JPS6063372A - Manufacture of thin boron nitride film of high hardness - Google Patents

Abstract

PURPOSE:To manufacture a thin boron nitride film of high hardness contg. cubic boron nitride as the principal component on the surface of a substrate by properly regulating the atomic ratio between boron and nitrogen contained in an evaporating source and an ion seed and the quantity of energy for accelerating ions. CONSTITUTION:An evaporating source contg. boron is vapor-deposited on a substrate, and an accelerated ion seed is irradiated simultaneously with the vapor deposition to form a thin boron nitride film of high hardness on the substrate. The vapor deposition and the irradiation may be alternately carried out. At this time, the atomic ratio between boron and nitrogen (B/N) contained in the evaporating source and the ion seed is regulated to 0.5-3, and the quantity of energy for accelerating ions in the ion seed is regulated to 5-60KeV per one boron, nitrogen or inert gas atom contained in the ion seed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing a high-hardness boron nitride thin film, and more specifically to a method for producing a thin film of cubic densified boron nitride (c- The present invention relates to a method for manufacturing a high hardness boron nitride thin film mainly composed of 131N).

[Technical background of the invention and its problems]

Boron nitride (BN) is a type of ceramic and is one of the materials that has received a lot of attention in recent years.

This BN has three types of crystal structures: hexagonal thread (b-BN), hexagonal close-packed system (w-BN), and rhombic system (c-BN). Among these, C-B'N
It is unique in that it has the second highest hardness after LD diamond, is an electrical insulator, and has a high heating element 2n ratio and excellent wear resistance! I'm starving for sex.

However, this c-13N does not exist naturally;
In reality, under enemy pressure, high temperatures and pressures of tens of hundreds of degrees,
For example, it is produced using a catalyst such as magnesium. Although powder and granules can be produced using this method, it is extremely difficult to produce a film that covers the surface of the substrate.

For this reason, c-BN is currently used as abrasive grains in grindstones as it is, or as cutting tools made by sintering. However, c-BN was found on the surface of 19 bodies.
It is possible to form a thin film of d:, which means that c-B
By taking advantage of the useful properties of N, its uses can be dramatically expanded. 7. For example, the wear-resistant protective film of the protective tube, the surface of which is c −
These include cutting tools, heat sinks, and semiconductors exposed to BN.

On the other hand, thin film formation can be roughly divided into chemical vaporization methods and physical vaporization methods, and in particular, methods using ions are broadly classified into the following three methods.

First, the ion beam debosses the ionized atoms by accelerating them and then decelerating them to coat the surface of the substrate.
ion beam dcposition) method, cluster ion plating (Cluster ion plating), which accelerates ion beams and causes them to wander onto the substrate surface, depositing many atoms at once.
) method, an ion beam sputtering method in which atoms sputtered with an ionized and accelerated rare gas are deposited on the surface of a substrate.
g) method, fx tochi'; h le.

In these methods, the ion acceleration energy of the ion species is from several eV to several tens of eV at most, and rows of ions are not implanted into the substrate.

Therefore, although these methods are effective as film forming techniques, they are insufficient in terms of adhesion between the formed thin film and the substrate, and there is a problem that the thin film easily peels off from the substrate. .

The second method is to increase the ion acceleration energy of the ion species to several tens of
Ion implantation (Ionim
(plantation) method. In this method, ions are shot into the interior of the substrate, where they collide with the substrate's constituent atoms and form mulberry stabilizers with the substrate's constituent atoms to form an alloy or compound layer. (The body surface is revised 71
1, in this case, the formed thin film f11::, (Although the dense first property between the formed film and the substrate is improved, on the other hand, since the thin film is composed of the metastable P[, For example, when the temperature rises, reactions with atoms constituting the substrate progress, or the elements of the implanted ions themselves precipitate, resulting in changes in υ゛勺1.
It is necessary to implant i' ions, but in order to make the process possible in a short time, a highly efficient ion implantation device is essential.

The third method is ion mixing (I on mixin).
g) It is a law. In this method, (te) is applied to the surface of the substrate.
Steam'XgIff:! In this method, the ions are formed in advance and irradiated with ionized rare gas at an ion acceleration energy of g + 100 kcV. In this case, the deposited atoms recoil due to collision with the irradiated ions and enter the inside of the substrate. A new layer is then formed between the substrate and the deposited 115\jjJt atoms.

This method has the advantage that the relationship between the formed new layer and the substrate is good, the ion current is not so large, and the ion current does not need to be so large despite the high iU and 4C that consumes a large amount of energy. On the other hand, there is an unavoidable problem that it is extremely difficult to maintain a constant mixing ratio of each atom in a new layer formed of the vapor-deposited film-borrowing atoms and the substrate-bearing atoms. 5), it is difficult to form a layer with a constant composition.

For this reason, in the current Z-E”r, C-B
An effective method for forming a thin N film has not yet been published.

[Purpose of the invention]

The present invention is characterized in that the surface of the base is made of high hardness B mainly consisting of c-BN2.
The purpose of this invention is to provide a unique method for forming N-thin fS.

[Summary of the invention]

As a result of intensive research to achieve the above-mentioned object, the present inventors have determined that the atomic ratio of boron to nitrogen (I-I/N) contained in the evaporation and ions and the acceleration energy of the ions have been appropriately adjusted. The present invention was completed based on the discovery that a thin film mainly composed of c-BN can be produced on the surface of a substrate by adjusting the adjustment deviation.

In other words, in the actual J method, an evaporative gas containing boron is deposited on a substrate, and all accelerated ion species are irradiated simultaneously or alternately with the evaporator to deposit the vapor onto the substrate. The fish origin and the ion species (l) are highly hard boron nitride thin
A method for producing ions, wherein the atomic ratio CB/N of boron and nitrogen contained in the evaporation source and the ion species is 0°5 to 3, and the ion acceleration energy of the ion species is is 5 to 60 keV per atom of boron, nitrogen, or inert gas contained in the rice species.

In the method of the present invention, first, the substrate may be ceramics, superalloys, ceramics, or t;1. The material may be anything, such as gold 5 or an alloy of each fIj, and the material is not limited. However, if the substrate is an electrically insulating material, the θ properties of the S-k adhesion f formed there are different between the charged and uncharged locations, and the θ properties of the entire υ film are different. ! 1. lI
It is preferable for the 2-ζ body to be an electrical conductor, since it is easier to understand the variation in gender. However, T.I.
;.

Even if the material is a gas insulator, a thin film of an electrically conductive material may be formed on its surface by method 71.

Btus, BN, B2O3) are used.

The ion species are ion species that have a predetermined ion acceleration energy and act on the evaporation source containing B(il-) to
Any material that forms a thin film of BN may be used.

Specifically, nitrogen atom pentaton ion (N+); nitrogen molecule ion (N2+); ammonia ion (NL+), nitrogen compound ion, diborium ion (B+); volatile borohydride ion (like orchid) B2H6+)% boron compound ions such as boron nitride ions (BN'');
or an inert gas ion (for example, Ar+).

Such ion species are created by an apparatus described below, and are magnetically selected and supplied using a magnetron for mass spectrometry.

In the method of the present invention, a B-containing evaporation source is deposited on the substrate, or a deposited layer of an In-containing evaporation source is formed on the substrate.
J! , and then irradiate the upper H [dirty ion species 1
, the former glue contains B and the vaporized liquid 1-layer is the substrate surface VC7ζπi and then it and ijl L"+
ion irradiated to 1 (by the action of 1 ion):B
As soon as it becomes iC, the layer formation will start. In the latter case, the layer of the evaporation source that already exists as a evaporator is then affected by the irradiated ionic species. In this latter case, if the formation of the evaporation t7 layer of the B-containing evaporation source and the ion irradiation are performed alternately with anti-tp, the IN
The N layer will grow thicker.

In addition, if there is an evaporation source containing B and a B iN layer, the required ion acceleration energy is only 1", and it is possible to grow a c-BN thin film efficiently. , inert gas ions can also be used as the ionic species.

On the substrate surface, the evaporation source 12, ions 4'ili and V
The atomic ratio (B/N) of B and heto contained in C is (), 5 to 3
In addition, the ion acceleration energy of ion I4ii is controlled to be t3, which is contained in one layer of the ion.
Alternatively, it is necessary to control the voltage to 5 to 60 keV per atom of N or inert gas.

If B/N is smaller than 0.5, the crystal structure of the formed thin film will be amorphous or h-BN type and will not be CBN. Further, when the B/N becomes larger than 3, the formed thin film becomes amorphous. It is particularly preferable that the B/N is about 1 to 2.5.

When the ion acceleration energy of the ion species is less than 5 keV, the number of ion species implanted into the deposited film decreases and the spanter phenomenon becomes dominant, and when it exceeds 60 keV, the deposited layer on the substrate surface also deteriorates. Since the ion species are implanted fairly deeply, it becomes difficult to generate high-hardness BN mainly composed of c-BN in the deposited layer, and the deposition layer is not heated to too high a temperature so that the formation of h-BN becomes dominant. High hardness BN mainly composed of c-BN
becomes difficult to generate.

The method of the present invention is carried out as follows using the apparatus illustrated in the figures.

First, a gas to be ionized, for example, N2, is introduced into the ion source 2 via the leak pulp 1, where it is ionized, and then accelerated by the accelerator 3 to be given a predetermined ion acceleration energy. The ions are then introduced into the analysis magnet 4, where only the desired ion species are magnetically selected and supplied to the reaction chamber 5.

The reaction chamber 5 is heated to 10' by a vacuum pump (for example, a turbomolecular pump) 6. It is kept high It empty below orr. The substrate 7 has a hard surface Jz on the substrate holder 8, and is irradiated with the above-mentioned ions a=t. During irradiation, the ion species are passed through a converging lens 9 in order to uniformly irradiate the substrate with the ion species.

10 is a vapor deposition device 11 arranged under the base 7.

As a heating method for the device, an appropriate method such as electron beam heating or laser beam heating is used. The evaporator with B is housed in this. The evaporation rate n and the evaporation rate of the evaporation source containing B may be measured by a vibrating film thickness meter 11 using, for example, a quartz plate, which is disposed beside the substrate holder 8.

In addition, the number of atoms of the ion species, that is, the ion current is calculated as follows:
It can be measured accurately by

In such an apparatus, the substrate 7 is placed in a predetermined position, the interior of the reaction chamber 5 is kept at a predetermined degree of vacuum, and the vapor deposition device 10 is operated to deposit a predetermined amount of an evaporation source containing B onto the substrate 7.
By irradiating it with a predetermined ion acceleration energy, a thin film with high hardness B mainly composed of c-UN is formed on the surface of the substrate.

At this time, since the evaporation source and ion species containing Bfa- are evaporated or irradiated only from one direction of the substrate, the entire surface of the substrate tg-c-B has a high hardness B mainly composed of N.
Nii! ! , to form a film, rotate this substrate,
It is sufficient to give luck vJJ such as swinging.

[Embodiments of the invention]

Examples 1 to 3 High purity iNz gas was introduced into the PIG type ion chamber 2 from the IJ-Kvalp 1 using the apparatus shown in the figure.

The generated ions are given various types of acceleration energy by an accelerator 3. This ion beam was subjected to quality analysis using an analysis magnet 4, and only N2 was magnetically selected.

On the other hand, a tantalum plate was used as the base, and the inside of the reaction chamber 5 was heated to a vacuum U of I
I/C was maintained.

Next, Kameko beam evaporation equipment 1 containing gold JQ3B is installed.
0 was activated to cause the metal B to evaporate, and at the same time as the r'12+ ions were irradiated, nX was circulated to the surface of the tantalum plate 7.

Steaming method T ii'+ of B, steaming, 'j frog degree, vibration type H', 1ljl with 5 thickness and J1, and the number of N2 ions is -
61", 1ltll was determined by 1 piece of product 31 cuts, and the B/N was calculated.

The ion acceleration energy/l energy of N2+ ions was also changed, and the 8 vaporization fan was changed, and the unity of 'Aq deformation number formation/c0 was collectively shown in the table.

As is clear from the crystallization, the thin film obtained by the method of the present invention has an electrical resistance of 1 J of IX10 to 2XiO! of,
Up with C'fi, the crystal value is c -13N 7 (!
I is the main character, however, the film forming strip f4= of the present invention is mainly c B N T (tl (Main 1!)
It was found that t, teh -13N and t1 amorphous B were constructed.

Example 4 A thin film was formed in the same manner as in Example I, except that the substrate was a WC-Co-based cemented carbide and the ion acceleration energy of N2+ ions was 40 keV. '/N was 2.5. Evaporation time was 120 minutes.

A thin film with a thickness of about 20,000 Å was formed. When this thin film was subjected to X-ray diffraction analysis, a c-BN diffraction line was observed.

Further, when a micro Vickers hardness load of 5 g was measured, the hardness of the substrate was 200 QHv, but the hardness of the film was 3890 IV).

Example 5 Using the apparatus shown in the figure, an electron beam was used to irradiate h-IJN@ with Ar ions with an acceleration energy of 601 ceV and simultaneously evaporate the AlzOa-TiC-based alumina ceramic substrate for 60 minutes. l-'/N is 1.0.

A thin film with a thickness of about 5000 OA was formed. When this thin film was subjected to X-ray diffraction analysis, a c-BN diffraction line was observed.

"t, ta, micro Vickers hard load i5 g)
The hardness of the B substrate was 2050 iv, and the hardness from the top of the film was 4130 Hv.

Example 6 Using the apparatus shown in the figure, metal B was evaporated with an acceleration energy of 4 Qke onto a silicon wafer substrate at a VC of 120 minutes at the same time as the p-atw ions were irradiated. L
3/N was set to 3.0.

About 20,000A of pJl! is formed/this. When X-ray diffraction analysis was performed on this thin film, c -B N
A diffraction line was observed.

Further, when the micro-Vickers hardness was measured under a load of 5g)k, the hardness of the substrate was 100 o Hv, but on the film it was 405Q)iv.

〔Effect of the invention〕

According to the method of the present invention, the surface ω1&′(a, i′ l
i, l C-13N as the main component -6 hardness IJN Since it intersects the Sung Dynasty at the interface, it is of great benefit from an engineering point of view to have excellent VC.

This is an explanatory diagram showing an example of a suitable apparatus for carrying out this method.

J...Leak pulp, 2...Imen u51, :3...
・External device.

4... Analysis magnetoft, 5... Anti tail, b:,'rm
6... True thrust pump, 7... Substrate, 8... Substrate holder, 9... Imen convergence lens 510... kζ2α device N, 11... Vibration type 1 conversion thickness h1 using quartz plate .12・
・Electrode for repelling secondary electrons, J3...Calculate the current value B1゜

Claims (1)

[Scope of Claims] 1. The evaporation source is deposited on the substrate by vapor depositing a spontaneous vapor containing boron, and simultaneously or alternately irradiating the VC-accelerated ionic species with the vapor deposition. and the ionic species yc to produce high hardness boron nitride thin 11.3, the atomic ratio (11/N) of boron and nitrogen contained in the evaporated content and the ionic species is O05 to 3. 5~
60 keV. 2. The boron-containing evaporation source is selected from gold, a boron compound, or a mutual solid solution of these. A method for producing a high hardness boron nitride thin film according to claim 1, wherein the ion species is at least one of nitrogen atom ions, nitrogen molecular ions, nitrogen compound ions, boron ions, and boron compound ions. or inert gas ions. 4. The substrate is made of cemented carbide, cermet, ceramics, or various gold metals or alloys. A method for producing a high (iJi) boron nitride thin film according to claim 1.