JPH11200035A - Sputter chemical vapor deposition combined equipment - Google Patents

Abstract

(57) Abstract: Provided is a combined sputter chemical vapor deposition apparatus in which cross-contamination of processes is effectively prevented, an occupied area is not significantly increased, and problems such as a decrease in productivity do not occur. A transport mechanism (11) includes a sputtering chamber (2) for performing sputtering and a CVD chamber (3) for performing chemical vapor deposition.
Are connected in a gas-tight manner via a transfer chamber 1 provided with a buffer chamber 4 between the transfer chamber 1 and the CVD chamber 3. The buffer chamber 4 has a purge gas introduction system 46 therein, and a heating unit 43 and a cooling unit 44 for the substrate 9. An auxiliary transfer mechanism for transferring the substrate 9 between the buffer chamber 4 and the CVD chamber 3 is provided, and a gate valve 10 provided between the buffer chamber 4 and the CVD chamber 3 Pressure is CVD
It is opened only when it is higher than inside the chamber 3. A titanium nitride thin film is formed on the titanium thin film formed by sputtering in the sputtering chamber 2 by CVD in the CVD chamber 3 to obtain a structure of a diffusion preventing layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus which is originally a different kind of apparatus and a chemical vapor deposition.
The present invention relates to a combined sputter chemical vapor deposition apparatus which is combined with a Vapor Deposition (CVD) apparatus.

[0002]

2. Description of the Related Art Both a sputtering apparatus and a chemical vapor deposition apparatus are conventionally known as apparatuses for forming a desired thin film on the surface of an object. Sputtering is a type of film forming technique called physical vapor deposition. Sputtering is performed by accelerating an ionized gas molecule by an electric field and causing it to collide with a target. Particles (usually atoms) are bombarded from the target by the collision, and the particles are made to fly and adhere to the target to form a film. On the other hand, chemical vapor deposition is also called chemical vapor deposition. Chemical vapor deposition is a technique in which a desired material is deposited on the surface of an object by utilizing a reaction such as decomposition of a reactive gas, and is grown into a thin film.

[0003] Sputtering equipment and chemical vapor deposition equipment are LSI
(Large-scale integrated circuits) are frequently used in the process of manufacturing electronic devices. For example, a sputtering apparatus is frequently used for forming various wiring materials such as aluminum, and a chemical vapor deposition apparatus is often used for forming various insulating films. Although the sputtering apparatus and the chemical vapor deposition apparatus are both apparatuses for forming a thin film, they are considered to be completely different apparatuses because they employ completely different mechanisms of a physical process and a chemical process. For example,
Chemically inert gas such as argon gas is used for the sputtering device, and the use of a magnetic field to enhance efficiency, etc.
Physical ingenuity is applied. On the other hand, in the case of a chemical vapor deposition apparatus, special consideration is given to chemical conditions such as a temperature and a gas flow rate which determine a chemical reaction rate.

However, according to the study of the inventor, L
In the manufacturing process of electronic devices such as SI, it has been found that it is very effective in some cases to combine sputtering and chemical vapor deposition into one apparatus. This will be described below.

In the manufacturing process of an LSI having a structure such as an FET (field effect transistor), a structure in which a diffusion preventing layer for preventing mutual diffusion between a base semiconductor layer and a wiring layer is provided as a wiring structure to an electrode portion is employed. Have been. This diffusion prevention layer often has a structure in which a titanium thin film having a small electric resistance and a titanium nitride thin film having a high barrier property are laminated. Such a diffusion preventing layer has been formed by sputtering. For example, when laminating a titanium thin film and a titanium nitride thin film, a titanium thin film is first formed by sputtering a target made of titanium with argon gas. Thereafter, the gas is sputtered instead of nitrogen to form a titanium nitride thin film while utilizing the reaction between nitrogen and titanium in an auxiliary manner.

It is an important issue to form such a diffusion preventing layer with a sufficient thickness on the inner surface (bottom surface and side surface) of a fine hole. That is, it is necessary to form a diffusion prevention layer with a sufficient thickness on the inner surface of a contact hole provided in an insulating layer for ensuring conduction to the channel of the FET or an interlayer through hole in a multilayer wiring structure. A bottom coverage ratio is often used as one of the indexes for evaluating a technique for forming a thin film on the inner surface of such a fine hole. The bottom coverage ratio is a ratio of a film formation rate on the bottom surface of the hole to a film formation rate on a surface around the hole (a surface other than the hole). If the bottom coverage ratio is insufficient in the formation of the above-mentioned diffusion preventing layer, the effect of preventing diffusion at the bottom surface of the hole becomes insufficient, causing a problem of deteriorating device characteristics due to mutual diffusion. Therefore, film formation with a high bottom coverage ratio is demanded.

On the other hand, the aspect ratio of a hole (the ratio of the depth of a hole to the width or diameter of a hole) has been increasing year by year in response to higher integration and higher functionality of LSI. For example, in a 256 Mbit class DRAM (a random write / read memory that requires a memory holding operation), the hole diameter is 0.25 μm and the aspect ratio is about 4, and in a 1 Gbit class DRAM, the hole diameter is 0.18 μm. It is said that the aspect ratio becomes about 6 to 7.

It is becoming difficult to form a diffusion preventing layer by forming a film with a required bottom coverage ratio for a hole having a high aspect ratio. Although the thin film constituting the diffusion prevention layer is formed by sputtering as described above, in the case of sputtering, in order to form a film having a high bottom coverage rate, particles emitted from the target (hereinafter, sputtered particles) are formed by holes. It is necessary to reach the bottom much. However, as the aspect ratio increases, the amount of sputter particles that reach the bottom of the hole decreases.
That is, only a limited number of particles that enter the substrate almost perpendicularly can reach the bottom surface. Therefore, the deposition rate at the bottom of the hole is reduced, and the bottom coverage ratio is reduced.

In order to solve such problems, collimated sputtering and low-pressure remote sputtering have been developed as improved sputtering techniques. A collimated sputter is a member (referred to as a collimator) that selectively passes only sputter particles that fly almost perpendicular to the substrate.
Is a technique that uses In the collimated sputtering, although the bottom coverage ratio is improved as compared with the normal sputtering, there is a problem that the efficiency is poor because sputter particles attached to the collimator portion are lost.

In the low-pressure remote sputtering, the distance between the substrate and the target is set to three to five times that of the normal sputtering.
This is a technique of performing sputtering at a low pressure of about mTorr or less.
Since the distance between the substrate and the target is increased, a large amount of sputtered particles flying almost perpendicular to the substrate are incident on the substrate. Further, since the pressure is low, such sputtered particles flying vertically do not easily scatter. Therefore, a film having a high bottom coverage ratio can be formed. However, in the low-pressure remote sputtering, the intensity of the sputter discharge cannot be increased so much as to operate at a low pressure, and the sputter particles emitted from the target do not reach the substrate because the target is away from the substrate. There are many things that are wasted. Therefore, the efficiency of film formation as a whole is poor.

Further, in the low-pressure remote sputtering, there is a problem that non-uniformity occurs in film formation on a hole in a peripheral portion of a substrate, particularly on a side wall of the hole. That is, the thin film is deposited almost evenly on the inner surface of the hole at the center of the substrate. However, a relatively thin film is deposited on the side wall from the outside on the side facing the hole in the peripheral portion of the substrate, but the thin film is deposited only thinly on the side wall from the inside.
This is for the following reasons. At the center of the substrate, the sputtered particles are slightly shifted left and right about the direction perpendicular to the substrate and uniformly incident. However, in the peripheral portion of the substrate, the number of sputtered particles obliquely incident outward increases, and as a result, the film thickness on the side wall from the inside of the hole becomes insufficient. When the film thickness is insufficient,
The effect of preventing mutual diffusion cannot be sufficiently obtained, which is a factor that hinders device characteristics. From such a problem, it is said that low-pressure remote sputtering is limited to the production of a device having an opening diameter (or width) of 0.25 μm (approximately 4 in aspect ratio).

On the other hand, an ionization sputtering method has been developed as a further improved sputtering method in response to a higher degree of integration of devices. The ionization sputtering is a method in which sputter particles emitted from a target are ionized, an electric field perpendicular to the substrate is set, and the ionized sputter particles are accelerated by the electric field and vertically incident on the substrate. In this ionized sputtering, there is no reduction in film formation efficiency and non-uniformity of film formation on the side wall of the hole in the peripheral portion of the substrate as seen in low-pressure remote sputtering. However, when performing reactive sputtering, there is a problem that the effect of ionization sputtering cannot be sufficiently obtained.
For example, when a titanium target is sputtered while introducing nitrogen to form a titanium nitride film, nitrogen reacts with titanium on the target surface and titanium nitride is emitted as sputtered particles. Alternatively, sputtered particles of titanium react with nitrogen to form titanium nitride. However, such titanium nitride has poor ionization efficiency, and does not provide the effect of improving the coverage of the inner surface of the hole as in the case of forming a film of titanium alone.

[0013]

Turning now to the case of chemical vapor deposition, which is a completely different film forming technique, a titanium nitride thin film can be formed by a chemical vapor deposition technique. For example, it is possible to form a titanium nitride thin film on the surface of a substrate by utilizing a hydrogen reduction reaction of a reactive gas containing Ti atoms such as TiCl ₄ . The energy used for the reaction is provided in the form of heat or plasma.
The former method is called thermal CVD, and the latter method is called plasma CVD. The gas used is TiCl
₄ , H ₂ , N ₂ , NH _3, etc. In the case of film formation by such a chemical vapor deposition method, it is a method basically utilizing a gas phase reaction of gas, and the gas can freely diffuse and reach the hole, so that it can be applied to a hole having a high aspect ratio. Film formation can be performed with a sufficient bottom coverage ratio.

In consideration of the above, according to the technology for forming a diffusion prevention layer in a fine device of 1 gigabit (typical hole diameter is about 0.18 μm) or later, a titanium thin film is formed by ionization sputtering and nitrided. Titanium thin films are expected to be very effective to make by chemical vapor deposition.
In other words, it is expected that in next-generation apparatuses, it will be important to combine different kinds of film forming techniques of sputtering and chemical vapor deposition. However, according to the study of the inventor, the combination of the different film forming techniques of sputtering and chemical vapor deposition causes a problem of cross-contamination of the processes due to the heterogeneity of the two processes. It is not possible to develop a complex sputter chemical vapor deposition apparatus. This point will be specifically described below.

When designing a combined sputtering and chemical vapor deposition apparatus capable of forming a diffusion preventing layer by combining sputtering and chemical vapor deposition, a processing chamber for performing sputtering (hereinafter, referred to as a sputtering chamber) and a processing chamber for performing chemical vapor deposition (hereinafter, referred to as a chamber). (CVD chamber) so that both processes can be performed continuously in a vacuum. In a configuration in which the substrate is once taken out to the atmosphere side between the two processes, the surface of the titanium thin film is contaminated with the atmosphere before stacking the titanium nitride, and there is no point in combining the two processes.

However, on the other hand, when the sputtering chamber and the CVD chamber are connected in an airtight manner, the possibility that the gas diffuses from one chamber to the other chamber and contaminates the process increases. For example, CV
Residual products such as chlorine gas after chemical vapor deposition are floating in the D chamber. When the chlorine gas diffuses into the sputtering chamber and adheres to the substrate, it reacts with the formed titanium thin film and forms an altered layer on the surface of the titanium thin film. When such an altered layer is formed, the electrical characteristics of the device are significantly impaired, which causes a product failure. still,
The sputter chamber and the CVD chamber are separated by a gate valve. The gate valve is opened and closed when the substrate is loaded and unloaded.

In order to suppress such a problem of cross-contamination, it is considered to be effective to interpose a transfer chamber between the sputtering chamber and the CVD chamber. 6 and 7 are schematic plan views illustrating the structure of the invention made in the course of conceiving the invention of the present application, and are diagrams showing the structure of a combined sputter chemical vapor deposition apparatus in which mutual contamination is suppressed.

First, in the combined sputter chemical vapor deposition apparatus shown in FIG. 6, a transfer chamber 1 is interposed between a sputter chamber 2 and a CVD chamber 3. That is, a transfer chamber 1 is provided at the center, and a plurality of processing chambers 2, 3, and 7 are provided therearound. A transfer mechanism 11 is provided in the transfer chamber 1. One of the processing chambers is a sputter chamber 2 and another is a C chamber.
VD chamber 3. And each chamber 1,
A gate valve (not shown) is provided at the boundary between 2, 3, and 7. According to such a configuration, the gas in the processing chambers 2, 3, and 7 cannot be diffused to the other processing chambers 2, 3, and 7 without passing through the transfer chamber 1.
The problem of cross-contamination can be suppressed to some extent. However,
It is considered that it is difficult to sufficiently suppress the problem of cross-contamination because there is a case where the particles stay in the transfer chamber 1 to some extent and then diffuse into the other processing chambers 2, 3, and 7.

In the example shown in FIG. 7, two transfer chambers 1A and 1B are provided. That is, a first transfer chamber 1A for the sputtering chamber 2 and a second transfer chamber 1B for the CVD chamber 3 are provided.
In the example shown in FIG. 7, for example, the gas in the CVD chamber 3 cannot reach the sputtering chamber 2 without passing through the first and second two transfer chambers 1A and 1B. Thus, the problem of cross-contamination is expected to be significantly reduced.
However, in the example shown in FIG. 7, since the two transfer chambers 1A and 1B are used, there is a problem that the area occupied by the apparatus becomes very large. In addition, since the time required for transportation is long, a reduction in productivity is a problem. Further, the two transfer chambers 1A and 1B and the transfer mechanism 11
However, there is also a disadvantage that the cost becomes very high.
Further, the problem of mutual contamination between the CVD chambers 3 cannot be basically solved.

The invention of the present application has been made to solve such a problem, and it is possible to effectively prevent cross-contamination of processes, not to greatly increase the occupied area, and to reduce the productivity. It is an object of the present invention to provide a combined sputter chemical vapor deposition apparatus which does not cause the above problems.

[0021]

According to a first aspect of the present invention, there is provided a transfer chamber including a sputtering chamber for performing sputtering, a CVD chamber for performing chemical vapor deposition, and a transfer mechanism. Is a sputter chemical vapor deposition combined apparatus having a structure in which a sputter chamber and a CVD chamber are hermetically connected through a buffer chamber provided between the transfer chamber and the CVD chamber or between the transfer chamber and the sputter chamber. The sputtering chamber and the CVD chamber are configured to be airtightly connected to the transfer chamber via the transfer chamber and the buffer chamber. In order to solve the above problem, the invention according to claim 2 is the configuration according to claim 1, wherein the sputtering chamber and the CVD chamber are one of processing chambers that are hermetically connected around the transfer chamber. . According to a third aspect of the present invention, there is provided an auxiliary transfer mechanism for transferring a substrate between the buffer chamber and the CVD chamber or the sputtering chamber. Is provided. According to a fourth aspect of the present invention, in the configuration of the first, second, or third aspect, the buffer chamber includes the transfer chamber and the CVD chamber.
A purge valve is provided between the buffer chamber and the CVD chamber. The gate valve is provided between the buffer chamber and the CVD chamber.
It is configured to be opened only when the pressure is higher than the pressure in the D chamber. According to a fifth aspect of the present invention, there is provided the invention as set forth in the first, second, third or fourth aspect, wherein the heating means for heating the substrate to a predetermined temperature in the buffer chamber or the substrate is heated to a predetermined temperature And a cooling means for cooling.

[0022]

Embodiments of the present invention will be described below. FIG. 1 is a plan view illustrating a schematic configuration of a combined sputter chemical vapor deposition apparatus according to an embodiment. The apparatus shown in FIG. 1 is a multi-chamber type apparatus like the apparatuses shown in FIGS. 6 and 7, and includes a transfer chamber 1 disposed at the center and a plurality of processing chambers 2 provided around the transfer chamber 1. , 3, 4, 5, 6, and two load lock chambers 8. Each chamber 1, 2, 3, 4, 5, 6, 7, 8
It is a vacuum vessel evacuated by a dedicated exhaust system. Further, each chamber 2, 3, with respect to the transfer chamber 1
Gate valves 10 are provided at connection points of 4, 5, 6, 7, and 8, respectively.

In the transfer chamber 1, a transfer mechanism 11 is provided. The transport mechanism 11 takes out the substrates 9 one by one from one of the load lock chambers 8 and sends them to each of the processing chambers 2, 3, 4, 5, and 6, and sequentially performs the processing. Then, after the last processing is completed, it is returned to the other load lock chamber 8. As the transfer mechanism 11, an articulated robot provided with an arm for mounting and holding the substrate 9 at the tip is suitably used. It is preferable to provide two arms so that the two substrates 9 can be moved independently independently at the same time, because the efficiency of transportation is improved. Also, transfer chamber 1
The inside is evacuated by an exhaust system (not shown) and is constantly 10 ⁻⁶ to
A vacuum pressure of about 10 ^-8 Torr is maintained. Therefore,
As the transport mechanism 11, a mechanism that can operate under this vacuum pressure is employed.

The sputter chemical vapor deposition apparatus of this embodiment combines sputter and chemical vapor deposition as the name implies. That is, one of the processing chambers is a sputtering chamber 2 and another is a CVD chamber 3. First, referring to FIG.
Will be described. FIG. 2 is a schematic front view showing the configuration of the sputtering chamber 2 shown in FIG.

As shown in FIG.
A sputtering system 22 for evacuating the interior, a target 23 provided in the sputtering chamber 2 so as to expose a surface to be sputtered, a sputtering power supply 231 for applying a predetermined power to the target 23, and a , A gas introducing means 25 for introducing a predetermined sputtering gas into the sputtering chamber 2, and a substrate for disposing the substrate 9 at a predetermined position in the sputtering chamber 2 facing the target 23. It is mainly composed of a holder 26.

The evacuation system 22 uses a vacuum pump 221 such as a cryopump to evacuate the inside of the sputtering chamber 2 to 10 ^-8.
It is configured to be able to exhaust to about Torr. Exhaust system 22
Has an exhaust speed adjuster 222 such as a variable orifice. The target 23 is attached to the sputtering chamber 2 via an insulating material 232. Target 2
3 is made of titanium in this embodiment. The sputtering power source 231 supplies a negative high voltage or a high frequency voltage to the target 23.
To be applied.

The magnet mechanism 24 includes a columnar central magnet 241 disposed at the center, a ring-shaped peripheral magnet 242 surrounding the central magnet 241, a central magnet 241 and a peripheral magnet 242.
And a yoke 243 connecting the two. The front surface of the center magnet 241 and the front surface of the peripheral magnet 242 have different magnetic poles, and an arch-shaped magnetic force line 244 as shown in FIG. The electric field set by the sputtering power supply 231 in the sputtering chamber 2 via the target 23 is orthogonal to the magnetic field near the apex of the arch-shaped line of magnetic force 244. For this reason,
In the formed sputter discharge, the electrons perform a magnetron motion, and a magnetron discharge is achieved. Therefore, the efficiency of ionization of neutral gas molecules is increased, and sputtering can be performed with high efficiency.

In the present embodiment, the gas introducing means 25 introduces an argon gas as a sputtering gas. The gas introduction means 25 includes a pipe 251 connecting the cylinder 250 storing argon gas and the sputtering chamber 2.
And a valve 252 and a flow controller 2 provided on the pipe 251.
53 and the like.

The substrate holder 26 is configured to place and hold the substrate 9 on the upper surface. The substrate holder 26 is provided with an electrostatic attraction mechanism for fixing the substrate 9 at a predetermined position by electrostatic attraction as needed. Further, a heater 261 for heating the substrate 9 to a predetermined temperature is provided in the substrate holder 26.

In this embodiment, the film is formed in the sputtering chamber 2 by ionization sputtering. That is, the sputtering chamber 2
3 has ionization means 27 for ionizing sputtered particles emitted from 3. The ionization means 27 is adapted to ionize sputtered particles by high-frequency energy, and includes an ionization electrode 271 provided in the sputtering chamber 2 and a high-frequency power supply 272 for supplying high-frequency energy to the ionization electrode 271. .

The ionization electrode 271 is provided so as to surround the flight space of the sputtered particles from the target 23 to the substrate 9. As the ionization electrode 271, for example, a metal mesh formed into a cylindrical shape or a coil-shaped one is used. As the high-frequency power supply 272, for example, a power supply having a frequency of 13.56 MHz and an output of about 1 kW is used.
The high-frequency electric field set in the sputtering chamber 2 by the ionization electrode 271 forms a plasma P ′ by high-frequency discharge separately from the plasma P by sputter discharge. Neutral sputtered particles emitted from the target 23 pass through the plasma P ′ when passing through the plasma P ′.
It is designed to collide with ions and electrons in the material and to be ionized (hereinafter, ionized sputtered particles).

On the other hand, the substrate holder 24 is provided with electric field setting means 28. The electric field setting means 28 is configured to set an electric field perpendicular to the substrate 9 in the sputtering chamber 2 and to cause the ionized sputtered particles to be perpendicularly incident on the substrate 9. In the present embodiment, as the electric field setting means 28, a high frequency power supply for substrate 281 which applies a high frequency voltage to the substrate holder 26 and gives a negative self-bias voltage to the substrate 9 by the interaction between the high frequency and the plasma P 'is employed. ing. As the substrate high-frequency power supply 281, for example, 1
Those with a 3.56 MHz output of about 300 W can be used.

A matching device 282 is provided between the substrate high-frequency power supply 281 and the substrate holder 26.
Further, when the substrate 9 and the substrate holder 26 are both conductors, a predetermined capacitor is provided in a high-frequency transmission path, and a high-frequency voltage is applied to the substrate 9 via the capacitor. When a high-frequency voltage is applied to the substrate 9 via a capacitance such as a capacitor, electrons and positive ions in the plasma P ′ act on charging and discharging of the capacitance,
A negative self-bias potential is generated on the substrate 9 due to the difference in mobility between electrons and positive ions. The space potential of the plasma P ′ is almost ground potential or a positive potential of about 20 volts,
An electric field whose potential gradually decreases toward the substrate 9 is set between the substrate 9 where the negative self-bias potential is generated and the plasma P ′. The direction of the electric field is perpendicular to the substrate 9, and the positively ionized sputtered particles are accelerated by the electric field and vertically incident on the substrate 9.

Next, the operation of the apparatus in the sputtering chamber 2 will be described with reference to FIG. First, the substrate 9 is carried into the sputtering chamber 2 from the transfer chamber 1 through the gate valve 10 by the transfer mechanism 11. The inside of the sputtering chamber 2 is exhausted to a predetermined pressure by an exhaust system 22 in advance, and the substrate 9 is placed on a substrate holder 26. The heater 261 in the substrate holder 26 is operated in advance, and the substrate 9 placed on the substrate holder 26 is rapidly heated to a predetermined temperature by the heat of the heater 261 and the temperature is maintained.

After the gate valve 10 is closed, the gas introducing means 25 operates, and an argon gas as a sputtering gas is introduced into the sputtering chamber 2. The flow rate of the argon gas is adjusted by the flow rate adjuster 253 of the gas introducing means 25 and the exhaust rate is adjusted by the exhaust rate adjuster 221 of the exhaust system 22 to maintain the pressure in the sputtering chamber 2 at a predetermined pressure.

In this state, the sputtering power supply 231 is operated to generate a sputtering discharge in the argon gas to sputter the target 23. At the same time, the high-frequency power source 272 of the ionization unit 27 and the high-frequency power source 27 of the electric field setting unit 27
1 is operated. The ionized sputtered particles generated when passing through the plasma P ′ formed by the ionizing means 27 are accelerated by the electric field set by the electric field setting means 28 and are incident on the substrate 9 at an almost vertical angle. As a result, it becomes easier to reach the bottom and side surfaces of the fine holes formed on the surface of the substrate 9, and a thin film is formed with sufficient coverage on the bottom surface and side surfaces.

After performing such film formation for a predetermined time, the electric field setting means 28, the ionization means 27, and the sputtering power supply 231
The operation of the gas introduction means 25 is stopped, and the inside of the sputtering chamber 2 is again evacuated to a predetermined pressure by the exhaust system 22. After that, the gate valve 10 is opened and the substrate 9 is taken out of the sputtering chamber 2. Thus, a series of operations in the sputtering chamber 2 is completed.

Next, the configuration of the CVD chamber 3 shown in FIG. 1 will be described. FIG. 3 is a front view showing a schematic configuration of the CVD chamber 3 and the buffer chamber 4 shown in FIG. The CVD chamber 3 shown in FIG. 3 includes an exhaust system 32 for exhausting the inside, gas introducing means 33 for introducing a predetermined CVD gas into the inside, and a substrate holder 34 for disposing the substrate 9 at a predetermined position. ing.

As will be described later, since a highly active chlorine-based gas is introduced into the CVD chamber 3, the exhaust system 3
2 requires the use of a high-performance vacuum pump 321 with a high pumping speed. Specifically, the evacuation system 32 uses a turbo-molecular pump having an evacuation speed of about 1000 liters / second as the vacuum pump 321, and the inside of the CVD chamber 3 is 1
0 constituted to be evacuated to an ultimate pressure of about ^{-7 Torr~10 -8} Torr. The exhaust system 32 has an exhaust speed adjuster 322 such as a variable orifice.

The gas introducing means 33 is configured to be capable of introducing a mixed gas of titanium tetrachloride, hydrogen, nitrogen or ammonia and silane as a CVD gas. Each gas introduction system is provided with a valve 331 and a flow controller 332. Hydrogen and silane are mainly introduced for the reduction reaction of titanium tetrachloride. Note that the nitrogen gas also has a function of facilitating the start of high-frequency discharge by the plasma forming means 36 described later. Also, nitrogen or ammonia gas is
Introduced as a nitrogen supply gas for nitriding titanium.

The substrate holder 34 is configured to place and hold the substrate 9 on the upper surface. The substrate holder 34 is provided with an electrostatic attraction mechanism for fixing the substrate 9 at a predetermined position by electrostatic attraction as needed.

The substrate holder 34 is provided with a holder elevating mechanism 341. Holder elevating mechanism 34
1 moves the arm 342 fixed to the holder support 340 supporting the substrate holder 34 up and down to move the substrate holder 3
4 is raised and lowered. As the holder lifting mechanism 341, a mechanism using a fluid drive such as an air cylinder, or a combination of a ball screw and a servomotor can be adopted. Note that the holder support 340 passes through the bottom plate of the CVD chamber 3 in an airtight manner. A mechanical seal using a magnetic fluid is provided in the penetrating portion. As a result, leakage from the penetrating portion is prevented while allowing the holder support 340 to move up and down.

A heater 35 for heating the substrate 9 to a predetermined temperature is provided in the substrate holder 34. Heater 3
Reference numeral 5 denotes, for example, a type that generates Joule heat by energization, and is configured so that the substrate 9 can be heated and maintained at about 400 to 700 ° C. The temperature of the substrate 9 is detected by a temperature sensor such as a thermocouple (not shown), and is subjected to negative feedback control by a control unit (not shown).

Further, the CVD chamber 3 in the present embodiment performs plasma CVD. That is, the CVD chamber 3 is provided with plasma forming means 36 for forming a plasma P ", and is configured to form a film by the action of the plasma P". The plasma forming means 36 includes a high-frequency electrode 361 provided in the CVD chamber 3 and a high-frequency power supply 362 for supplying high-frequency power to the high-frequency electrode 361. Gas introduction means 3
The CVD gas introduced into the CVD chamber 3 by 3 receives energy from the high-frequency electric field set by the high-frequency electrode 361, and a plasma P ″ is formed.

The high-frequency electrode 361 is formed in a plate shape having holes for blowing out gas uniformly, or in a mesh shape. The CVD gas is diffused downward through the high-frequency electrode 361 to form a plasma P ″. As the high-frequency electrode 361, a hollow disk-shaped one having a gas blowing hole on the lower surface is used. There is a case where the gas for CVD is introduced after the gas is once accumulated in the internal space of the high-frequency electrode 361.

The titanium tetrachloride introduced by the gas introducing means 33 is decomposed by the action of the plasma P ″ and reacts with the mixed nitrogen to deposit titanium nitride on the surface of the substrate 9 and deposit a titanium nitride thin film. The pressure in the CVD chamber 3 is monitored by a CVD vacuum gauge 37.

The major feature of the apparatus according to the present embodiment is that, as shown in FIGS.
The point is that the buffer chamber 4 is interposed between the VD chamber and the VD chamber. The buffer chamber 4 is an airtight vacuum container, and is airtightly connected to the transfer chamber 1 and the CVD chamber 3 via a gate valve 10. A dedicated exhaust system 41 is provided in the buffer chamber 4 so that the inside of the buffer chamber can be exhausted to about 10 ⁻⁸ Torr.

In the buffer chamber 4, there is provided a staying stage 42 on which the substrate 9 temporarily stays. The staying stage 42 is a cylindrical or columnar member, on which a substrate is placed. A heating unit 43 and a cooling unit 44 are provided in the stay stage 42. Heating means 43
Is for generating Joule heat when energized, and a cartridge heater or the like can be used. Further, the cooling means 44
Is for circulating the refrigerant along the refrigerant flow passage 420 provided in the staying stage 42. The cooling means 44 includes an introduction pipe 441 for introducing the refrigerant into the refrigerant flow path 420, a discharge pipe 442 for discharging the refrigerant from the refrigerant flow path 420, and a circulator 443 connecting the introduction pipe and the discharge pipe. In the circulator 443, the refrigerant is sent to the introduction pipe 441 while maintaining the refrigerant at a predetermined low temperature.

When the substrate 9 placed on the holding stage 42 is heated to a predetermined temperature by the heating means 43 before being carried into the CVD chamber 3, preliminary heating for heating in the CVD chamber 3 is performed, and This has the effect of shortening the heating time. Further, if the substrate 9 is heated to a predetermined temperature, there is an effect that the residual gas in the CVD chamber 3 diffused into the buffer chamber 4 is easily desorbed even if it adheres to the substrate 9, that is, an effect of degassing. .

Further, when the substrate 9 carried out of the CVD chamber 3 is cooled to a predetermined temperature by the cooling means 44,
Cooling can be performed while the substrate 9 stays. Even when cooling is performed in another processing chamber 6, the buffer chamber 4
By performing the cooling in, the cooling efficiency is improved, which leads to an improvement in the productivity of the entire apparatus. The heating means 43 and the cooling means 4
Needless to say, it cannot be operated simultaneously with 4. Further, in the present embodiment, both the heating means 43 and the cooling means 44 are provided, but it is also possible to provide only one of them.

The staying stage 42 is provided with an elevating mechanism 45 for moving the staying stage 42 up and down. A stage support 421 is provided at the lower end of the staying stage 42 and extends downward. The elevating mechanism 45 moves the stage support 421 up and down to move the staying stage 42 up and down. The stage support 421 passes through the bottom plate of the buffer chamber 4 in an airtight manner. A mechanical seal using a magnetic fluid is provided in the penetrating portion. For this reason, the stage support 42
1 is allowed to move up and down, and leakage from the penetrating portion is prevented.

The buffer chamber 4 is provided with a purge gas introduction system 46 for introducing a purge gas therein. The purge gas introduction system 46 introduces an inert gas such as nitrogen into the buffer chamber 4 as a purge gas. The pressure in the buffer chamber 4 is monitored by a buffer vacuum gauge 47. On the other hand, the measurement data of the buffer vacuum gauge 47 is sent together with the measurement data of the CVD vacuum gauge to the control unit 101 which controls the opening and closing of the gate valve 10 between the buffer chamber 4 and the CVD chamber 3. ing. The control unit 101 compares the two measurement data,
Only when the pressure in the buffer chamber 4 is higher than the pressure in the CVD chamber 3, the valve driving mechanism 102 is operated to open the gate valve 10.

Next, the operation of the apparatus in the CVD chamber 3 will be described with reference to FIG. First, the substrate 9 is carried into the CVD chamber 3 from the transfer chamber 1 via the buffer chamber 4 as described later. CV
The inside of the D chamber 3 is exhausted to a predetermined pressure by an exhaust system 32 in advance, and the substrate 9 is placed on a substrate holder 34. The heater 35 in the substrate holder 34 is operated in advance, and the substrate 9 placed on the substrate holder 34 is rapidly heated to a predetermined temperature by the heat of the heater 35, and the temperature is maintained.

After the gate valve 10 is closed, the gas introducing means 33 operates and a predetermined CVD gas is supplied.
It is introduced into the chamber 3. The flow rate and the mixing ratio of the CVD gas are adjusted by the respective flow rate adjusters 332 of the gas introducing means 33, and the exhaust rate adjusters 321 of the exhaust system 32 are adjusted.
The evacuation speed is adjusted to keep the inside of the CVD chamber 3 at a predetermined pressure.

In this state, the plasma forming means 36 is operated. That is, the high-frequency power source 362 supplies the high-frequency electrode 361
, And a high-frequency electric field is set in the CVD chamber 3. The high-frequency electric field generates a high-frequency discharge in the introduced CVD gas to form a plasma P ″. The introduced titanium tetrachloride is decomposed by the action of the plasma P ″ and reacts with nitrogen to react with the nitrogen. Titanium nitride is deposited on the surface. After a predetermined time,
This titanium nitride grows into a thin film, and a titanium nitride thin film having a predetermined thickness is formed.

Thereafter, the operations of the plasma forming means 36 and the gas introducing means 33 are stopped, and the inside of the CVD chamber 3 is again evacuated to a high vacuum. Then, the gate valve 10 opens,
The substrate 9 is taken out of the CVD chamber 3. Thus, a series of operations in the CVD chamber 3 is completed.

An auxiliary transfer mechanism for transferring the substrate 9 between the buffer chamber 4 and the CVD chamber 3 is provided. The configuration of the auxiliary transport mechanism will be described with reference to FIGS. FIG. 4 is a schematic perspective view of the buffer chamber 4 and the CVD chamber 3 shown in FIGS. 1 and 3, and FIG. 5 is a schematic front view illustrating the configuration of the auxiliary transport mechanism. In FIG. 4, the buffer chambers 4 and C
The VD chamber 3 is, for example, a portion above the middle height,
Some illustrations are omitted. As shown in FIGS. 4 and 5, the auxiliary transport mechanism includes a movable body 481 that transports the substrate 9 placed on the upper surface, a magnetic coupling 482 that horizontally moves the movable body, and the like.

As shown in FIG. 4, the moving body 481 includes an upper plate portion 483 in a horizontal position, and both side plate portions 484 provided to extend downward from both sides of the upper plate portion. The moving body 481 has an opening in the center of the upper plate portion 483. This opening is smaller than the diameter of the substrate 9 and larger than the dwell stage 42. Further, as shown in FIG. 5, the moving body 481 has a large number of small magnets (hereinafter, moving body side magnets) 485 at the end of the side plate portion 484. Each moving body side magnet 485
Have magnetic poles on the upper and lower surfaces. And this magnetic pole,
As shown in FIG. 5, the magnetic poles are alternately reversed in the arrangement direction.

On the other hand, the magnetic coupling 482 is a round bar-shaped member. As shown in FIG. 5, the magnetic coupling 482 has a helically extending elongated magnet (hereinafter, coupling-side magnet) 486. The coupling-side magnet 486 is provided with two magnetic poles different from each other, and has a double spiral shape. The magnetic coupling 482 is arranged such that the coupling-side magnet 486 faces the moving-body-side magnet 485 with the partition wall 487 interposed therebetween. Partition wall 48
Numeral 7 is formed of a material having high magnetic permeability, and the moving body-side magnet 485 and the coupling-side magnet 486 are separated from each other by a partition 487.
Through magnetic coupling. The moving body 4 of the partition 487
The space on the 81 side is the vacuum side (the inside of the buffer chamber 4), and the space on the magnetic coupling 482 side is the atmosphere side.

The magnetic coupling 482 is provided with a rotation mechanism (not shown). This rotation mechanism rotates the magnetic coupling 482 around a central axis. When the magnetic coupling 482 rotates,
The double spiral coupling side magnet 486 also rotates. At this time, the state in which the coupling-side magnet 486 rotates is such that, when viewed from the moving-body-side magnet 485, a plurality of small magnets having different magnetic poles are alternately arranged in a line and linearly move integrally along the direction of the arrangement. It becomes a state equivalent to. Therefore,
The moving-body-side magnet 485 coupled to the coupling-side magnet 486 moves linearly with the rotation of the coupling-side magnet 486. As a result, the moving body 481 moves linearly as a whole.

The magnetic coupling 482 and the partition 487
Is the CVD chamber 3 together with the buffer chamber 4
Is also provided. Therefore, the moving body 481 is configured to move horizontally (moving back and forth) between the buffer chamber 4 and the CVD chamber 3.

Next, the operation of transporting the substrate 9 through the buffer chamber 4 will be described with reference to FIGS. First, the substrate 9 is loaded into the buffer chamber 4 by the transport mechanism 11 in the transport chamber 1. At this time, the staying stage 42 is located at a predetermined ascending position and receives the substrate 9. Thereafter, the gate valve 10 between the transfer chamber 1 and the buffer chamber 4 is closed.

The substrate 9 is removed from the buffer chamber 4 by CVD.
When sending to the chamber 3, the staying stage 42 is lowered to a predetermined retracted position. The retracted position is set such that the upper surface of the staying stage 42 is located below the upper plate portion 483 of the moving body 481. Therefore, when the staying stage 42 descends to the retreat position, the substrate 9 is
On top of.

After confirming that the pressure in the buffer chamber 4 is higher than the pressure in the CVD chamber 3 as described above,
The gate valve 10 is opened. Then, the moving body 481 is moved into the CVD chamber 3 by rotating the magnetic coupling 482. The moving body 481 stops at a position where the center of the substrate 9 coincides with the central axis of the substrate holder 34. The substrate holder 34 is located at a standby position below the inside of the CVD chamber 3. Then, the substrate holder 34 rises, passes through the opening of the moving body 481, and
It reaches a position at a predetermined height higher than the upper surface plate 483 of 81. In this operation, the substrate 9 separates from the moving body 481 and rests on the substrate holder 34.

Thereafter, the magnetic coupling 482 rotates in the opposite direction, and the moving body 481 moves backward. At this time, a notch 485 is provided in the upper plate portion 483 of the moving body 481 so as to extend from the opening to the front end so that the holder support 341 of the substrate holder 34 and the moving body 481 do not interfere with each other. When the moving body 481 retreats, the holder support 341 passes through the notch 485. The moving body 481 is
As described above, it retreats and returns from the CVD chamber 3 to its original position in the buffer chamber 4. Thereafter, the gate valve 10 between the buffer chamber 4 and the CVD chamber 3 is closed. And, as described above, C
A film forming process is performed in the VD chamber 3.

The recovery of the substrate 9 from the CVD chamber 3 is performed in a completely reverse operation. That is, the gate valve 10 is opened while the substrate holder 34 is at the predetermined raised position, and the moving body 481 is moved into the CVD chamber 3. Then, the substrate 9 is placed on the moving body 481 by lowering the substrate holder 34. Thereafter, the moving body 481 is retracted to the buffer chamber 4 and the gate valve 10
Close. In the buffer chamber 4, the staying stage 42 moves up to receive the substrate 9 from the moving body 481. Thereafter, the gate valve 10 on the transfer chamber 1 side is opened, and the transfer mechanism 11 in the transfer chamber 1 picks up the substrate 9 from the stay stage 42. The substrate 9 is transferred to the next chamber via the transfer chamber 1.

Next, returning to FIG. 1, the configuration of another processing chamber will be described. One of the other processing chambers is configured as an etching chamber 5 for cleaning the substrate 9 by sputter etching before film formation.
A natural oxide film or a protective film may be formed on the surface of the substrate 9 carried into the apparatus. If such a film remains formed, there is a problem that the electrical characteristics of the thin film to be formed are deteriorated or the adhesion of the thin film is deteriorated. Therefore, prior to the film formation, the surface of the substrate 9 is sputter-etched to remove the natural oxide film and the protective film.

The etching chamber 5 includes means for introducing a gas for sputter etching such as argon, means for forming a plasma by supplying high-frequency energy to the introduced gas, and means for extracting positive ions from the plasma. Means for setting an electric field to be incident on the substrate 9. When positive ions in the plasma enter the surface of the substrate, a natural oxide film and a protective film on the surface are removed by sputter etching. As a result, a clean surface of the original material of the substrate 9 is exposed.

Another one of the other processing chambers is configured as a preheat chamber 6 for preheating the substrate 9 before film formation. The preheat chamber 6
A substrate holder (not shown) similar to the substrate holder 26 described above is provided. A heater of a resistance heating type or the like is provided in the substrate holder so that the substrate 9 placed on the substrate holder can be heated to about 200 to 300 ° C. The heating time is about 100 to 200 seconds.
The substrate 9 may be electrostatically attracted to the substrate holder to improve the thermal conductivity, or a gas for improving the thermal conductivity may be supplied to a gap between the substrate holder and the substrate 9. The main purpose of the preheating is to degas, that is, to heat and release the occluded gas of the substrate 9. Further, if the substrate 9 is heated to a predetermined temperature in advance, there is an advantage that the time required for heating in the sputtering chamber 2 can be reduced.

The description of the configuration of the apparatus according to the present embodiment has been completed above, and then the overall operation of the apparatus will be described. As an example of the operation, a case where the above-described process of forming the diffusion prevention layer is performed will be described. In FIG. 1, a predetermined number of substrates 9 are carried into one load stock chamber 8 by an autoloader (not shown), and stored in a cassette 81 in the load lock chamber 8. Transport mechanism 1
1 takes out one substrate 9 from the one load lock chamber 8 and sends it to the etching chamber 5 first. In the etching chamber 5, the natural oxide film and the protective film on the surface are removed as described above. Next, the transport mechanism 11 sends the substrate 9 to the preheat chamber 6. Substrate 9
Is preheated in the preheat chamber 6 and degassed.

Thereafter, the transport mechanism 11 sends the substrate 9 to the sputtering chamber 2. In the sputtering chamber 2, the titanium target 23 is sputtered with argon gas as described above, and a titanium thin film is deposited on the surface of the substrate 9. At this time, the sputtered particles emitted from the target 23 are ionized and more vertically incident on the substrate 9 by the electric field, so that the coverage of the inner surface of the fine hole is improved.

Thereafter, the transport mechanism 11 converts the substrate 9 into a CV
Send to D chamber 3. In the CVD chamber 3, as described above, a titanium nitride thin film is deposited on the surface of the substrate 9 by plasma CVD of a CVD gas containing titanium tetrachloride and nitrogen. Thus, a structure of a diffusion preventing layer in which the titanium nitride thin film is laminated on the titanium thin film is obtained.

Thereafter, the transport mechanism 11 converts the substrate 9 into a CV
It is taken out of the D chamber 3 and sent to the other load lock chamber 8. Note that one of the other processing chambers 7 is a cooling chamber as needed. The cooling chamber has a water-cooled substrate stage, and is configured to cool the substrate 9 by placing the substrate 9 on the substrate stage for a predetermined time. After cooling in this manner, the substrate 9
Is transported to the other load lock chamber 8 and stored in the cassette 81.

As described above, for one substrate 9,
The processing is continuously performed while transporting the etching chamber 5, the preheat chamber 6, the sputtering chamber 2, and the CVD chamber 3 in this order, and a titanium thin film and a titanium nitride thin film are continuously formed in a vacuum. When one substrate 9 is sent to the preheating chamber 6 and preheated, the next substrate 9 is carried into the etching chamber 5 and processed, and each substrate 9 is transferred to each of the chambers 5, 6, and 6. 2,
3 are successively carried into a single-wafer processing. Therefore, the productivity of the entire apparatus is extremely high.

In the apparatus of the present embodiment having the above-described configuration and operation, the sputtering chamber 2 and the CVD chamber 3
It combines a completely different processing chamber. In such a case, since the contents of the processing are different, the atmospheres of the processing chambers 2 and 3 are also different from each other. Therefore, a problem arises that the atmospheric gases diffuse to each other and contaminate the respective atmospheres. In particular, since a highly reactive gas such as a chlorine-based gas is used in the CVD chamber 3, if such a gas diffuses into the sputter chamber 2, the quality of processing in the sputter chamber 23 is likely to be significantly impaired.

However, in the present embodiment, the buffer chamber 4 is provided between the transfer chamber 1 and the CVD chamber 3. Therefore, in order for the residual gas in the CVD chamber 3 to reach the sputtering chamber 2, the gas must pass through two chambers, the buffer chamber 4 and the transfer chamber 1. Therefore, CV
Diffusion of the residual gas in the D chamber 3 to the sputtering chamber 2 is greatly suppressed. Diffusion of the gas in the sputtering chamber 2 into the CVD chamber 3 is similarly suppressed. Further, when two CVD chambers 3 are provided as shown in FIG. 1 and different gases are used, mutual contamination between the CVD chambers 3 is also prevented.

In the present embodiment, an auxiliary transfer mechanism for transferring a substrate between the buffer chamber 4 and the CVD chamber 3 is provided. Therefore, when the substrate 9 is transferred between the buffer chamber 4 and the CVD chamber, the buffer chamber 4 and the transfer chamber 1 are transferred.
Is closed. When the substrate is transferred between the buffer chamber 4 and the transfer chamber 1, the gate valve 10 between the buffer chamber 4 and the CVD chamber 3 is closed. That is, the gate valve 10 between the buffer chamber 4 and the CVD chamber 3 and the gate valve 10 between the buffer chamber 4 and the transfer chamber 1 do not open simultaneously.

The above point also greatly suppresses the residual gas in the CVD chamber 3 from diffusing into the sputtering chamber 2 and the like via the transfer chamber 1. If there is no auxiliary transfer mechanism, the transfer mechanism 11 in the transfer chamber 1 must transfer the substrate 9 between the buffer chamber 4 and the CVD chamber 3.
0 may be open at the same time.

The gate valve 1 between the buffer chamber 4 and the CVD chamber 3 is provided only when the pressure in the buffer chamber 4 is higher than that in the CVD chamber 3.
Since 0 is opened, the diffusion of the residual gas in the CVD chamber 3 is further suppressed.

A structure in which a getter material for adsorbing the residual gas is provided inside the CVD chamber 3 or the buffer chamber 4 is also effective in preventing the diffusion of the residual gas. The getter material has a configuration in which a block of a material such as zirconium or titanium is heated to a predetermined temperature.

[0081]

Next, an example belonging to the above embodiment will be described. In the following embodiments, as in the above-described operation example, the formation of the diffusion prevention layer is taken as an example. First, the sputtering conditions in the sputtering chamber 2 include the following conditions. Gas for sputtering; Argon Gas flow rate: 100 cc / min Pressure: 60 mTorr Output voltage of sputtering power supply: -500 V Substrate temperature: 300 ° C. High frequency power supply for ionization means: 13.56 MHz 800
W ・ High frequency power supply of electric field setting means; 13.56 MHz 200
W Under the above conditions, a titanium thin film can be formed at a deposition rate of about 500 angstroms per minute. The bottom coverage ratio for holes having an aspect ratio of 5 is about 40%.

Further, the CVD in the CVD chamber 3
The following conditions may be mentioned as conditions for Gas for CVD; mixed gas of TiCl ₄ , N ₂ , H _2, and SiH ₄ Gas flow ratio: TiCl ₄ : N ₂ : H ₂ : SiH ₄ = 5:
20: 500: 1 ・ Total gas flow rate: 526 cc / min ・ Pressure: 0.12 Torr ・ Temperature of substrate: 485 ° C. ・ High frequency power supply of plasma forming means: 60 MHz 500 W Under the above conditions, at a film forming rate of about 100 Å / min. A titanium nitride thin film can be formed. The bottom coverage ratio for a hole having an aspect ratio of 5 (ratio of the film forming rate on the bottom surface of the hole to the surface around the hole) is:
It is about 70%.

In the above description, the formation of the diffusion preventing layer is taken as an example of the use of the combined sputter chemical vapor deposition apparatus. It is valid.

Although the buffer chamber 4 is provided between the transfer chamber 1 and the CVD chamber 3,
It may be provided between the transfer chamber 1 and the sputtering chamber 2. Also in this case, a mechanism similar to the above-described auxiliary transport mechanism can be provided in the buffer chamber 4. Further, a buffer chamber 4 may be provided between the transfer chamber 1 and the etching chamber 5 or the preheat chamber 6. Although the low-pressure remote sputtering has the above-mentioned problems, the present invention does not exclude the configuration in which the low-pressure remote sputtering is performed in the sputtering chamber.

The embodiment of the first aspect of the present invention is not an arrangement of chambers as shown in FIG. 1, but an arrangement of an in-line type apparatus in which a sputter chamber, a transfer chamber and a CVD chamber are vertically installed as an example. . Also in this case, a buffer chamber is provided between the sputtering chamber and the transfer chamber or between the transfer chamber and the CVD chamber. A load lock chamber is provided on the transfer path before the sputtering chamber, and an unload lock chamber is provided on the transfer path behind the CVD chamber. Compared with such an in-line apparatus, the chamber arrangement shown in FIG. 1 has the advantage that the transfer path can be shortened and the area occupied by the apparatus can be reduced.

[0086]

As described above, according to the first or second aspect of the present invention, the buffer chamber is provided between the sputtering chamber and the CVD chamber in addition to the transfer chamber. Cross-contamination is effectively prevented. In addition, there is no significant increase in the occupied area as compared with the configuration in which two transfer chambers are provided, and there is no problem such as a decrease in productivity. According to the third aspect of the present invention, in addition to the above effects, a buffer chamber and a CVD
When the substrate is transferred between the chamber and the sputtering chamber, the gate valve between the transfer chamber and the buffer chamber can be closed, so that cross-contamination is further suppressed in this respect. According to the fourth aspect of the present invention, in addition to the above effects, the diffusion of the residual gas in the CVD chamber to another chamber via the buffer chamber is suppressed. For this reason, the problem of the contamination of the atmosphere of the other chamber by the residual gas in the CVD chamber is further suppressed. According to the fifth aspect of the present invention, in addition to the above effects, the operation of heating the substrate in the buffer chamber to perform degassing or cooling the substrate can be performed, so that the quality of the process can be improved. The effect of improving the productivity of the entire apparatus can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of a combined sputtering chemical vapor deposition apparatus according to an embodiment.

FIG. 2 is a front view showing a schematic configuration of a sputtering chamber 2 shown in FIG.

FIG. 3 is a front view showing a schematic configuration of a CVD chamber 3 and a buffer chamber 4 shown in FIG.

FIG. 4 is a schematic perspective view of a buffer chamber 4 and a CVD chamber 3 shown in FIGS. 1 and 3;

FIG. 5 is a schematic front view illustrating the configuration of an auxiliary transport mechanism.

FIG. 6 is a schematic plan view illustrating the configuration of the invention made in the process of conceiving the invention of the present application, and is a diagram showing the configuration of a combined sputter chemical vapor deposition apparatus in which mutual contamination is suppressed.

FIG. 7 is a schematic plan view illustrating a configuration of the invention made in the process of conceiving the invention of the present application, and is a diagram illustrating a configuration of a combined sputter chemical vapor deposition apparatus in which mutual contamination is suppressed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transport chamber 10 Gate valve 11 Transport mechanism 2 Sputter chamber 22 Exhaust system 23 Target 231 Sputter power supply 24 Magnet mechanism 25 Gas introduction means 26 Substrate holder 27 Ionization means 28 Electric field setting means 3 CVD chamber 32 Exhaust system 33 Gas introduction means 34 Substrate holder Reference Signs List 35 heater 36 plasma forming means 4 buffer chamber 41 exhaust system 42 staying stage 43 heating means 44 cooling means 45 elevating mechanism 46 purge gas introduction system 47 buffer vacuum gauge 481 moving body 482 magnetic coupling 5 etching chamber 6 preheat chamber 7 other processing Chamber 8 Load lock chamber 9 Substrate

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[Procedure amendment]

[Submission date] February 5, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

In an LSI having a structure such as an FET (field effect transistor), a structure in which a diffusion preventing layer for preventing mutual diffusion between an underlying semiconductor layer and a wiring layer is provided as a wiring structure to an electrode portion. . This diffusion prevention layer often has a structure in which a titanium thin film having a small electric resistance and a titanium nitride thin film having a high barrier property are laminated. Such a diffusion preventing layer has been formed by sputtering. For example, when laminating a titanium thin film and a titanium nitride thin film, a titanium thin film is first formed by sputtering a target made of titanium with argon gas. Thereafter, the gas is sputtered instead of nitrogen to form a titanium nitride thin film while utilizing the reaction between nitrogen and titanium in an auxiliary manner.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

It is becoming difficult to form a diffusion preventing layer by forming a film with a required bottom coverage ratio for a hole having a high aspect ratio. Although the thin film constituting the diffusion prevention layer is formed by sputtering as described above, in the case of sputtering, in order to form a film having a high bottom coverage rate, particles emitted from the target (hereinafter, sputtered particles) are formed by holes. It is necessary to reach the bottom much. However, as the aspect ratio increases, the amount of sputter particles that reach the bottom of the hole decreases.
That is, only a limited number of particles that enter the substrate almost perpendicularly can reach the bottom surface . Therefore, the deposition rate at the bottom of the hole is reduced, and the bottom coverage ratio is reduced.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Further, in the low-pressure remote sputtering, there is a problem that non-uniformity is generated in a film formed on a hole in a peripheral portion of a substrate , particularly on a side wall of the hole. That is, the thin film is deposited almost evenly on the inner surface of the hole at the center of the substrate. However, on the inner surface of the hole at the peripheral portion of the substrate, a relatively thin film is deposited on the outer side wall, but only a thin film is deposited on the inner side wall. This is for the following reasons. At the center of the substrate, the sputtered particles are slightly shifted left and right about the direction perpendicular to the substrate and uniformly incident. However, in the peripheral portion of the substrate, the number of sputtered particles obliquely incident outward increases, and as a result, the film thickness on the side wall from the inside of the hole becomes insufficient. When the film thickness is insufficient in this manner, the effect of preventing mutual diffusion cannot be sufficiently obtained, which is a factor that impairs device characteristics. Due to such a problem, the low-pressure remote sputtering has an opening diameter (or width) of 0.25 μm.
It is said that the fabrication of devices up to (with an aspect ratio of about 4) is the limit.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

[0021]

According to a first aspect of the present invention, there is provided a transfer chamber including a sputtering chamber for performing sputtering, a CVD chamber for performing chemical vapor deposition, and a transfer mechanism. Is a combined sputter chemical vapor deposition apparatus having a structure in which a sputter chamber and a CVD chamber are hermetically connected through a buffer chamber provided between the transfer chamber and the CVD chamber or between the transfer chamber and the sputter chamber. The sputtering chamber and the CVD chamber are connected via a transfer chamber and a buffer chamber.
It has a configuration that it is connected in an airtight manner . In order to solve the above problem, the invention according to claim 2 is the configuration according to claim 1, wherein the sputtering chamber and the CVD chamber are one of processing chambers that are hermetically connected around the transfer chamber. . According to a third aspect of the present invention, there is provided an auxiliary transfer mechanism for transferring a substrate between the buffer chamber and the CVD chamber or the sputtering chamber. Is provided. According to a fourth aspect of the present invention, in order to solve the above problem, in the configuration of the first, second or third aspect, the buffer chamber is provided between the transfer chamber and the CVD chamber. A gate valve provided between the buffer chamber and the CVD chamber is opened only when the pressure in the buffer chamber is higher than the pressure in the CVD chamber. It has a configuration that is. According to another aspect of the present invention, there is provided a semiconductor device comprising:
According to a preferred embodiment of the present invention, in the configuration of the first, second, third or fourth aspect, a heating unit for heating the substrate to a predetermined temperature in the buffer chamber or a cooling unit for cooling the substrate to a predetermined temperature is provided. Having.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

[0022]

Embodiments of the present invention will be described below. FIG. 1 is a plan view illustrating a schematic configuration of a combined sputter chemical vapor deposition apparatus according to an embodiment. The apparatus shown in FIG. 1 is a multi-chamber type apparatus like the apparatuses shown in FIGS. 6 and 7, and includes a transfer chamber 1 disposed at the center and a plurality of processing chambers 2 provided around the transfer chamber 1. , 3, 4, 5, 6 , 7 and two load lock chambers 8. Each chamber 1,2,3,4,5,6,7,8
Is a vacuum vessel evacuated by a dedicated exhaust system.
Further, each chamber 2, 3, with respect to the transfer chamber 1
Gate valves 10 are provided at connection points of 4, 5, 6, 7, and 8, respectively.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

In the transfer chamber 1, a transfer mechanism 11 is provided. The transport mechanism 11 takes out the substrates 9 one by one from one of the load lock chambers 8 and sends them to the processing chambers 2 , 3 , 4 , 5 , 6 , and 7 for sequential processing. Then, after the last processing is completed, it is returned to the other load lock chamber 8. As the transfer mechanism 11, an articulated robot provided with an arm for mounting and holding the substrate 9 at the tip is suitably used. It is preferable to provide two arms so that the two substrates 9 can be moved independently independently at the same time, because the efficiency of transportation is improved. The inside of the transfer chamber 1 is evacuated by an exhaust system (not shown).
^- vacuum pressure of about ⁶ to 10 ^-8 Torr is maintained.
Therefore, as the transport mechanism 11, a mechanism that can operate under this vacuum pressure is adopted.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

The evacuation system 22 uses a vacuum pump 221 such as a cryopump to evacuate the inside of the sputtering chamber
^It is configured to be able to exhaust up to about ^-8 Torr. Exhaust system 2
2 is an exhaust speed adjuster 222 such as a variable orifice.
Having. The target 23 is attached to the sputtering chamber 2 via an insulating material 232. The target 23 is made of titanium in this embodiment. The sputtering power supply 231 is configured to apply a negative high voltage to the target 23. In addition, a high frequency voltage is applied to the target 23.
In some cases.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

On the other hand, the substrate holder 26 is provided with electric field setting means 28. The electric field setting means 28 is configured to set an electric field perpendicular to the substrate 9 in the sputtering chamber 2 and to cause the ionized sputtered particles to be perpendicularly incident on the substrate 9. In the present embodiment, as the electric field setting means 28, a high frequency power supply for substrate 281 which applies a high frequency voltage to the substrate holder 26 and gives a negative self-bias voltage to the substrate 9 by the interaction between the high frequency and the plasma P 'is employed. ing. As the substrate high-frequency power supply 281, for example, 1
Those with a 3.56 MHz output of about 300 W can be used.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction contents]

The major feature of the apparatus according to the present embodiment is that, as shown in FIGS.
The point is that the buffer chamber 4 is interposed between the VD chamber and the VD chamber. The buffer chamber 4 is an airtight vacuum container, and is airtightly connected to the transfer chamber 1 and the CVD chamber 3 via a gate valve 10. The buffer chamber 4 is provided with a dedicated exhaust system 41 so that the inside of the buffer chamber 4 can be exhausted to about 10 ⁻⁸ Torr.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction contents]

In the buffer chamber 4, there is provided a staying stage 42 on which the substrate 9 temporarily stays. The staying stage 42 is a cylindrical or columnar member, on which the substrate 9 is placed. A heating unit 43 and a cooling unit 44 are provided in the stay stage 42. Heating means 4
3 is to generate Joule heat by energization,
A cartridge heater or the like can be used. Also, the cooling means 4
Numeral 4 circulates the refrigerant along a refrigerant flow passage 420 provided in the staying stage 42. The cooling means 44
It comprises an inlet pipe 441 for introducing the refrigerant into the refrigerant flow passage 420, a discharge pipe 442 for discharging the refrigerant from the refrigerant flow path 420, and a circulator 443 connecting the inlet pipe and the discharge pipe. In the circulator 443, the refrigerant is sent to the introduction pipe 441 while maintaining the refrigerant at a predetermined low temperature.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction contents]

The buffer chamber 4 is provided with a purge gas introduction system 46 for introducing a purge gas therein. The purge gas introduction system 46 introduces an inert gas such as nitrogen into the buffer chamber 4 as a purge gas. The pressure in the buffer chamber 4 is monitored by a buffer vacuum gauge 47. On the other hand, the measurement data of the buffer vacuum gauge 47 is sent together with the measurement data of the CVD vacuum gauge 37 to the control unit 101 which controls the opening and closing of the gate valve 10 between the buffer chamber 4 and the CVD chamber 3. Has become. The control unit 101 compares the measured data with each other, and determines that the valve driving mechanism 102 is used only when the pressure in the buffer chamber 4 is higher than the pressure in the CVD chamber 3.
Is operated to open the gate valve 10.

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction contents]

Thereafter, the operations of the plasma forming means 36 and the gas introducing means 33 are stopped, and the inside of the CVD chamber 3 is again evacuated to a high vacuum. And-out gate valve 10 is opened,
The substrate 9 is taken out of the CVD chamber 3. Thus, a series of operations in the CVD chamber 3 is completed.

[Procedure amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0057

[Correction method] Change

[Correction contents]

An auxiliary transfer mechanism for transferring the substrate 9 between the buffer chamber 4 and the CVD chamber 3 is provided. The configuration of the auxiliary transport mechanism will be described with reference to FIGS. FIG. 4 is a schematic perspective view of the buffer chamber 4 and the CVD chamber 3 shown in FIGS. 1 and 3, and FIG. 5 is a schematic front view illustrating the configuration of the auxiliary transport mechanism. In FIG. 4, the buffer chambers 4 and C
The VD chamber 3 is, for example, a portion above the middle height,
Some illustrations are omitted. As shown in FIGS. 4 and 5, the auxiliary transport mechanism includes a movable body 481 that transports the substrate 9 on the upper surface thereof, a magnetic coupling 482 that horizontally moves the movable body 481 , and the like.

[Procedure amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

As shown in FIG. 4, the moving body 481 includes an upper plate portion 483 in a horizontal posture and both side plate portions 484 provided to extend downward from both sides of the upper plate portion 483 .
The moving body 481 has an opening in the center of the upper plate portion 483.
This opening is smaller than the diameter of the substrate 9 and larger than the dwell stage 42. Further, as shown in FIG.
81 has many small magnets (hereinafter referred to as moving body side magnets) 485 at the end of the side plate portion 484. Each moving body side magnet 48
5 has magnetic poles on the upper and lower surfaces. The magnetic poles are alternately opposite magnetic poles in the arrangement direction as shown in FIG.

[Procedure amendment 16]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

The etching chamber 5 includes means for introducing a gas for sputter etching such as argon, means for forming a plasma by supplying high-frequency energy to the introduced gas, and means for extracting positive ions from the plasma. Means for setting an electric field to be incident on the substrate 9. When positive ions in the plasma enter the surface of the substrate 9 , the natural oxide film and the protective film on the surface are removed by sputter etching. As a result, a clean surface of the original material of the substrate 9 is exposed.

[Procedure amendment 17]

[Document name to be amended] Statement

[Correction target item name] 0069

[Correction method] Change

[Correction contents]

Another one of the other processing chambers is configured as a preheat chamber 6 for preheating the substrate 9 before film formation. The preheat chamber 6
A substrate holder (not shown) similar to the substrate holder 26 described above is provided. A heater of a resistance heating type or the like is provided in the substrate holder so that the substrate 9 placed on the substrate holder can be heated to about 200 to 300 ° C. The heating time is about 100 to 200 seconds.
Incidentally, it may or providing improved thermal conductivity of the substrate 9 is electrostatically adsorbed on the substrate holder, the gap gas to improve the thermal conductivity between the substrate holder and the substrate 9.
The main purpose of the preheating is to degas, that is, to heat and release the occluded gas of the substrate 9. Further, if the substrate 9 is heated to a predetermined temperature in advance, there is an advantage that the time required for heating in the sputtering chamber 2 can be reduced.

[Procedure amendment 18]

[Document name to be amended] Statement

[Correction target item name] 0070

[Correction method] Change

[Correction contents]

The description of the configuration of the apparatus according to the present embodiment has been completed above, and then the overall operation of the apparatus will be described. As an example of the operation, a case where the above-described process of forming the diffusion prevention layer is performed will be described. In FIG. 1, a predetermined number of substrates 9 are transferred to one row by an autoloader (not shown).
It is carried into the lock chamber 8 and housed in the cassette 81 in the load lock chamber 8. Transport mechanism 1
1 takes out one substrate 9 from the one load lock chamber 8 and sends it to the etching chamber 5 first. In the etching chamber 5, the natural oxide film and the protective film on the surface are removed as described above. Next, the transport mechanism 11 sends the substrate 9 to the preheat chamber 6. Substrate 9
Is preheated in the preheat chamber 6 and degassed.

[Procedure amendment 19]

[Document name to be amended] Statement

[Correction target item name] 0071

[Correction method] Change

[Correction contents]

Thereafter, the transport mechanism 11 sends the substrate 9 to the sputtering chamber 2. In the sputtering chamber 2, the titanium target 23 is sputtered with argon gas as described above, and a titanium thin film is deposited on the surface of the substrate 9. At this time, the sputtered particles emitted from the target 23 are ionized and more vertically incident on the substrate 9 by the electric field, so that the coverage of the inner surface of the fine hole is improved.

[Procedure amendment 20]

[Document name to be amended] Statement

[Correction target item name] 0077

[Correction method] Change

[Correction contents]

In this embodiment, an auxiliary transfer mechanism for transferring the substrate 9 between the buffer chamber 4 and the CVD chamber 3 is provided. When the substrate 9 is transferred between the buffer chamber 4 and the CVD chamber, the buffer chamber 4 and the transfer chamber 1 are transferred.
Is closed. When the substrate 9 is transferred between the buffer chamber 4 and the transfer chamber 1, the gate valve 10 between the buffer chamber 4 and the CVD chamber 3 is closed. That is, the gate valve 10 between the buffer chamber 4 and the CVD chamber 3 and the gate valve 10 between the buffer chamber 4 and the transfer chamber 1 do not open simultaneously.

[Procedure amendment 21]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Change

[Correction contents]

Further, according to an embodiment of the present invention, instead of the chamber arrangement shown in FIG. 1, a sputter chamber, a transfer chamber and a CVD chamber are used.
The configuration of a vertically installed in-line type device is exemplified . Also in this case, a buffer chamber is provided between the sputtering chamber and the transfer chamber or between the transfer chamber and the CVD chamber. A load lock chamber is provided on the transfer path before the sputtering chamber, and an unload lock chamber is provided on the transfer path behind the CVD chamber. Compared with such an in-line apparatus, the chamber arrangement shown in FIG. 1 has the advantage that the transfer path can be shortened and the area occupied by the apparatus can be reduced.

[Procedure amendment 22]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (5)

[Claims] 1. A sputtering chamber for performing sputtering,
A CVD chamber for performing chemical vapor deposition, and a sputter chamber and C through a transfer chamber provided with a transfer mechanism.
A combined sputter chemical vapor deposition apparatus having a structure in which a VD chamber is hermetically connected, wherein a buffer chamber is provided between the transfer chamber and the CVD chamber or between the transfer chamber and the sputter chamber. And a CVD chamber, wherein the sputtering chamber is hermetically connected to the transfer chamber via a transfer chamber and a buffer chamber. 2. The sputtering chamber and the CVD.
The combined sputter chemical vapor deposition apparatus according to claim 1, wherein the chamber is one of processing chambers that are air-tightly connected around the transfer chamber. 3. The combined sputter chemical vapor deposition apparatus according to claim 1, further comprising an auxiliary transfer mechanism for transferring a substrate between the buffer chamber and the CVD chamber or the sputtering chamber. . 4. The buffer chamber is provided between the transfer chamber and the CVD chamber, and has a purge gas introduction system for introducing a purge gas into the buffer chamber. 4. The combined sputter chemical vapor deposition apparatus according to claim 1, wherein the gate valve provided in the step (c) is opened only when the pressure in the buffer chamber is higher than the pressure in the CVD chamber. 5. The apparatus according to claim 1, further comprising a heating unit for heating the substrate to a predetermined temperature in the buffer chamber or a cooling unit for cooling the substrate to a predetermined temperature.
5. The combined sputter chemical vapor deposition apparatus according to 3 or 4.