JPH11150070A - Manufacture of semiconductor, and its apparatus and semiconductor wafer and semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a gas capturing means to simplify a device constitution and secure high productivity, by contriving enough atomization. SOLUTION: In a manufacture of a semiconductor wafer which forms a film for a semiconductor element on a wafer 11, using liquid material for film growth or liquefied material 16 made by liquefying solid material, after arranging a wafer 11 within a vacuum container 10 whose inside is in roughly vacuum environment, the material is gasified before it reaches the surface of the wafer 11, and the gasified material is supplied to the surface of the wafer 11 so as to form a film on the wafer 11, by supplying liquid material or liquefied material into the vacuum container 10 after acceleration of the atomization of the liquid material or liquefied material by inducing a turn flow with a turn plate 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method and a semiconductor manufacturing apparatus for forming a thin film for a semiconductor element on a substrate using a liquid material or the like, a semiconductor wafer, and a semiconductor element.

[0002]

2. Description of the Related Art In the manufacture of semiconductors, for example, a thin film for a semiconductor element is formed on a substrate.
A liquefied raw material obtained by liquefying a liquid raw material or a solid raw material as well as a gas raw material (hereinafter, these are collectively referred to as liquid raw material, etc. as appropriate)
Can be used. The formation of a thin film using such a liquid raw material and the like is performed not only in the manufacture of semiconductors but also in the field of electrostatic coating and the like.

As a known technique relating to the formation of a thin film using a liquid material or the like, there is, for example, a method described in JP-A-6-306181. In this method, an organic optical thin film is formed by spraying a liquid raw material in a vacuum and applying it to a substrate, and heating the substrate to volatilize a volatile solvent in the liquid. Specifically, this is performed as follows. That is, a wafer is held and heated on a susceptor arranged in a vacuum vessel, and a liquid material (or an inorganic optical thin film material made of an organic optical thin film material is dissolved in a volatile solvent). Is sprayed into the vacuum container through the control nozzle unit. The sprayed liquid raw material turns into droplets in a vacuum and reaches the wafer as droplets. In the liquid raw material applied in a liquid state on the wafer in this manner, the solvent component is volatilized by heat from the susceptor and the surface heating device arranged beside the susceptor, and only the solid component remains on the wafer to form a thin film. At this time, the solvent component volatilized by the heat becomes a gas and is released into the vacuum vessel. A part of this gas is exhausted out of the container by a vacuum exhaust unit connected to the vacuum container, but most of the gas is adsorbed by gas trapping means (cold trap) arranged in the vacuum container and cooled to a low temperature. Condenses into a liquid. Thus, a required vacuum in the vacuum container is maintained. The method according to this known technique can be applied to the manufacture of semiconductors, although not particularly specified.

[0004] Further, as a known technique relating to atomization of a liquid raw material in forming a thin film using a liquid raw material or the like, for example, JP-A-62-14959 and JP-A-63-171
No. 658 is described. These known techniques relate to the shape of the spraying means when spraying a liquid raw material for electrostatic coating or the like. That is, a mounting body forming an annular inner space opened to the rear surface is fixed to the tip of the rotating shaft, and a cup-shaped rotary atomizing head is provided on the outer periphery of the mounting body. At the time of spraying, the rotating shaft is driven to rotate the mounting body and the rotary atomizing head at a high speed, and the liquid paint is dropped into the inner space through the supply pipe inserted into the inner space from the rear side. Liquid paint droplets are guided to the inner peripheral surface of the rotary atomizing head by using centrifugal force from a supply hole formed in the outer peripheral portion of the mounting body. This droplet is finely divided by a guide groove formed on the inner peripheral surface of the rotary atomizing head,
It is atomized by the action of the centrifugal force and the electrostatic field, and is applied to an object to be coated.

[0005]

Problems to be Solved by the Invention
According to the method described in Japanese Patent Application Laid-Open No. 1 (1993) -1995, the liquid material sprayed from the control nozzle does not have a sufficiently fine particle size, and atomization is insufficient. Therefore, from the wafer (or from the vacuum vessel) within the time from spraying to flying over the wafer
The solvent component alone does not volatilize even when the radiation heat is applied, and the sprayed droplets are applied to the wafer in a liquid state. Then, when the wafer is heated to volatilize the solvent component from the applied droplets, the solvent component volatilizes from the droplets at once, so that the pressure in the vacuum vessel rapidly rises, which greatly affects the vacuum environment. give. As a countermeasure, the required pressure is maintained by condensing volatile components in the cold trap again, so extra equipment called a cold trap must be placed in the vacuum vessel, and the vacuum vessel becomes large. As a result, the evacuation unit for evacuating the container becomes large, and the whole apparatus becomes large. In addition, equipment for supplying a refrigerant to the cold trap is required, so that the configuration of the apparatus is complicated. Therefore, handling and operation of the apparatus become complicated, and productivity is deteriorated.

[0006] In addition, the structure described in Japanese Patent Application Laid-Open Nos. 62-14959 and 63-171658 can achieve relatively sufficient atomization. A new problem arises. That is, in semiconductor manufacturing, the above-mentioned Japanese Patent Application Laid-Open No.
As in the case of Japanese Patent Publication No. 181, the film forming operation is performed on a wafer in a vacuum state in a vacuum chamber. However, Japanese Patent Application Laid-Open
In the structures described in JP-A-14959 and JP-A-63-171658, the inner space behind the mounting body into which the liquid paint is dropped is open to the atmosphere with an open rear surface. The supply pipe for supplying the paint also has a structure in which the end is opened into the inner space, and the liquid ejection path is not airtight. Therefore, when this structure is applied to film formation in a vacuum vessel, bubbles are mixed into a liquid material or the like in an inner space opened to the atmosphere, and the mixed bubbles expand in a vacuum environment to cause a liquid ejection path. Therefore, the liquid cannot be ejected into the vacuum container. In addition, the rotating shaft, mounting body, and rotary atomizing head are all rotating members, and when applied to semiconductor manufacturing, they can be freely rotated via a support member such as a bearing on the wall side of the vacuum vessel which is a fixed side member. Although it is necessary to support, there is a high possibility that minute dust generated from rotation is generated from this support member, and it cannot satisfy the strict dust-proof requirement in semiconductor manufacturing. For the above two reasons, it is practically impossible to apply to semiconductor manufacturing.

Further, the existence of the rotating member as described above requires an extra power source for rotating the rotating member, resulting in lower efficiency, and the presence of a movable member causes a corresponding failure. There is also a problem that the probability of occurrence is high and reliability is low.

An object of the present invention is to provide a semiconductor manufacturing method and apparatus capable of ensuring high productivity by simplifying the apparatus configuration by eliminating the need for gas trapping by sufficiently atomizing the semiconductor, and manufacturing the semiconductor by the manufacturing method. It is to provide a semiconductor wafer and a semiconductor element. Another object of the present invention is to provide a method and apparatus for manufacturing a semiconductor which can ensure high efficiency and reliability by sufficiently atomizing without using a rotating member, and a semiconductor wafer and a semiconductor element manufactured by the manufacturing method. Is to provide.

[0009]

(1) In order to achieve the above object, according to the present invention, a substrate is placed in a container having a substantially vacuum environment inside, and a liquid material or a solid material for film formation is liquefied. In a semiconductor manufacturing method of forming a thin film for a semiconductor device on the substrate using the liquefied raw material, the atomization of the liquid raw material or the liquefied raw material is promoted by an atomization promoting mechanism, and then supplied into the container. The raw material is vaporized before reaching the substrate surface, and the vaporized raw material is supplied to the substrate surface to form the thin film on the substrate. By evaporating the liquid raw material or the liquefied raw material before reaching the substrate surface, it is possible to suppress an increase in the pressure in the container as compared with the related art in which droplets are applied to the substrate as they are and then volatilized. That is, first, when a minute amount of the material which has been promoted to be atomized is supplied into the container, it evaporates after a short period of time and a small pressure rise occurs, but the vaporized material reaches the substrate and has a very small thickness. When the film is formed, the pressure decreases again. After that, the next minute amount of raw material is supplied, and the same
The film is formed by lowering. In this way, the film thickness is sequentially increased, and this pressure increase / decrease is repeated until the film formation of the predetermined thickness is completed. As a result, the maximum value of the pressure rise can be suppressed to an extremely small amount as compared with the related art, so that gas trapping means such as a cold trap can be eliminated. Therefore, since the device configuration can be simplified, the handling and operation of the device can be simplified, and the productivity can be improved.

(2) In the above (1), preferably,
The atomization promoting mechanism promotes atomization by inducing a swirling flow in the jet of the liquid raw material or the liquefied raw material. When the swirling flow is induced in the jet flow, microscopically, the minute liquid column which has been elongated in the ejection axis direction is pulled radially outward by the swirling flow. As a result, the spread portion becomes a kind of thin film, so that the liquid droplets are more easily divided, and the atomization can be promoted.

(3) In the above (2), more preferably, the atomization promoting mechanism is configured to pour the raw material from a radially outer side into a discharge hole provided in a discharge axis direction of the raw material, so that the discharge hole is formed. Induces a swirling flow in the jet from the jet. By inducing a swirling flow using the flow from the radial outside to the radial inside, sufficient atomization can be achieved without using a rotating member. As a result, extra power sources and movable members can be omitted as compared with the related art in which atomization is performed by rotating the rotating member at high speed, so that efficiency and reliability can be improved.

(4) In the above (1), preferably, when supplying the liquid raw material or the liquefied raw material into the container, the liquid raw material or the liquefied raw material is supplied intermittently through an opening / closing mechanism that opens and closes intermittently. Since the raw material is vaporized before reaching the substrate surface, the volume is greatly increased, so that the amount of the raw material required for film formation is relatively smaller than that of the conventional technology in which liquid droplets are applied to the substrate. By performing the intermittent opening and closing, the micro-supply control can be optimally performed.

(5) In the above (4), it is more preferable that at least a part of the opening / closing mechanism and its surrounding members are covered with a silicon-based material or made of a silicon-based material. Thus, the abrasion of the opening / closing mechanism and its surrounding members can be suppressed, so that it is possible to prevent the abrasion powder from being mixed into the wafer together with the raw material, thereby causing the failure of the semiconductor element.

(6) In the above (4), preferably, at least a part of the opening / closing mechanism and its surrounding members are coated with the same material as the thin film to be formed. This allows
Even if the opening / closing mechanism and its surrounding members are worn and the abrasion powder is mixed with the raw material into the wafer, the abrasion powder is made of the same material as the thin film, thereby preventing the semiconductor element from being defective.

(7) In the above (1), preferably,
The reaction for forming the thin film on the substrate is a chemical vapor deposition reaction.

(8) Preferably, in order to achieve the above object, there is provided a semiconductor wafer manufactured by using the above (1) to (7).

(9) Preferably, in order to achieve the above object, there is provided a semiconductor device manufactured by using the semiconductor manufacturing method according to any one of the above (1) to (7).

(10) In order to achieve the above object, the present invention provides a container in which a substrate is disposed, a vacuum exhaust means for making the inside of the container a substantially vacuum environment, and a liquid material for film formation. Or a supply means for supplying a liquefied raw material obtained by liquefying a solid raw material into the container, and in a semiconductor manufacturing apparatus for forming a thin film for a semiconductor element on the substrate, the supply means comprises the liquid raw material or the liquefied raw material. An atomization promoting mechanism for promoting atomization is provided.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The present embodiment is an embodiment in which a thin film for a semiconductor element is deposited on the surface of a wafer as a semiconductor substrate by low pressure chemical vapor deposition.

FIG. 1 is a schematic layout diagram showing the entire structure of a semiconductor manufacturing apparatus for performing the semiconductor manufacturing method according to the present embodiment. As shown in FIG. 1, the semiconductor manufacturing apparatus includes:
Roughly speaking, a gas-phase chemical reaction device 1, a vaporization mechanism 2, a vacuum exhaust unit 3, a gas processing unit 4, a gas supply unit 5, a preliminary chamber 6,
A wall temperature controller 8 and a nozzle operation controller 9 are provided.

The gas-phase chemical reactor 1 comprises a susceptor 1 on which a wafer (semiconductor substrate) 11 is placed in a vacuum vessel 10.
The vacuum container 10 is provided with a vacuum gauge 14. Although not particularly shown, a pipe through which a fluid for performing wall surface temperature control (described later) is disposed in the wall surface of the vacuum vessel 10. In the vaporization mechanism 2, the liquid raw material (or the liquefied raw material obtained by liquefying the solid raw material, the same applies hereinafter) 16 stored in the liquid raw material tank 15 is supplied from the liquid raw material delivery gas supply unit 18 via the liquid raw material delivery gas pipe 19. The liquid source 16 is pressure-fed by the sent gas for liquid source delivery, and the pressure-fed liquid source 16 is supplied to a vaporization nozzle 22 mounted above the vacuum vessel 10 via a liquid source supply pipe 20 and a liquid source supply valve 21. It has become. At this time, the vaporizing nozzle 22 is provided with a ball valve 30 (described later), a valve rod 32 (the same), and an opening / closing mechanism 23 having a drive source for driving the valve rod, and a control signal from the nozzle operation controller 9 is provided. The liquid material is intermittently supplied into the vacuum vessel 10 by opening and closing the ball valve 30 intermittently according to The vacuum exhaust unit 3 includes a vacuum exhaust pipe 24 connected to the vacuum vessel 10 and a vacuum exhaust valve 2 provided on the vacuum exhaust pipe 24.
The vacuum chamber 10 is evacuated via the exhaust gas 5, and the discarded gas is guided to the gas processing unit 4 via the exhaust pipe 26 to be subjected to a predetermined process. ing. The gas supply unit 5 includes a gas supply pipe 7 connected to the vacuum container 10 and a gas supply pipe 7 provided in the gas supply pipe 7, and a carrier gas (inert gas) and a gas source (Described later). The preparatory chamber 6 is for taking the wafer 11 in and out while keeping the airtightness in the vacuum vessel 10, and includes a wafer handler 6a, a preparatory chamber first gate valve 6b, and a preparatory chamber second gate valve 6c. ing. The wall temperature controller 10 controls the temperature of the fluid (oil or the like) guided through the first wall temperature control pipe 28 and the second wall temperature control pipe 29 connected to the pipes in the wall of the vacuum vessel 10 described above. , Thereby controlling the temperature inside the vacuum vessel 10.

The essential part of this embodiment resides in that a swirling flow is induced in the jet of the raw material in the vaporizing nozzle 22. FIG. 2 is a longitudinal sectional view showing the detailed structure of the tip of the vaporizing nozzle 22.
Shown in In FIG. 2, the tip 2 of the vaporizing nozzle 22
2A is an orifice 22 formed at the tip as an ejection hole.
Aa and a valve seat 22Ab formed on the upstream side of the orifice 22Aa. A ball valve 30 fixed to the tip of a ball valve rod 32 driven up and down is seated on the valve seat 22Ab. ing. Further, inside the tip portion 22A, a turning plate 31 as an atomization promoting mechanism for promoting atomization of the liquid raw material is disposed.

The detailed structure of the turning plate 31 is shown in FIGS. 3 (a) to 3 (c). 3 (a) is a top view of the turning plate 31, FIG. 3 (b) is a longitudinal sectional view taken along the line IIIB-IIIB in FIG. 3 (a), and FIG. 3 (c) is FIG. 3 (b). Medium IIIC-III
It is a cross-sectional view by C surface. These FIGS. 3A to 3
As shown in FIG. 2 (c) and FIG. 2, the swivel plate 31 is provided in the direction of the ejection axis of the liquid raw material and has a guide hole 31a in which the ball valve 30 (see FIG. 2) moves up and down, and the orifice 22Aa through the guide hole 31a. Fluid passages 31b arranged so that the liquid raw material flows from the outside in the radial direction toward
Are formed. At this time, each of the fluid passages 31b has an inflow hole 31b1 whose upper end is opened on the upper surface of the turning plate 31 and is formed in the direction of the ejection axis of the liquid raw material (vertical direction in FIG. 3B).
And a swivel groove 31b2 formed in a radial direction (for example, the left-right direction in FIG. 3B) that is communicated with the inflow hole 31b1 and formed on the lower surface of the swivel plate 31 at right angles to the direction of the ejection axis. The diameter d of the inflow hole 31b1 is much larger than the gap δ between the ball valve 30 and the guide hole 31a (the gap formed by the difference in diameter between the guide hole 31a and the ball valve 30, see FIG. 2). 3 (a) and FIG.
As shown in (c), the connecting portions of the swivel grooves 31b2 of the four fluid passages 31b to the guide holes 31a are the guide holes 3a.
The structure is eccentric from the axis 1a.

In the above configuration, the vacuum exhaust unit 3, the vacuum exhaust pipe 24, and the vacuum exhaust valve 25 constitute a vacuum exhaust unit that makes the inside of the vacuum vessel 10 a substantially vacuum environment.
Delivery gas supply section 18 of vaporization mechanism 2, liquid source delivery gas pipe 19, liquid source tank 15, liquid source supply pipe 2
The liquid source supply valve 21, the opening / closing mechanism 23, the vaporizing nozzle 22, and the turning plate 31 constitute a supply unit that supplies a liquefied raw material obtained by liquefying a liquid raw material or a solid raw material for film formation into the vacuum vessel 10. .

In the above configuration, first, the vacuum vessel 10
After the inside is evacuated by the evacuation unit 3, an inert gas from the gas supply unit 5 is introduced into the vacuum vessel 10. Subsequently, the supply of the inert gas is stopped, and the vacuum container 10 is evacuated again by the evacuation unit 3. By repeating such evacuation and introduction of the inert gas several times, the vacuum vessel 10
Replace the gas inside. Next, the first gate valve 6b is opened, and the wafer 11 held in the preliminary chamber 6 is loaded onto the susceptor 12 heated by the heater 13. 1st after loading
The gate valve 6b is closed, and the gas in the vacuum vessel 10 is replaced again. Thereafter, the liquid raw material 16 guided from the vaporizing mechanism 2 is supplied into the vacuum container 10 through the vaporizing nozzle 22 in a state where the inside of the vacuum container 10 is in a substantially vacuum environment (for example, about 133 Pa). In addition, the gaseous raw material from the gas supply unit 5 is also supplied into the vacuum vessel 10 if necessary. At this time, the liquid raw material 16 is sufficiently atomized (detailed later) by the swirling plate 31 in the vaporizing nozzle 22 and then sprayed into the vacuum vessel 10, thereby being vaporized before reaching the wafer 11. ), A film is formed on the wafer 11 in a gaseous state. When the film formation is completed, gas replacement is performed again, and the wafer 11 on the susceptor 12 is replaced with a new wafer placed in the preliminary chamber 6. The above is the manufacturing cycle in the semiconductor manufacturing method of the present embodiment.

As described above, the most significant feature of the operation of this embodiment lies in the promotion of atomization in the vaporizing nozzle 22 and the subsequent vaporization. The atomization promoting action in the evaporation nozzle 22 and the subsequent evaporation of the liquid raw material will be described in detail below. (1) Acceleration of Atomization by Inducing Swirl Flow In FIG. 2, the liquid raw material supplied to the vaporization nozzle 22 flows from above the ball valve rod 32 toward the orifice 22Aa of the tip 22A. On the other hand, at this time, the diameter d of the inflow hole 31b1 of the swirl plate fluid passage 31b is much larger than the gap δ between the ball valve 30 and the guide hole 31a wall surface of the swivel plate 31 as described above. Therefore, most of the liquid material flows into these inflow holes 31b1 and further flows into the swirl grooves 31b2. In this state, when the ball valve 30 of the opening / closing mechanism 23 is driven to move upward for a very short time, the liquid material from the swivel groove 31b2 and the guide hole 31a is sprayed into the vacuum vessel 10 through the orifice 22Aa. At this time, most of the liquid raw material flows from the swirl groove 31b2 so as to gather at the orifice 22Aa at the center in the radial direction, so that a swirl flow in the plane direction orthogonal to the jet axis is induced in the jet of the liquid raw material. . When the swirling flow is induced in the jet flow in this way, microscopically, the minute liquid column which has been elongated in the ejection axis direction is pulled radially outward by the swirling flow. As a result, the spread portion becomes a kind of thin film, so that the droplet is more likely to be divided, which can promote the atomization. Can be formed.

(2) Evaporation of droplets by promoting atomization In this embodiment, by promoting atomization as described in (1) above, after the liquid raw material is sprayed into the vacuum vessel 10, The main purpose is to vaporize before reaching 11. The present inventors conducted a vaporization experiment on droplets using an apparatus similar to the apparatus shown in FIG. 1 in order to study the relationship between atomization and ease of vaporization. FIG. 4 shows the results of this experiment. As experimental conditions, the pressure in the vacuum vessel 10 was maintained at about 133 Pa, and the distance from the vaporizing nozzle 22 to the susceptor 12 was set to 15 cm. The reason for setting the distance of 15 cm is that, in the case of this type of apparatus, including the apparatus of the present embodiment shown in FIG.
The distance from the position where the film forming raw materials (liquid raw material and gaseous raw material) are introduced into the vacuum vessel 10 to the susceptor 10 where the wafer 11 to be formed is placed is at most 20 to 30 c.
This is because if the vaporization is performed at a distance of 15 cm, which is slightly shorter than this, the vaporization of the liquid droplets in the actual apparatus is surely secured. Further, as a liquid supplied from the vaporization mechanism 2 to the vaporization nozzle 22, a film is formed in order to accurately measure a ratio of gasification (vaporization ratio) before the liquid is introduced into the vacuum vessel 10 and reaches the susceptor 12. Not used white spirits. Then, the temperature of the susceptor 12 was changed from 20 ° C. to 300 ° C., and droplets were sprayed from the vaporizing nozzle 22 at each temperature to gradually increase the particle diameter of the droplets. While the particle diameter is sufficiently small, the droplet from the vaporizing nozzle 22 is vaporized before reaching the susceptor 12, but the particle diameter has a certain limit value (the droplet is vaporized 100% and the vaporization rate =
When the particle diameter becomes 1 (hereinafter, appropriately referred to as a vaporization limit particle diameter), a part of the liquid droplets does not vaporize and adheres to the susceptor 12 as droplets. FIG. 4 shows the value of the vaporization limit particle diameter d at each susceptor temperature T measured in this way.

As shown in FIG. 4, the temperature T of the susceptor 12
= Vaporization limit particle size d 限界 25 μm at 20 ° C., d ＝ 32 μm at T = 100 ° C., d ≒ 36 μm at T = 200 ° C., T =
At 300 ° C., d ≒ 45 μm, and the susceptor 12
It can be seen that the higher the temperature of, the larger the vaporization limit particle size d, and even larger droplets vaporize before reaching the susceptor 12. Further, even when the susceptor temperature T is the lowest, T = 20 ° C., if the droplet diameter is set to 20 μm or less, vaporization completely occurs before reaching the susceptor 12. Here, the lowest temperature is set to T = 20 ° C. for the following reason. That is, it is most preferable that all droplets sprayed from the vaporizing nozzle 22 fly straight onto the wafer 11 placed on the susceptor 12,
In some cases, a part of the sprayed droplet may bend and fly to the wall surface of the vacuum vessel 10. This is because the temperature of the wall surface of the vacuum vessel 10 is usually much lower than the temperature of the susceptor 12, and about 20 ° C. is conceivable in the lowest case. Therefore, according to the results of FIG. 4, if the droplet diameter is set to 25 μm or less, the vacuum container 10
The droplets flying on the wall surface can also be vaporized. However,
Since the relationship between the temperature T and the vaporization limit particle diameter d may be slightly different depending on the type of liquid, the inventors of the present application consider a margin and set the droplet diameter to 20 μm or less to obtain a vacuum. It was determined that all the droplets, including the droplets flying on the wall surface of the container 10, could be completely vaporized.

Here, in the present embodiment, the vaporizing nozzle 22
The inventors of the present application have confirmed that fine particles having a particle size of 20 μm or less can be always formed by inducing a swirling flow by the swirling plate 31 to promote atomization. Thereby, after the liquid raw material is sprayed from the vaporization nozzle 22 into the vacuum vessel 10, all droplets can be vaporized before reaching the wafer 11 on the susceptor 12.

According to the embodiment described above, the following effects can be obtained. (I) Simplification of Apparatus Configuration by Suppressing Pressure Increase That is, since the liquid raw material is vaporized before reaching the surface of the wafer 11, the pressure increase in the container is higher than in the conventional technique in which the liquid material is applied to the wafer as droplets and then volatilized. Can be suppressed. This will be described with reference to FIGS. 5A and 5B. 5 (a) and 5 (b) conceptually show a rise in pressure and a change with time of a film thickness in a vacuum vessel after a liquid material is sprayed from a vaporizing nozzle. FIG. 5A shows the present embodiment, and FIG. 5B shows, for comparison, a case in which gas trapping means such as a cold trap is not provided in a conventional technique in which liquid droplets are applied to a wafer and then volatilized. ing. In each of the figures, the change in the pressure P is indicated by a solid line, and the change in the film thickness h is indicated by a broken line.

First, in the prior art shown in FIG.
After continuing to spray the liquid material and applying it to the wafer as droplets, if heating is started after a certain period of time, the solvent component evaporates from the applied droplets and film formation of a predetermined thickness is completed quickly I do. However, at this time, a large amount of the solvent component is volatilized from the applied droplets at once, so that the pressure in the vacuum container rapidly rises immediately after the start of heating, which greatly affects the vacuum state. Therefore, as a countermeasure, a required pressure is maintained by condensing volatile components again in the cold trap, and it is necessary to arrange an extra equipment called a cold trap in the vacuum vessel.

On the other hand, in the present embodiment, FIG.
As shown in (a), first, when a very small amount of material whose atomization is promoted is supplied into the vacuum vessel 10, it is vaporized after a short time, and the pressure P rises by a very small amount.
When the vaporized raw material reaches the wafer 11 and forms a thin film, the pressure is reduced again. Thereafter, the next minute amount of raw material is supplied, and a small pressure rise and decrease are similarly performed to form a film. In this way, the film thickness is sequentially increased, and this pressure increase / decrease is repeated until the film formation of the predetermined thickness is completed. As a result, the maximum value of the pressure rise can be suppressed to an extremely small amount as compared with the related art, so that gas trapping means such as a cold trap can be eliminated. Therefore, since the apparatus configuration can be simplified, the handling and operation of the apparatus can be simplified, and the productivity can be improved.

(II) Ensuring High Efficiency and High Reliability That is, the swirling flow is induced by using the flow from the radially outer side to the radially inner side of the four fluid passages 31b in the four swirling plates 31 by the swirling plate 31. Sufficient atomization can be achieved without using a rotating member. As a result, extra power sources and movable members can be omitted as compared with the related art in which atomization is performed by rotating the rotating member at high speed, so that efficiency and reliability can be improved.

(III) Others In the present embodiment, since the liquid raw material is vaporized before reaching the surface of the wafer 11, the volume is greatly increased, and a 100% high-concentration film-forming raw material is supplied to the wafer 11. Therefore, the amount of the liquid raw material 16 required for film formation can be reduced as compared with the related art in which the droplets are applied to the wafer 11 as they are. Then, by adjusting the supply amount of the liquid raw material 16 by intermittent opening / closing by the opening / closing mechanism 23, the minute supply control can be optimally performed with high accuracy and high response.

In the above-described embodiment, the material constituting each device / member in the semiconductor manufacturing apparatus is not particularly limited. However, the ball valve 30 constituting a part of the opening / closing mechanism 23 and its surrounding members are used. May have the following limitations in terms of wear resistance and the like. That is, each device / member in the semiconductor manufacturing apparatus is generally made of metal, and for example, the side surface of the ball valve 30 sliding on each other, the wall surface of the guide hole 31a of the swivel plate 31, and the ball valve contacting each other. The tip of 30, the orifice 22Aa, the valve seat 22Ab, and other members of the sliding portion in the portion through which the liquid material passes are also made of metal. Since the liquid material is usually filled around these members, even if the members slide each other, the liquid material acts as a lubricant and the generation of wear powder is almost prevented.
In the event that abrasion powder is generated from these members, the abrasion powder may fly on the wafer 11 together with the sprayed liquid raw material and be taken into the formed film, which may cause a failure of the semiconductor element. . Therefore, by considering the wear resistance of these members, for example, by coating the surface with a silicon-based material, it is possible to prevent the occurrence of defects due to metal powder generated by the wear. Further, the vaporizing nozzle 22
By manufacturing all of the components not necessarily made of metal, such as the orifice 22Aa, from a silicon-based material, the reliability can be further improved. Furthermore, if the surface of a member that may be worn as described above is coated in advance with the same material as the thin film to be formed, the liquid material sprayed by generating abrasion powder by sliding should be used. Even if it is included in the film formed and contained therein, it is the same component as the thin film, so that semiconductor defects due to generated abrasion powder can be suppressed as much as possible.

Further, in the above embodiment, FIG.
Although the turning plate 31 having the structure shown in FIGS. 3A to 3C is used, the present invention is not limited to this, and other modifications are also possible. These modifications will be described with reference to FIGS. FIG. 6 shows the structure of a turning plate 131 according to a first modification.
FIG. 6A is a top view of the turning plate 131, and FIG.
(A) It is a longitudinal cross-sectional view by AOB plane. As shown in FIGS. 6A and 6B, this turning plate 1
31 is a guide hole 13 in which the ball valve 30 moves up and down.
1a and four fluid passages 131b arranged so as to allow the liquid material to flow from the outside in the radial direction toward the orifice 22Aa via the guide holes 131a. In particular, the point different from the turning plate of FIG. 3 is that each fluid passage 31b has a straight pipe shape arranged obliquely with respect to the ejection axis direction. In addition, the total height of the turning plate 131 is correspondingly increased. This turning plate 131 also provides the same atomization promoting action as the turning plate 31.

FIG. 7 shows a turning plate 23 according to a second modification.
7A is a top view of the turning plate 231, FIG. 7B is a side view of the turning plate 231, and FIG.
FIG. 7C is a cross-sectional view taken along the line VIIC-VIIC in FIG. As shown in FIGS. 7 (a) to 7 (c), the turning plate 231 has a guide hole 231a in which the ball valve 30 moves up and down, and a radially outward direction toward the orifice 22Aa via the guide hole 231a. And four fluid passages 231b arranged so that the liquid raw material flows therethrough. At this time, each fluid passage 231b has an upper end opening on the upper surface of the turning plate 231 and a radially outer opening on the outer peripheral portion of the turning plate 231 in a direction oblique to the direction of the ejection axis of the liquid material. Formed swivel groove 23
1b1 and an outflow groove 231b2 communicating with the swivel groove 231b1 and formed on the lower surface of the swivel plate 231 in a radial direction orthogonal to the ejection axis direction. In particular, the difference from the turning plate of FIG. 3 is that the center line of the outflow groove 231b2 formed in the radial direction corresponding to the turning groove 31b2 of FIG. 3 is not eccentric with respect to the axis of the guide hole 231a, The main function of inducing the swirl flow is the swirl groove 23 on the outer periphery of the swirl plate 231.
That is what 1b1 plays. This turning plate 231
Thus, the atomization promoting action similar to that of the turning plate 31 is obtained.

The swivel plates 31, 131,
The number of the fluid passages 31b, 131b, and 231 of the 231 is four, but is not limited thereto, and may be one to three or five or more. In these cases, a similar effect is obtained.

[0039]

According to the present invention, sufficient atomization can be achieved, thereby eliminating the need for gas trapping means, simplifying the apparatus configuration, and ensuring high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic layout diagram illustrating an entire structure of a semiconductor manufacturing apparatus that performs a semiconductor manufacturing method according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view illustrating a detailed structure of a tip of a vaporizing nozzle illustrated in FIG.

FIG. 3 is a top view of the turning plate shown in FIG. 2, IIIB-III.
It is the longitudinal section by plane B, and the cross section by IIIC-IIIC plane.

FIG. 4 is a diagram showing the results of a droplet vaporization experiment performed to study the relationship between atomization and ease of vaporization.

FIG. 5 is a diagram showing a pressure rise in a vacuum vessel and a change with time of a film thickness after spraying a liquid raw material from a vaporization nozzle in comparison with a conventional technique.

FIG. 6 is a diagram illustrating a modification example of the turning plate.

FIG. 7 is a diagram illustrating a modification example of the turning plate.

[Explanation of symbols]

 2 Vaporization mechanism (supply means) 3 Vacuum exhaust unit (vacuum exhaust means) 10 Vacuum container (container) 11 Wafer (substrate) 15 Liquid source tank 16 Liquid source 18 Delivery gas supply unit 19 Liquid source delivery gas pipe 20 Liquid source Supply pipe 21 Liquid material supply valve 22 Vaporization nozzle (supply means) 22Aa Orifice (ejection hole) 23 Opening / closing mechanism (Supply means) 24 Vacuum exhaust pipe (Vacuum exhaust means) 25 Vacuum exhaust valve (Vacuum exhaust means) 31 Giving swivel plate ( Atomization promoting mechanism, supply means)

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideki Tomioka 2326 Imai, Ome-shi, Tokyo Inside the Hitachi, Ltd.Device Development Center (72) Inventor Akira Okawa 2326 Imai, Ome-shi, Tokyo Hitachi, Ltd. Inside the center

Claims (10)

[Claims] 1. A semiconductor wherein a substrate is placed in a container having a substantially vacuum environment inside, and a thin film for a semiconductor element is formed on the substrate using a liquid material obtained by liquefying a liquid material or a solid material for film formation. In the manufacturing method, the atomization of the liquid raw material or the liquefied raw material is promoted by an atomization promoting mechanism, and then the raw material is vaporized before reaching the substrate surface by supplying the raw material into the container. Supplying the substrate to the substrate surface and forming the thin film on the substrate. 2. The method of manufacturing a semiconductor according to claim 1, wherein the atomization promoting mechanism promotes atomization by inducing a swirl flow in the jet of the liquid material or the liquefied material. Semiconductor manufacturing method. 3. The method of manufacturing a semiconductor according to claim 2, wherein the atomization promoting mechanism is configured to pour the raw material from a radially outer side into a discharge hole provided in a discharge axis direction of the raw material. A swirling flow is induced in a jet flow from the substrate. 4. The method of manufacturing a semiconductor according to claim 1, wherein when the liquid material or the liquefied material is supplied into the container, the liquid material or the liquefied material is supplied intermittently through an opening / closing mechanism that opens and closes intermittently. Semiconductor manufacturing method. 5. The method of manufacturing a semiconductor according to claim 4, wherein at least a part of the opening / closing mechanism and its surrounding members are covered with a silicon-based material or are made of a silicon-based material. Semiconductor manufacturing method. 6. The method for manufacturing a semiconductor according to claim 4, wherein at least a part of the opening / closing mechanism and its surrounding members are coated with the same material as the thin film to be formed. 7. The method according to claim 1, wherein the reaction for forming the thin film on the substrate is a chemical vapor deposition reaction. 8. A semiconductor wafer manufactured using the method for manufacturing a semiconductor according to claim 1. 9. A semiconductor device manufactured by using the method of manufacturing a semiconductor according to claim 1. 10. A container in which a substrate is placed, a vacuum exhaust means for making the inside of the container a substantially vacuum environment, and a liquefied raw material obtained by liquefying a liquid material or a solid material for film formation is supplied into the container. A semiconductor device for forming a thin film for a semiconductor element on the substrate, wherein the supply means has an atomization promoting mechanism for promoting atomization of the liquid raw material or the liquefied raw material. Semiconductor manufacturing equipment.