JPS62149876A - Formation of oxide film - Google Patents

Abstract

PURPOSE:To obtain an oxide film having good quality by introducing a metallic element, compd. having an alkoxy group or alkyl group, oxygen or compd. contg. oxygen and active seed into a film forming space and forming the oxide film. CONSTITUTION:The compd. A expressed by the formula I or the compd. B expressed by the formula II, oxygen or the compd. contg. oxygen and active 0seed are introduced into the film forming space and the oxide film is deposited. In the formula I, the formula II, M, M'; metallic element, R; an alkyl group, m; the positive integer equal to the valency of M or the integer times of said valency, n; the positive integer equal to the valency of M' or the integer times of said valency. The compd. contg. oxygen is alcohols R-OH (R; an alkyl group of 1-4C) and the active seed is a hydrogen radial.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming an oxide film, and more particularly to a method for forming an oxide film intended to lower the film forming temperature, improve film quality, etc.

[Prior art and its findings] Oxidation 11'+! It is widely used as an insulating film, an element region, and a passivation 1 or 2 for the element surface in semiconductor devices. In particular, the quality of the gate oxide film in insulated gate transistors is important for the breakdown voltage, durability, and electrical performance of the transistor. It is known that it greatly affects the characteristics. Furthermore, with the increasing integration of single circuits, it has become an important technology for the manufacture of integrated circuits to inexpensively form a high-quality oxide film at a low film-forming temperature.

However, conventional thermal CVD method, plasma CVD method or MOGVD (Metal Organic Chemistry
It could not be said that the Act on Vapor Deposition (Mical Vapor Deposition) etc. sufficiently satisfied the requirements of Article L.

First, in the thermal CVD method, it is necessary to raise the temperature of the substrate or deposition surface on which the oxide film is deposited to 500 to 1200° C., and there are significant restrictions on the selection range of the substrate material and the like. In addition, the crystallinity was poor and there were many pinholes, making it impossible to obtain a sufficient film quality.

Although low-temperature film formation is possible with the plasma CVD method,
The reaction process is more complex than the n-method, and there are many parameters for forming the oxide film (e.g., substrate temperature, pressure, gas flow rate, high-frequency power, electrode structure, etc.). For this reason, film forming conditions tend to become unstable, making it difficult to fully satisfy uniformity of film thickness and film quality, and mass productivity. Furthermore, the plasma CV method (1) has the problem that damage remains on the deposited film because plasma is generated in the film-forming space.

Furthermore, in MOCVD 7J, an oxide film is deposited by introducing an organometallic gas and an oxidizing agent, but the intermediate products produced at this time are complex, making it difficult to determine the conditions for producing a high-quality film.

Furthermore, since the intermediate product is decomposed only by ), (plate temperature ((2), if the decomposition temperature of the intermediate product is high, it is necessary to increase the substrate temperature, which limits the selection range of the substrate material. On the other hand, if we use the method 2 (decomposing intermediate products using plasma or light in a rotating reaction chamber without raising the substrate temperature), damage will remain on the surface of the deposited thin film, resulting in poor crystallinity and defect severity. etc.) will have a negative impact.

[Means for Solving the Problems] In order to solve the problems of the prior art, the method for forming an oxide film according to the present invention is based on the following general formula. The method is characterized in that an oxide film is deposited by introducing the expressed compound A or B, oxygen or a compound containing oxygen, and active species into a film formation space.

Compound A...M(OR)m Compound B...M' Rn However, M and M' are metal elements, R is an alkyl group, m is equal to or equal to the valence of M a positive integer multiple of integers, n is equal to the valence of M' or Each indicates a positive integer that is an integer multiple of .

[Description of action, etc.] Here, the active species has the role of causing a chemical interaction with the above compound A or B or/and the above oxygen or a compound containing oxygen to make them into a state where an oxide film can be formed. say something

Such active species are generated in an activation chamber different from the film forming chamber and introduced into the film forming space. The active species may not only be excited by electric discharge, light, energy such as light, or a combination thereof in the activation chamber, but also be generated by contact with or addition of a catalyst or the like.

Since such active species are introduced into the film forming space and an oxide film is formed mainly through a chemical process, the deposited film is not damaged unlike the plasma CVD method.

Furthermore, even if the combination of gas species produces an intermediate product that is difficult to decompose, the intermediate product can be decomposed at a low temperature. Therefore, the deposition rate can be significantly improved compared to the conventional CVD method, and in addition, the substrate temperature and humidity can be lowered during the formation of the deposited film.

Therefore, the deposition progresses smoothly, and a high-quality oxide film with good crystallinity and few electron capture levels can be obtained.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The accompanying drawings are schematic diagrams of manufacturing equipment used to carry out the present invention.

In the figure, a substrate holder +02 is arranged in a film forming chamber 101, and a substrate 103 is fixed on a temporary holder 102.Furthermore, the substrate holder 102 is provided with a heater for heating the substrate 103. Set to desired temperature.

Raw material gases A and B are introduced into the formation space in the film forming chamber 101 from the gas introduction pipe 104 and 05, and hydrogen radicals are introduced from the transport pipe 106.

Hydrogen radicals as active species are generated by applying activation energy to an active species generating substance (H2, D2, HD, etc.) introduced into the activation chamber 107. Examples of activation energy include thermal energy such as infrared heating, laser light, light energy equivalent to a mercury lamp, and electric energy using discharge by microwaves, RF, etc. In this example, microwave discharge is used. was used.

Although not shown, the doping gas is also introduced into the film forming space in the film forming chamber 101 through another gas introduction pipe.

The gas in the film forming chamber 101 is exhausted by the exhaust system through the control valve 108, and the pressure in the film forming chamber 101 can be controlled by the control valve 108.

Next, one embodiment of the method for forming an oxide film according to the present invention will be described using such a manufacturing apparatus.

First, a substrate 103 on which an oxide film is to be deposited is placed in the substrate holder 102.

Materials for the substrate 103 include, for example, glass, quartz, semiconductor, sapphire, and ceramic, but a glass substrate was used here because low-temperature film formation is possible in the present invention. Note that the oxide film has a thickness of 1α on the glass substrate fill.
It may be formed directly on the glass plate 1031, or may be formed on a semiconductor layer, metal electrode, etc. previously formed on the plate 1031.

Next, H2 gas as an active species generating substance is introduced into the activation chamber 107, and hydrogen radicals as active species are generated by microwave discharge. This hydrogen radical is transported to the transport pipe 10.
through B, and the original gases A and B as shown in the table below.
into the film forming chamber 101 through gas introduction pipes 104 and 105.
oxide film (AI 203 or Ta2
0 s).

Table 1 Table 2 In this way, hydrogen radicals are introduced into the film forming space as active species, and the source gas A and source gas B ('t
By using the T& film method in which C2Hs OH) is introduced into the film formation space, a high-quality oxide film with good crystallinity and few electron trapping levels in the film is formed at a low substrate temperature of an optimum temperature of 200 to 400°C. be able to. Therefore, if the above oxide film is used as an insulating film of an insulated gate transistor, the breakdown voltage, durability, and stability of electrical characteristics of the transistor can be improved.

[Effects of the Invention] As explained in detail above, the method for forming an oxide film according to the present invention is to combine a metal element, a compound of an alkoxy group or an alkyl group, oxygen or a compound containing oxygen, and an active species into a J & film formation space. 1 to form an oxide film by introducing
It has the following excellent effects.

(1) Since the oxide film can be formed at a low temperature of 200 to 400° C., a high quality oxide film can be obtained, and furthermore, glass can be used for the substrate, so cost reduction can be promoted. Furthermore, it is easy to maintain a uniform deposition surface temperature during formation, a large area of molten resin can be formed, and the t1 knee productivity is excellent.

(2) When forming oxide 1112, the deposition surface is cleaned by active species, so the adhesion of oxide 1 to the deposition surface is improved, and the deposition starts smoothly, resulting in a high-quality oxide film free of impurities. can be formed.

(3) Since active species are generated in an activation chamber separate from the film-forming chamber and introduced into the film-forming space, conventional plasma CVD
Compared to the method, the reaction process is simpler and the film forming conditions are more stable.

In addition, unlike the conventional MOCVD method, there is no need to decompose intermediate products using thermal energy, light, plasma, etc., so conditions for forming a high-quality oxide film with good crystallinity and low defect density can be easily created. Can be set to

[Brief explanation of drawings]

The accompanying drawings are schematic diagrams of manufacturing equipment used to carry out the invention. 101...Film forming chamber 102...Substrate holder 103@...substrate 104, 105-...Gas introduction pipe 1013 Action/transport pipe 107...Activation chamber

Claims (4)

[Claims] (1) An oxide film characterized in that the oxide film is deposited by introducing a compound A or B each represented by the following general formula, oxygen or a compound containing oxygen, and an active species into a film-forming space. How to form. Compound A...M(OR)m Compound B...M'Rn where M and M' are metal elements, R is an alkyl group, m is a positive integer equal to the valence of M or an integral multiple thereof, n represents a positive integer equal to the valence of M' or an integral multiple thereof. (2) The above oxygen-containing compound is an alcohol R-OH
(However, R is an alkyl group having 1 to 4 carbon atoms.) The method for forming an oxide film according to claim 1, wherein R is an alkyl group having 1 to 4 carbon atoms. (3) The method for forming an oxide film according to claim 1, wherein the active species is a hydrogen radical. (4) The method for forming an oxide film according to claim 1, wherein the oxide film is formed at a temperature of 400° C. or lower.