JPS60145994A - Formation of diamond-like carbon film on substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for forming a die-shaped carbon coating on a substrate.

Slowly accelerated carbon ions or neutral atoms can be used to form a hard coating on a substrate, and such carbon coatings are similar in properties to graphite and diamond, so they are ) carbon or diamond-like carbon.

Although the exact structure of diamond-like carbon is not known, it is known that diamond is not extremely hard, but it is harder than hardened steel. In addition, Dai-X7 diamond-like carbon has good insulation properties and is chemically inert.
It is also known to have a refractive index similar to that of diamond. However, the properties of diamond-like carbon are dependent on deposition conditions such as ion energy, substrate humidity, and the number and types of other ions that impinge on the coating.

One use of such coatings is as a protective coating for optical lenses due to their high hardness.Another use is in the medical field (C) as a device for insertion into the human body. . Since the carbon coating applied to the IJ method of the present invention is chemically inert and has an insulation value of ↑+1, medical instruments coated with such a coating have an anticoagulation rate of 1/1 (47). The line '-') h does not substantially result in the formation of II encine. Additionally, the method of the present invention can be used to prevent the growth of diamonds in the primary bitaxy. (1978'L19th October 19th issue ``Nature v-J (Nature) Magazine No. 27!
See Volume 634-635. ) There are a number of techniques that have been used to avoid the growth of diamond-like films. For example, in 1971 'i+■++ Applied Physics magazine (J, Appl, Phy
s, Volume 42, page 2953 discloses a method for depositing carbon in the form of carbon using a carbon-argon beam emitted from an ion whale. and the graphite cathode)) a Rougone glow discharge occurs. The cathode is sputtered by a discharge and some of the sputtered lJ carbon 1jii +' is ionized in fliE. However, with this method, 1! There is a vacancy in which the concentration of carbon ions in the i-den is very low. Therefore, another method is to crack the hydrocarbon gas in either a DC or radio frequency (RF) glow discharge. The equipment for the latter method is similar to that used in RF sputtering equipment. The substrate is placed on an electrode connected to the central crossbody of the coaxial cord through a suitable circuit, and is negatively biased, m depending on the input voltage.

Coatings produced using these methods often contain undesirable suspended graphite, which reduces resistance and light transmission, and in high concentrations can increase hardness. It is thought that as the thickness of the 10 coating increases to 1 (Q), the ratio of graphite increases due to the formation of graphite nucleation centers.

Furthermore, the diamond-like carbon coating produced by many conventional techniques contains a large amount of hydrogen (approximately 30% in atomic percentage).
It is included. This causes mechanical compressive stress and absorption of infrared rays by the coating due to C-1-1 bonds. As a result, the thickness of coatings according to the prior art could not exceed approximately 1 meter.

In accordance with the above conventional technology, chemical compounds other than hydrocarbon gas 2;'.

Active gas such as W in 02) prevents peeling of the ink! It has been shown that there is a strict limit η. In contrast, the ions of these gases remove undesired graphite from the substrate and provide good die-like carbon formation. I discovered that.

Since the gas for removing graphite also removes a certain amount of syndoid carbon, the gas 1) Ll must not be in excess. Contrary to the general suggestion that the presence of such gases must be avoided, and if they do exist, they must be minute.
The applicant proposes to improve this J, 4j gas [, L coating, and to reduce the f posit velocity to an excessively high value. I found out.

Therefore, an object of the present invention is to provide a method for forming a diamond-like carbon film on a substrate using graphite, hydrogen, and hydrogen. Another purpose of this invention is 1.
The purpose of the present invention is to provide a coating of tie-A7 carbon, which can have a thickness exceeding micrometers.

The present invention is a method of forming a diamond-like carbon film on a substrate using a carbon ion source, and carbon ions form a film on a substrate such as an optical lens. The substrate is also exposed to ions to selectively remove undesirable forms of carbon, including graphitic carbon, from the substrate coating by chemical sputtering. The film obtained in this manner has the feature of extremely low graphite and hydrogen content, and it is possible to form a stable film with a thickness of 1 micrometer or more.

Carbon ions are generated by glow discharges in hydrocarbon gases, and often by radio frequency discharges.

Another method is to use an ion source using hydrocarbon gas.

The energy of the incident ions in the radio frequency discharge (which varies with the instantaneous value of the radio frequency voltage, the average value of which varies with the momentary value of the radio frequency voltage) depends on the J value. -The ion source generates a nearly uniform energy.

The generation of carbon ions occurs through the dissociation of hydrocarbon scum and at least one gas that selectively removes graphite from the substrate coating 111 by chemical sputtering. In general, the latter sludge is carbon, and sludge containing only hydrogen (l[], excluding carbon-hydrocarbon scum, carbon 1M element, chlorine, fluorine, Selected from scum containing elements. Preferred scum for graphite removal is selected from carbon dioxide, diluted carbon dioxide, -carbon oxide, tetrafluoride carbon fiber, and tetrafluorinated carbon 2 (-8). Also contains carbonaceous material inside the ion source and to the electrodes.
There is an advantage in minimizing the fL product.

Although any type of hydrocarbon sludge can be used in the method of the invention, the ratio of carbon to water sludge may be lowered to reduce the concentration of hydrogen present in the discharge. Preferably, a gas is used. J, octopus J, u<1-:;? Preferably, the hydrogen chloride gas contains at least 40% carbon by atomic percentage. The most preferred residues L, -1j', are cetylene and benzene.

If an oxygen-containing gas (for example, 02.CO2 or C○) is selected as the gas for selectively removing graphite carbon, hydrogen gas or a suitable isotope thereof may be used instead of some of the oxygen-containing gas. (e.g. deuterium). If oxygen is present at a wavelength of 9.
This is based on the fact that infrared rays around 5 micrometers are absorbed.

The amount of hydrogen to be replaced by the oxygen-containing gas is determined to be no more than about 6-8% to limit the absorption of infrared radiation by 1 micrometer at a wavelength of about 9.5 micrometers. .

As a result, according to the method of the invention, water lrj during the discharge
Oi can be controlled to 1/r. This reduces hydrogen enrichment in the coating and improves the mechanical properties of the coating. Furthermore, in the present invention, an inert gas such as argon can be used to stabilize the discharge if necessary.

In the present invention, specific 8uf I in J3 and Devodine 1-
jJ-i, 1 is said to be about 100 to 200°C, so it is ideal to remove graphite.
``Oneness is improved.

Next, one embodiment of the present invention will be described with reference to the drawings. The following explanation relates to the object d3 and effects of the present invention. However, the embodiment shown in Drawing J3 has been mentioned for the purpose of explanation in A-A. In Figure 33, the ion source 10 cannot be newly limited in any way.
A water-cooled graphite cathode 12 is shown on the right. A hydrocarbon gas (eg, allebourene gas) and a gas that selectively removes graphite by chemical sputtering (eg, carbon dioxide) enter the interior of the ion source 10 through an inlet 16. When nortylene gas and carbon dioxide are used, the infection caused by these gases is similar to that caused by air.
Assuming that thermal lightning versus vacuum pressure is measured, the pressure ratio of these gases is approximately 3 to 1:1 at 0.5"-5.0:1'F. I'm so jealous. This jL power is h!!
Measured in the discharge chamber before the start of the discharge. During discharge, the pressure is approximately 5
It will be about 0% higher. Particularly good results were obtained when a ratio of 1:1 was adopted. Early stages of deposit (
(up to 500 angstroms) (for better layering, a higher concentration of hydrocarbon gas is utilized, then the concentration of hydrocarbon gas is reduced to 1:1).

A grounded anode 14 is disposed at the end of the ion source facing the cathode 12. The anode 14 is made of a stainless steel plate and is provided in its central part with a hole, typically about 2R11+ in diameter, through which the plasma beam can pass into the depot 1-chi1 fan 20. The side of the anode 14 facing the cathode 12 is partially covered with an insulating material 18 to increase the density of the plasma in the anode 140 region.

The voltage between anode 14 and cathode 12 is typically about 500-800 milliamps, with an operating current of about 60-100 milliamps.
Pol 1 to preferably about 600 volts.

The plasma beam enters the deposition chamber 20.

Grid 22 is located approximately 3 mm from anode 14 and has a frontage of 7 nodes. The grid 22 is at a potential approximately 50-100 pol 1 higher than the anode 1/I, and the plasma beam passes through the grid 22 and impinges on the substrate 2G.

To increase the path length of the electrons in the plasma beam, a magnetic coil 28 is placed around the ion source that creates an axial magnetic field of several hundred Gauss, which allows the present invention to be used even at low gas concentrations within the ion source. It is now possible to implement this method. This effect can be further enhanced by utilizing a cylindrical anode of 11 as well as a cylindrical wall.

The carbon film formed on the base body 26 has excellent insulation properties. For this reason, a negative bias mesh 24 made of stainless steel wires arranged in parallel in one direction is provided immediately before the base body 26. The f1 bias voltage to the ground side is approximately -1
500 volts, the coating on the substrate 26 is the grid 22
A negative bias condition of approximately −200 pol 1− will occur. This is because when ions of the plasma beam collide with the mesh 24, primary electrons are emitted from the MEC 1.24 and the ions are removed from the plasma beam. When the mesh 24 is in a floating state, the base 26 is opposed to the grid 12.
The voltage will be approximately -20 volts. Base voltage is grid 2
This can be further enhanced by forming a weak magnetic field perpendicular to the plasma beam between the second mesh 24 and removing electrons from the plasma beam. If such a magnetic field exists and the voltage on the mesh 24 with respect to the ground side is approximately -150 volts, the substrate voltage will be lυ with respect to the grid voltage.
It is about 1 volt lower than (). Applicants believe that the average ion energy is approximately equal to the potential difference between grid 22 and substrate 26.

To ensure uniform coating formation, the substrate 26 is continuously moved in a sawtooth direction perpendicular to the wires of the mesh 24 and the plasma beam. Electron density in the plasma beam can also be increased by conventional methods such as placing a negatively biased thermionic emitter in the plasma beam.

Enters from the frontage of the anode 14/V residual gas IJυ1
The deposit is discharged from the deposit button 20 via the outlet connection 30. The pressure in the chamber 20 to the deposit 1 is approximately 10
The thermal pressure of ions equal to torr of nitrogen is 1iQ.

A customary cleaning product made by ion sputtering is made into 1'
; After that, add alebrene and carbonated charcoal in a ratio of 3:1.9
It is preferable to first perform a discharge using θf, where the total pressure of these substrates is approximately 0.1 to 0.2 tOrl· with air equal to the thermocouple vacuum 1 reading before discharge. At such an early stage, about -1 to the ground side! A potential difference of IOO volts is applied to the mesh 24, resulting in a potential difference of 1200 volts to the substrate 26 with respect to the grid 22. It is maintained for about 3 minutes until reaching the micrometer.

Next, alebrene Q'H is measured as above C・approximately 1=1
The potential of Metsun J24 increases by about -100 to -1000 pol to the ground side, and the coating has a negative bias of about -1 to -60 pol to the grid 22. join. In this second working phase, the substrate 2
6 is maintained at a humidity of about 100-150°C and the coating is deposited onto the substrate at a rate of about 1 micrometer per hour.

The higher the ion energy, the harder the film becomes, and conversely, the lower the ion energy, the more absorbed! [is weakened. By utilizing the methods described above, very similar ion energies can be used without the formation of hydrocarbon polymer coatings. Furthermore, the higher the initial energy, the better the adhesion of the film.

As a result of testing various coatings, the following JKona 1)■
gender was measured.

Thickness: 2 micrometers or less Oxygen content m; Approximately 2 to 25% (atomic percent*) hydrogen content m
: Approx. 5% (atomic percentage) Carbon goldstone n : Remaining tri : 1200Ky/mm' at 100 load (
Severe abrasion test: No effect, American mill standard No. M - C-675C) 2 Electrical resistance: Approximately 1 Q ollm CIn refractive index: 07.7 when measured in infrared rays: I ”Make thick comb
23 Approximately 2.0 The visible spectrum is between black and brown.
The O,'1 absorption was minute, and no C-1-1 bond was observed.

Hydrogen fluoride, sulfuric acid: None and reaction with nitric acid Reaction with organic solvent: None Up to 500°C in vacuum: No effect Heating The above explanation uses a single ion source device! (However, the invention may be practiced in other embodiments.

For example, using two ion source devices (.

A first ion source is used for a hydrocarbon gas and an inert gas, such as argon, to stabilize the discharge, and a second ion source is used for these selected sources. It can be used to selectively remove graphite and other undesirable forms of carbon by chemical sputtering.

Note that these ion sources are arranged at an angle such that the plasma beam that will be passed therethrough comes into contact with the surface of the substrate.

In another embodiment, the first ion source is a hydrocarbon gas 11i, an inert gas such as argon to stabilize the voltage, and the second ion source is These selected gases can be used to selectively remove graphite and other undesirable forms of carbon by chemical sputtering, and the ion source can be used to selectively remove graphite and other undesirable forms of carbon by chemical sputtering. There is a method of arranging them at an angle so that they touch each other.

In any of the embodiments employing these two ion source devices, if one ion source is in a negative bias state with respect to the other and the substrate is fixed in position, the mesh can be omitted. be able to.

[Brief explanation of the drawing]

The figure is a schematic cross-sectional view of an apparatus for forming a carbon film in the shape of a Gui X7L, showing an embodiment of the present invention. 10... Ion source 12... Cathode 14... Anode 16... Inlet 18... Insulation 20
・・・Debojino 1-bu 1 Humba 22... Grid 24... Messhi 12G... Base
28...Magnetic coil 30...1x for discharge Applicant: Techni A, SuNage & Debe [Tsubmen 1-・) 77 Undation Limited Representative, Patent Attorney Oka [U.

Claims (1)

[Scope of Claims] (1) An ion source of carbon ions is disposed, and the carbon ions are directed toward the substrate under conditions that form a diamond-like carbon film, and the diamond-like carbon contained in the film is disposing a second ion source for ions of a second gas other than hydrocarbons sufficient to selectively remove other forms of carbon by chemical sputtering; characterized in that said second gas is pumped onto said substrate under said strip '1' in a manner suitable to promote the selective removal by chemical sputtering of carbon in forms other than said diamond-like carbon. A method for forming a diamond-like carbon film on a substrate. (2) 1! that the carbon ions and the ions of the second gas are simultaneously pushed into the substrate with the same number; i
A yno method for forming a diamond-like carbon film on a substrate according to claim 1, where m is a diamond-like carbon film. (3) 1-II indicates that the carbon in a form other than diamond-like carbon is graphite.
A 7j method for forming a diamond-like carbon film on the substrate described in Section 7. (4) The ions of the second gas are carbon λ, oxygen, I! ll
The substrate according to claim 1 of the present invention is ionized with at least one gas other than hydrocarbon containing at least one element selected from the group consisting of hydrogen, fluorine, and hydrogen. A method for forming a carbon film. (5) The second gas is selected from among carbon dioxide, oxygen, carbon oxide, carbon tetrachloride, and carbon tetrafluoride. +Yr A method for forming a diamond-like carbon film on a λ1 body according to claim 4. (6) A small talk gas is used to stabilize the discharge of the ions of the carbon ions J3 and the second gas.Claim 1:L !
Forming a diamond-like carbon film on the base of the sword. (7) A method for forming a diamond-like carbon film on a substrate according to claim 6, wherein the inert gas is argon. (8) For forming a diamond-like carbon film on a substrate according to claim 1, wherein at least one type of hydrocarbon gas is used as the ion source of the carbon ions. the method of. (9) the hydrocarbon gas has an atomic percentage of at least 40
% of carbon. A method for forming a diamond-like carbon coating on a substrate according to claim 8. (10) A method for forming a diamond-like carbon film on a substrate according to claim 9, wherein the hydrocarbon gas is selected from acetylene and benzene. (11) The ions of the second gas are ions of oxygen gas, and the ions of the second gas are approximately 9.
Adding an amount of hydrogen-containing gas to about 6 to 8% or less to prevent absorption of infrared rays with a wavelength of 5 micrometers is 4? jCharacter'Ml i+'l Claim f
A method for forming a diamond-like carbon coating on the 14 bodies described in IB No. 41n. (12) A method for forming a diamond-like carbon film on a substrate according to claim 11, wherein the hydrogen-containing gas is selected from hydrogen gas and deuterium. (13) Alebren is added to the front carbon ion source, and the second
Carbon dioxide is used as the ion source for each of the gases, and the ratio of acetylene and carbon dioxide k'+ (is approximately 05 to 50 as measured by a thermocouple of 1!81 in the air before the start of discharge. : 1!I method 1 for forming a carbon film on a substrate according to claim 1, (14) the ratio of acetylene to carbon dioxide; is at the initial stage of Debojitsu 1 ~ [Ma 3:1
9'. A method for forming a tie-like carbon covering on a substrate according to claim 13, wherein the ratio of the ratio of the ratio of the ratio of the ratio to the ratio of the ratio of the ratio of the ratio to the ratio of the ratio of the ratio of the ratio to the ratio of the ratio of the ratio of the ratio to the ratio of the ratio of the ratio of the ratio to the ratio of the ratio of the ratio of the ratio of the number of (a) to 1 to 1 to approximately 1:1 is set, to the ratio of 1:1 to 1:1. (15) A method for forming a carbon-like carbon film on the substrate according to claim 1, characterized in that the substrate is heated to about 100 to 200°C. (16) A diamond-like carbon coating is applied to the substrate according to claim 1, wherein the carbon ions and the ions of the second gas are generated by a similar radio frequency discharge to the substrate. A method for forming. (17) The substrate is in contact with a radio frequency electrode. A method for forming a diamond-like carbon film on a substrate according to claim 1, characterized in that carbon ions and ions of the second gas are generated from a single ion source. (19) The carbon ions and the second gas ions are generated from separate ion sources to form first and second plasmas or ion beams, and these ion beams are directed toward the substrate. Make contact with the surface of the surface!
) Scope of Revision u1 Required J/J method for forming a diamond-like carbon film on one body described in item 18. (20) Ions of the second gas, such as the carbon ions, are generated from separate ion sources and form an ion beam with the first, second and second plasmas; A method for forming a carbon film in the form of a die A71 on a substrate according to claim 18, characterized in that the ion beam contacts the front side of the substrate. A special product characterized in that one of the ion beams is in a negative bias state with respect to the other ion beam. Claim 191nbL/<i';2
1) Method for forming a die 17 (-1:-shaped carbon coating) on the substrate according to any one of Items 0 to 1. (22) removing the electron portion of the Bushism Mahi 11 by generating a plasma beam containing the carbon ions and electrons, and applying a magnetic field with a direct magnetic field of λ to the plasma beam; j sign and sword 1, "11." 1
A method for forming a Gui