JPS6119780A - Apparatus for gaseous phase growth of chemically active metal membrane - Google Patents

Abstract

PURPOSE:To provide a gaseous phase growing apparatus capable of forming a chemically active metal membrane having high bonding strength, good step coverage and good quality onto a substrate, constituted by mounting an exhaust system capable of evacuating a vacuum container to resistance stable pressure or less. CONSTITUTION:A substrate 31 is set on the substrate holder 33 in a vacuum container 11 and the container is evacuated to predetermined resistance stable pressure P0 or less and, thereafter, a base plate 42 is heated by a heater power source 42. When the base plate 42 reaches predetermined temp., predetermined gas is introduced into the container 11 through a variable leak 53 and a membrane 32 is adhered to the surface of the substrate 31. As shown by the drawing, if the membrane 32 is formed after the container 11 is evacuated to pressure P0 of 1X10<-7>torr or less, a chemically active high purity metal having good quality is obtained almost errorlessly. With due regard to economical efficiency in the preparation of the membrane, it is effective to perform the formation of the membrane by a process such that resistance stable pressure is calculated with respect to an indivisual material before the container is evacuated to the pressure equal to or less than said calculated pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to an apparatus for growing metal thin films in a gas phase. Particularly suitable for growing highly pure thin films.
Among these, it is particularly effective when applied to the production of thin films of pure metals or mixtures of these compounds.

(Conventional Pakjutsu and its problems) Equipment that creates thin metal films in the gas phase (hereinafter simply referred to as vapor phase growth equipment) generally creates thin films at high temperatures, and the growth of the film is caused by reactions with the surface of the substrate. Compared to films made using submerging or taring equipment, the film has superior characteristics such as greater adhesion strength and better step coverage.

In recent years, the step coverage in particular has been reconsidered, and it is being reconsidered for use in producing thin films for electrodes in microelectronics such as semiconductors. I represented by Rumi
It appears more frequently when creating films of chemically active metals such as the UB group, the IVA group represented by Ti, the VA group represented by Nb, and the VIA group represented by Mo.

(Object of the Invention) The object of the present invention is to provide an apparatus capable of eliminating these drawbacks and producing a high-quality film with low electrical resistance.

Another object of the present invention is to provide an apparatus capable of depositing a thin film of uniform Y even inside a deep hole and producing a highly pure thin film.

(Structure of the Invention) 4 The present invention achieves the above object by using a vapor phase growth apparatus equipped with an exhaust system that can evacuate the inside of a vacuum container to a level below a "resistance stable pressure" (the definition of which will be described later).

(Example) According to experiments conducted by the inventor of the present application, the electrical resistance of the thin film can be stably reduced to a low value by lowering the ultimate pressure of the device, that is, the vacuum container, and the hardness of the film can also be kept to a moderately low value. There was found. Conventionally, this type of device has been able to convert reactions from 1 to 0.
．． Since this is carried out at a relatively high pressure of approximately ITorr, the influence of the ultimate pressure of the apparatus has been ignored. The ultimate pressure of conventional equipment is estimated to be 10 Torr at most, as estimated by the exhaust system of conventional equipment that uses an oil recirculation pump or a mechanical booster pump as a vacuum pump.
It was about. The inventor of the present application has confirmed that it is possible to create advanced thin films by installing a powerful exhaust system and evacuating the device to an ultra-high vacuum pressure of approximately 10 Torr or less. .

Next, the present invention will be explained in detail by examples based on the drawings.

FIG. 1 is a diagram showing a basic embodiment of the present invention.
0 is a vacuum system, 11 is a vacuum container, 12 is for francs, ? It is. The vacuum container 11 is made of a material that releases little gas, such as stainless steel, so that the inside of the container can be evacuated to an ultra-high vacuum. It is desirable that the internal surface of the vacuum container be subjected to acid treatment, blasting treatment, etc. Reference numeral 20 denotes an evacuation system, which has the characteristics of the present invention, and uses a vacuum pump 21 capable of evacuation to an ultra-high vacuum, such as a cryopump, a trap and oil diffusion pump, or a turbo molecular pump. Of course, if an auxiliary exhaust system is required, add the necessary system. 22 is the main valve.

30 is a substrate system, 31 is a substrate, 32 is a thin film created,
33 is a substrate holder. 40 is means for heating the substrate, 41 is a heater, and 42 is a power source thereof. 50 is
51 is a cylinder for introducing a gas to cause a reaction;
52 is a flow meter, and 53 is a burr 7 pull leak.

The device operates as follows. First, the pair flange 12 is opened, the board 31 is set on the board holder 33, and the 7 flange 12 is closed. Next, when the temperature reaches the above temperature, a predetermined gas is introduced into the vacuum vessel 11 through the barrier pull leak 53 using the introduction system 50. Then, a thin film is attached to the surface of the substrate 31. FIG. 2 shows an example in which a thin aluminum film 32 is created by introducing a reaction gas mainly consisting of tri-butyl aluminum through the barrier pull leak 53, and the horizontal axis represents the ultimate pressure of the apparatus (hereinafter referred to as Po). As mentioned above, as Po becomes smaller, the specific resistance R of the thin film increases.

shows a stable value, and the vertical axis shows the resistance ratio R when this stable resistance value is taken as 1. As shown in the figure, R shows a stable constant value at the ultimate pressure PO below MIXIO Torr, but exhibits an unstable value at the ultimate pressure Po higher than that. By examining this in more detail, the ultimate pressure at which the resistance becomes constant regardless of the ultimate pressure (this is referred to as resistance stabilization pressure in this application).
It was found that the difference varies slightly depending on the temperature of the substrate, and also varies depending on the type of thin film to be formed and the composition of the gas introduced.

However, what can be said in common with various thin film materials is that if the thin film 32 is created after evacuating the inside of the vacuum chamber 11 to a pressure of 1X10 Torr or less, it will almost certainly be a high-purity, high-quality thin film. It is possible to make However, from the economic point of view of thin film production, it is effective to find a resistance stabilizing pressure for each material, and then evacuate to a pressure lower than that and then perform thin film production.

In this way, by creating a thin film with the ultimate pressure Pa equal to or lower than the resistance stability pressure, it is possible to industrially and stably mass-produce a film with high purity and good step coverage, although it is not a single crystal. In particular, it is possible to create a thin film that is extremely useful for use in microelectronic devices.

In this study, electrical resistance was used as a detection parameter for creating a stable thin film, but this cannot be done because electrical resistance is easily affected by residual gas and is sensitive. It is clear that various other properties besides electrical resistance can be used as detection parameters.

In addition, in the device of this embodiment, shoes, gas introduction system 5
Although only one system is used in 0, multiple systems may be used if necessary, or a bubbling device may be used depending on the type of reaction gas. In addition, if the surface of the substrate 310 is cleaned immediately before attaching the thin film 32, clean it by introducing a chemically active gas or applying a voltage to the substrate 31 and cleaning it by bombarding it with electrons or ions. or

FIG. 3 shows yet another embodiment.

In this embodiment, the apparatus has a multi-chamber structure (a royal room in this embodiment) and is designed for continuous mass production. The vacuum chambers are equipped with chambers 11, 13, and 14, and each chamber is separated from the outside by valves 15, 16, 17, and 18. Each chamber has a main valve and a vacuum pump, 24 and 23.22 and 21.2.
6 and 25 are closed, the exhaust system 23 and 24 are used to exhaust the air, the pulp 16 is opened and the substrate is transferred into the chamber 11, the valve 16 is closed and the thin film is deposited, and the chamber 14, which has been previously evacuated by opening the valve 17, is Then, valve 17 is closed, valve 18 is opened to introduce atmospheric air, and the substrate is taken out into a space at atmospheric pressure. The pulp 18 is closed and the inside of the container 14 is evacuated by exhaust systems 25 and 26. These steps are performed either singly or in parallel. Other symbols are the same as those in the embodiment shown in FIG. In the embodiment of FIG.
Since the interior is always kept in a vacuum, it is not possible to contain highly active gases such as O2, which can cause an increase in electrical resistance when creating thin metal films.
．． NZ, Co., 002. H2O etc. can be extremely reduced and a high quality thin film can be created.

It goes without saying that the above description does not have a limiting meaning and many variations are possible.

(Effects of the Invention) According to the present invention, a high quality chemically active metal thin film with high adhesion strength and good step coverage can be created on a substrate.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the properties of the thin film produced, and FIG. 3 is a diagram showing another embodiment. 11.13 in the figure. i4 is a vacuum vessel, 20 is an exhaust system, 31
40 is a substrate, 40 is a heating means, and 50 is a means for introducing gas. Patent applicant: Nichiden Anerunoku Co., Ltd. 1.3' Al, n to qAh-Torr P. FIG. 2 Procedural Amendment (Voluntary) Commissioner of the Patent Office July 27, 1985 1
, Indication of the case 1982 Patent application No. 139970Yu 1, Name of the invention Chemically active metal thin film vapor phase growth apparatus 3, Person making the amendment Relationship to the case Patent applicant address Yotsuya, Fuchu City, Tokyo 5-[3-1 Name Nichiden Anelva Co., Ltd. Representative Ori 1) Zenjibe 7 4. Agent -7.・Address
5-8-1 Yotsuya, Fuchu-shi, Tokyo 6, detailed description of the invention and drawings in the specification subject to amendment. (Attachment) Details of the amendment (1) [Figure 2 is] on page 5, line 11 of the specification box is amended to the following sentence. [For curves 1 and 2 in FIG. 2, (2) Correct [the following] on page 6, line 8 of the specification to the following sentence. -6 [or less (1 x 10' Torr or less when the film forming temperature is low)] (3) [Effective] on page 6, line 14 of the specification. After this, insert a new line and insert the following sentence. [Furthermore, almost the same thing can be said when forming a tungsten silicide thin film from tungsten hexafluoride and silane at a temperature of about 350°C. Furthermore, when the substrate is heated after evacuation, gas is released from the substrate holder 33 and surrounding structures, and the pressure increases by approximately 10 times (the stable resistance pressure in this heated state is designated as Pot). If you create a thin film while monitoring the pressure in this state, it will look like curve 3, and the pot will be approximately 1xlo-5 Torr.
becomes. Pots vary greatly depending on how dirty the vacuum equipment is. In this way, the resistance stability pressure varies depending on the state of the vacuum system, but it is still outside the vacuum range that can be achieved with oil rotary pumps and mechanical booster pumps. (4) On page 7, line 12 of the statement box, insert the following sentence after [strong gas]. [For example, Plasma Chemistry an
d Plasma Processing, Vo.
lume l Number 4 (December
Gases shown in the Ga5es column of Table II (page 331, fluorine-based plasma) and Table IV (page 347, chlorine and bromine-based plasma) of issue 1981) (5) Statement box page 8, line 18 can [be able to]. After the line break, insert the following sentence. [For example, in the example shown in Fig. 1, the pots vary as shown by arrow 4 in Fig. 2 between the high temperature and high temperature periods and the low temperature and dry periods, which means that sometimes a good film can be formed and other times it cannot. I can clearly see that there is. Furthermore, in order to demonstrate the effects of the present invention, when water vapor was forcibly mixed into the vacuum container 11, its partial pressure and R
The relationship with curve 3 almost coincided with curve 3. This is supported by the fact that most of the gas emitted from vacuum equipment is generally water vapor. If the partial pressure of water vapor is further increased, in extreme cases the thin film may no longer adhere. As described above, according to the apparatus of the present invention, (6) FIG. 2 is corrected to the attached one. Y set a 蓼 + 16w-force and Tarr) P. 1G2 -ζ1-

Claims (1)

[Claims] A container that evacuates the inside, an exhaust system that exhausts the inside of the container,
In the apparatus for forming a thin film on the substrate by placing a substrate in the container and having means for heating the substrate to a predetermined temperature and means for introducing a predetermined gas into the container, the exhaust system 1. An apparatus for vapor phase growth of chemically active metal thin films, comprising: an exhaust system capable of evacuating the inside of the container to a pressure below a stable resistance.