JPH08144057A - Formation of titanium nitride thin film - Google Patents

Abstract

PURPOSE: To stably form a high-quality TiN thin film on the surface of a substrate at the time of forming a TiN film on a substrate with a gaseous mixture of Ar and N2 as the discharge gas and Ti as the target. CONSTITUTION: A gaseous mixture of Ar and N2 as the discharge gas is supplied in a vacuum vessel 8, a high voltage is impressed between a Ti target 3 and a substrate 5 to produce plasma, hence Ti atom is emitted from the target to deposit Ti on the substrate 5, and the Ti is nitrided by the gaseous N2 to form a TiN film. In this case, the impressed voltage and the Ar/N2 ratio in the discharge gas are fixed, the amt. of the discharge gas to be supplied to the vacuum vessel 8 is made larger than a specified amt. to nitride the target 3 surface, and then the gas flow rate is decreased to form a TiN thin film on the substrate 5 to such an extent that the TiN film is maintained on the target surface. The Ti grain depositing on the inner wall of the vessel 8 or on a shield plate 7 is released due to the low gas flow rate and low gas pressure, hence the TiN thin film on the substrate 5 is not damaged, and a high- quality TiN thin film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a TiN thin film used to prevent diffusion between different materials in electronic devices such as semiconductors, and particularly has a significant effect on device characteristics and yield. The present invention relates to a method for suppressing the generation of process foreign matter.

[0002]

2. Description of the Related Art FIG. 6 shows, for example, "sputtering phenomenon".
FIG. 1 is a schematic diagram showing the configuration of a conventional sputtering apparatus described in (1985 University of Tokyo Press).
The thin film is formed by this kind of sputtering device. In the figure, 1 is a first electrode through which cooling water flows, and a negative high voltage is applied by a power supply 2. Reference numeral 3 is a target made of a Ti material held by the first electrode 1.

Reference numeral 4 is a second electrode arranged at a position facing the first electrode 1, reference numeral 5 is a substrate placed on the second electrode 4, and reference numeral 6 is a space between the target 3 and the substrate 4. The shutter 7 is arranged so as to block the light, 7 is a shield plate arranged so as to surround the first electrode 1 and the target 3, 8 is a container as a film forming chamber for housing these 1 to 7, and 9 is this container. Container 8
One end of a gas introduction pipe 10 for introducing a mixed gas of Ar and N as a discharge gas is connected to the container 8,
The other end is an exhaust pipe connected to a vacuum pump (not shown).

Next, a conventional method of forming a TiN thin film, which is carried out by the sputtering apparatus having the above structure, will be described. First, after operating the vacuum pump to evacuate the inside of the container 8 to a high vacuum of approximately 10 ⁻⁶ Torr or less through the exhaust pipe 10, the gas containing pipe 9 containing A ₂ containing N ₂ gas is supplied.
Introducing r gas as discharge gas into the interior, 10 ^-3 Tor
Adjust to about r. Then, in this state, both electrodes 1, 4
A predetermined high voltage is applied by the power source 2 between the target 3 and the substrate 5 to ionize the gas introduced into the container 8 to generate plasma.

The ionized discharge gas (Ar
+, N ₂ +, N +, etc.) are attracted to the target 3 which is a cathode, accelerated, and collide with the target 3. Then, due to the collision of the ions, Ti on the surface of the target 3 is
Atoms are thrown away. This phenomenon is sputtering, and the repelled Ti atoms fly toward the substrate 5 arranged at a position facing the surface of the target 3 and adhere to and deposit on the surface of the substrate 5. Also, an electrically neutral gas that is not ionized flies around in the container 8 due to molecular motion and collides with the target 3 and the substrate 5. Then, N ₂ gas among the flying gases forms TiN thin film by nitriding Ti deposited and deposited on the surface of the target 3 and the surface of the substrate 5.

Next, the process of forming this TiN thin film will be described with reference to FIG.
Will be described. FIG. 7 is a characteristic curve diagram showing the relationship between the gas flow rate of the discharge gas and the film formation rate. In the figure, in addition to the gas flow rate, the discharge power, which is a factor affecting the film formation rate, and the mixing ratio of N ₂ gas and Ar gas are constant. First, when the gas flow rate is gradually increased from the low flow rate region, only the Ti thin film is formed and the TiN thin film is not formed up to the flow rate at a certain critical point as shown in the figure.
The film forming rate is also high, reflecting the high sputtering rate.

However, when the gas flow rate exceeds a certain critical point, the film formation rate rapidly decreases, the formation of the Ti thin film is stopped, and the formation of the TiN thin film starts. Therefore, conventionally, the critical point is determined according to each sputtering apparatus, and the TiN thin film is formed in the region where the gas flow rate is larger than this.

[0008]

Since the conventional method of forming a TiN thin film is as described above, the Ti atoms repelled from the target 3 collide with the discharge gas as shown in FIG. Since they are scattered, they also adhere to the inner wall of the container 8 other than the substrate 5, the shield 7, and the like. And, of these adhered substances, the deposit adhered to the portion (back side) that is shaded when viewed from the target 3 is formed from particles that have been scattered and reached many times, and the adhesive force is weak,
When the foreign matter is peeled off and becomes a foreign matter and flies to and adheres to the surface of the substrate 5, the film quality is impaired. Further, when the foreign matter adheres to a fine pattern of a semiconductor or the like, a short circuit or a disconnection of a circuit occurs, which results in a product There was a problem that reliability was lowered.

The present invention has been made to solve the above problems, and provides a method for forming a TiN thin film capable of suppressing the generation of foreign matter and improving the reliability of products. The purpose is to do.

[0010]

A method of forming a TiN thin film according to claim 1 of the present invention uses Ar and N ₂ as a discharge gas and Ti as a target, respectively.
In a method for forming a TiN thin film for forming an iN thin film, a first step of nitriding a target surface at a predetermined rate, and a nitride layer of the target surface formed in the first step that is slower than the nitriding rate in the first step The second step of forming a film on the substrate at a desired nitriding rate within the range that can maintain

The method for forming a TiN thin film according to claim 2 of the present invention is the method for forming a TiN thin film, wherein Ar and N ₂ are used as a discharge gas and Ti is used as a target, and a TiN thin film is formed on a substrate. A first step of nitriding the surface of the target at a gas flow rate higher than a predetermined gas flow rate of the gas, and a range lower than the predetermined gas flow rate and capable of maintaining the nitrided layer on the target surface formed in the first step The second step of forming a film on the substrate at a desired gas flow rate is included.

Further, a method for forming a TiN thin film according to a third aspect of the present invention is the method according to the second aspect, wherein a predetermined gas flow rate value is preset.

The TiN thin film forming method according to a fourth aspect of the present invention is the method according to the second aspect, wherein the gas flow rate is controlled by adjusting the opening degree of the gate valve on the exhaust pump side.

The method for forming a TiN thin film according to a fifth aspect of the present invention is the method for forming a TiN thin film, wherein Ar and N ₂ are used as discharge gases and Ti is used as a target, and the TiN thin film is formed on a substrate. A first step of nitriding the surface of the target with a predetermined input power smaller than the maximum input power capable of nitriding the surface of
The second step of forming a film on the substrate with a desired input power that is larger than a predetermined input power and smaller than the maximum input power.

Further, a method of forming a TiN thin film according to a sixth aspect of the present invention is such that, in the fifth aspect, a predetermined input power value is preset.

The method of forming a TiN thin film according to claim 7 of the present invention is the method of forming a TiN thin film, wherein a TiN thin film is formed on a substrate by using Ar and N ₂ as a discharge gas and Ti as a target. Gas Ar
The mixing ratio of N ₂ to N is higher than the minimum mixing ratio capable of nitriding the surface of the target. Second, a film is formed on the substrate with a desired mixing ratio within a range that can maintain the nitrided layer on the target surface.
And the process of.

Further, a method for forming a TiN thin film according to an eighth aspect of the present invention is such that, in the seventh aspect, a value of a predetermined mixing ratio is preset.

[0018]

In the method for forming a TiN thin film according to claim 1 of the present invention, the target surface is nitrided at a predetermined rate in the first step, and the second step is slower than the nitriding rate in the first step, and By forming the film on the substrate at a desired nitriding rate within a range capable of maintaining the nitrided layer on the target surface formed in the first step, the discharge gas pressure is lowered and the generation of foreign matter is suppressed.

Further, in the method for forming a TiN thin film according to claim 2 of the present invention, the target surface is nitrided at a gas flow rate higher than a predetermined gas flow rate of the discharge gas in the first step, and the predetermined step is performed in the second step. By forming the film on the substrate at a desired gas flow rate that is lower than the gas flow rate and within which the nitride layer on the target surface formed in the first step can be maintained, the discharge gas pressure is lowered and the generation of foreign matter occurs. Suppress.

Further, in the method for forming a TiN thin film according to claim 3 of the present invention, in the first step, the target surface is nitrided at a gas flow rate higher than a predetermined gas flow rate set in advance.

Further, in the method for forming a TiN thin film according to the fourth aspect of the present invention, the opening of the gate valve on the exhaust pump side is adjusted to control the gas flow rate of the discharge gas.

According to a fifth aspect of the present invention, in the method of forming a TiN thin film, the target surface is formed by the first step.
The target surface is nitrided with a predetermined input power smaller than the maximum input power capable of nitriding, and a film is formed on the substrate with a desired input power larger than the predetermined input power and smaller than the maximum input power in the second step. By doing so, the discharge gas pressure is lowered and the generation of foreign matter is suppressed.

In the method of forming a TiN thin film according to claim 6 of the present invention, in the first step, the target surface is nitrided with a predetermined input power set in advance.

In the method of forming a TiN thin film according to claim 7 of the present invention, the target surface is formed by the first step.
The mixing ratio of N _{2 to} Ar in the discharge gas is nitrided at a predetermined mixing ratio higher than the minimum mixing ratio capable of nitriding the surface of the target, and is lower than the predetermined mixing ratio in the second step and in the first step. By forming a film on the substrate with a desired mixing ratio within a range where the formed nitride layer on the target surface can be maintained, the discharge gas pressure is lowered and the generation of foreign matter is suppressed.

Further, in the method for forming a TiN thin film according to claim 8 of the present invention, in the first step, the surface of the target is nitrided at a predetermined mixing ratio set in advance.

[0026]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a state diagram in which, in reactive sputtering using N ₂ gas mixed with Ar gas as a discharge gas, the formation state of Ti and TiN thin films was experimentally obtained using the gas flow rate Q of the discharge gas as a parameter. In the figure, a Ti thin film is formed in a region where the film formation speed is high, and a TiN thin film is formed in a region where the film formation speed is low. Regarding the relationship between the film forming rate and the gas flow rate Q, as is clear from the figure, the remarkable fact that the film forming rate has hysteresis is recognized as an experimental fact.

That is, when the discharge power and the discharge gas mixing ratio N ₂ : Ar are kept constant and the gas flow rate Q of the discharge gas is gradually increased, only a Ti thin film is initially formed on the substrate. When the gas flow rate Q is further increased, the film formation rate sharply decreases (about 1/3) as indicated by a curve A in the figure with a certain critical gas flow rate (indicated by Q ₁ in the figure) as a boundary. The TiN thin film starts to be formed from that point. As described above, the conventional TiN thin film forming method is
The N thin film is formed.

By the way, after the TiN thin film is once formed, if the gas flow rate Q is successively decreased, the area where the TiN thin film can be stably formed even after the critical point (the position of the gas flow rate Q ₁ ) is passed. Exists. Then, when the gas flow rate Q is further reduced, the film formation rate sharply increases as shown by a curve B in the figure with a certain critical point (position of the gas flow rate Q ₂ ) smaller than the critical point as a boundary. At the same time Ti
A thin film begins to form. That is, as the gas flow rate increases / decreases, the film formation rate does not reciprocate on one curve,
Move on B and draw hysteresis.

Next, the reason why the film forming rate has a hysteresis as the gas flow rate Q increases and decreases as described above will be described in detail. First, the magnitudes of the sputter erosion rate and the nitriding rate on the surface of the target are compared, and it is considered that the TiN thin film is formed on the substrate when the nitriding rate is higher than the sputter erosion rate. Here, the sputter erosion rate is proportional to the discharge power, and as the power increases, this rate also increases. Since the change in the gas flow rate Q is not so much affected, it may be considered to be constant with respect to the gas flow rate Q. On the other hand, the nitriding speed is proportional to the nitrogen partial pressure P because it is proportional to the number of N ₂ gas hitting the target. The nitrogen partial pressure P is given as the gas flow rate Q divided by the exhaust speed A.

The present invention is characterized in that the pumping speed A is considered in detail. In other words, focusing on the gas storage capacity of the vapor-deposited film, the effective exhaust speed obtained by adding the gas storage capacity to the pump exhaust capacity was taken into consideration. The Ti thin film has a significantly higher gas storage capacity than the TiN thin film. This is also understood from the fact that Ti is practically used as a gas storage plate for a sublimation pump. Therefore, if the adsorption / exhaust rates of the Ti thin film and the TiN thin film are ATi and ATiN, then ATi> ATiN. The pumping speed of the pump is expressed as AP and is considered to be constant here.

Therefore, when the gas flow rate Q is increased in FIG. 1, the Ti deposited on the inner wall of the film forming chamber up to the point where the Ti film forming area switches to the TiN film forming area (corresponding to the gas flow rate Q ₁ ). Works as an effective pump. And
The nitriding speed of the target surface in this state is proportional to the nitrogen partial pressure P ₁ at this time, and this nitrogen partial pressure P ₁ is given by the following equation (1). P ₁ = Q ₁ / (AP + ATi) (1) On the other hand, when the gas flow rate Q is reduced starting from the TiN film forming region in FIG. 1, the TiN film forming region is changed to the Ti film forming region. nitrogen partial pressure P ₂ at a point (corresponding to the gas flow rate Q ₂₎ to switch is given by the following formula (2). P ₂ = Q ₂ / (AP + ATiN) (2)

At the critical point (corresponding to the gas flow rates Q ₁ and Q ₂ ) at which the Ti film forming region and the TiN film forming region are switched, when the discharge power and the gas mixture ratio N ₂ : Ar are constant. Since the sputter erosion rate of the target whose surface is nitrided has a certain constant value, the nitriding rate equal to this is also a certain constant value. And, this constant nitriding speed should be realized only with a certain constant nitrogen partial pressure P ₀ , that is, P ₁ and P ₂ in the above equations 1 and ₂ are equal. However, as described above, AP + ATi>
Since there is a magnitude relationship of AP + ATiN, it follows that P ₁ = P ₂ means that Q ₁ and Q ₂ have different values, and it can be understood that there is hysteresis.

Therefore, in the first embodiment, the target surface is nitrided at the predetermined speed (flow rate of Q ₁ or more) in the first step as in the conventional method, and then in the second step, the nitriding in the first step is performed. The film formation is performed on the substrate at a desired nitriding speed (flow rate between Q ₂ and Q ₁ ) lower than the speed and within a range in which the nitride layer on the target surface formed in the first step can be maintained. That is, in this way, the pressure at the time of sputtering can be lowered while maintaining the formation of the TiN thin film, so that it is possible to prevent the Ti particles from wrapping around by the gas as shown in FIG. Small deposits are reduced and it becomes possible to suppress the generation of foreign matter.

Embodiment 2 FIG. FIG. 2 is for explaining a method of forming a TiN thin film in Example 2 of the present invention.
It is a figure which shows the gas flow rate dependence of iN film-forming. In Example 2, a predetermined gas flow rate capable of nitriding the target surface was set in advance by an experiment or the like, and the target surface was nitrided at a gas flow rate higher than the preset predetermined gas flow rate in the first step. Then, in the subsequent second step, a desired gas flow rate shown in the figure, which is smaller than the gas flow rate in the first step and within a range in which the nitride layer on the target surface formed in the first step can be maintained. To form a film on the substrate.

That is, in this way, the pressure at the time of sputtering can be lowered while maintaining the formation of the TiN thin film as in the case of Example 1, so that the Ti particles wrap around by the gas as shown in FIG. It is possible to prevent the occurrence of foreign matter, and to reduce the generation of foreign matter by reducing the amount of deposits with a small adhesive force. In addition, it is possible to preset a predetermined gas flow rate capable of nitriding the target surface. Therefore, it becomes easy to control the gas flow rate in the first step, and the working time can be shortened.

Example 3. Although the control of the gas flow rate is not described in the second embodiment, it may be performed by adjusting the opening of the gate valve on the exhaust pump side. In this case, in the first step, the gate valve It is needless to say that the opening degree is small, and in the second step, it may be larger than the opening degree in the first step, and the same effect as in the second embodiment can be exhibited.

Embodiment 4 FIG. In the second embodiment, the case where the predetermined gas flow rate is obtained by experiments and set in advance is explained. However, when the gas flow rate is gradually increased and the Ti film formation region is switched to the TiN film formation region, A certain gas flow rate thereafter may be determined as a predetermined gas flow rate without departing from the gist of the present invention.

Embodiment 5 FIG. FIG. 3 is for explaining a method of forming a TiN thin film in Embodiment 5 of the present invention.
It is a figure which shows the discharge power dependence of iN film-forming. In the figure, the mixing ratio of N ₂ : Ar is constant. As described in Example 1, the sputter erosion rate of the target is proportional to the discharge power. Therefore, the hysteresis of the film forming speed shifts to the right as shown by the solid line in the figure when the discharge power is large, and shifts to the left as shown by the broken line in the figure when the discharge power is small.

Therefore, in Example 5, a predetermined input power (shown in the figure) smaller than the maximum input power (shown in the figure) capable of nitriding the target surface was set in advance by experiments or the like. In the first step, as shown by the broken line in the figure, the target surface is nitrided with this predetermined input power, and then in the second step, a value larger than the predetermined input power and the maximum input power described above. A film is formed on the substrate with a desired input power (shown in the figure) having a smaller value.

That is, in this way, the pressure during sputtering can be lowered while maintaining the formation of the TiN thin film as in the case of the first embodiment, so that the Ti particles wrap around by the gas as shown in FIG. It is possible to prevent the occurrence of foreign matter and to suppress the generation of foreign matter by reducing the amount of deposits having a small adhesive force. In addition, a predetermined input power for nitriding the target surface is set in advance. Therefore, the control of the input power in the first step becomes easy and the working time can be shortened.

Example 6. Further, in the above-mentioned fifth embodiment, the case has been described in which the predetermined input power is obtained and set in advance through experiments or the like. However, the input power is gradually increased so that the Ti film formation region can be switched to the TiN film formation region at the maximum. A given input power smaller than the input power may be determined as the predetermined input power without departing from the gist of the present invention.

Embodiment 7 FIG. FIG. 4 is for explaining a method of forming a TiN thin film in Example 7 of the present invention.
iN is a diagram showing an N ₂ gas dependency of film formation. In the figure, the discharge power is constant. As described in Example 1, the nitriding speed of the target is proportional to the number of nitrogen gases colliding with the target, that is, the nitrogen partial pressure. Therefore, the hysteresis of the film formation speed shifts to the left as shown by the broken line in the figure when the nitrogen partial pressure, that is, the mixing ratio of N ₂ gas to Ar gas is high, and conversely when the mixing ratio of N ₂ gas is low, the solid line in the drawing shows. Move to the right as shown in.

Therefore, in the fifth embodiment, the mixing ratio of N _{2 to} Ar in the discharge gas is higher than a predetermined mixing ratio (shown in the drawing) which is higher than the minimum mixing ratio (shown in the drawing) capable of nitriding the target surface. ) Is preset by being obtained by experiments, etc., and the target surface is nitrided at this predetermined mixing ratio in the first step as shown by the broken line in the figure, and then in the second step this predetermined mixing is performed. The film is formed on the substrate at a desired mixing ratio (shown in the figure) that is lower than the ratio and within the range in which the nitride layer on the target surface formed in the first step can be maintained.

That is, in this way, the pressure at the time of sputtering can be lowered while maintaining the formation of the TiN thin film as in the case of Example 1, so that the Ti particles wrap around by the gas as shown in FIG. It is possible to prevent the occurrence of foreign matter and suppress the generation of foreign matter by reducing the amount of deposits having a small adhesive force. In addition, it is necessary to preset a predetermined mixing ratio of N ₂ that nitrides the target surface. Therefore, it becomes easy to control the mixing ratio in the first step, and the working time can be shortened.

Example 8. Further, in the above-mentioned Example 7, the case where the predetermined mixing ratio of N ₂ was obtained by experiments or the like and set in advance was explained, but the mixing ratio of N ₂ is gradually decreased to
A certain mixing ratio higher than the minimum mixing ratio that can switch from the i film forming region to the TiN film forming region may be determined as the predetermined mixture ratio without departing from the gist of the present invention.

[0046]

As described above, according to claim 1 of the present invention, T and T forming a TiN thin film on a substrate using Ar and N ₂ as discharge gases and Ti as a target, respectively.
In the method of forming an iN thin film, a first step of nitriding a target surface at a predetermined rate, and a range that is slower than the nitriding rate in the first step and can maintain a nitride layer on the target surface formed in the first step Since the second step of forming a film on the substrate at a desired nitriding speed is included, it is possible to suppress the generation of foreign matter and improve the reliability of the TiN thin film. A forming method can be provided.

According to a second aspect of the present invention, in the method of forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, a predetermined discharge gas is used. A first step of nitriding the surface of the target with a gas flow rate higher than the flow rate, and a desired gas flow rate lower than a predetermined gas flow rate and within a range capable of maintaining the nitrided layer on the target surface formed in the first step. Since the second step of forming a film on the substrate is included, it is possible to provide a method for forming a TiN thin film capable of suppressing the generation of foreign matter and improving the reliability of the product. it can.

Further, according to claim 3 of the present invention, in claim 2, the predetermined gas flow rate is set in advance, so that the generation of foreign matter is suppressed and the reliability of the product is improved. It is of course possible to provide a method for forming a TiN thin film capable of shortening the working time, as well as being able to achieve the above.

According to the fourth aspect of the present invention, in the second aspect, the gas flow rate is controlled by adjusting the opening degree of the gate valve on the exhaust pump side. It is of course possible to provide a method for forming a TiN thin film, which can shorten the working time, as well as improving the reliability.

According to a fifth aspect of the present invention, in the method of forming a TiN thin film, wherein a TiN thin film is formed on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, the surface of the target is nitrided. A first step of nitriding the surface of the target with a predetermined input power smaller than the maximum input power obtained, and a step of forming a film on the substrate with a desired input power larger than the predetermined input power and smaller than the maximum input power Since the second step is included, it is possible to provide a method for forming a TiN thin film capable of suppressing the generation of foreign matter and improving the reliability of the product.

Further, according to claim 6 of the present invention, in claim 5, the predetermined input power value is set in advance, so that the generation of foreign matter is suppressed and the reliability of the product is improved. It goes without saying that it is possible to improve
It is possible to provide a method for forming a TiN thin film that can reduce the working time.

According to a seventh aspect of the present invention, in the method of forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, in a discharge gas containing N and Ar. The mixing ratio of ₂ is higher than the minimum mixing ratio capable of nitriding the surface of the target, and the first step of nitriding the surface of the target with a predetermined mixing ratio, and the mixing ratio lower than the predetermined mixing ratio and formed in the first step Since the second step of forming a film on the substrate with a desired mixing ratio within a range capable of maintaining the nitrided layer on the target surface is included, the generation of foreign matter is suppressed and the reliability of the product is improved. It is possible to provide a method for forming a TiN thin film that can be improved.

Further, according to claim 8 of the present invention, the value of the predetermined mixing ratio is set in advance in claim 7, so that the generation of foreign matter is suppressed and the reliability of the product is improved. It is of course possible to provide a method for forming a TiN thin film, which can shorten the working time, not to mention the improvement.

[Brief description of drawings]

FIG. 1 is a state diagram obtained by an experiment in which a Ti and TiN thin film is formed in a reactive sputtering process in which N ₂ gas is mixed with Ar gas to form a discharge gas, using a gas flow rate Q of the discharge gas as a parameter.

FIG. 2 is a diagram showing a gas flow rate dependency of TiN film formation for explaining a method of forming a TiN thin film in Example 2 of the present invention.

FIG. 3 is a diagram showing discharge power dependence of TiN film formation for explaining a method of forming a TiN thin film in Example 3 of the present invention.

FIG. 4 is a diagram showing N ₂ gas dependence of TiN film formation for explaining a method for forming a TiN thin film in Example 7 of the present invention.

FIG. 5 is a schematic diagram showing a scattered state of Ti atoms when sputtering is performed by the method for forming a TiN thin film according to the present invention.

FIG. 6 is a schematic diagram showing a configuration of a conventional sputtering apparatus.

FIG. 7 is a characteristic curve diagram showing a relationship between a gas flow rate of discharge gas and a film formation rate.

FIG. 8 is a schematic diagram showing a scattering state of Ti atoms when sputtering is performed by a conventional sputtering device.

[Explanation of symbols]

1 1st electrode, 2 power supply, 3 target, 4 2nd
Electrodes, 5 substrates, 6 shutters, 7 shield plates, 8
Container, 9 gas introduction pipe, 10 exhaust pipe.

Claims (8)

[Claims] 1. A method of forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, in the method of forming a TiN thin film, the first step of nitriding the target surface at a predetermined rate, A second step of forming a film on the substrate at a desired nitriding rate that is slower than the nitriding rate in the first step and within a range that can maintain the nitride layer on the target surface formed in the first step. A method for forming a TiN thin film, comprising: 2. A TiN thin film forming method for forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, wherein a target gas flow rate of the target gas is higher than a predetermined gas flow rate of the discharge gas. First step of nitriding the surface and film formation on the substrate at a desired gas flow rate lower than the predetermined gas flow rate and within a range capable of maintaining the nitrided layer on the target surface formed in the first step And a second step of performing the step of forming a TiN thin film. 3. The method for forming a TiN thin film according to claim 2, wherein the value of the predetermined gas flow rate is preset. 4. The method for forming a TiN thin film according to claim 2, wherein the gas flow rate is controlled by adjusting the opening degree of the gate valve on the exhaust pump side. 5. A TiN thin film forming method for forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, wherein a predetermined power smaller than a maximum input power capable of nitriding the surface of the target is used. A first step of nitriding the surface of the target with an input power, and a second step of forming a film on the substrate with a desired input power that is larger than the predetermined input power and smaller than the maximum input power. A method for forming a TiN thin film, comprising: 6. The method for forming a TiN thin film according to claim 5, wherein the value of the predetermined input power is preset. 7. A method of forming a TiN thin film for forming a TiN thin film on a substrate using Ar and N ₂ as a discharge gas and Ti as a target, respectively, wherein the mixing ratio of N _{2 to} Ar of the discharge gas is set to the surface of the target. A first step of nitriding the surface of the target at a predetermined mixing ratio higher than the minimum mixing ratio capable of nitriding Al, and a nitriding layer on the target surface formed in the first step at a lower mixing ratio than the predetermined mixing ratio. And a second step of forming a film on the substrate at a desired mixing ratio within a range capable of maintaining the above condition. 8. The method for forming a TiN thin film according to claim 7, wherein the value of the predetermined mixing ratio is set in advance.