JPH0251407A - Production of thin aluminum nitride film - Google Patents

Abstract

PURPOSE:To obtain a thin AlN film having high purity by coating a substrate with a soln. contg. an org. compd. of Al and an org. compd. of a rare earth element and by calcining the coated substrate in a nitrogen atmosphere. CONSTITUTION:An org. compd. of Al such as aluminum ethoxide and an org. compd. of at least one kind of rare earth element such as Y(OC3H7)3 are dissolved in an org. solvent. A substrate is coated with the resulting soln. and this coated substrate is calcined at 1,400-1,600 deg.C in a nitrogen atmosphere to form a thin AlN film having <=10mum thickness and high heat conductivity on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method of manufacturing an aluminum nitride thin film, particularly to an IC
The present invention relates to a method for producing a highly thermally conductive aluminum nitride thin film useful as a substrate for other semiconductor devices, optical devices, and electronic circuits.

(Conventional technology) Recently, as semiconductor devices become more highly integrated and faster, and the density of device packaging increases, the heat dissipation of their packages and heat sinks has become a major issue, and the generally used aluminum oxide substrates have not been able to solve this problem. It's becoming impossible. For this reason, highly thermally conductive heliaria and silicon carbide have been used in some cases, but due to problems such as economic efficiency and toxicity, there is a need for high thermally conductive and highly insulating materials to replace them. It has become to.

For this reason, aluminum nitride (hereinafter referred to as A12N), which has a thermal conductivity comparable to Berilya, was developed.
Some of them have been put into practical use. This AQN is usually produced by adding yttrium oxide and carbon to alumina, firing the mixed powder in a nitrogen atmosphere to produce AaN powder, pulverizing this ARN powder into a fine powder, and then adding an organic binder. The resulting slurry is made into a sheet by a doctor blade method, etc., and the sheet is heated to 1800℃.
It is manufactured using a method of firing before and after.

(Problems to be Solved by the Invention) However, the method described above requires a large number of steps to form the A&N film, and furthermore, whether it is dry grinding or wet grinding, the powder is pulverized by mechanical grinding. It is undeniable that the grain size is large, and the thickness of the AgN film inevitably increases, making it impossible to manufacture a thin film of 108 m or less.

On the other hand, it is conceivable to apply known thin film techniques such as sputtering and vapor deposition methods to the production of A(!N thin films.
These methods require expensive equipment for thin film formation;
Moreover, the production efficiency is low and the loss of raw materials is large, so it is not economically satisfactory.

Therefore, the technical object of the present invention is to enable efficient production of a highly thermally conductive AaN thin film with a thickness of <10 μm or less using simple operations.

(Means for Solving the Problems) As a means for solving the above problems, the present invention applies a solution containing an organic compound of aluminum and an organic compound of at least one rare earth element onto a substrate, and forms the coating film. The present invention provides a method for producing an aluminum nitride thin film, which is characterized by firing at a temperature of 1400 to 1600°C in a nitrogen atmosphere.

In the present invention, if necessary, a solution of an organic compound of an alkaline earth metal may be added to the solution, and aluminum nitride can be produced using the solution.

The organic compounds of aluminum used in the present invention include aluminum alkoxides such as aluminum ethoxide, aluminum isoproboquine, and aluminum ethoxide; aluminum fatty acid salts, resinates,
Aluminum soaps such as naphthenates: aluminum acetylacetonado; and aminoalkoxides can be used, but in either case, organic compounds with a relatively small number of carbon atoms, e.g. Preference is given to using compounds. This is because when the coating film is fired, the organic compounds of aluminum decompose and generate carbon, so as the number of carbon atoms in the organic compound increases, the amount of carbon m precipitated in the AaN thin film increases. This is because it takes a long time to bake in the air to remove the particles.

The amino alkoxide includes, for example, dipropoxy
(2-Hydroxyethylamino)ethquino)aluminum [AC(OC3I47)2[N(C2H,OH:L
-C21r, 0]]? ; Contains.

Further, as organic compounds of rare earth elements and alkaline earth metals, alkoxides, soaps, acedelacetonates, aminoalkoxides, etc. of these metals may be used, similar to the organic compounds of aluminum.

In addition, as the material of the substrate, when baking the coating film, Ai!
Any material can be used as long as it does not react with or melt the N constituent elements.
Examples include alumina and zirconia.

(For use) In the method of the present invention, at least Y of alumina l,
A solution containing an l-organic compound and a rare-earth element compound is applied onto a substrate by an appropriate method such as dipping or spin coating, and the coating film is coated in a nitrogen atmosphere.
When fired at a predetermined temperature, the Moekishiki compound decomposes and reacts directly with aluminum or nitrogen, and at the same time sinters due to the action of rare earth elements and alkaline earth metals that act as sintering aids, forming a sintered material on the substrate. An AσN thin film is formed.

(Example I) A (OC3l-17) 298, 1 part by weight and Y(OC3l-17)298, 1 part by weight
3H? ) 319 parts by weight and 500 parts by weight of isopropyl alcohol.
Prepare a solution by dissolving in m&. This solution was applied onto an alumina substrate by a dipping method to form a coating film with a desired thickness of J7, and then this was heated to a temperature of 1400 to
When fired at 1600°C, an Al2N thin film was obtained.

When the thermal conductivity of this AQN thin film was measured, it was found to be 0.30.
cal/cm-sec-'C.

(Example 2) AQ(OC3H?)2[N (C2H401-V)2・
C, f-1, 0]983 parts by weight, Y(OC31(7)
2 "N(C7[1-0[-1)2・C,H40]1,7
A solution for forming a coating film is prepared by dissolving parts by weight in 500 mg of Medil Cellosolve.

This solution was applied onto an alumina substrate by spin coating to form a coating film of the desired thickness, and then baked at 1400 to 1600°C in a nitrogen atmosphere.
An AQN thin film was obtained.

When the thermal conductivity of this AσN thin film was measured, it was 0.3
cal/cm-sec·°C.

(Example 3) Aρ(OCaH7), [N(C2H40H)2 ・
A solution for forming a coating film is prepared by dissolving 97.3 parts by weight of C2H,O] and 2.7 parts by weight of yttrium octylate in 500 m& of methyl cellosolve. This solution was applied onto an alumina substrate by spin coating to form a coating film of the desired thickness, and then coated at 140° C. in a nitrogen atmosphere.
When fired at 0 to 1600°C, an A(N thin film was obtained).

When the thermal conductivity of this AQN thin film was measured, it was found to be 0,3
cal/cm-sec ·'C.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, A[N is directly generated by firing the coating film, so A[N is synthesized as a surface step as in the conventional method. It is not necessary and can be produced with a simple operation.Also, since the crystal grains are extremely small at around 0.1 μm, it is possible to change the concentration of the raw material solution for film formation or to reduce the number of repetitions of film formation and firing. With appropriate settings, even ultra-thin films of 1 μm can be manufactured, and since no expensive equipment is required, it can be manufactured at low cost and can be mass-produced.

Furthermore, compared to conventional methods, the firing temperature is lower and the number of steps is smaller, which reduces costs, and there are no impurities mixed in during the manufacturing process, making it possible to manufacture high-purity ACN thin films. is obtained.

Claims (1)

[Claims] (1) Aluminum nitride, characterized in that a solution containing an organic compound of aluminum and at least one organic compound of a rare earth element is applied onto a substrate, and the resulting coating film is fired at a temperature of 1400 to 1600°C in a nitrogen atmosphere. Method for manufacturing thin films.