JPH03110840A - Deposition of film - Google Patents

Abstract

PURPOSE:To make it possible to deposit a low-resistance Mo film with good controllability by a method wherein the molybdenum film is selectively formed on the electron donative surface of a substrate having the electron donative surface and a non-electron donative surface at the decomposition temperature or lower of a molybdenum compound and within a range of temperature of 800 deg.C or lower in an atmosphere containing molybdenum compound molecules and hydrogen gas. CONSTITUTION:Molybdenum compound molecules and hydrogen gas are fed on a substrate 1 having an electron donative surface and a non-electron donative surface, the temperature of the electron donative surface is maintained at the decomposition temperature or lower of a molybdenum compound and within a range of temperature of 800 deg.C or lower and a molybdenum film is selectively formed on said electron donative surface. Here, a substrate temperature of 800 deg.C or higher can not be used, the substrate temperature of 600 deg.C or lower is desirable and the range of the most desirable substrate temperature is 450 to 550 deg.C. Thereby, the low-resistance and dense Mo film can be selectively deposited on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming a deposited film, and particularly to a method for forming a Mo deposited film that can be preferably applied to wiring of semiconductor integrated circuit devices and the like.

[Prior Art] Conventionally, in electronic devices and integrated circuits using semiconductors, electrodes and wiring have mainly been made of aluminum (An) or Aluminum (An).
l1-5i etc. have been used. Here, AjZ is inexpensive and has high electrical conductivity, and since a dense oxide film is formed on the surface, the inside is chemically protected and stabilized, and it has good adhesion with Si. It has many advantages such as:

However, with the increase in integration, self-alignment (self-positioning) eliminates the need for mask alignment between the gate electrode and the diffusion layer.
Technology is essential. Because this process requires high temperatures, metals with low melting points such as A1 cannot be used. In conventional MO5LSIs, heavily impurity-doped polycrystalline Si has been widely used as gate electrode wiring that enables self-alignment. However, as the degree of integration increases, a problem arises in that the electrical resistance of fine polycrystalline Si interconnections and the like increases. This is fatal to high-speed operation of the device. Therefore, the volume resistivity is lower than that of polycrystalline Si.
Furthermore, there is a need for a high melting point metal that can be self-aligned. Furthermore, even if Afl can be used, Si reacts with the wiring /l during heat treatment at the contact electrode portion with the Si layer, resulting in disconnection and increased resistance of the wiring. For this reason, metals with high melting points and low electrical resistance have come to be used as electrode wiring materials and as barrier metals to prevent the reaction between Si and Al in the contact portion. In particular, MO has a sufficiently high melting point (2620℃) and low electrical resistance (4
, 9 μΩ·cm), and so on.

Conventional Mo films used for MO main electrode wiring and the like have been deposited by electron beam evaporation or sputtering. However, as dimensions become smaller due to increased integration, the surfaces of LSIs and other devices become oxidized.

The unevenness has become severe due to diffusion, thin film deposition, etching, etc. For example, electrodes and wiring metal must be deposited on a stepped surface without disconnection, or must be deposited in a deep and minute diameter pier hole. 4Mbit or 16Mbit
In a DRAM (dynamic RAM) and the like, the aspect ratio (pierhole depth/pierhole diameter) of a pierhole on which wiring metal must be deposited is 1.0 or more, and the pierhole diameter itself is 1 μm or less. Therefore, there is a need for a technology that can deposit wiring metal even in peer holes with large aspect ratios.

In particular, in order to make a reliable connection to a device under an insulating film such as Sin, it is necessary to deposit metal so as to fill only the peer holes of the device rather than forming a film. For this purpose, a method is required in which the wiring metal is deposited only on the Si or metal surface, and not on the insulating film such as 5i02.

Such selective deposition or selective growth cannot be achieved by conventionally used electron beam evaporation or sputtering methods. Since the sputtering method is a physical deposition method based on the flying of particles sputtered from a target in a vacuum, the film thickness becomes extremely thin at step portions and side walls of the insulating film, and in extreme cases, disconnection may occur. . And, uneven film thickness and disconnections are caused by LSI
This will significantly reduce the reliability of the system.

By applying a bias to the substrate and using the sputter etching action and deposition action on the substrate surface, A is applied only to the peer hole.
A bias sputtering method has been developed in which JZ or Yabu alloy or MO silicide is deposited in a buried manner.

However, since a bias voltage of several hundred volts or more is applied to the substrate, adverse effects such as a change in the threshold value of the MO5-FET occur due to charged particle damage. Furthermore, since the etching action and the deposition action coexist, there is also the problem that the deposition rate cannot be improved due to the quality of the wood.

In order to solve the above problems, various types of (
:VD([t+emical vapor depos
tion) method has been proposed. These methods utilize some form of chemical reaction of the source gas during the film formation process.

In plasma CvD and photo-CvD, decomposition of the source gas occurs in the gas phase, and the active species generated thereby further react on the substrate to form a film. Since these CVD methods involve reactions in a gas phase, surface coverage against irregularities on the substrate surface is good. However, carbon atoms contained in the source gas molecules are incorporated into the film. In particular, plasma CvD has problems such as damage caused by charged particles (so-called plasma damage) as in the case of sputtering.

In the thermal CVD method, a film grows mainly by a surface reaction on the substrate surface, so that it has good surface coverage over irregularities such as steps on the surface. In addition, it can be expected that the deposition within the pier hole will be easier to dissect. Furthermore, disconnections at stepped portions can be avoided.

For this reason, various thermal CV[+ methods have been studied as a method for forming Mo1li. For example, there are hydrogen reduction methods for MoCJ25 and Si reduction methods for MoFa using normal pressure CVD or low pressure CVD, as introduced in Chapter 4 of Semiconductor Research Vol. 20 (Kogyo Kenkyukai, 1983). But M
The hydrogen reduction method of oCJ15 has a problem in that a plurality of molybdenum halides such as @0Cj23 and other molybdenum halides are generated in addition to MO in a portion other than the heated substrate surface in the film forming apparatus. Therefore, it is difficult to control film formation. Although film formation is possible, selective deposition is not observed.

In the MoFa Si reduction method, the presence of Si causes MoF to react and precipitate Mo, but at this time Si is etched. Therefore, electronic circuits on the Si wafer are damaged. 5in2 is also etched. However, for this reason, in the Si reduction method of MoF, deposition occurs on the Si substrate, but not on the Si substrate. This can be considered as selective deposition of Mo. However, as mentioned above, Si is also 5i
Since 02 is also subject to etching, there is a practical problem if it is left as it is. Also, as another method, Th1n SolidF
There is an example of the atmospheric pressure CVD method of Mo (Co) a as described in i1ms Vol. 63 (1979), page 169.

In this method, M is
An o film can be deposited on the substrate. However, this method has a problem in that a considerable amount of oxygen and carbon are incorporated into the Mo film as impurities. Therefore, there is a problem that the electrical resistance of the deposited film increases. Also, selective deposition is difficult even with this method.

As mentioned above, the conventional Mo film deposition method has poor coverage of the steps on the LSI surface, unnecessarily etches the Si surface of the LSI, damages the 5102, and makes it difficult to control the deposition reaction. Otherwise, there were problems such as a large amount of impurities being mixed into the Mo film.

[Problems to be Solved by the Invention] As described above, in the semiconductor technical field where higher integration has been desired in recent years, in order to provide a highly integrated and high-performance semiconductor device at a low price, There was much room for improvement. Therefore, an object of the present invention is to provide a method for depositing a Mo film without damaging Si wafers or Sin.

Another object of the present invention is to provide Mo with high step coverage on the LSI surface.
An object of the present invention is to provide a method for depositing a film.

Still another object of the present invention is to provide a method for selectively depositing a Mo film, which is effective for filling pier holes and the like.

Still another object of the present invention is to provide a method for depositing a Mo film that can deposit a low resistance Mo film with good controllability.

[Means for Solving the Problems] In order to achieve the above objects, the deposited film forming method of the present invention includes:
(a) supplying molybdenum compound molecules and hydrogen gas to a substrate having an electron-donating surface and a non-electron-donating surface, and (b) at a temperature below the decomposition temperature of the molybdenum compound, and
The present invention is characterized by comprising a step of maintaining the temperature of the electron-donating surface within a range of 00° C. or lower and selectively forming a molybdenum film on the electron-donating surface.

[Function] In the Mo film deposition method of the present invention, organic M is used as a raw material gas.
o compound and H2 gas are used. Examples of f-type Mo compounds include Mo (Co) a and Mo (CI+3), which are solid at room temperature.
A Mo film is deposited by sublimating Mo. Although the detailed mechanism of the reaction is not necessarily clear, it is thought that Mo ((:O)6, etc. reacts with H2 gas on the surface of a heated electron-donating substrate such as a metal or semiconductor, producing Mo. Since this reaction is difficult to proceed unless the substrate surface is electron-donating, it is thought that film deposition on the non-electron-donating surface is difficult to occur.Mo (GO)
Thermal decomposition of 6 alone occurs at around 400℃, and 300℃
However, partial decomposition occurs. If the pressure is high and ■
Without 2, these decomposition products would deposit on the substrate without selectivity. Moreover, at this time, a considerable amount of carbon and oxygen are incorporated into the Mo film, resulting in an increase in electrical resistance.

Therefore, 112 gas is essential during the reaction in order to prevent impurities from entering the film. When the substrate temperature is 300°C or higher and the pressure of the reaction gas is high, the film is deposited in the form of Sin, or A.
This also occurs on non-electron-donating surfaces such as 12O5, reducing the selectivity of the deposition. Reaction pressure is 100To
Selective deposition will not occur unless it is below rr, and in practice it is 10T.
Orr or less is desirable. If the temperature of the substrate is too high, Mo
(Go) is actively thermally decomposed without the help of H2 or an electron-donating surface, so impurities in the film increase again and the selectivity of deposition is lost. A substrate temperature of 800° C. or higher cannot be used, and a temperature of 600° C. or lower is preferable. The most desirable temperature range is 450-550°C. Methods of reducing MoCλ5, MoF, etc. with H2 or St are known, but these methods may cause damage such as mixing of halogen elements into the film or etching of the St substrate or 5i02 film, and may affect the characteristics of the substrate. deteriorate. Therefore, the characteristics of devices using this may deteriorate. According to the method of the present invention, since no halogen element is used, it is possible to selectively deposit a Mo film without any of the above problems. In addition to Mo (co) 6, Mo (f;) I3) may be used as the raw material gas. Mo (CH3
) 6 is more desirable than Mo (Go) a in terms of obtaining a high-purity film. The organic compounds of Mo are not limited to these.

[Example] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a deposited film forming apparatus to which the present invention can be applied.

Here, 1 is a substrate for forming a Mo film. A substrate 1 is placed on a substrate holder 3 provided inside a reaction tube 2 for forming a substantially closed space for forming a deposited film as seen in the figure.

The material constituting the reaction tube 2 is preferably quartz, but it may also be made of metal. In this case, it is desirable to cool the reaction tube. Further, the substrate holder 3 is made of metal, and is provided with a heater 4 so as to heat the substrate placed thereon. The substrate temperature can be controlled by controlling the heat generation temperature of the heater 4.

The gas supply system is configured as follows.

Reference numeral 5 denotes a gas mixer, which mixes the raw material gas and the reaction gas and supplies the mixture into the reaction tube 2 . Reference numeral 6 denotes a raw material gas vaporizer provided to vaporize organic metals as raw material gases.

Since the organic metal used in the present invention is solid at room temperature, a carrier gas is passed near the surface of the organic metal in the vaporizer 6 to sublimate it into saturated vapor, which is then introduced into the mixer 5. At this time, heating the gas or the organic metal itself greatly promotes sublimation.

The exhaust system is configured as follows.

Reference numeral 7 denotes a gate valve, which is opened when a large volume of gas is evacuated, such as when evacuating the inside of the reaction tube 2 before forming a deposited film. 8
is a slow leak valve, which is used for reaction tube 2 during deposition film formation.
Used when evacuation of a small volume, such as when adjusting internal pressure. Reference numeral 9 denotes an exhaust unit, which is composed of an exhaust pump such as a turbo molecular pump.

The transport system for the substrate 1 is configured as follows.

Reference numeral 10 denotes a substrate transfer chamber capable of accommodating substrates before and after the formation of a deposited film, and is evacuated by opening a valve 11. Reference numeral 12 denotes an exhaust unit for evacuating the transfer chamber, and is composed of an exhaust pump such as a turbo molecular pump.

The valve 13 is opened only when the substrate 1 is transferred between the reaction chamber and the transfer space.

As shown in FIG. 1, in the gas generation chamber 6 for generating raw material gas, H2 or 8r( or other inert gas) to produce a gaseous organic MO compound, which is transported to the mixer 5. II2 as a reaction gas is sent to the mixer 5 from another route.
transported to. The flow rate of each gas is adjusted so that its partial pressure becomes a desired value.

As raw material gas, Mo (co) 6 and Mo (CH
3) 6 is good. Also, Mo (GO) a and Mo (
CH3)6 may be used in combination.

FIGS. 2(a) to 2(e) show selective growth of an MO film according to the present invention.

FIG. 2(a) is a diagram schematically showing a cross section of a substrate before formation of an MO deposited film according to the present invention. 90 is a substrate made of an electron-donating material, and 91 is a thin film made of a non-electron-donating material.

When a mixed gas containing Mo (CO) as a raw material gas and 112 as a reaction gas is supplied onto the substrate 1 heated to a temperature range above the decomposition temperature of Mo (GO) and below 800 ° C. , MO is deposited on the substrate 90, and the second
A continuous film of MO is formed as shown in Figure (b). Here, the pressure inside the reaction tube 2 is preferably 10-3 to 760 Torr, and the partial pressure of Mo (co) is preferably 1.0 x 10-5 to 1.5 Xl0-' times the pressure inside the reaction tube.

If Mo deposition continues under the above conditions, the state shown in FIG. 2(C) will be reached, and the Mo1li will become thin [
It grows to the top level of 91.

As a result of analysis using Ausch electron spectroscopy and photoelectron spectroscopy, no impurities such as carbon or oxygen were found to be present in this film.

The resistivity of the deposited film thus formed is as follows:
In the case of zero people, the resistivity is 8 to 30 μΩ·CIII at room temperature, which is quite close to the MO bulk resistivity, lower than that of polycrystalline Si, and results in a continuous and flat film. The reflectance in the visible light wavelength range is also 70~
80%, and a thin film with excellent surface flatness can be deposited.

As mentioned above, it is desirable that the substrate temperature be higher than the decomposition temperature of the raw material gas containing MO (for example, 350°C or higher) and lower than 800°C.
), when the substrate temperature is 400-600℃, MO (in H3)
In the case of a, the temperature is preferably 350°C to 550°C.

More preferably, in the case of Mo (co), the substrate temperature is 4
50℃~550℃, 400℃ for MO(CH3)II
~500°C, and the MO film deposited under these conditions contains carbon,
It does not contain oxygen and has sufficiently low resistance.

In the apparatus shown in the first figure, Mo can only be deposited on one substrate in one deposition. Although a deposition rate of approximately 100 persons/minute can be obtained, this is insufficient for depositing a large number of sheets in a short period of time.

As a deposited film forming apparatus that improves this point, there is a low pressure CVD apparatus that can simultaneously load a large number of cubes and deposit MO. MO deposition according to the present invention uses a surface reaction on the heated electron-donating substrate surface, so if the hot wall type low pressure CVD method in which only the substrate is heated, Mo (co)6 and can be deposited.

The reaction tube pressure is 10-' to 760 Torr, preferably 0
．． 1 to 5 Torr, substrate temperature 350°C to 800°C,
Preferably, the temperature is 400°C to 600°C, and the MO (niO) 6 partial pressure is lXl0-' times the reaction tube internal pressure to 1.5 XIG-'
double, and MO is deposited only on the electron-donating substrate.

FIG. 3 is a schematic diagram showing a deposited film forming apparatus to which the present invention can be applied.

57 is a substrate for forming an MO film. 50 is an outer reaction tube made of quartz that forms a space for forming a deposited film that is substantially closed to the surroundings; 51 is an outer reaction tube made of quartz that is installed to separate the flow of gas in the outer reaction tube 50; The inner reaction tube 54 is a metal flange for opening and closing the opening of the outer reaction tube 50, and the base 57 is installed in a base holder 56 provided inside the inner reaction tube 51. Note that the base holder 56 is preferably made of quartz.

Furthermore, the present device can control the substrate temperature using the heater section 59. The pressure inside the reaction tube 50 is controlled by the gas exhaust port 5.
The exhaust system is configured to be controlled by an exhaust system connected via 3.

The raw material gas is supplied to the reaction tube from the raw material gas inlet 52 (similar to the apparatus shown in FIG. 1, having a first gas system, a second gas system, and a mixer (all of which are not shown)). 50
be introduced internally. When the raw material gas passes through the inside of the inner reaction tube 51, as shown by the arrow 58 in FIG.
reacts on the surface of the substrate, and Mo is deposited on the substrate surface. The gas after the reaction passes through the gap formed by the inner reaction tube 51 and the outer reaction tube 50 and is exhausted from the gas exhaust port 53.

When inserting or removing the base, the metal flange 54 is lowered together with the base holder 56 and the base 57 by an elevator (not shown), and is moved to a predetermined position to attach or remove the base.

By using such an apparatus and forming a deposited film under the conditions described above, high-quality An films can be simultaneously formed on all wafers in the apparatus.

As described above, the film obtained by the <Mo film forming method according to the present invention contains few impurities such as carbon and has a sufficiently low electrical resistance. Furthermore, there is no damage to the substrate surface and controllability is good.

It also has significant advantages such as being able to selectively deposit onto a substrate.

(Example 1) First, the procedure for forming a Mo film is as follows. Using the apparatus shown in FIG. 1, the inside of the reaction tube 2 is approximately I
Exhaust to X 10-6 Torr. However, even if the degree of vacuum in the reaction tube 2 is worse than I x 10-'Torr, the Mo film can be formed.

After cleaning a substrate such as a Si wafer, the transfer chamber 10 is released to atmospheric pressure and the Si wafer is loaded into the transfer chamber. Approximately the transfer room
After exhausting to X 1G"" Torr, the gate valve 13 is opened and the substrate is mounted on the wafer holder 3.

After mounting the base on the wafer holder 3, the gate valve 13
is closed, and the degree of vacuum in reaction chamber 2 is approximately lXl0-'Torr.
Exhaust until

In this example, Mo (Go) 6 is supplied from the first gas line.
sublimated and supplied. N2 was used as the carrier gas for the Mo (CO) 6 line. The second gas line is for N2.

Flow N2 from the second gas line and slowly leak valve 8.
The pressure inside the reaction tube 2 is brought to a predetermined value by adjusting the opening degree of the reaction tube 2.

Thereafter, the heater 4 is energized to heat the base. After the substrate temperature reaches a predetermined temperature, Mo (CO) 6 is introduced into the reaction tube through the Mo (Co) a line. The total pressure is approximately 1.5 Torr, and the partial pressure of Mo (co) is approximately 1.5 x 10-' Torr. Mo (co
), is introduced into the reaction tube 2, MO is deposited. After a predetermined deposition time has elapsed, the supply of Mo (CO) is stopped. Next, heating of the heater 4 is stopped and the base is cooled. 1
12 After the gas supply is stopped and the inside of the reaction tube is evacuated, the substrate is transported to a transfer chamber, and after only the transfer chamber is brought to atmospheric pressure, the substrate is taken out. The above is an outline of the MO film forming procedure.

Next, sample preparation in this example will be explained.

Hydrogen combustion method (N2:
4β/M, 02: 2°C/M) at a temperature of 1000°C.

The film thickness is 7,000 ± 500, and the refractive index is 1,46.
Met. Apply photoresist to the entire surface of this Si substrate,
A desired pattern is printed using an exposure machine.

Pattern is 0.25μm Xo, 25μm P-100
It appears to have various holes of μm x 100 μm. After developing the photoresist, reactive ion etching (R
5i02 as the base using photoresist as a mask using IE) etc.
was etched to partially expose the Si substrate. In this way 0.25μo+xo, 25μm N100
Prepare samples with 5 in2 holes of various sizes of μm x 100 μm, vary the substrate temperature, and adjust the total pressure to 1.5 Torr Mo (GO) a partial pressure to 1.5 x according to the procedure described above at each substrate temperature. 10""To
The AJZ film was deposited under the conditions of rr.

Mo films deposited while varying the substrate temperature were evaluated using various evaluation methods. The results are shown in Table 1.

In the above sample, Si
Almost no Mo was deposited on O□, and Mo was deposited only on the portion where 5i02 was opened and St was exposed.

(Example 2) First, the procedure for forming an MO film is as follows. The inside of the reaction tube 2 is evacuated to approximately I.times.10-' Torr by the exhaust equipment 9. The degree of vacuum in the reaction tube 2 is I x 10-'Torr.
Even if it is worse, MO will form a film.

After cleaning the Si wafer, the transfer chamber 10 is released to atmospheric pressure and S
i Load the wafer into the transfer chamber. Approximately 1x 10 transport chambers
-'Torr, then open the gate valve 13 and attach the wafer to the wafer holder 3.

After mounting the wafer on the wafer holder 3, the gate valve 1
3 is closed, and the degree of vacuum in reaction chamber 2 is approximately I x 1O-8To.
Exhaust until rr.

In this example, the first gas line is for Mo (GO) 6. Mo (II:O), the line carrier gas is 8r). The second gas line is for H2.

Flow ■2 from the second gas line, slow leak valve 8
The pressure inside the reaction tube 2 is set to a desired value by adjusting the opening degree of the reaction tube 2.

Typical pressure in this example is approximately 1.5 Torr. Thereafter, the heater 4 is energized to heat the cube. After the wafer temperature reaches a desired temperature, Mo (GO) 6 is introduced into the reaction tube through the No (co) 6 line. The total pressure is approximately 1.5 Torr, and the partial pressure of Mo (Go) is approximately 1.5 x 10-' Torr. The Ar partial pressure is approximately 0.5 Torr. When Mo(co)6 is introduced into the reaction tube 2, Mo is deposited. After the desired deposition time has elapsed, the supply of Mo (CO) is stopped. Next, heating of the heater 4 is stopped and the wafer is cooled. After stopping the supply of H2 gas and evacuating the inside of the reaction tube, the wafer is transferred to the transfer chamber, and only the transfer chamber is brought to atmospheric pressure, and then the wafer is taken out. The above is an outline of MO film formation.

Even when Ar was used as the carrier gas, the resistivity and carbon content of the deposited film formed were slightly high, but at a level that poses no practical problems, and the results were roughly the same as in Example 1. Obtained.

Also, the selective deposition properties depending on the substrate were almost the same as in Example 1.

(Example 3) Using the low pressure CVD apparatus shown in FIG. 3, Mo
A film was formed.

Preparation of Sample 8-1 A thermally oxidized 5in2 film was formed as a non-electron-donating second substrate surface material on single crystal silicon as an electron-donating first substrate surface material. Patterning was performed by a photolithography process as shown in 1, and the single crystal silicon surface was partially exposed.

At this time, the thickness of the thermally oxidized 5in2 film was 7000 mm, and the exposed portion of the single crystal silicon, that is, the size of the opening, was 38 m x 3 μm. Sample 8-1 was thus prepared. (
Below, such a sample is referred to as “thermal oxidation 5iO2 (hereinafter T-
(abbreviated as 5iO2)/single crystal silicon).

Preparation of Samples 8-2 to 8-179 Sample 8-2 is an oxide film (
(hereinafter abbreviated as 5i02)/single crystal silicon, sample 8-
3 is a poron-doped oxide film (hereinafter abbreviated as BSG)/single crystal silicon formed by atmospheric pressure CVD, and sample 8-4 is a phosphorus-doped oxide film (hereinafter abbreviated as PSG)/single crystal silicon formed by atmospheric pressure CVD. , Sample 8-5 is a phosphorus- and boron-doped oxide film (hereinafter abbreviated as BSPG)/single crystal silicon deposited by atmospheric pressure CVD, and Sample 8-6 is a nitride film deposited by plasma CVD (hereinafter P-5: N sample 8-7 is a thermal nitride film (hereinafter abbreviated as T-5: N)
/single crystal silicon, sample 8-8 is a nitride film formed by low pressure DCVD (hereinafter abbreviated as LP-5IN)/single crystal silicon, sample 8-9 is a nitride film formed by an ECR device (hereinafter referred to as E
CR-5iN)/single crystal silicon. Furthermore, samples 8-11 to 8-179 shown in Table 2 were prepared by combining the electron-donating first substrate surface material and the non-electron-donating second substrate surface material. The first substrate surface materials include single crystal silicon (single crystal St), polycrystalline silicon (polycrystalline Si), tungsten (W), molybdenum (Mo), tantalum (Ta), tungsten silicide (WSi), and titanium silicide (TiSi). )
, Aluminum (A°C), Aluminum Silicon (A°C
-5i), titanium aluminum (81-Ti), titanium nitride (Ti-N), copper (Cu), aluminum silicon copper (AIL-5t-u), aluminum palladium (AI!, -Pd), titanium (Ti),
Molybdenum silicide (Mo-5i) and tantalum silicide (Ta-5i) were used. These samples and AIL203 substrate.

A 5i(h glass substrate was placed in the low pressure CVD apparatus shown in Fig. 3, and a Mo film was formed within the same badge.The film forming conditions were a reaction tube pressure of 0.2 Torr, and a Mo(Go)a partial pressure of 1.OX.
The temperature was 10-' Torr and the substrate temperature was 450°C.

As a result of film formation under these conditions, samples 8-1 to 8
In all of the samples patterned up to -179, the Mo film was deposited only on the electron-donating first substrate surface, completely filling the 7000 mm deep opening. The film quality of the Mo film was very good, showing the same properties as those shown in Example 1 at a substrate temperature of 450°C. On the other hand, no Mo film was deposited on the surface of the second substrate, which was electron-donating, and perfect selectivity was obtained. Mo2203 substrate and 5in2 glass substrate, which are non-electron donating, are also used.
No film was deposited.

(Example 4) Using the low pressure CVD apparatus shown in FIG. 3, Moji was formed on a substrate having the structure described below.

Polycrystalline Si as an electron-donating first substrate surface material is formed on a thermal oxide film as a non-electron-donating second substrate surface material, and a photolithography process as shown in Example 1 is carried out. Patterning was performed to partially expose the surface of the thermal oxide film.

The film thickness of polycrystalline silicon at this time was 2000 mm, thermal oxidation @
The size of the exposed portion or opening was 3 μm x 3 μm. Such a sample is designated as 9-1. The second substrate surface material which is non-electron donating (T-5i02.CVD-5
i(h, [lsG, PsG, BPSG, P-5iN, T
-SiN.

LP-5iN, εCR-5IN) and the electron-donating first substrate surface material (polycrystalline Si, Ai, W, Mo, Ta
, WSi, TiSi.

Taxi, ^f-5i, ^It-Ti, Ti
N, Cu, A1. -5i-Cu, 8℃-Pd, T
i, Mo-5i), 9- shown in Table 3
Samples 1 to 9-169 were prepared. These samples were placed in the low pressure CVD apparatus shown in FIG. 3, and a Mo film was formed within the same badge. Film forming conditions are reaction tube pressure 0.2T.
orr, Mo(GO)6 partial pressure 1. Ox 10””Tor
r, the substrate temperature is 450°C. As a result of film formation under these conditions, in all samples from 9-1 to 9-169, all <l films were deposited in the openings where the non-electron-donating second substrate surface was exposed. First, about 5000 Mo was deposited only on the first substrate surface, which is electron-donating, and complete selectivity was obtained. The quality of the deposited Mo film was very good, showing the same properties as those shown in Example 1 at a substrate temperature of 450°C.

(Example 5) Using MO(C113)6 as the raw material gas, the total pressure
2.0 Torr Mo (CH3) 6 partial pressure 3 x 10-'Tor
When the deposition was carried out using the same procedure as in Example 1, it was found that, as in Example 1, the substrate surface material contained almost no carbon impurities and had low electrical resistance in the substrate temperature range of 350°C to 550°C. A Mo thin film with excellent selectivity was deposited.

[Effects of the Invention] As explained above, according to the present invention, a low-resistance, dense Mo film could be selectively deposited on a substrate.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a deposited film forming apparatus to which the present invention can be applied, FIG. 2 is a schematic cross-sectional view illustrating a deposited film forming method according to the present invention, and FIG. 3 is a schematic diagram showing an example of a deposited film forming apparatus to which the present invention can be applied. FIG. 3 is a schematic diagram showing another example of a deposited film forming apparatus. 1... Substrate, 2... Reaction tube, 3... Substrate holder, 4... Heater, 5... Mixer, 6... Vaporizer, 7... Gate valve, 8... - Slow leak valve, 9... Exhaust unit, 10-... Transfer chamber, 11... Valve, 12... Exhaust unit, 50... Quartz outer reaction tube, 51... Quartz inner reaction tube Pipe, 52... Raw material gas inlet, 53... Gas exhaust port, 54... Metal flange, 56... Substrate holder, 57... Substrate, 58... Gas flow, 59 ...Heater section. Figure 2

Claims (1)

[Claims] 1) (a) A step of supplying molybdenum compound molecules and hydrogen gas to a substrate having an electron-donating surface and a non-electron-donating surface, and (b) decomposition of the molybdenum compound. below the temperature, and 8
A deposited film forming method comprising the step of maintaining the temperature of the electron-donating surface within a range of 00° C. or lower and selectively forming a molybdenum film on the electron-donating surface. 2) The deposited film forming method according to claim 1, wherein the molybdenum compound is Mo(CO)_6. 3) The deposited film forming method according to claim 1, wherein the molybdenum compound is Mo(CH_3)_6. 4) The deposited film forming method according to claim 1, wherein the pressure during film formation is 100 Torr or less.