JPH04187592A - Device of preparing thin film - Google Patents

Abstract

PURPOSE:To obtain an oxidized thin film having uniform distribution of film thickness and film qualities by making a gas channel from oxygen-active seed generating mechanism to a treating chamber and each inner wall face of the treating chamber of a specific material. CONSTITUTION:This device of preparing a thin film is equipped with a treating chamber having airtight structure and inner space maintained in vacuum, a substrate 6 which is set in a treating chamber 1 and has the surface on which a thin film is formed, an exhaust system to evacuate the treating chamber 1, a substrate holder 5 which retains the substrate 6 and has temperature regulating mechanism to control temperature of the substrate 6, mechanism of generating an oxygen active seed, one kind of raw material gases and raw material gas feeding mechanism of feeding each of at least two kinds of raw material gases to the treating chamber 1. Further, a gas channel from the active oxygen seed generating mechanism to the treating chamber 1 and each inner wall face of the treating chamber 1 are made of any material of glass, ceramics, a metal surface treated material and polymer compounds.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a thin film production device, and in particular to a sensor,
The present invention relates to a thin film production apparatus for producing films such as insulator films, protective films, and semiconductor films used in optical components, audio products, semiconductor devices, and the like.

[Conventional technology]

2. Description of the Related Art Conventionally, with the increase in the density of LSIs, the patterns of semiconductor elements have become finer and three-dimensional. In the manufacture of such highly integrated semiconductor devices, it is important to flatten these steps and undulations by forming a flat thin film on top of patterns with large steps and undulations. Therefore, the problem is how to produce a thin film with good flatness.

From the above point of view, what process should be used to planarize a silicon oxide film as an interlayer insulating film?
Various methods are currently being considered.

These methods include, for example, plasma CVD, sputtering, and the like. Among these methods, one of the methods that is attracting attention is a CVD technique using tetraethoxysilane (also referred to as tetraethyl orthosilicate, hereinafter abbreviated as TEO8).

Note that TE01 is an organic compound of silicon, which is a semiconductor, but in this specification, such semiconductor organic compounds will also be collectively referred to as organometallic compounds.

Regarding the CVD technology using the above-mentioned TE01, for example, Ikeda et al., "Electrical Science J Vol. 56 No.

7 (1988) P, 527-P, 532 and the cited documents therein have descriptions regarding this method. Ikeda et al.
By using atmospheric pressure CVD using E01 and ozone, a silicon oxide film with good flatness and good coverage of stepped portions is manufactured.

In this case ozone is used as the oxidation source, thereby
It is possible to produce a silicon oxide film at a low temperature of 00° C., and the number of OH groups in the film is reduced to obtain a high quality silicon oxide film. However, according to the technique of Ikeda et al., the deposition rate is approximately 1
400 people/min, and it has the disadvantage that it takes about 7 minutes to fabricate a silicon oxide film having a thickness of 1 μm.

Therefore, this technology can achieve a film formation rate of 1 μm, which is required for single-wafer processing equipment.
/min.

Also, J. Eleclroc of R. A. Levy et al.
hem, Sac, V.

l, 134. N6.7 (1987) P, 1744-P
, 1749 and its cited documents introduce the production of a silicon oxide film using oxygen and TE01.

In this case, the film formation temperature is 550°C, which is much higher than the method using ozone, but the film formation rate is slow at 300 people/m'+n, and this film formation method However, it has not yet reached a level where it can be used industrially.

Furthermore, in the patent publication, JP-A-61-7'7
``Vapor phase growth method'' according to Publication No. 695 and U.S. Patent Nos. 3 and 9
There is a film forming method according to No. 34,060, but like the prior art described above, these also cannot be said to have reached a satisfactory level in terms of film forming speed and film quality.

In addition, in Lecture No. 29-(,-5) of the 35th Joint Conference on Applied Physics (Spring 1988), Noguchi et al. ) shows that the carbon content in the produced film is reduced compared to when tetramethylsilane (hereinafter abbreviated as TMS) is used. However, the film made using this 1MO8 teeth,
A large number of OH groups were observed from the infrared absorption spectrum, and it is clear that the film was not necessarily good.

This is considered to be due to insufficient supply of oxygen active species.

Another example using oxygen atoms is described in JP-A-63-83275, ``rCVD Apparatus'', in which oxygen atoms and silane are reacted. This reaction is usually
It progresses rapidly at room temperature and under reduced pressure, producing silicon oxide powder dust. Furthermore, since the reaction occurs rapidly, it is difficult to introduce and mix the two gas components into the reaction processing chamber, making it difficult to produce a film with good uniformity. In order to solve this problem, Japanese Patent Application Laid-Open No. 63-83275 discloses that the reaction between oxygen atoms and silane is suppressed by cooling the gas outlet, and the reaction is then carried out by introducing the gas onto the heated surface of the substrate to be treated. It shows a device designed to wake people up. However, with this method, it is necessary to cool the gas outlet,
Therefore, the device becomes complicated, and it is impossible to completely suppress the reaction in a space away from the substrate surface, which has the disadvantage that some dust is inevitably generated.

In the invention disclosed in JP-A-2-163379, a high temperature non-equilibrium plasma or a high temperature equilibrium plasma is used instead of microwave discharge to generate a large amount of oxygen active species, and by using TE01 and 1MO8 with low reactivity,
Insulating films with little dust are fabricated at high speed, but when the film is formed at the industrially required rate of about 1 μm/min using a single-wafer system, the presence of OH groups in the film was confirmed by infrared absorption analysis. .

[Problem to be solved by the invention]

As explained above, the conventional film forming method using ozone + TEO8 system or the film forming method using oxygen + TEO3 system has the problem that it is not possible to obtain the film forming rate required industrially.

In addition, in the film formation method using oxygen atoms + silane, which allows for a fast film formation rate, reactions occur rapidly in the mixing part of both gases, so it is necessary to cool the mixing part and the gas outflow part to suppress the reaction. Therefore, there is a problem that the apparatus becomes complicated and, in addition, it is impossible to suppress the generation of dust due to reactions in the space.

In addition, oxygen atoms created by microwave discharge and 1MO
The film forming method using No. 8 has the problem that the film contains OH groups.

Furthermore, by using TE01 and a large amount of oxygen active species obtained by high-temperature non-equilibrium plasma or high-temperature equilibrium plasma, we were able to obtain an insulating film at high speed and with little dust. This is a problem because OH groups are still observed in the film formed at a deposition rate of min.

By the way, when oxygen atoms generated by plasma are brought into contact with various materials and their concentrations are measured, the results show that in the case of metals such as stainless steel, they are different from those of glass, Teflon, polyimide, ceramics, etc. A comparison revealed that most of the oxygen atoms were deactivated.

This not only reduces efficiency but also causes silicon oxide (S
102) When manufacturing a film, silicon oxide adheres to the inner wall surface of the processing chamber and changes over time, causing problems. On the other hand, if glass, Teflon, etc. are used effectively, the active oxygen atoms will lose their activity (hereinafter referred to as deactivation).
It can be seen that this can be prevented.

SUMMARY OF THE INVENTION An object of the present invention has been made to solve the above-mentioned problems, and is to provide a thin film forming apparatus for performing a film forming method using oxygen active species, which uses the glass etc. mentioned above to form a film using oxygen active species. The deactivation of the film is reduced, the film quality is good, and a film formation rate sufficiently useful for industrial use can be obtained, and the film quality and film formation rate do not change over time, and furthermore, as a single-wafer type device, it is possible to obtain a film formation rate that is sufficiently useful for industry. It is an object of the present invention to provide a thin film forming apparatus that can obtain a high quality thin film with few OH groups even when forming a film at a required film forming rate.

[Means to solve the problem]

In order to achieve the above object, the thin film production apparatus according to the present invention includes a processing chamber that has an airtight structure and whose internal space is kept in a vacuum, and a substrate that is installed in the processing chamber and on which a thin film is produced. an exhaust device that exhausts the processing chamber; a substrate holder that holds the substrate and includes a temperature control mechanism that adjusts the temperature of the substrate; and an oxygen active species generator that generates oxygen active species that is a type of raw material gas. a gas flow path from the oxygen active species generation mechanism to the processing chamber and each of the processing chambers; The inner wall surface is
It is characterized by being formed of any one of glasses, ceramics, metal surface-treated objects, polymer compounds, or a combination thereof.

In the thin film production apparatus according to the present invention, in the above configuration, the glass is quartz glass, lead potassium soda, soda lime, lead potassium soda, alkali zinc borosilicate, soda zinc, borosilicate, soda barium, soda barium silicate, 96 % silicic acid, titanium silicic acid, and glass ceramics, and each inner wall surface is formed of a material consisting of these materials or a combination of these materials including ceramics, metal surface treatment objects, and polymer compounds. It is characterized by

In the thin film production apparatus according to the present invention, in the above configuration, the ceramics are any one of alumina, steatite, silicon carbide, magnesia, silicon nitride, and boron nitride; Each of the inner wall surfaces is formed of a combination of materials including glasses, metal surface-treated objects, and polymer compounds.

In the thin film production apparatus according to the present invention, in the above configuration, the metal surface treatment object is subjected to an oxidation treatment of aluminum, an oxidation treatment of stainless steel, an oxidation treatment of copper, an oxidation treatment of tantalum, an oxidation treatment of iron, and an oxidation treatment of molybdenum. , titanium oxidation treatment, polytetrafluoroethylene coating, polycarbonate coating, polytrifluorochloride ethylene coating, polyimide coating, and these materials or these materials include glass and ceramics. Each of the inner wall surfaces is formed of a material made of a combination of materials including polymer compounds and polymer compounds.

In the thin film production apparatus according to the present invention, in the above configuration, the polymer compound is any one of polytetrafluoroethylene, polycarbonate, boimide, polytrifluorochloroethylene, and these materials or The inner wall surface is formed of a combination of these materials including glasses, ceramics, and metal surface-treated objects.

[Effect]

In the thin film production apparatus according to the present invention, the inner wall surface of the gas flow path from the oxygen active species generating mechanism to the processing chamber and the inner wall surface of the processing chamber container are made of glass, ceramics, metal surface treated bodies, or polymer compounds. By forming an object made of a material made of any one of the following or a combination thereof, oxygen active species can be efficiently supplied at a constant concentration, and the various matters described in the above objectives can be satisfied. I can do it. When producing a thin film using oxygen active species created by plasma and an organometallic compound such as TE01 or 7MO3, the area between the oxygen active species generation mechanism and the inner wall surface of the processing chamber container is exposed to the oxygen active species. It uses an inert material to efficiently supply it, induces a chemical reaction only on the surface of the substrate set at a predetermined temperature, and creates an oxide film with uniform thickness and film quality distribution.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front cross-sectional view showing one embodiment of a thin film manufacturing apparatus according to the present invention. In this thin film manufacturing apparatus, a film forming method using CVD technology is carried out, and at least two types of raw material gases, active oxygen and TE01, for example, are used. or used.

In FIG. 1, 1 is a container made of stainless steel, for example, and forms a processing chamber. The processing chamber 1 has, for example, a diameter of about 40 cm, a height of about 35 cm, and a side wall having a cylindrical shape. Wall portions are also formed at the upper and lower parts of the processing chamber 1 in the figure, and the entire chamber is formed to have an airtight structure that can be evacuated or kept airtight. In the processing chamber 1, a mechanical booster pump 3 is installed through a valve 2 on the earthen wall, and by driving the mechanical booster pump 3 with an oil rotary pump 4, the inside of the processing chamber 1 is evacuated and the inside of the processing chamber 1 is evacuated. It is possible to create a vacuum. The inside of the processing chamber 1 is evacuated as necessary.

Further, a base body holder 5 having a space inside is arranged in the earthen wall portion, and a base body 6 is attached to the lower surface of this base body holder 5 and held therein. In the internal space of the base holter 5,
A heater 7 is disposed close to the base 6, and a thermocouple 8 is also provided.
is installed.

In FIG. 1, illustration of a power supply unit for supplying heating power to the heater is omitted. The substrate holder 5, the heater 7, etc. disposed inside the substrate holder 5 constitute a substrate temperature adjustment mechanism.

With this substrate temperature adjustment mechanism, it is possible to raise the temperature of the substrate holder 5 up to about 450° C., for example, when the substrate holder 5 has a diameter of 3 Qcm.

Further, according to the thermocouple 8, the temperature of the substrate holder 5 can be adjusted by controlling the heater 7 by using P control, P1 control, PID control, or simple 0N10FF control by using a temperature controller (not shown) and a thyrisk unit in combination. It becomes possible to adjust the temperature of the substrate holder 5 optimally by adjusting the applied electric power. Furthermore, it is also possible to use a water cooling mechanism in this part if necessary.

There are also 9 vacuum gauges installed on the earthen wall. The vacuum gauge 9 is for measuring the pressure inside the processing chamber 1. In the embodiment described above, the internal pressure of the processing chamber 1 is kept constant by adjusting the opening and closing of the valve 2.

Next, the configuration of the items installed on the lower wall side of the processing chamber 1 will be explained.

10 is a bubbler container containing TEOSll in a liquid state. The TEOS II in the bubbler container 10 is bubbled with argon gas 13, which is supplied from an argon (Ar) horn (not shown) and whose flow rate is controlled by a mass flow controller (MFC) 12. TE01, now in a gas state, is connected to pipe 14 and valve 1.
5 into the gas blowing mechanism 16 and supplied into the processing chamber 1.

Activated oxygen, which is a reactive gas other than the TEOS gas, is supplied to the processing chamber 1 via a gas blowing mechanism 16 . The active oxygen generation mechanism includes a discharge tube 20, a discharge chamber 21 formed inside the discharge tube 20, and a coil 22 disposed outside the discharge tube 20 so as to surround the discharge chamber 21. , and a high frequency power supply 23 for supplying high frequency (several KHz to several hundred MHz) to the coil 22. 24 is ground. Oxygen (02), which is a discharge gas and a reactive gas, is introduced into the discharge tube 20 via a mass flow controller 25 and a valve 26 as shown by the arrow. The discharge tube 20 is generally made of an insulator, but in this device, quartz glass is particularly used. Although not shown strictly in the illustrated example, in practice, since there is a risk that quartz glass will melt due to the high temperature of the discharge plasma, the discharge tube 20 is formed as a double tube made of quartz glass, and there is a gap between the inner and outer tubes. It is configured so that cooling water flows through the

In the active oxygen generation mechanism having the above configuration, the power source 23
When a high frequency voltage is applied to the coil 22, a discharge occurs in the high frequency inductively coupled discharge space inside the discharge tube 20, and as a result, active oxygen is generated. The active oxygen generated in this way is transferred to the processing chamber 1 via the passage leading to the processing chamber 1.
The gas is introduced into the gas blowing mechanism 16 inside. The reference numeral 27 provided in the middle of the passage is a stainless steel buffer to keep the pressure stable, and a buffer cover 28 made of Pyrex glass is disposed inside it to reduce deactivation of active oxygen. ing. This buffer cover 28
This prevents active oxygen from coming into contact with the stainless steel buffer 27, which would cause the active oxygen to lose its activity. Discharge tube 20 in the figure
The upper end opening is connected to a buffer cover 28, and the buffer cover 28 is further connected to the gas blowing mechanism 16 provided on the lower wall of the processing chamber 1 via a Teflon tube 29 having a diameter of 22 mm, for example.

Next, a gas blowing mechanism 16 provided on the lower wall of the processing chamber 1
I will explain in detail. The gas blowing mechanism 16 has a structure that mixes the two reactive gases, ie, the TEOS gas and the active oxygen gas, which are the raw materials, just before the base 6 in order to avoid contamination due to a spatial reaction between the two. A schematic enlarged sectional view of the gas blowing mechanism 16 is shown in FIGS. 2 and 4, and a perspective view of a part of the upper surface of the gas blowing mechanism is shown in FIGS. 3 and 5.

First, the supply of active oxygen in the gas blowing mechanism 16 will be explained based on FIGS. 2 and 3.

Active oxygen is introduced into the space 32 between the inner cylindrical block 30 and the outer cylinder 31 via the plurality of tubes 29.
It is divided into four equal parts and introduced. The active oxygen is then diffused and released into the front space of the base 6 through a plurality of holes 34 with a diameter of about 1 mm formed in the active oxygen diffusion plate 33. The shaded area in FIGS. 2 and 3 indicates the spatial region of the active oxygen flow path. Note that since the lower wall 1a of the processing chamber 1 is made of stainless steel, a Teflon sheet 35 is laid on the inner surface of the lower wall 1a, and a polyimide tape is wrapped around the TEO3 introduction pipe 36 disposed at the center. I did it like that. The cylindrical block 30, the cylinder 31, and the active oxygen diffusion plate 33,
The TEO8 diffusion plate 37 is made of aluminum, and its surface is anodized.

Furthermore, a buffer cover 40 made of Pyrex glass is disposed to cover the inner surface of the peripheral wall of the container forming the processing chamber 1 and the inner surface of the lower wall other than the portion where the gas blowing mechanism 16 is formed.

Next, TE01, which is another reaction gas, is introduced into the space 38 formed inside the cylindrical block 30 through the TEO3 introduction pipe 36 together with the argon gas, and the T
A length of 3 mm inserted into multiple holes of the EO3 diffusion plate 37
It passes through a plurality of Teflon tubes 39 each having a diameter of 1 mm, and is emitted while being diffused into the space in front of the base 6. In FIGS. 4 and 5, the shaded area indicates the spatial region of the flow path for TEOS gas, etc.

As is clear from the configuration of the gas blowing mechanism 16 described above,
Since the TEOS gas, argon gas, and active oxygen are completely separated and sealed from each other within the gas blowing mechanism 16, they are not mixed until they are blown onto the upper side of the active oxygen diffusion plate 33.

According to the thin film forming apparatus having the above configuration, the film forming conditions include, for example, the internal pressure of the processing chamber 1 is 17o+r, and the oxygen flow rate is 2.
00ml/min, 500g of liquid TEO3II
Maintain the temperature at 55°C with the filled bubbler container 10,
The flow rate of argon gas used for bubbling is 20m I/
min, temperature of substrate holder 5 is 400°C, 56MHz
High frequency power5. Under the condition of OKW, approximately 1.2
A silicon oxide film can be obtained at a deposition rate of μm/min. Furthermore, even though silicon oxide was attached to the inner wall surface of the processing chamber 1, there was no change in the concentration of oxygen active species, and no changes over time were observed in film quality and film formation rate. The silicon oxide film was found to be of good quality, with no carbon contamination observed by infrared absorption spectroscopy, and almost no OH groups (see FIG. 6), with little contamination due to spatial reactions.

It should be noted that the fact that a high-quality film was obtained at the above-mentioned film formation rate of about 1.2 μm/min is industrially important, and satisfies the film formation rate of 1 μm/min required for single-wafer type equipment. It is something.

Also, the aforementioned buffer cover 28.40, Teflon tube 29.39, cylindrical block 30, cylinder 31, lower wall 1as Teflon sheet 35, active oxygen diffusion plate 33, TE
The materials or surface treatments for each of the O3 diffusion plates 37 include quartz glass, lead potassium soda, soda lime, lead potassium soda, alkali zinc borosilicate, soda zinc, borosilicate, soda barium, soda barium silicate, 96% silicic acid, Titanium silicate, glass ceramics, alumina, steatite, silicon carbide, magnesia, silicon nitride, boron nitride, oxidation treatment of aluminum, oxidation treatment of stainless steel, oxidation treatment of copper, oxidation treatment of tantalum, oxidation treatment of iron, molybdenum oxidation treatment,
Oxidation treatment of titanium, polytetrafluoroethylene coating, polycarbonate coating, polytrifluorochloroethylene coating, polyimide coating, polytetrafluoroethylene, polycarbonate, polyimide, polytrifluorochloroethylene, or Any combination of these can be used, and similar effects can be obtained even if these are used appropriately.

Furthermore, in the above structure, the same effect can be obtained by using magnesium oxide in place of silicon oxide, Teflon, aluminum oxide, or polyimide.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in an apparatus for producing a thin film using at least two types of raw material waste, oxygen active species and organometallic compound produced by plasma,
By using materials such as glass in the flow path of oxygen active species, it is possible to reduce the deactivation of oxygen active species, efficiently supply oxygen active species to the processing chamber, and make a high-quality film by reacting with TE01. , it is possible to produce films at industrially useful film formation speeds, and it can be used to produce insulator films, protective films, and semiconductor films used in sensors, optical components, semiconductor devices, audio products, etc.

[Brief explanation of the drawing]

FIG. 1 is a front vertical sectional view of the thin film production apparatus according to the present invention, FIG. 2 is a schematic enlarged sectional view of the gas blowing mechanism, FIG. 3 is a partial perspective view of the top of the gas blowing mechanism, and FIG. FIG. 5 is a schematic enlarged sectional view of the gas blowing mechanism, FIG. 5 is a partial perspective view of the top surface of the gas blowing mechanism, and FIG. 6 is a graph showing characteristics. [Explanation of symbols] 1... Processing chamber 5... Substrate holder 6... Substrate 7... Heater 10... Bubbler container 11... ... Liquid TEO3 16 ... Gas blowing mechanism 20 ... Discharge tube 21 ... Discharge chamber 22 ... Coil 23 ... High frequency power supply 27 ...・Stainless steel buffer 28...Buffer cover 29・φ・-・Teflon tube 30...Cylindrical block 31...Cylinder 33...Active oxygen diffusion plate 37... ...TEO8 diffusion plate 39 ... Teflon tube 40 ... Buffer cover Applicant Nichiden Anelva Co., Ltd. Agent Patent attorney Hiroshi Tamiya Figure 2 Figure 3

Claims (5)

[Claims] (1) A processing chamber that has an airtight structure and whose internal space is kept in a vacuum, a substrate that is installed in the processing chamber and on which a thin film is formed, an exhaust device that exhausts the processing chamber, and the substrate. a substrate holder equipped with a temperature adjustment mechanism for holding and adjusting the temperature of the substrate; an oxygen active species generating mechanism for generating oxygen active species, which is one type of raw material gas; A gas flow path from the oxygen active species generation mechanism to the processing chamber and each inner wall surface of the processing chamber are provided with a raw material gas introduction mechanism provided for introducing the raw material gas into the chamber, and the gas flow path from the oxygen active species generating mechanism to the processing chamber and each inner wall surface of the processing chamber are arranged to accommodate glass, ceramics, or metal surface-treated objects. A thin film production device characterized in that it is formed of any one of materials selected from the group consisting of polymer compounds, or a combination thereof. (2) In the thin film production apparatus according to claim 1, the gas flow path from the oxygen active species generating mechanism to the processing chamber and each inner wall surface of the processing chamber are made of quartz glass, lead potassium soda, soda lime, lead Potassium soda, alkali zinc borosilicate, soda zinc, borosilicate, soda barium, soda barium silicate, 96% silicic acid, titanium silicate, glass ceramics, or these materials combined with ceramics, metal surface treatment objects, and polymers. A thin film production device characterized in that it is formed of a material made of a combination of materials including compounds. (3) In the thin film production apparatus according to claim 1, the gas flow path from the oxygen active species generation mechanism to the processing chamber and each inner wall surface of the processing chamber are made of alumina, steatite,
It is characterized by being made of any one of silicon carbide, magnesia, silicon nitride, and boron nitride, or a combination of these materials including glasses, metal surface treatment objects, and polymer compounds. thin film fabrication equipment. (4) In the thin film production apparatus according to claim 1, the gas flow path from the oxygen active species generation mechanism to the processing chamber and each inner wall surface of the processing chamber are subjected to aluminum oxidation treatment,
Oxidation treatment of stainless steel, oxidation treatment of copper, oxidation treatment of tantalum, oxidation treatment of iron, oxidation treatment of molybdenum, oxidation treatment of titanium, polytetrafluoroethylene coating, polycarbonate coating, polytrifluoroethylene chloride coating, polyimide coating A thin film production device characterized in that it is made of a material of any of the surface-treated objects, or a combination of these materials including glasses, ceramics, and polymer compounds. (5) In the thin film production apparatus according to claim 1, the gas flow path from the oxygen active species generation mechanism to the processing chamber and each inner wall surface of the processing chamber are made of polytetrafluoroethylene, polycarbonate, Polyimide, polytrifluorochloride ethylene, or these materials with glass,
A thin film production device characterized in that it is formed from a combination of materials including ceramics and metal surface-treated objects.