The way to create a diamond-like carbon films on a substrate and a product with such a film on a substrate

 

The invention can be used to obtain high-quality diamond-like carbon films on partially bounded surfaces or surfaces with a high degree of uncouthness by chemical vapour deposition. In an environment of gaseous hydrocarbon generate plasma and carry out impact on the substrate. Use the plasma with electron density not exceeding 5x10¹⁰on 1 cm³and the shell thickness is less than 2 mm under the condition of high current density of ions and ion bombardment managed low energy. The ion current density is chosen by more than 20 a/m²and the bias voltage on the substrate in the range from 100 to 1000 C. the Product contains a substrate with an angular surface and a film of diamond-like carbon with a hardness higher than 20 GPA. This film has no discernible grain diameter 3x10^-8mor more when viewed from the 50,000-fold magnification using a scanning microscope with cold emission. The advantages of the invention lie in the creation of diamond-like films with a dense film structure and high hardness is obtained at a high deposition rate. 2 C. and 17 C.p. f-crystals, 17 tab., 5 table.

Isobama deposition of parasol phase of high-quality diamond-like carbon films on partially restricted surfaces or surfaces with a high degree of uncouthness.

Solid, thin films of hydrogenated amorphous carbon (a-C:H), also called diamond-like carbon films (FMA), you can create on metal surfaces by plasmodiophoromycota chemical vapour deposition (PSHOP). In the known processes PSHOP used to create these films, creates a low density of ions (~10¹⁶m^-3). In the known processes, the plasma is generated at a greater thickness of the shell (410^-3of-1.010^-2m), which does not repeat small uneven surface of the substrate (~ 10^-4m). Therefore, ions are accelerated in the known processes in the direction transverse to the shell, get acceleration directed at right angles to the macroscopic surface of the substrate. In such conditions, the angular surface of the substrate, for example, edge razor blades (which are usually collected in a stack, and the gaps between the ends of the blades are 100m) are the interaction of oblique flow of reactive ions. These conditions presumably cause samosatene some precipitating substances, resulting in a columnar formations in the films and osenia on the surface of the substrate. Deposition in low surface mobility of adatoms, for example, at low temperatures of the substrate (T/T_{the Plava}<0,1) and low flux density of ions presumably leads to an increase of the columnar structures in the films a-C:H deposited on surfaces with a high degree of uncouthness. Such columnar formations lead to the presence in the films of voids and grain boundaries, causing the mechanical strength of the film decreases. Columnar formations are observed at PSHOP films a-C:H, carried out in a plasma reactor low density with RF capacitive coupling, on substrates with a high degree of uncouthness, for example, razor blades.

Another disadvantage of this approach is the low deposition rate. At low electron density in the well-known approaches is not effective dissociation of the supplied gaseous hydrocarbon. Therefore, the number of molecular fragments precursors in plasma low density small. For example, for PSHOP a-C:h in the capacitive coupling plasma deposition rate is typically in the order of 3.310^-10m/S. Low deposition rate have a negative impact on processing performance and CH is th vapor deposition of films of a-C:H on the surface of the substrate, for example, on the surface of the metal substrate. In a broad sense, the invention includes chemical vapor deposition of films of a-C:H in terms of providing conformal shell, high density of the ion flux and the ion bombardment managed low energy. The invention includes the impact on the substrate environment of gaseous hydrocarbon and generating plasma in the medium with electron density greater than about 510¹⁰on cm³and with the shell thickness, less approximately 2 mm, under conditions of high flux density of ions and ion bombardment managed low energy.

Conditions correspond to the invention, which provide a conformal shell, high density of the ion flux and the ion bombardment managed low energy, include the ion current density (J_i) greater than about 20 a/m²and the bias voltage (-V_offsetin the range from about 100 to about 1000 C. Such conditions enable the formation of hard, dense diamond-like carbon films (a-C:H) on the needle-sharp points, edges, razor blades, cutting edges, and the edges and other sharp, angular or sharp surfaces, partially restricted or ball in composing the rod, and so on) in the absence in the film of the columnar formations, characteristic of other known processes.

In particular, according to one aspect of the invention for the dissociation of the supplied gaseous hydrocarbon, for example With₄H₁₀used reactor plasmodiophoromycota chemical vapour deposition with inductive coupling, in which the power control plasma is produced regardless of bias on the substrate. The substrate or workpiece, for example, razor blades, packaged in a pile, set in a vacuum plasma reactor chamber in the holder.

The holder is connected to the high frequency (HF) power source (for example, 13.56 MHz) through a chain of matching impedance. The plasma is generated under conditions of maximized density of the ion current (i.e., the filing of high power RF plasma with electromagnetic coupling) and a moderate bias to the substrate (for example, J_i>~30 a/m²and ~200 < V<SUB>offset

In accordance with another aspect of the invention, between the substrate and the film of diamond-like carbon can be used intermediate layer. This intermediate layer can be selected from an aggregate consisting of silicon, silicon carbide, vanadium, tantalum, Nickel, niobium, molybdenum and alloys of these materials. Experience has shown that, as a material for such an intermediate layer is particularly suitable silicon.

High efficiency plasma inductive link can generate a flow of ions, which can be about ten times more than in the conventional plasma with RF capacitive coupling. These conditions cause other benefits, such as reducing the width of the shell, increasing the ion-atomic relations and a very high deposition rate. Reducing the width of the shell provides a conformal coating of smaller structures and variations on the surface of the substrate. In the presence of conformal shell ions are forced to strike the surface perpendicular or at small angles that the mobility of the adatoms and the deposition of films of higher density. Increasing the deposition rate, due to more complete dissociation of the plasma leads to increased productivity and greater efficiency.

These advantages give the opportunity to create a diamond-like carbon films, which have a dense film structure (i.e., with greatly reduced or missing columnar grains or voids which reduce the mechanical strength (for example, when observing from 50,000-fold magnification using a scanning electron microscope with cold issue no discernible grain diameter of 310^-8m or more]) and high hardness (the hardness of the film exceeds about 20 HPa) at a high deposition rate, resulting in lower cost per part. The process may have some additional advantages, which may include samosatene (sharpening spray) cutting edges due to the intensive bombing by the flow of ions, high speed cleaning chamber using an oxygen plasma, and good performance during any stage of preliminary plasma treatment, which can be applied before the deposition.

The present invention can be better understood from navset a schematic view in section of the reactor plasmodiophoromycota chemical deposition from the vapor phase with an inductive link, useful when implementing the present invention; Fig.2 is a graph which illustrates the present invention in relation to the ion current/RF power induction, the average bias on the substrate and the thickness of the shell; Fig. 3 is a graph which illustrates the hardness of the films created in accordance with the present invention, as a function of RF power induction and medium-bias on the substrate; Fig. 4 is a graph which illustrates the hardness of the films created in accordance with the present invention, as a function of the average displacement on the substrate; Fig. 5 is a photomicrograph (taken at the 50,000-fold magnification) of the cross-section of the diamond-like film deposited on a razor blade by conventional plasmodiophoromycota chemical deposition from the vapor phase with capacitive coupling; Fig. 6 is a photomicrograph (taken at the 50,000-fold magnification) of the cross-section of the diamond-like film deposited on a razor blade during the demonstration test of the present invention; Fig. 7 is a photomicrograph (taken at the 50,000-fold magnification) of the cross section of diamond-like films, Osage is, 8 is a photomicrograph (taken at the 50,000-fold magnification) of the cross-section of the diamond-like film deposited on a razor blade during the demonstration test sequence of the present invention; Fig. 9 is a photomicrograph (taken at the 50,000-fold magnification) of the cross-section of the diamond-like film deposited on a razor blade during the demonstration test sequence of the present invention;
Fig. 10 is a photomicrograph (taken at 50000-fold increase) enlarged view in perspective of the diamond-like film deposited on a razor blade by conventional plasmodiophoromycota chemical deposition from the vapor phase with capacitive coupling;
Fig. 11 is a photomicrograph (taken at the 50,000-fold magnification) of the cross-section of the diamond-like film deposited on a razor blade by conventional plasmodiophoromycota chemical deposition from the vapor phase with capacitive coupling;
Fig. 12 is a photomicrograph (taken at 50000-fold increase) enlarged view in perspective of the diamond-like film deposited on a razor blade in sootvetstvii) cross-section of diamond-like films, deposited on a razor blade in accordance with the present invention;
Fig. 14 is a graph which illustrates the deposition rate in accordance with the present invention as a function of RF power induction;
Fig. 15A is a diagram illustrating an additional embodiment of the present invention;
Fig. 15B is a graph illustrating a variant of the RF bias, is shown in Fig.15A, the modulated pulse signal;
Fig. 16 is a graph illustrating the dependence of hardness from internal stress film for films that served the offset of the modulated pulse signal in accordance with the present invention, in comparison with the schedule for the film, which is offset under the law of the continuous wave;
Fig. 17 is a block diagram of the algorithm, illustrating a variant of the process implementing the present invention.

The present invention provides an improvement in the formation of diamond-like carbon films on substrates by plasmodiophoromycota chemical vapour deposition. In accordance with the present invention, dissociative high flux density of ions and ion bombardment managed low energy ensures the formation of a solid, a dense film of a-C:H on the substrate in the absence of any columnar formations characteristic of other known processes, even if the substrate has an unusual shape or includes sharp corners. The invention includes impact in itself on the substrate environment of gaseous hydrocarbon and generating plasma in the medium with electron density greater than about 510¹⁰on cm³and the thickness of the shell, less approximately 2 mm, under conditions of high flux density of ions and ion bombardment managed low energy. Such conditions can be obtained by independently control the flux of ions and deposition on the substrate in order to maximize the flow of ions, but at the same time to maintain a moderate bias on the substrate. These conditions include the ion current density (J_i) greater than about 20 a/m²and the bias voltage (-V_offsetin the range from about 100 to about 1000 C.

According to one implementation variant of the present invention, for creating an angular substrate dense, solid films of a-C:H, which meets the present invention, used reactor plasmodiophoromycota chemical deposition from the vapor phase with the inductive is a mini-deposition from the vapor phase with an inductive link, you can also use other processes for generating plasma, capable of generating a plasma of high density.

In Fig. 1 shows a reactor with an inductive link, which is used to implement the present invention. The reactor depicted in Fig.1, includes an induction plasma generator 10 connected to a vacuum plasma chamber 12, in which the holder 14 of the substrate is placed in a plasma field under the quartz window 11. Typically, the holder 14 has water cooling. Although water cooling is the predominant, say some heat. Thus, it is possible also to use a large heat sink.

The plasma generator 10 includes a radio frequency (RF) channel 16, is connected to the induction coil 18 through the capacitor 20. Inside the plasma chamber 12, the substrate or workpiece 22 (shown as razor blades, packaged in a stack) is placed on the holder 14. The holder 14 is associated with a high frequency (HF) (typically 13.56 MHz) power source 24 through the circuit matching the impedance 26. RF power source 24 of the holder 14 controls the energy of ions extracted from the plasma and directed to the workpiece 22. Supplied gaseous hydrocarbon, liable the hat is₄H₁₀but you can also use other gaseous hydrocarbons, for example, CH₄With₂H₂With₆H₆With₂H₆and/or C₃H₈.

Preferably, the workpiece 22 is set at 0.05 to 0.15 m below (under the quartz window 11) and maintained at room temperature by means of the holder 14 with water cooling.

Using the above apparatus were made of a series of tests at various power levels induction plasma and bias voltage on the substrate. Below are two examples of deposition on the edges of the blades, which illustrate the present invention (see tab. 1).

In these examples refers to the "density" of the films. This indicator corresponds to a semi-quantitative classification system of the coating edge of the blade, whereby the microstructure of the coating is measured using the scanning electron microscope with cold emission, giving 50000-fold increase. Based on the availability of granular hollow structure, the index is assigned in accordance with table. 2.

The results of the above examples and other series of tests shown in the graphs of Fig.2-4. Fig.2 graphically illustrates sootvetstvenno on the substrate and the shell thickness. The figure also shows the area that meets the preemptive variant of implementation of the present invention. From the figure it is seen that the magnitude of the ion current has an effect on bar formation in the films. Lower values of the ion current lead to an increase of the columnar structures in the films. Higher values of the ion current cause less columnar microstructure. Although the shape is not quite clear, wide plasma membrane can lead to increased the columnar microstructures.

It is evident from Fig.2 also shows that the average displacement of the substrate affects the hardness of the films. At lower average bias on the substrate film to be relatively soft. With an increase in the average values of the bias increases and the hardness of the films. However, an excessively high bias on the substrate result in damage to the film and reduce the hardness of the film due to graphitization.

Fig. 2 also shows that the thickness of the shell varies as a function of density of the ion current and the bias on the substrate. As follows from Fig.2, the thickness of the plasma membrane increases with increasing the bias on the substrate. Thus, increasing the bias on padlock the and of the present invention, includes ion current density (J_i) in excess of about 20 a/m²and the average bias on the substrate (-V_offsetin the range from about -100 to about -1000 Century Conditions that generate this preferential option implementation (which is shown in Fig.2 in the form of a large selection labeled "Preferred"), include ion current density (J_i) greater than or equal to about 30 a/m²the average bias on the substrate (-V_offset) in the range of from about -200 to about -500 V and the thickness of the shell is less than or equal to approximately 1.7 mm (for edges of the blades, packaged in a stack).

For comparison, on the bottom right, the highlighted region of Fig.2 (marked "Accepted APA") outlines the terms and characteristics associated with chemical vapor deposition with a low density and capacitive coupling. Similar conditions conventional process (RF power is supplied to the electrode substrate), see table. 3.

During the chemical vapor deposition capacitively coupled, the ion current density is small (approximately 3 a/m²), and the shell wide. On the edges of the blades are observed columnar film.

Fig. 3 shows that the hardness of the generated films varies as fu is (e). It is evident from Fig.2 shows that with increasing displacement on the substrate and RF power induction increases the hardness of the film. Again, an excessively high bias on the substrate causes a decrease in the hardness of the film due to graphitization.

Fig. 4, which shows the hardness created the film as a function of the average displacement on the substrate by RF power induction, equal 200-800 watts, shows that at moderate average bias on the substrate (for example, from about 200 to about -500 V) obtained higher film hardness. The solid line in Fig. 4 best fits the location of the data points. The dashed lines correspond to the limits of the 95% deviation from the best fit.

The following additional options PSHOP on the blades demonstrate the effects of changes in power induction/ion current on the width of the shell and column formation. All conditions were constant except power induction/ion current (see tab. 4).

The results of these series of tests is depicted in the micrographs, respectively, of Fig.5-9, each of which is made at the 50,000-fold magnification by a scanning electron microscope with cold emission (SEM). In the coatings is shown in Fig.5 and 6, which are matched in Fig. 7, which corresponds to a series of tests 3, has an intermediate view, but stanchest still replaced. The films depicted in Fig.8 and 9, which correspond to the series of tests 4 and 5, respectively, when observed with a scanning electron microscope with cold emission (SEM) at 50000-fold increase neither in the images of the surface, nor in the image of the cross section cannot be distinguished any columnar structure (e.g., distinct grains with a diameter of 310^-8m or more). Thus, as shown in Fig.2, according to a preferential implementation variant, the lower limit of the ion current is set approximately equal to 30 a/m²that corresponds to the capacity of induction, equal to about 400 watts.

The micrograph in Fig. 10-13 demonstrate the superior quality of the films a-C:H deposited in accordance with the present invention. These micrographs made from 50,000-fold magnification by scanning electron microscope with cold emission (SEM). In each of figs.10 and 11 shows a film of a-C: H deposited at the edge of the razor blade through the conventional methods plasmodiophoromycota chemical deposition from the vapor phase with capacitive light is in each of figs.12 and 13 shows a film of a-C:H, deposited on the edge of a razor blade in accordance with the present invention. In Fig. 12 and 13 by means of a scanning electron microscope with cold emission (SEM), giving 50000-fold increase, one can clearly see a good deposition of the film on the edge of the blade without the observed columnar formations or the observed grains. In the film deposited in accordance with the present invention, can not see any columnar microstructure, or void.

Additionally illustrating the present invention and showing the growth of the deposition rate associated with the present invention, Fig.14 is a graph showing the deposition rate as a function of RF power induction. Gradually increase the amount of plasma with electromagnetic coupling, the deposition rate increases significantly. The beginning of the graph corresponds to applying to the substrate only RF bias, which causes the deposition rate of 1.710^-10m/s and samospaseniyu -300 C. This corresponds plazmostimulirovannom deposition from the vapor phase with capacitive coupling. With increasing power induction power offset is adjusted to maintain -300 Century When the power of the induction of 800 W, the deposition rate of the composition is stimulirovannoi deposition from the vapor phase with the capacitive connection.

According to the above versions of the invention, on a substrate or workpiece is continuously applied RF power of 13.56 MHz, to provide a bias on the substrate. According to an additional aspect of the invention, the supply bias applied to the substrate or workpiece can be modulated pulse signal. According Fig.14A and 15B, the sine wave from the RF power source 24 is modulated by a rectangular wave produced by the generator 30 square wave, using the modulator 32 to form a modulated rectangular signal RF bias voltage 34.

According to a variant implementation corresponding to Fig.15A and 15B, the duty cycle is the time offset as a proportion of the full period of the rectangular wave. Changing the duty cycle of the pulses can give two advantages: 1) it is possible to reduce the average bias voltage (ion energy), but at the same time to maintain the peak voltage in the optimal range, and 2) you can narrow the shell to a thickness corresponding to zero offset (for example, about 30 μm) during the "off" period, which can provide a good conformal coating of the workpiece during this period.

In Fig. 16 shows the influence of the internal stress is m, when the film is fed offset, obeying the law of the continuous wave (CW). Pulse technique allows to reduce the tension of the film regardless of hardness, which is an additional special characteristic of the present invention.

In accordance with an additional aspect of the invention, between the substrate and the film of diamond-like carbon can be used intermediate layer. This intermediate layer can be selected from an aggregate consisting of silicon, silicon carbide, vanadium, tantalum, Nickel, niobium, molybdenum and alloys of these materials. Experience shows that as the material for such an intermediate layer is best suited silicon.

In Fig. 17 depicts an illustrative algorithm of the manufacturing process that meets the present invention. Usually useful to pass the workpiece through the pre-cleaning stage 36 to improve the adhesion layer ASD. This can be done in a single camera RF induction (high speed) or in the conventional chamber glow discharge FR (with low speed and greater processing time). In the camera pre-treatment can be submitted procurement for two or more chambers 38, 40 deposition ASD, using sources of plasma in the measure, 40, will be cleared. Cleaning should be carried out, because the film growing on the walls of the chamber, from time to time may crack, resulting in clogging of the particulate. Additional illustrative algorithm of this process is outlined in the table. 5.

Illustrative process conditions for the above algorithm include the following:
1) Pre-cleaning of the stack:
the RF power induction: - 300 W
the voltage of the RF bias: - -300 watts
time: - 30-60
gas: argon
the pressure to 0.7 PA
consumption: - 8,310^-7m³/s
2) Deposition of UPA:
Is carried out in accordance with the present invention.

3) clean the camera:
the RF power induction: - 1000 watts
the voltage of the RF bias: - -200
time: approx. 2 x time of deposition ASD
gas: oxygen
the pressure to 0.7 PA
consumption: - 1,710^-6m³/s
In accordance with the above, although the present invention is illustrated as applied to plazmostimulirovannom chemical vapor deposition with an inductive link, you can also use other processes capable of generating a plasma of high density. These other processes include the generation of a plasma microwave razreda plasma, for example, generating a plasma using a source of spiral waves and spiral resonator.

The above description is not intended to limit the present invention. Possible alternative options for implementation. Accordingly, the scope of the invention should be determined by appended claims and legal equivalents, but not described and depicted above its variants implementation.

Claims

1. The way to create a diamond-like carbon films on a substrate, including the impact on the substrate environment of gaseous hydrocarbon and generating plasma in said medium, characterized in that use plasma with electron density exceeding 5x10¹⁰on 1 cm³and shell thickness smaller 2 mm, under the condition of high current density of ions and ion bombardment managed low energy, while choosing the density of the ion current of more than 20 a/m²and bias voltage on the substrate is in the range from 100 to 1000 C.

2. The method according to p. 1, characterized in that as the environment of gaseous hydrocarbons using gas from the group comprising From₄H₁₀CH₄With₂H₂With₆H₆,dstanley a metal surface.

4. The method according to p. 1 or 2, characterized in that said substrate is a metallic substance having a surface layer containing a material selected from the group including silicon, silicon carbide, vanadium, tantalum, Nickel, niobium, molybdenum and their alloys.

5. The method according to any of paragraphs.1-4, characterized in that the plasma is generated by reactor inductive link.

6. The method according to p. 5, characterized in that the use of a reactor with an inductive link, providing an ion current density of 30 a/m²and the bias voltage on the substrate in the range from 200 to 500 C.

7. The method according to any of paragraphs.1-6, wherein generating the plasma with a shell thickness of less than 1.7 mm

8. The method according to any of paragraphs.1-7, characterized in that the bias voltage on the substrate modulate the pulse signal.

9. The product containing the substrate and the diamond-like carbon film on the surface of the substrate, wherein the substrate has an angular surface, a film of diamond-like carbon has a hardness of greater than 20 GPA, and has no discernible grain diameter 3x10^-8mor more when viewed from the 50,000-fold magnification using scanning on carbon is a film of a-C : H.

11. The product under item 9 or 10, characterized in that the substrate is a metallic substance having a surface layer containing a material selected from the group comprising silicon, silicon carbide, vanadium, tantalum, Nickel, niobium, molybdenum and their alloys.

12. Product according to any one of paragraphs.9-11, characterized in that it is a razor blade.

13. Product according to any one of paragraphs.9-11, characterized in that the said surface is an edge razor blades.

14. Product according to any one of paragraphs.9-11, characterized in that it is a detail of the writing instrument.

15. Product according to any one of paragraphs.9-11, characterized in that it is a feather pen.

16. Product according to any one of paragraphs.9-11, characterized in that it is a part of the writing shaft, intended for planting ball.

17. Product according to any one of paragraphs.9-11, characterized in that it is a needle tip.

18. Product according to any one of paragraphs.9-11, characterized in that it constitutes a cutting edge.

19. The product under item 18, characterized in that said cutting edge is on the cutting edge.