JPH05179433A - Integrated circuit and production thereof and thin film forming device thereof - Google Patents

Abstract

PURPOSE:To improve a barrier property and to obtain the large-scale integrated circuit having a high-quality semiconductor barrier layer by using titanium oxynitride for the barrier layer to be used for the substrate of a wiring film. CONSTITUTION:This large-scale integrated circuit consists of a wiring layer 60, the barrier layer 65 consisting of TiON and an insulating layer 62. Gaseous O2 is introduced near a substrate 7 in a vacuum chamber by a pipe 40 and gaseous N2 is introduced from a pipe 43 into an electron beam leader electrode 45. A prescribed vacuum degree is maintained in the vacuum chamber. A bias voltage is so impressed to an electron beam releasing means 44 in such a manner that the electron beam is released from this means toward the electrode 45. The released thermelectrons are brought into collision against the gaseous N2 in the electrode 45 to form plasma and to effect ionization. The N ions are accelerated by an accelerating electrode 46 and are led out of a porous electrode 47. The substrate 7 is irradiated with these ions. The vapor or clusters of Ti from a crucible 12 of a vapor generating source 1 are then partly ionized and these ions are accelerated to be brought into collision against the substrate 7. As a result, the reaction is efficiently progressed and the thin film of the TiON is deposited by evaporation on the substrate 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-scale integrated circuit (L) using a titanium oxynitride thin film as a barrier layer under a wiring film.
SI) and its thin film forming apparatus.

[0002]

2. Description of the Related Art Conventionally, titanium nitride is used at the boundary between an LSI wiring material and an insulating film to prevent the wiring material from diffusing into the insulating film and to increase the adhesive force between the wiring material and the insulating layer. And other materials are used as a barrier layer or an adhesion layer. As the miniaturization of LSI progresses, the thinning of each layer also progresses, the film quality is affected by the underlying layer, and a high quality barrier layer is required.

FIG. 4 shows the Nikkei Microdevice February issue (19
64MD of simple stack type cell structure published in 91)
The structure of the wiring portion of the RAM is shown, where 60 is a wiring layer of aluminum / silicon / copper alloy, 61 is a barrier layer of titanium nitride, and 62 is an insulating layer of silicon dioxide. These silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ),
Compound thin films such as titanium nitride (TiN) can be formed by vacuum deposition,
Each semiconductor layer is coated by a method such as a sputtering method or a CVD method. However, when the compound thin film formed by such a method is thinned, the variation of the characteristics on the surface becomes remarkable, the composition is insufficient, the adhesion is weak, etc. There was a problem.

On the other hand, FIG. 5 shows the minutes of the 7th symposium on ion source and ion assist technology (Proc.
needs of the seventh Sv
mpodium on Ion Source and
Reactive Cluster Ion Beam (R-IC), which is a thin film forming apparatus capable of forming a film of relatively high quality, which is published in Ion Assisted Technology.
B) is a conceptual diagram showing the apparatus, in which 5 is a vacuum chamber 6
Is a vacuum exhaust system for maintaining a predetermined vacuum degree, 4 is a reactive gas introduction system, for example, a gas cylinder 41 filled with a reactive gas such as oxygen, and a flow rate adjustment for introducing the reactive gas into the vacuum chamber 6. The valve 42 and the reactive gas are introduced into the gas introduction pipe 4
It consists of three. Reference numeral 1 denotes a vapor generation source, which comprises a closed crucible 12 having a nozzle 11, a filament 13 for heating the crucible 12 and a heat shield plate 14. Reference numeral 15 is a vapor deposition material filled in the crucible 12, and 16 is a cluster (lumped atomic group) formed by ejecting vapor of the vapor deposition material 15 from the nozzle 11 of the crucible 12. An ionization means 2 for the cluster 16 is an electron beam emitting filament 21, an electron extraction electrode 22 for extracting and accelerating electrons from the filament 21, and a heat shield plate 23.
Composed of. 3 is an acceleration electrode for accelerating the ionized cluster 16 with an electric field to give kinetic energy, 7 is a substrate on which an oxide thin film is formed, 8 is a DC power supply 81, 82, 83 for bias and filament heating Is a power supply device in which power supplies 84 and 85 for use are stored.

First, the function of each bias power supply in the power supply device 8 is as follows. The first DC power supply 81 is arranged so that the thermoelectrons emitted from the crucible heating filament 13 heated by the filament heating power supply 84 collide with the crucible 12 so that the thermoelectrons collide with the crucible 12.
Bias the potential of the positive. Next, the second DC power supply 82 extracts the thermoelectrons emitted from the ionized filament 21 heated by the power supply 85 for heating the filament, and draws out the electrode 2
The electric potential of the extraction electrode 22 is positively biased with respect to the filament 21 so as to be drawn inside. Also,
The third DC power supply 83 positively biases the potentials of the electron beam extraction electrode 22 and the crucible 12 with respect to the acceleration electrode 3 which is the ground potential, and accelerates the positively charged cluster ions by the electric field lens formed therebetween. To do.

Next, the operation will be described. Vacuum exhaust system 5
After the inside of the vacuum tank 6 is evacuated to a vacuum degree of 10 ⁻⁴ Torr or less, the flow rate adjusting valve 42 is opened and the reactive gas is introduced through the gas introducing pipe 43. On the other hand, crucible 12
When the electrons emitted from the crucible heating filament 13 by the electric field applied by the DC power supply 81 are made to collide with the crucible 12 and heated to a temperature at which the vapor pressure in the crucible becomes several Torr, the vapor deposition substance 15 evaporates, and the vapor deposition material 15 evaporates from the nozzle 11. Jet into a vacuum. When the vapor to be injected passes through the nozzle 11, the vapor is accelerated and cooled by adiabatic expansion and condensed to form a cluster of massive atoms called a cluster 16. The clusters 16 are partially ionized by the electrons emitted from the ionization filament 21 to become cluster ions, and are further accelerated by the electric field formed by the acceleration electrode 3 to form an unionized neutral cluster on the substrate 7. collide. On the other hand, a reactive oxygen gas exists in the vicinity of the substrate 7, and the reaction between the cluster of the deposition material 15 and the reactive gas proceeds on the substrate 7 to deposit the oxide thin film on the substrate 7.

Since the above apparatus is configured as described above, the reactive gas in the vacuum chamber 6 is in a molecular state and has low activity, so that the reaction efficiency is low and most of the reactive gas is exhausted. There is a problem that the reactive gas involved in the thin film formation is very small. In order to solve the above problems, attempts have been made to increase the reaction efficiency by exciting, dissociating, and partially ionizing and activating the reactive gas.

For example, FIG. 6 shows a conventional compound thin film forming apparatus in which a gas ion source is added to the ICB source shown in Japanese Patent Publication No. 63-11662, and the ICB source is the same as that in FIG. The description is omitted. 90 is a gas injection nozzle, 92 is an electron beam emitting means provided in a portion corresponding to the passage of the reactive gas, 91 is an electron beam extraction electrode for extracting this electron beam, 93 is an acceleration electrode for accelerating gas ions, and 94 is This is an internal tank for sealing the entire gas ion source 9. Power supply device 10 for this gas ion source 9
Is a power source 101 for heating the filament, which is the electron beam emitting means 92, and a DC power source 1 for biasing the electron beam extraction electrode 91 to the filament 92 at a positive potential.
02, a DC power supply 103 for biasing the electron beam extraction electrode 91 to a positive potential with respect to the acceleration electrode 93.

Next, the operation of this compound thin film forming apparatus will be described. By adjusting the flow rate adjusting valve 42 from the gas cylinder 41 into the vacuum chamber 6 kept in a high vacuum by the vacuum exhaust device 5, a reactive gas is introduced from the gas injection nozzle 90 into the vacuum chamber 6 to form a vacuum layer. The gas pressure in 6 is adjusted to be about 10 ⁻⁴ to 10 ⁻³ Torr. At this time, the gas pressure in the internal tank 94 is kept higher. On the other hand, a bias voltage is applied by the DC power supply 102 so that the heating power supply 101 emits electrons from the heated filament 92, which is the electron beam emission means, to the electron beam extraction electrode 91 arranged downstream of the gas injection nozzle 90. Upon application, thermionic electrons are emitted to excite, dissociate or partially ionize the reactive gas to form an activated state.

Next, the vapor pressure in the crucible 12 is several Tor.
When the crucible heating filament 13 is heated to a temperature of r, the vapor deposition material 15 is evaporated and jetted from the nozzle 11. This steam or cluster 16
Is partially ionized by the electrons emitted from the ionization filament 21 and is accelerated by the electric field formed by the acceleration electrode 3 to collide with the substrate 7 together with the non-ionized vapor or cluster.

On the other hand, excitation is applied to the substrate 7 and the vicinity of the substrate 7,
The dissociated or ionized reactive gas exists and collides with the vapor or cluster of the vapor deposition material to cause the reaction to proceed to deposit the compound thin film on the substrate 7. On the other hand, when a bias voltage is applied to the accelerating electrodes 3 and 93 by the DC power supplies 83 and 103, the above-mentioned ions are accelerated and reach the substrate 7, so that the ions are incident on the substrate 7 by changing the accelerating voltage at this time independently. It is possible to independently control the reactive gas ions and the kinetic energy of the vapor or clusters, and thereby the physical properties and crystallinity of the compound thin film formed on the substrate 7 (single crystal, polycrystal, amorphous etc.). The characteristics of the thin film can be controlled.

[0012]

The titanium nitride barrier layer 61 used in the large-scale integrated circuit formed by the conventional manufacturing method has a wiring layer 60 and an insulating layer 6 as the thickness thereof is further reduced.
There is a problem that the interaction with 2 and the diffusion effect cannot be sufficiently suppressed. Further, the conventional compound forming apparatus, especially the thin film forming apparatus shown in FIG. 6, has higher reactivity than the apparatus shown in FIG. 5, but in the case of forming oxynitride, There is a problem that it is difficult to control the composition ratio of oxygen and nitrogen. The present invention has been made to solve the above problems, and an object thereof is to obtain a high-quality semiconductor barrier layer, and to control the high-quality oxynitride barrier thin film efficiently on the surface of the substrate. An object is to obtain a thin film forming apparatus capable of vapor deposition.

[0013]

An integrated circuit according to claim 1 of the present invention uses a titanium oxynitride thin film as a barrier layer used as a base of a wiring film.

In the method for manufacturing an integrated circuit according to the second aspect of the present invention, oxygen gas is introduced near the substrate in the vacuum chamber, while titanium is deposited by a cluster type ion source while irradiating the substrate with nitrogen ions. To form a titanium oxynitride thin film.

According to a third aspect of the present invention, in the method for manufacturing an integrated circuit, a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element is introduced near the substrate in the vacuum chamber, Titanium is deposited by a cluster ion source while irradiating the substrate with argon ions to form a titanium oxynitride thin film.

According to a fourth aspect of the present invention, there is provided a thin film forming apparatus including a cluster type ion source having a gas introducing pipe for introducing oxygen gas, which is provided in the vicinity of the substrate, and gas ions having gas ionizing means for ionizing nitrogen gas. With a source.

A thin film forming apparatus according to a fifth aspect of the present invention is a cluster type having a gas introducing pipe for introducing a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element, which is provided near the substrate. It is provided with an ion source and a gas ion source having gas ionization means for ionizing argon gas.

[0018]

The titanium oxynitride according to the present invention has a good barrier property as compared with the conventional titanium nitride barrier layer even if it is thinned.

In the titanium oxynitride thin film forming apparatus according to claim 4 of the present invention, the oxygen gas introduced in the vicinity of the substrate is activated and vapor-deposited while being irradiated with nitride ions. In the thin film forming apparatus according to the method, since the oxygen and nitrogen introduced near the substrate are vapor-deposited while irradiating with argon ions, the reaction efficiency with vapor or cluster becomes very high, and the composition of oxygen and nitrogen in the film is increased. Since the ratio can be controlled, a high quality thin film is formed even if the film quality on the surface is thin due to the substance.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional structure of an LSI wiring portion according to an embodiment of the present invention. Reference numeral 60 is a wiring layer, 65 is a titanium oxynitride barrier layer, and 62 is an insulating layer. FIG. 2 is a sectional view schematically showing a titanium oxynitride thin film manufacturing apparatus according to an embodiment of the present invention. In the figure, the same or corresponding parts as those in FIGS. Is omitted.

Reference numeral 40 is a gas introducing pipe for introducing oxygen gas into the vicinity of the substrate 7, 41 is a nitrogen cylinder, 42 is a gas flow rate adjusting valve, 43 is a gas introducing pipe, 44 is a filament (cathode) which is an electron beam emitting means, 45 is an electron beam extraction electrode (anode) that forms plasma inside, 46 is an acceleration electrode that accelerates and controls ions to irradiate the substrate 7 through the porous electrode 44, and 48 heats a filament 47 that is an electron beam emission means. Filament heating power supply, 49
Reference numeral 50 is a DC power source for biasing the electron beam extraction electrode 45 to a positive potential with respect to the filament 44 which is an electron beam emitting means, and 50 is a DC power source for biasing the electron beam extraction electrode 45 to a positive potential with respect to the acceleration electrode 46. is there.

In another embodiment of the present invention, 40 is a gas introducing pipe for introducing a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element in the vicinity of the substrate 7.
1 is an argon cylinder.

Next, the operation of this titanium oxynitride thin film forming apparatus will be described. An oxygen gas is introduced into the vicinity of the substrate 7 by a gas introduction pipe 40 into a vacuum chamber (not shown) kept in a high vacuum by an evacuation device (not shown), and a flow control valve 42 is installed from a gas cylinder 41. By adjusting the electron beam extraction electrode 4 of the gas ion source
Nitrogen gas is introduced into the chamber 5 through the gas introducing pipe 43, and the gas pressure in the vacuum layer is adjusted to 10 ^-5 to 10 ^{-3 by} combining oxygen partial pressure and nitrogen partial pressure.
Adjust to about Torr. When a bias voltage is applied by a DC power source 49 so that an electron beam is emitted from a heated filament 44, which is an electron beam emission means, toward an electron beam extraction electrode 45 by a filament heating power source 48, the emitted thermoelectrons are emitted. Collide with the nitrogen gas in the electron beam extraction electrode 45 to form plasma, which is ionized. The generated nitrogen ions are accelerated by the electric field formed by the acceleration electrode 46, extracted from the porous electrode 47, and irradiated on the substrate 7.

Next, the vapor pressure in the crucible 12 is several Torr.
When the crucible heating filament 13 is heated to a temperature of, the titanium, which is the vapor deposition material 15, evaporates and is ejected from the nozzle 11. The evaporated titanium vapor or clusters 16 are partially ionized by the electrons emitted from the ionization filament 21 next, and are accelerated by the electric field formed by the acceleration electrode 3, and are vaporized together with the non-ionized vapor or clusters to form the substrate. Clash with 7.

On the other hand, the oxygen gas supplied from the gas introducing pipe 40 is present in the substrate 7 and the vicinity of the substrate 7, and is in an active state where it is excited, dissociated or ionized by the irradiation of nitrogen ions, and the vapor of titanium vapor or The titanium oxide nitride thin film is deposited on the substrate 7 by colliding with the clusters and efficiently advancing the reaction. At this time, if the amount of nitrogen ions with which the substrate 7 is irradiated is changed, the composition ratio of oxygen and nitrogen in the film changes, so that the composition ratio can be freely controlled.

In another embodiment of the present invention, a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element is introduced from the gas introduction pipe 40 to the vicinity of the substrate 7 while the argon cylinder 41 is used. By adjusting the flow rate adjusting valve 42, argon gas is introduced into the electron beam extraction electrode 45 of the gas ion source through the gas introduction pipe 43, and the gas pressure in the vacuum layer is adjusted to the partial pressure of the mixed gas of oxygen and nitrogen and the argon pressure. The pressure is adjusted so as to be about 10 ⁻⁵ to 10 ⁻³ Torr. The thermoelectrons emitted toward the electron beam extraction electrode 45 collide with the argon gas in the electron beam extraction electrode 45 to form plasma, which is ionized. The generated argon ions are accelerated by the electric field formed by the acceleration electrode 46, extracted from the porous electrode 47 from which ions can be easily extracted, and irradiated on the substrate 7.

On the other hand, a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element supplied from the gas introduction pipe 40 exists in the substrate 7 and the vicinity of the substrate 7,
It is excited, dissociated, or ionized by the irradiation of argon ions, and is in an active state, and collides with titanium vapor or clusters of a vapor deposition material to cause a reaction to proceed efficiently, and a titanium oxynitride thin film is deposited on the substrate 7. At this time, when the amount of argon ions with which the substrate 7 is irradiated changes the mixing amount of oxygen gas and nitrogen gas, the composition ratio of oxygen and nitrogen in the film changes, so that the composition ratio can be freely controlled. This is the same as the above embodiment.

FIG. 3 shows a gas ion source according to another embodiment of the present invention, and 51 is a magnetic field applying means provided outside the gas ion source.

Next, the operation will be briefly described. Similarly to the gas ion source of the embodiment shown in FIG. 2, nitrogen gas is introduced into the gas ion source through the gas introduction pipe 43, and oxygen gas is introduced into the vacuum layer near the substrate 7 through the gas introduction pipe 40. In addition, the gas pressure is adjusted to be about 10 ⁻⁵ to 10 ⁻³ Torr. An electron beam is emitted from the electron beam emission means 44 toward the electron beam extraction electrode 45 to ionize the nitrogen gas in the plasma. At this time, it is possible to further increase the ionization efficiency by spirally moving the electron beam by the magnetic field applying means 51 provided outside the ion source. In this way, the ionized nitrogen gas is accelerated by the substrate 7 to activate the oxygen gas in the vicinity of the substrate 7 to react with titanium vapor or clusters generated from the ICB source to form a titanium oxynitride thin film. This is the same as the embodiment of the invention shown in FIG.

[0030]

As described above, according to the present invention, since the titanium oxynitride thin film is used for the barrier layer used as the underlayer of the wiring film, the interaction and the diffusion action between the wiring layer and the insulating layer are prevented. There is an effect that it can be sufficiently suppressed and the barrier property is improved. Further, according to the thin film forming apparatus of the present invention, not only the reaction efficiency with vapor or clusters is increased, but also the composition ratio of oxygen and nitrogen can be freely changed, so that a high quality titanium oxynitride thin film can be obtained. The effect is that it can be formed.

[Brief description of drawings]

FIG. 1 is a sectional view of a large scale integrated circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a thin film forming apparatus according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a thin film forming apparatus according to another embodiment of the present invention.

FIG. 4 is a sectional view showing an example of a conventional large-scale integrated circuit.

FIG. 5 is a configuration diagram showing an example of a conventional thin film forming apparatus.

FIG. 6 is a configuration diagram showing another example of a conventional thin film forming apparatus.

[Explanation of symbols]

 1 vapor generation source 2 ionization means 3 acceleration electrode 7 substrate 9 gas ion source 12 crucible 40 oxygen gas introduction tube 43 nitrogen gas introduction tube 44 electron beam emission means 45 electron beam extraction electrode 46 acceleration electrode 47 porous electrode 51 magnetic field application means 60 wiring Layer 65 Barrier layer 62 Insulation layer

Claims (5)

[Claims] 1. An integrated circuit using a titanium oxynitride (TiON) thin film as a barrier layer used as a base of a wiring film. 2. A titanium oxynitride (TiON) thin film is formed by introducing oxygen gas into the vicinity of a substrate in a vacuum chamber and irradiating the substrate with nitrogen ions while depositing titanium (Ti) by a cluster type ion source. Method of manufacturing integrated circuit. 3. A mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element is introduced in the vicinity of the substrate in the vacuum chamber, while a cluster type ion source is used while irradiating the substrate with argon ions. Titanium (Ti)
A method for manufacturing an integrated circuit, wherein a titanium oxynitride (TiON) thin film is formed by vapor deposition. 4. A vacuum chamber maintained at a predetermined degree of vacuum, a substrate provided in this vacuum layer, a gas introducing pipe for introducing oxygen gas in the vicinity of the substrate, and a vapor deposition material directed toward the substrate. A vapor source for ejecting vapor to generate vapor or clusters of the vapor deposition material, and an ionization means for ionizing a part of the vapor or clusters of the vapor deposition material,
A cluster-type ion source configured by an acceleration means that accelerates and controls ionized vapor or cluster ions and transports them to a substrate together with vapor or clusters of non-ionized vapor deposition material, and nitrogen gas provided in the vacuum layer. A gas ionization means for ionizing nitrogen gas, which comprises an introduction tube, an electron beam extraction electrode arranged in the introduction part of nitrogen gas, and an electron beam emission means, and acceleration control of nitrogen ions ionized by this gas ionization means A thin film forming apparatus for an integrated circuit, comprising: a gas ion source configured by an acceleration means. 5. A vacuum chamber maintained at a predetermined degree of vacuum, a substrate provided in this vacuum layer, a mixed gas of oxygen gas and nitrogen gas or a mixed gas containing oxygen element and nitrogen element in the vicinity of this substrate. A gas introduction pipe for introducing the vapor, a vapor source for ejecting vapor of the vapor deposition material toward the substrate and generating vapor or clusters of the vapor deposition material, and a portion of the vapor or cluster of the vapor deposition material. A cluster-type ion source configured by an ionization means and an acceleration means for accelerating and controlling vapor or cluster ions that have been ionized and transporting them to a substrate together with vapor or clusters of non-ionized vapor deposition material, and provided in the vacuum layer. Argon gas introduction pipe, electron beam extraction electrode and electron beam emission means arranged at the argon gas introduction part. Becomes, a gas ionizing means for ionizing the argon gas, the thin film forming apparatus of the integrated circuit and a configured gas ion source by an acceleration means for acceleration control argon ions ionized by the electron beam emitting means.