD method using W(CO), the reaction formula is W(
Co), -4W+6CO, and the problematic F and Si are not included in the reaction. Therefore, the problems of corrosion of Sl and inclusion of 81 in the alloy can be completely eliminated. Also, in this CVD, C1
By appropriately selecting CVD conditions, the content of 0%0 in the alloy can be controlled, and the first objective is also achieved at the same time.

Regarding alloying elements other than W, HF generated by CVD
Alternatively, in order to avoid the problem of Sl, it is desirable to use a material that does not have a metal-fluorine bond for the source. In this case, even if the reduction reaction is performed with a horse, H
No F was generated and the 81 substrate was not eroded. In addition, the reducing agent
Since it is not IH4, 81 does not dent into the alloy. Added impurities include B%P in addition to C%N and O.
Also available.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited to these Examples.

Example 1゜ An embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a sectional view of the CVD apparatus of the present invention. The main body of the CVD reaction vessel consists of a source gas generation chamber 1 and a reaction chamber 2, which are connected by a variable conductance orifice 5.

The source gas is obtained from a source material 13 set in a source container 14 placed inside the gas generation chamber 1 by heating the source substance 13 overnight with gas generation. The gas introduction pipe 9 is for introducing carrier gas. On the other hand, inside the reaction chamber 2, a film forming substrate 6 is set on the substrate heater 4. The gas introduction pipe 10 is used when a reduction reaction using hydrogen is used in the chemical reaction during film formation, etc.
This is used to introduce gas other than the source gas when it is required.

Further, a heater 8 for heating the reaction container is provided around the gas generation chamber and the reaction chamber to prevent the vaporized source from solidifying or condensing again. The reaction chamber 2 also has an exhaust port 1
The exhaust pump 12 is connected to the exhaust pump 12 through the pump 5, and the internal pressure is reduced.

Therefore, the source gas that was inside the gas generation chamber 1 is introduced into the reaction chamber, and a film is formed by the CVD method.

At this time, the unreacted source gas is guided from the exhaust port 15 to the exhaust pump 12 together with the gas generated by the reaction. However, since the trap heater 3 inside the hot trap 11 on the way to the exhaust pump 12 is set at a higher temperature than the decomposition temperature of the source gas, the source gas causes a CVD reaction on the trap heater 5 and forms a gas. However, only the gas generated by the reaction reaches the exhaust pump 12.

With this exhaust trap 11, the conventional solid source W (Co
)- was used to form a W model, the oil of the exhaust pump 12 absorbed W(Co)s and deteriorated after 0 days of operation, and the other one became W(CO), No longer takes damage from.

Another advantage of this top is that film formation in the trap only occurs over the course of 3 hours, which is the hottest part.
There is very little pollution in the exhaust pipe. This heater 5
Since it is removable, it is easy to clean and reuse if it becomes heavily contaminated.

Another advantage is that the internal heater 5 can be used as a baking heater for the exhaust pipe. Conventional baking requires wrapping a heater around the outer circumference of the pipe and then wrapping insulation material from above, which is a cumbersome process and requires sufficient space around the pipe.

On the other hand, if the heater 3 of this embodiment is used, just by wrapping a heat insulating material around the trap 11,
Baking of the exhaust pipe is possible.

By performing this baking, it is possible to see the adhered substances inside the exhaust pipe, and the degree of vacuum in the reaction chamber is reduced to 1 x 10".
''Torr could be lowered to I.times.10-'Torr.

Next, using this device, W (CO) and W due to thermal decomposition reaction
Film formation was performed. In this case, only the source gas is needed and no reaction gas is needed, so the gas introduction pipe 1o is not used. First, in order to check the capacity of the source gas generator, the partial pressure of the source gas W(CO) in the reaction chamber was measured.

Figure 12 is a graph showing the results. In the present invention, the amount of W(CO) is more than twice that of the conventional method of transporting source gas from a gas generator to the reaction chamber through an inlet pipe.
-We were able to obtain partial pressure. Furthermore, since the gas generator of the present invention does not require a gas introduction pipe, it has an advantage over the conventional method in that there is no need to consider keeping the introduction pipe warm. Furthermore, rounding allows for increased fundductance when introducing the source gas, and the source gas can be introduced without necessarily using a carrier gas. Therefore, it is possible to reduce or eliminate the entrapment of carrier gas into the formed wedge.

FIG. 3 is a graph showing the rate of formation of WIIK on the substrate at the time of death when the temperature of the substrate 6 is 500°C.
cb) of the present invention can be formed at a rate four times faster than that of cb).

FIG. 4 shows data regarding claim 2. Generally CVD
In the device, the amount of Saone gas flowing into the reaction chamber can be controlled by changing the pumping speed, and if the pumping speed is high, the amount of source gas flowing in will also increase.

However, in the case of a source material that has a low vapor pressure and is difficult to form a gas, if the rate of outflow of the source gas from the gas generation chamber is too high, gas formation will not be able to keep up, and the amount of gas outflow itself will become unstable.

In Figure 4, the ratio m4 of the initial outflow gas weight m at 1 second and the weight M of the saturated source gas filling the gas generation chamber is m4.
is (a), α1 (b) is (L 15 (c), 1
It is 12. In this case, only the second condition is satisfied and the source gas is stably supplied. If the 3 momme is 11 or more, the outflow rate of gas is too high and the V(
The partial pressure of CO) gradually decreases, making it impossible to keep the film formation conditions constant.

As described above, although sufficient improvements are made in the source gas supply and the gas formation rate in this embodiment, the film quality is not sufficiently improved.

Example 2 Next, a CVD apparatus will be described which has a gas generator and a reaction vessel integrated with a reaction chamber, and has an inner wall having an exhaust port inside the reaction chamber.

A schematic cross-sectional view of the reaction vessel is shown in FIG. CVD with natural
It is possible to equip the device with a hot trap as shown in FIG. Arrows indicate gas flow.

The exhaust port 17 provided in the inner wall 16 is located at a position symmetrical to the υ axis with respect to the center of the substrate, and the gas is exhausted isotropically with respect to this axis, contributing to uniformity of the olfactory quality. FIG. 6 shows measurement results showing the degree of W conversion formed in this example. In order to use W as wiring in a semiconductor device, it is necessary to lower the resistance by increasing the purity of the formed W. However, Wlllj formed by the w(cO)s thermal decomposition method conventionally contains polyelectronic C and O as impurities.

FIG. 6(a) shows a pattern formed using a conventional technique.

On the other hand, in the result (b) of this example, both C and O are reduced to about B or less compared to the conventional technique, and the grade is improved to Daifuku. In FIG. 6, the high C10 portion on the surface is a surface adhesion layer and has no relation to the quality of the filter film.

According to this example, w(co), -w+6c on 810m obtained by e-oxidizing the 81 substrate.

w* was formed by the thermal decomposition reaction of As shown in Fig. 6, the obtained W odor has a content of C and O, which are impurities, less than the conventional hυ, and the specific resistance of the odor is also aO
μΩ・country, which is about % of the value according to the prior art, about 15 μΩ・1. Therefore, even after forming the W wiring by performing photoetching after forming the W film, the wiring resistance was reduced to the conventional value.

Also, using this low vapor pressure source W(Co)-, 90VD
Unlike other CVD techniques that use WF, WC4, etc., corrosive gases such as HF%HCA are not generated, and there are no defects caused by these corrosive gases, and high quality wiring can be formed. . Therefore, a semiconductor device having wiring with low resistance and high damage resistance can be manufactured.

FIG. 12 is a cross-sectional view showing a MOS device using W for wiring, and FIG. 15 is a cross-sectional view showing a biport vice. In this figure, W
A barrier layer is used under the wiring 71 to form a good contact with Sl, but this barrier layer can be introduced only at the interface with $1 as shown in FIG. 12, or as shown in FIG. 15. It is also possible to introduce it all over the lower layer of the wiring as shown in FIG. When wiring of semiconductor devices uses W sliding doors formed by CVD method,
Compared to AL wiring formed by the conventional sputtering method, the I heat resistance is higher, the step coverage is improved, and higher integration is possible.

CV exhibiting the same effect as the reaction gas exhaust mechanism shown in Fig. 5
The D device is shown in FIG. A similar effect can be obtained with an exhaust mechanism having pores uniformly over the entire wall of the reaction chamber as shown in FIG. Note that this example is not limited to the formation of a W film by the W(CO) thermal decomposition method;
CsH4FsO*)-rich I(, Cu film formation by reduction,
It can be used in many CVD techniques, such as ptA formation by 4 reduction of Pt(Co)gc4.

Examples & In the 90VD device shown in Example 1, the number of variable conductance orifices 5 is not necessarily one! ! It is also possible to provide a plurality of them as shown in FIG. At this time, the orifices are provided on concentric circles with the center of the substrate as an axis in order to ensure uniformity of the thickness formed on the substrate.

According to this embodiment, the internal thickness of the substrate can be reduced from ±10% in the case of one orifice to within ±5%. Another important advantage of this embodiment is the stabilization of the source gas flow. The orifice is 1 as in Example 1.
In this case, the area around the orifice in the gas generator will be in a low pressure state due to the outflow of gas, causing large pressure unevenness within the gas generator and making the supply amount of source gas unstable. On the other hand, in the case of having multiple orifices as in this embodiment, the amount of gas flowing out per orifice can be reduced, and the pressure unevenness around the orifice in the generator can also be kept to a minimum. This is effective in stabilizing source gas supply.

The structure of the plasma CVD apparatus according to the present invention is shown below.
This will be explained using figures. FIG. 9 is a sectional view showing a plasma CVD reaction vessel, and its basic structure is the same as the reaction vessel of the CVD apparatus shown in Figure 'M1. New power supply 2o for high frequency plasma generation, insulator 21 for electrode insulation
, and a variable conductance orifice (also used as a high frequency electrode) 19 are added. Generally, plasma CVD uses thermal C
While VD mainly involves reactions near the substrate surface, it has a reaction region that is spatially spread out, called a plasma generation region. Therefore, the source reacts quickly to form the target substance. Therefore, prompt supply of source gas is even more important than thermal CVD.

Figures 10 and 11 show W(Co)s and NH, and WNl from
The results of Auger analysis of the fusuma formed when llI was formed into a film by plasma CVD are shown. FIG. 10 shows the WN@% of the prior art, and FIG. 11 shows the present embodiment. In this example, the film formation speed was higher than that of the conventional method due to the prompt supply of source gas.
．． It was 5 times more. Here, a WN film was formed on a kA substrate, and the most important feature in this case is that in this example, the amount of N contained in the Ats plate is much smaller than in the conventional method. This is because W(CO)・ is quickly supplied in the final method, so the formed W particles are
With N, the N source can be effectively consumed to form a film, whereas in the conventional method, the formation rate of W particles is slow.
This is because the excessive N source mainly reacts with the AL of the substrate.

In this way, the source gas supply method according to the present invention is also effective in plasma CVD. Furthermore, by using the reaction gas exhaust mechanism shown in FIG. 5, impurities in the plasma CVD 11I can be reduced as in the thermal CVD method.

EMBODIMENT OF THE INVENTION One embodiment of the present invention will be explained in detail with reference to FIG. 1
5 is an N source and W(Co)-.

In addition, Art was used as a carrier gas for W(Co).

The alloy barrier formed in this example has T1 and W as metals.
of which T1 is 5 vt X. Since the amount of T1 is small, the amount of T1 source supplied can be small, and in this embodiment, H! was introduced as a carrier gas. Ti(CaH@)m(Co) for T1 source
Proverb: Ti(CsHs)s, Ti(N(CHs))
4 was used. Here the carrier gas horse is T1
It also serves as a reducing agent for the sauce.

When using a conventional CVD device, W source W(Co)s
Not only was it difficult to supply, but the acid contained hydrocarbons such as C+Hs or intermediate products generated from the T1 source, and the formed pattern was brittle and bulky, and its adhesion was poor. On the other hand, in this embodiment, the reaction products can be quickly exhausted, so that it is possible to form a dense structure with good adhesion to the substrate.

During film formation, the reaction chamber 2 is heated to 50 to 200°C, and the substrate 6 is heated to 400 to 70°C by the substrate heater 6.
It is heated to 00°C. In addition, during CVD, the reaction chamber 2 is maintained at (L1 to 10 Torr) and the source gas is flowed. The ratio of T1 and W in the formed acid can be controlled by the flow rates of the two types of source gases and the substrate temperature. In addition, the amount of C, O, and N introduced into 1Iil is 5% because Co, etc. generated by the reaction is quickly exhausted.
The concentration of C and OlN in this region can be controlled by controlling the substrate temperature.

When introducing N as an additive element, add N to the carrier gas.
2 or NH. In case of B%Pm addition, B
! H1l, p)! , Closed and supplied. Also C10
When increasing the amount of carrier gas K C
The purpose of υ can be achieved by mixing gases such as o and CH4. FIG. 14 is a graph showing the relationship between substrate temperature, rate of gas formation, and gas composition. The film formation conditions were as follows: reaction tube internal pressure f Torr % W source: ri source flow ratio 10:1; carrier gas: W source: Ar
, Ti sauce is horse. The content of C10 varies depending on the substrate temperature, but satisfies the range of claim 12 when the substrate temperature is between 500°C and 700°C.

For CVD of alloy elements other than W, it is possible to use metal halides other than metal fluorides, metal fluoride, and organometallic compounds as source gases.

For example, in CVD of W-Mo alloy, MO source is
CI4. Mo(Co)a, ZrC4 in W-Zr,
Source materials such as Zr(C-exposed Hs)1C14° may be mentioned.

Examples & FIG. 15 is a cross-sectional view of a semiconductor device using the alloy film formed according to Example 5 as a barrier layer.

48 is an 81 substrate with partially thermally oxidized Sin! 47 is formed. Diffusion v41 is formed in necessary portions by ion implantation and annealing.

42 is a glass insulating layer formed by CVD method.

It has a thickness of 1 μm. A 1 .mu.m diameter strip (v-yf<-.mu.) is formed by photoetching on the required portion of the insulation@42. On top of that, according to Example 5, a barrier, Ti
W CV D alloy film 43 α1μm was formed and removed.

When forming KyI4 within μm hole μ with a diameter of 1 μm or less,
With sputtering method! The mawashi is bad, through-ho μ
Not enough thickness inside. Therefore, it is essential to form a barrier layer using the CVD method. Furthermore, At-Cu-
A film of 8i alloy 44 was formed by sputtering to a thickness of 1 μm. Thereafter, the wiring and the barrier layer were patterned simultaneously in a photo-etching process to form the semiconductor device shown in FIG. 15.

FIG. 16 shows the barrier performance of the semiconductor device manufactured according to this example in comparison with that of a case where TiW is formed by a conventional sputtering method. FIG. 17 shows the structure of the element used for evaluation.

A diffusion layer 16 with a thickness of 3 μm is formed on the P”-81 substrate 31, which serves as a barrier layer 43 and a kA alloy wiring 44.
I am in contact with. Contact area) is 1m thick. Figure 16 shows the reverse breakdown voltage of the p-/n+ diode.
In the prior art No. 16-(g)), the element becomes defective after annealing at 450°C for 120 minutes, whereas in the present example No. 1, the device becomes defective.
In Fig. 6-(a), it is operating normally even after 450"QX18Q minutes, and the performance of the pepper layer has improved compared to the conventional one.

Here, in order to obtain an alloy film containing C,OlN as an additive element with good reproducibility of its composition (because sputtering using a target containing C,OlN suffers from segregation of additive elements), C,OlN Even if a gas containing 20% is introduced during sputtering, the film formation process becomes complicated because reactive sputtering occurs at the same time.

Again, the reproducibility of the composition is not good. Therefore, as in this embodiment, the CVD method is suitable for forming a barrier alloy film for semiconductor devices in which C and O%N are added elements.

Here, CVDgI with a composition of 'ri:w=a: 92
FIG. 18 shows the relationship between the total concentration of C and O5N and the leakage current using 1 as a barrier. Leakage current is 450”C1
The measurement was performed by applying 15V to the sample after 20 minutes of annealing. When the additive concentration is less than α01 wt%, the leakage current increases and the barrier performance is not sufficiently improved. In addition, when the additive concentration exceeds 5 wt%, there is a phenomenon where the film is scratched or partially peeled off.
There is a problem with the dormitory.

〔Effect of the invention〕

With the CVD oxygen forming technology according to the present invention, 1. The conductance during transport of the source gas is large, and the fluctuation in the gas supply amount can be reduced.

2. The reaction gas generated during the CVD reaction can be quickly removed.

& Unreacted sources that reach the exhaust pipe can be disposed of without affecting the exhaust pipe or exhaust pump.

From the above three points, the present invention is a CVD method using a substance with a complex chemical structure and a low vapor pressure as a source.
This method is extremely effective in terms of speeding up film formation, improving film quality, and maintaining equipment.

The odor formed by the present invention has fewer impurities in the acid and therefore has lower resistance compared to the conventional technology, and is also produced by low pressure CVD.
Since it is a method, coverage in contact holes is also good and it is suitable for wiring of semiconductor devices. In particular, bipolar LSI, bipolar CM OSi, where execution speed is an issue
It is suitable for LSI wiring.

Furthermore, when a barrier alloy pattern is formed according to the present invention, C
Additive elements C, N%O or B%P during VD reaction
are incorporated into the barrier alloy with good reproducibility, and these added elements suppress the diffusion of 81 into the barrier alloy, which is effective in improving barrier performance.

In addition, there is virtually no HF generation during the CVD reaction,
Therefore, since there is no need to use Sin as a reducing agent, the 81 content in the barrier layer can also be kept low. The barrier pattern according to the present invention is particularly effective when used in semiconductor memory devices and semiconductor logic circuit devices. In other words, semiconductor memory devices are the most advanced in miniaturization.
A thin barrier is also desirable.

According to the present invention, the barrier properties can be improved and the barrier thickness can be made thinner than before, and it is suitable for this purpose. Also, semiconductor v
71 logic circuit! fil requires high-speed operation, and therefore reducing wiring resistance is also an important issue.

According to the present invention, since the barrier layer KSi is not included and there is no increase in resistance due to the inclusion of silicide, it is possible to lower the resistance of the entire wiring compared to the conventional method, and it is possible to increase the speed of the semiconductor ethical circuit device. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a CVD apparatus showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view of a CVD apparatus showing one embodiment of the present invention.
This graph shows the measurement results of the partial pressure of W(CO) in the reaction chamber when ・ is generated. 7. Figure 3 shows the substrate temperature at 500°C.
Figure 4 is a graph showing the W film formation rate when the temperature is 'C'.
W(Co) in the reaction chamber when the initial gas outflow velocity m is changed
Figure 5 is a schematic cross-sectional view of a device showing an embodiment of the present invention according to Ω, and Figure 6 is a graph showing changes in partial pressure. sxMs
Fig. 7 is a schematic cross-sectional view of an apparatus showing another embodiment of the present invention, and Fig. 8 is a graph detected from analysis. FIG. 3 is a cross-sectional view showing coupled reaction vessels. 9th
The figure is a sectional view showing the structure of an RF plasma CVD apparatus according to the present invention. Figures 10 and 11 are graphs showing the results of depth direction ocher analysis of the canopy formed when W(CO)- and N were formed using the Puds YCVD method. FIG. 10 is a graph showing the analysis results of the fusuma produced by the conventional CVD method, FIG. 11 is a graph showing the analysis results of the fusuma according to this example, FIG. 12 is a cross-sectional view of the MO8 device according to the present invention, and FIG. 13 is a cross-sectional view of the bipolar device according to the present invention. 14 is a graph showing the relationship between the substrate temperature, the formation rate, and the QIN composition when forming the Ti-W alloy layer according to this example. A cross-sectional view showing the structure and FIG. 16 are graphs showing the barrier properties of the barrier alloy according to this example, p7n? Reverse direction V-working characteristics after various annealing of diodes, 7XI &
- (a) is a graph showing the results of this example, Fig. 16 (b) is a graph showing the results of the conventional technique using the sputtering method, and Fig.
FIG. 18 is a cross-sectional view showing the structure of the semiconductor device used for the measurement shown in FIG. 6, and FIG. 18 is a graph showing the relationship between the total 1 degree of 0% 01N and the leakage current in the semiconductor device shown in FIG. 17. 1... Source gas generation chamber, 2... Reaction chamber, 3...
Trap heater 4... Substrate heater 5... Variable conductance orifice, 6... Substrate for pump formation,
7... Heater for gas generation 8... Heater for heating the reaction vessel 9... Carrier gas introduction pipe, 10... Reaction gas introduction pipe, 11... Hot trap, 12...
Exhaust pump, 13...CvD source material, 14...
Source container, 15...Exhaust port, 16...Inner wall of the reaction chamber, 17...Exhaust port, 18...Reaction chamber wall having pores on the entire surface, 19...Variable conductance orifice that also serves as an RF electrode , 20... RFt source, 21... Insulating insulator, 31... P type S1 substrate, 32... n1 defeat,
V,! 55...P diffusion soda, 54...Da diffusion, 1.3
5...n"diffusion-136・Sin,, 37...barrier oath, 38...W!il! line, 39...poly, silicon, 4o...barrier 1.41...diffusion 1.42
...CVD Glass Zetsu R Kan, 43 ・TiW CV D
Alloy barrier, 44-At-Cu-Si alloy, 45.
46... Voltage application terminal, 47... Oxidation sio,,
48...81 Substrate patent applicant Hitachi, Ltd.

Claims (1)

[Scope of Claims] 1. A method for forming a metal thin film in which a solid or liquid metal compound is gasified at room temperature in a reaction vessel, and the gas is reduced or decomposed on a substrate heated by a heating mechanism. A variable conductance orifice is provided between the source gas generating section and the thin film forming section in the container to independently control the amount of source gas generated and the degree of vacuum in the thin film forming section, and supplying the source gas at a low conductance. A method for forming a metal thin film, which is characterized by forming a high-purity metal thin film at high speed. 2. In the method for forming a metal thin film according to claim 1, when the source gas is introduced from the gas generating section to the thin film forming section through the orifice, the total weight of the gaseous source supplied to the thin film forming section per second. It is characterized in that the relationship between m and the total source weight M when the space in the gas generation section is filled with saturated source gas always satisfies the relationship of formula (1), m/M<0.1 (1). A method for forming a thin metal film. 3. In a CVD apparatus comprising a source gas generator, a reaction vessel, a reaction vessel heater, a film forming substrate, a substrate heater, an exhaust pipe, and an exhaust pump, the source gas generator is integrated with the reaction vessel; A CV characterized in that a variable conductance orifice is provided between the two.
D device. 4. The CVD apparatus according to claim 5, wherein an inner wall surrounding the substrate is provided inside the reaction vessel, and a plurality of exhaust ports are provided in the inner wall. 5. The CVD apparatus according to claim 3 or 4, wherein a plurality of variable conductance orifices are arranged concentrically around an extension of the center of the film forming substrate. 6. The CVD apparatus according to claim 4, wherein the inner wall does not have an exhaust port at a specific position and has uniform pores over the entire surface of the inner wall. 7. A plasma CVD apparatus according to any one of claims 3 to 6, further comprising a plasma generation mechanism. 8. In the CVD apparatus according to any one of claims 3 to 6, the exhaust pipe connecting the reaction vessel and the exhaust pump,
A CVD apparatus characterized in that at least a portion thereof is provided with a detachable built-in heater, and has means for setting the heater temperature to a temperature higher than the decomposition temperature of a CVD source gas. 9. A semiconductor device having a wiring film on a semiconductor element, wherein at least a part of the wiring film is formed by the CVD apparatus according to any one of claims 3 to 6. 10. A bipolar LSI device having a wiring film on a semiconductor element, wherein at least a part of the wiring film is formed by the CVD apparatus according to any one of claims 3 to 6. 11. The semiconductor device according to claim 9, wherein the wiring film is W.
Or in addition to W and W, Ti, Mo, V, Zr, Ta, Nb,
A semiconductor device comprising an alloy containing at least one element among Ni and Co. 12. Having a wiring film on a semiconductor element, and at least a part of this wiring film contains Ti, Mo, V, Zr, in addition to W and W.
In a semiconductor device that is an alloy containing at least one element among Ta, Nb, Ni, and Co, C, N,
The total concentration of one or more of O, B, and P is 0.0
A semiconductor device characterized by containing 1 wt% or more and 5 wt% or less. 13. The semiconductor device according to claim 12, wherein 0.01 wt% or more and 5 wt% or less of the metal elements in the alloy have bonds with C, O, and N. 14. W and other than W Ti, Mo, V, Zr, Ta, N
Formation of an alloy thin film on a semiconductor element, in a method for forming an alloy film containing at least one element among b, Ni, and Co by a CVD method, characterized in that the formation reaction of W is W(Co)_6→W+6CO. Method. 15. The method for forming an alloy thin film according to claim 14, wherein a source gas material having no metal-fluorine bond is used in the CVD reaction of an element other than W. 16. A semiconductor device, characterized in that at least a part of wiring in a semiconductor device is formed by the method for forming an alloy thin film according to claim 14 or 15. 17. A semiconductor memory device, characterized in that at least a part of the wiring of the semiconductor memory device is formed by the method for forming an alloy thin film according to claim 14 or 15. 18. A semiconductor logic circuit device, characterized in that at least a part of the wiring of the semiconductor logic circuit device is formed by the method for forming an alloy thin film according to claim 14 or 15. 19. In addition to W and W, Ti, Mo, V, Zr, Ta, Nb
, Ni, and Co, the total concentration of C, O, and N is 0.05wt% or more 5w
An alloy characterized by containing t% or less.