JP5053595B2 - DLC film forming method and DLC film manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for forming a diamond like carbon (DLC) film by plasma enhanced chemical vapor deposition (P-CVD) using pulse discharge (DC pulse discharge), and an apparatus for manufacturing a DLC film. The present invention can be applied to the production of photovoltaic elements used in solar cells.

  Conventionally, a method for producing a DLC film on the surface of a substrate by plasma chemical vapor deposition using plasma generated between electrodes has been developed. Further, it is known that when a DLC film is formed by this plasma chemical vapor deposition method, the film forming rate is increased by increasing the gas pressure of the source gas.

  However, when the gas pressure is actually higher than 250 Torr, the discharge becomes arc discharge, which may damage the substrate. In addition, the discharge start voltage becomes high and discharge may not be possible or may become unstable. Furthermore, there is a problem that the glow is biased to a part of the substrate, and the film cannot be formed on the entire substrate. Therefore, conventionally, the gas pressure could only be increased up to 250 Torr or less (see FIG. 1).

  On the other hand, a technique for forming a DLC film or a diamond film on a substrate by performing a plasma chemical vapor deposition method using a DC pulse power source at a high gas pressure has been proposed (see Patent Document 1).

  This technology is intended for coating with DLC film or diamond film. In order to improve film deposition speed and film adhesion, the rise time of pulse voltage during pulse discharge is set to 20 μs or less. It is.

  Among these, the diamond film has been proposed as a next-generation high-temperature operating semiconductor element material, while the DLC film has been attracting attention as a material capable of controlling the band gap because of its two main bonding states. Yes.

In other words, it is known that the band gap changes depending on the ratio of the graphite bond (sp ² ) and the diamond bond (sp ³ ). Therefore, by adjusting this ratio, the band gap can be controlled. There is.

If the band gap can be controlled, it is possible to produce a photovoltaic device having a multilayer structure with different spectral sensitivity, that is, a so-called tandem photovoltaic device, and this structure can convert a wide solar spectrum into electricity. As a result, conversion efficiency is improved.
JP 2004-169183 A

  However, in the above-described conventional plasma chemical vapor deposition method, since the plasma is generated around the substrate, the temperature around the substrate becomes high and the temperature of the substrate itself becomes high. This facilitates the growth of diamond particles, which makes it difficult to form a smooth DLC film. That is, there is a problem that it is not easy to form a DLC film having excellent characteristics.

Further, if the above-described band gap can be controlled, it is possible to improve the conversion efficiency of the photovoltaic device, but the specific method has not been established.
The present invention has been made to solve the above-described problems, and can easily form a smooth DLC film by suppressing the growth of diamond particles, and further, can form a DLC film capable of controlling a band gap. It is an object to provide a method and an apparatus for manufacturing a DLC film.

(1) The invention of claim 1 is a DLC film manufacturing apparatus for forming a DLC film by plasma enhanced chemical vapor deposition, wherein a substrate on which the DLC film is formed and a pair of opposed electrodes for performing plasma discharge are parallel to each other. And the two electrodes are one or a plurality of rod-shaped bodies, and the opposite tip sides of the two electrodes are rounded.
Conventionally, since the electrode to be used is a counter electrode (one electrode and the substrate that is the other electrode face each other), it is difficult to form a film on an insulator substrate, and when the gas pressure is increased, Although abnormal discharge (arc) often occurs and there is a problem that the film cannot be stably formed, the present invention can solve such a problem, prevent abnormal discharge, and the thickness of the DLC film to be formed. The distribution can be made uniform.
(2) The invention of claim 2 is a DLC film manufacturing apparatus for forming a DLC film by plasma enhanced chemical vapor deposition, wherein a substrate on which the DLC film is formed and a pair of opposed electrodes for performing plasma discharge are parallel to each other. The two electrodes are plate-shaped, and the corners on the front end sides of the two plate-shaped electrodes facing each other are rounded.
The present invention has the same effects as those of the first aspect of the invention.
(3) The invention according to claim 3, wherein using a DLC film manufacturing apparatus according to claim 1 or 2, a substrate placed in the source gas, met plasma enhanced chemical vapor deposition using pulse discharge In the DLC film forming method for forming the DLC film on the surface of the base material, the base material is cooled and the DLC film is formed by plasma chemical vapor deposition (by pulse discharge).

  In the present invention, when a DLC film is formed on the surface of a base material (for example, a substrate), the base material is cooled more than the ambient temperature. As a result, the substrate temperature is lowered, so that when the DLC film is formed by the plasma enhanced chemical vapor deposition method using pulse discharge, the growth of diamond particles can be suppressed, and therefore, compared with the case where the substrate is not cooled, The membrane can be smoothed. As a result, there is an advantage that a DLC film having excellent characteristics (for example, a clean bond can be formed, a low temperature process is possible, and a flexible substrate such as a plastic substrate can be used) can be obtained.

  In addition, as temperature to cool, it is suitable to set the temperature of a base material to 200 degrees C or less. Moreover, as a cooling method, the apparatus for cooling is arrange | positioned adjacent to a base material, and the method of cooling by water cooling, air cooling, etc. is mentioned.

( 4 ) The invention of claim 4 is characterized in that the gas pressure of the source gas is set to 300 Torr or more.
The present invention illustrates gas pressure. In the present invention, since pulse discharge is performed, by controlling the pulse voltage and the like, as illustrated in FIG. 1, even when the gas pressure is increased to 300 Torr or more, generation of arc and bias of glow are prevented, A DLC film can be formed suitably (at a high film formation rate). Incidentally, by setting the gas pressure to about 250 Torr, it is possible to more effectively suppress the occurrence of arc or glow bias.

( 5 ) The invention of claim 5 is characterized in that a gas containing hydrogen gas and hydrocarbon-based gas is used as the raw material gas.
As described above, the band gap changes depending on the existence state (ratio) of the graphite bond (sp ² ) and the diamond bond (sp ³ ). sp ³ ) (the more hydrogen gas, the greater the number of diamond bonds), and the amount of hydrocarbon gas related to the number of graphite bonds (sp ² ) (the more the hydrocarbon gas, the more It is clear that there are many graphite bonds.

  Therefore, the band gap can be controlled by controlling the quantity ratio between the hydrogen gas and the hydrocarbon gas. Therefore, since a photovoltaic element having a multilayer structure (tandem structure) with different spectral sensitivities can be produced in the photovoltaic element, a wide solar spectrum can be changed to electricity, and conversion efficiency can be improved.

Examples of the hydrocarbon-based gas include CH ₄ , C ₂ H ₄ , C ₂ H ₂ , C ₄ H ₆ , C ₄ H ₈ , and C ₅ H ₈ (the same applies hereinafter).
( 6 ) The invention of claim 6 is characterized in that the mixing ratio of the hydrocarbon-based gas in the raw material gas is controlled to 1% to 50% (volume ratio).

By changing the mixing ratio in this way, the band gap (BG) can be controlled from 3.9 eV to 0.5 eV according to the mixing ratio, as illustrated in FIG. 7 described later.
Here, the mixing ratio is the ratio of the hydrocarbon gas to the total of the hydrogen gas and the hydrocarbon gas even when a gas other than the hydrogen gas and the hydrocarbon gas is included.

In addition, as a mixing ratio, a molar ratio, a volume ratio, etc. are employable.
( 7 ) The invention of claim 7 is characterized in that a gas containing an argon gas and a hydrocarbon-based gas is used as a raw material gas.

The present invention enables more stable discharge.
( 8 ) The invention of claim 8 is characterized in that a gas containing argon gas, hydrogen gas, and hydrocarbon-based gas is used as the raw material gas.

The present invention enables more stable discharge. Further, the band gap can be controlled by adjusting the quantity ratio between the hydrogen gas and the hydrocarbon gas.
( 9 ) The invention of claim 9 is characterized in that an n-type semiconductor DLC film is formed using a gas containing argon gas, nitrogen gas, and hydrocarbon-based gas as a source gas.

  In the present invention, the effect of using the gas including the argon gas and the hydrocarbon-based gas described above is achieved, and the nitrogen gas is included in the source gas, so that an n-type semiconductor DLC film can be formed.

( 10 ) The invention of claim 10 is characterized in that a DLC film of an n-type semiconductor is formed using a gas containing hydrogen gas, argon gas, nitrogen gas and hydrocarbon-based gas as a source gas. .

In the present invention, the effect of the invention of the ninth aspect is achieved, and since hydrogen gas is included, the band gap can be controlled by adjusting the quantity ratio of the hydrogen gas to the hydrocarbon-based gas.

( 11 ) The invention of claim 11 is characterized in that a p-type semiconductor DLC film is formed using a gas containing hydrogen gas, trimethylboron gas, and hydrocarbon-based gas as a source gas.

  In the present invention, the effects of using the gas containing the hydrogen gas and the hydrocarbon-based gas described above are obtained, and the trimethylboron gas is contained in the source gas, so that a p-type semiconductor DLC film can be formed. .

( 12 ) In the twelfth aspect of the invention, the N-type semiconductor DLC film is formed by the formation method of the ninth or tenth aspect , and the p-type semiconductor DLC film is formed by the formation method of the eleventh aspect. According to the P process, an n-type semiconductor DLC film and a p-type semiconductor DLC film are stacked to form a pn junction semiconductor DLC film.

  In the present invention, for example, an n-type semiconductor DLC film is formed in an N process, and a p-type semiconductor DLC film is formed thereon in a P process. Or, conversely, a p-type semiconductor DLC film is formed in the P process, and an n-type semiconductor DLC film is formed thereon in the N process. Thus, a pn junction semiconductor DLC film can be easily formed. This pn junction semiconductor DLC film can be used as a photovoltaic element.

( 13 ) The invention of claim 13 is the formation method of claim 11 , the P step of forming a p-type semiconductor DLC film, and the i layer which is an intrinsic layer in the formation method of any of claims 3 to 8 A DLC film of the p-type semiconductor and a DLC film of the n-type semiconductor by the I process of forming the DLC film of the N-type semiconductor and the N process of forming the DLC film of the n-type semiconductor by the formation method of claim 9 or 10 . A DLC film of a pin junction semiconductor is formed by laminating with an i-layer DLC film interposed therebetween.

  In the present invention, for example, an n-type semiconductor DLC film is formed in the N process, an i-layer DLC film is formed in the I process, and a p-type semiconductor DLC film is formed in the P process. . Or, conversely, a p-type semiconductor DLC film is formed in the P process, an i-layer DLC film is formed in the I process, and an n-type semiconductor DLC film is formed in the N process. To do. As a result, a pin junction semiconductor DLC film can be easily formed. This pin junction semiconductor DLC film can be used as a thin film photovoltaic device.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
In this embodiment, as shown in FIG. 2, a DC pulse power supply 3 and a pair of discharge electrodes are used as a DLC film manufacturing apparatus 1 for forming a DLC film on a substrate surface by plasma chemical vapor deposition using DC pulse discharge. Electrodes 5 and 7 (anode or cathode), a substrate (for example, a Si wafer substrate) 9 disposed in the vicinity of the electrodes 5 and 7 on which a DLC film is formed, and the substrate 9 are placed and the substrate 9 is cooled. A substrate holder 11 to be performed, and a reaction chamber 13 in which the electrodes 5, 7 and the substrate 9, the substrate holder 11, etc. are accommodated and plasma chemical vapor deposition is performed are provided. The polarities of the electrodes 5 and 7 can be set as appropriate.

In addition, a hydrogen cylinder 19 is connected to the DLC film manufacturing apparatus 1 through a first air supply valve 15 and a first mass flow controller (MFC) 17 as a configuration for supplying a raw material gas into the reaction chamber 13. In addition, a hydrocarbon (C _X H _Y ) gas cylinder 25 is connected via a second air supply valve 21 and a second mass flow controller (MFC) 23. Furthermore, a vacuum exhaust pump 29 is connected via an exhaust valve 27 as a configuration for discharging the gas in the reaction chamber 13.

  Among these, as shown in FIG. 3A, the electrodes 5 and 7 are arranged such that a plurality of rod-shaped electrodes 5 and 7 are arranged in parallel so that their tip ends face each other and in parallel to the upper surface of the substrate 9. The tip side of each electrode 5 and 7 is rounded.

  Alternatively, as shown in FIG. 3B, the pair of left and right plate-like electrodes 31 and 33 may be arranged in parallel so that the tip ends face each other and in parallel with the upper surface of the substrate 9. The corners on the tip side of the plate-like electrodes 31 and 33 are rounded.

Each electrode 5, 7, 31, 33 can move in parallel to the substrate 9.
The substrate holder 11 supplies cooling water to the inside to adjust the temperature of the substrate 9 to 200 ° C. or lower, for example.

  Further, as shown in FIG. 4, the DC pulse power source 3 includes a DC power source 35, an intelligent power module 37 and a pulse transmitter 39 for intermittently outputting the DC power source 35, a high voltage transformer 41, a resistor 43, and a high voltage transformer 41. And a diode 45 for discharging the voltage from the high voltage side.

  In this DC pulse power source 3, the discharge for generating plasma is pulsed, and the rise time of the pulse voltage from the transmission of the pulse by the pulse transmitter 39 until the discharge voltage becomes the discharge start voltage is set to 20 μs or less, and the gas pressure below atmospheric pressure. A pulse discharge is performed to produce a thin film (DLC film) on the substrate 9.

  That is, by shortening the rise time of the pulse voltage to 20 μs or less, the intermittent time when the primary side of the DC power source 35 and the high voltage transformer 41 is intermittently connected by the intelligent power module 37 and the pulse transmitter 39 can be shortened. As a result, it is possible to obtain a high voltage (discharge start voltage) necessary for discharge that increases as the gas pressure increases.

  In addition, by adjusting the pulse period, the discharge and the discharge stop time, and adjusting the distance between the electrodes 5 and 7, the discharge does not become an arc but a stable discharge can be achieved. In this way, even when the gas pressure is increased to 300 Torr or more and atmospheric pressure, stable pulse discharge is possible without causing arc discharge, and the film deposition rate of the plasma chemical vapor deposition method can be greatly increased. In addition, the quality of the produced DLC film can be improved.

In particular, in this embodiment, the substrate 9 is cooled by the substrate holder 11 so that the substrate temperature does not rise excessively, and in plasma enhanced chemical vapor deposition using DC pulse discharge, hydrogen gas and hydro Carbon gas (CH ₄ , C ₂ H ₄ , C ₂ H ₂ , C ₄ H ₆ , C ₄ H ₈ , C ₅ H ₈ ) is used, and the mixing ratio is adjusted from 1% to 50% for the hydrocarbon gas. To do.

Thereby, the growth of diamond particles in the DLC film can be suppressed, and a DLC film in which the band gap is controlled from 3.9 ev to 0.5 eV according to the concentration of each hydrocarbon gas can be obtained.
[Second Embodiment]
By the plasma chemical vapor deposition method described above, at least hydrogen gas, argon gas, nitrogen gas, and hydrocarbon gases (CH ₄ , C ₂ H ₄ , C ₂ H ₂ , C ₄ H ₆ , By using a gas containing C ₄ H ₈ , C ₅ H ₈ ), an n-type semiconductor DLC film can be obtained.

In this case, a cylinder for supplying each gas is used as the cylinder of the DLC film manufacturing apparatus 1.
[Third Embodiment]
In the plasma chemical vapor deposition method described above, at least hydrogen gas, trimethylboron gas, and hydrocarbon gases (CH ₄ , C ₂ H ₄ , C ₂ H ₂ , C ₄ H ₆ , C ₄ H) are used as source gases. ₈ and C ₅ H ₈ ), a p-type semiconductor DLC film can be obtained.

In this case, a cylinder for supplying each gas is used as the cylinder of the DLC film manufacturing apparatus 1.
[Fourth Embodiment]
Gas containing hydrogen gas, argon gas, and hydrocarbon-based gas (CH ₄ , C ₂ H ₄ , C ₂ H ₂ , C ₄ H ₆ , C ₄ H ₈ , C ₅ H ₈ ) as a source gas It is possible to obtain a p-type semiconductor DLC film by using the plasma chemical vapor deposition and setting a boron target on the negative electrode and performing sputtering at the same time and doping the DLC film with boron.

  Hereinafter, embodiments of the present invention will be described in more detail by way of examples. Of course, the present invention is not limited to the following examples and the like, and it goes without saying that various aspects are possible in detail.

In this example, a DLC film was produced by the plasma chemical vapor deposition method using pulse discharge using the DLC film production apparatus 1 described above, and its properties were evaluated.
Specifically, in the DLC film manufacturing apparatus 1, after the inside of the reaction chamber 13 is evacuated by the vacuum exhaust pump 29, the exhaust valve 27 is closed, the first and second air supply valves 15, 21 are opened, and the first In addition, hydrogen (H ₂ ) and methane (CH ₄ ) having flow rates set by the second mass flow controllers 17 and 23 were respectively introduced into the reaction chamber 13.

  In this embodiment, the flow rate of hydrogen gas and the flow rate of methane are set to 100 SCCM, and the methane concentration (Cm) is set to 1%, 3%, 10%, 20%, 30%, 40%, 50% (volume%). A DLC film was formed at each concentration.

The film was formed with a gas pressure of 90 Torr, a pulse discharge repetition frequency of 800 Hz, and a duty ratio of 20%.
Although a glass substrate was used as the substrate for film formation, a Si substrate or a substrate with an ITO film can also be used.

Regarding the discharge, the voltage of the DC pulse power source 1 was increased, and the discharge was started between the cathode 5 and the auxiliary electrode 7 to form a film.
Then, at the time of each film formation, the emission spectrum of plasma discharge was examined by a plasma emission analyzer. For each DLC film, a Raman spectrum was measured by a Raman spectroscopic analyzer, and a band gap was further measured by a spectrophotometer.

FIG. 5 shows an emission spectrum of plasma discharge. It can be seen from the figure that the peak of carbon C ₂ increases as the methane concentration (Cm) increases.
FIG. 6 shows the measurement result of the Raman spectrum. It can be seen that the ratio of D peak around 1333 cm ^-1 from the drawing (die Mondo peak) and 1600 cm ^-1 vicinity of G peak (graphite peak) changes. This corresponds to sp ³ and sp ² bonds, respectively. Therefore, it can be seen from the figure that as the methane concentration increases, the G peak increases (sp ² bonds increase) and the band gap decreases.

  FIG. 7 shows a graph of band gap and methane concentration. From the figure, it was found that the band gap became smaller as the methane concentration increased, and it became 1.5 eV suitable for solar cells at a methane concentration of 30%. Note that Eg on the vertical axis is the energy of the band gap.

This shows that the band cap can be controlled by adjusting the mixing ratio of the methane concentration.
In the present embodiment, since the substrate 9 is cooled to 200 ° C. or lower by the substrate holder 11, the growth of diamond particles in the DLC film can be suppressed, whereby a smooth DLC film can be formed. did it. This could be confirmed by optical microscope observation and electron microscope observation.

  In this embodiment, when forming a DLC film by plasma enhanced chemical vapor deposition using pulse discharge, hydrogen gas, nitrogen gas, and methane gas are used as raw material gases in a ratio (volume ratio) of 80:10:10. did. In this embodiment, in addition to the configuration of the DLC film manufacturing apparatus 1, a configuration for supplying nitrogen gas is provided.

Thus, an n-type semiconductor DLC film could be obtained. When the conductivity of the n-type semiconductor DLC film was examined, the conductivity was improved from 2 × 10 ⁻¹² Ω · cm without nitrogen doping to 5 × 10 ⁻⁸ Ω · cm.

  In this embodiment, when a DLC film is formed by plasma enhanced chemical vapor deposition using pulse discharge, a gas containing hydrogen gas, methane gas, or trimethylboron gas is used as a source gas, and plasma chemical vapor deposition is performed. Boron was doped into the DLC film. In this embodiment, in addition to the configuration of the DLC film manufacturing apparatus 1, a configuration for supplying trimethylboron gas is provided.

As a result, a p-type semiconductor DLC film was obtained. When the conductivity of the p-type semiconductor DLC film was examined, the conductivity was improved from 2 × 10 ⁻¹² Ω · cm without boron doping to 3 × 10 ⁻⁶ Ω · cm.

In this example, a DLC film was formed by plasma chemical vapor deposition using pulse discharge using the DLC film manufacturing apparatus 51 shown in FIG.
In the DLC film manufacturing apparatus 51, the boron target 55 is installed on the negative electrode 53, the substrate 59 is disposed in the vicinity of the opposing anode 57, the substrate 59 is held above the substrate 59, and the substrate 59 is cooled. A substrate holder 61 was placed.

  Then, using a gas containing hydrogen gas and methane gas as a source gas, a DLC film was formed on the surface of the substrate 59 by plasma chemical vapor deposition, and simultaneously sputtered to dope the DLC film with boron.

As a result, a p-type semiconductor DLC film was obtained. When the conductivity of the p-type semiconductor DLC film was examined, the conductivity was improved from 4 × 10 ⁻¹² Ω · cm without boron doping to 5 × 10 ⁻⁶ Ω · cm.

In this example, a D-type semiconductor DLC film was formed by the method of Example 4, and an n-type semiconductor DLC film was stacked thereon by the method of Example 2.
As a result, as shown in FIG. 9, a solar cell (photovoltaic element) 71 having a pn junction structure can be manufactured.

  In this embodiment, a p-type semiconductor DLC film is formed by the method of the embodiment 4, and an intrinsic layer (i-layer) semiconductor DLC film is stacked thereon by the method of the embodiment 1. On top of that, an n-type semiconductor DLC film is laminated by the method of the second embodiment.

  Thereby, as shown in FIG. 10, a solar cell (photovoltaic element) 73 having a pin junction structure can be manufactured.

It is explanatory drawing which shows the stable glow discharge area | region of the plasma chemical vapor deposition apparatus by the pulse discharge of this invention. It is a conceptual diagram which illustrates the DLC film manufacturing apparatus at the time of using an auxiliary electrode. It is explanatory drawing which illustrates the structure of an electrode vicinity. It is a circuit diagram which illustrates DC pulse power supply. It is a graph which shows the emission spectrum of the plasma discharge at the time of changing methane concentration. It is a graph which shows the Raman spectrum of the DLC film formed into a film by changing methane concentration. It is a graph which shows the relationship between a methane density | concentration and a band gap. It is explanatory drawing which shows the DLC film manufacturing apparatus of Example 4. FIG. FIG. 6 is an explanatory diagram showing a photovoltaic element of Example 5. It is explanatory drawing which shows the photovoltaic element of Example 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 ... DCL film manufacturing apparatus 3 ... DC pulse power supply 5, 7, 31, 33, 53, 57 ... Electrode 9, 59 ... Substrate 11, 61 ... Substrate holder 13 ... Reaction chamber 19, 25 ... Cylinder

Claims (13)

A DLC film manufacturing apparatus for forming a DLC film by plasma enhanced chemical vapor deposition,
  The substrate on which the DLC film is formed and a pair of opposing electrodes for performing plasma discharge are arranged in parallel, and the two electrodes are one or a plurality of rod-shaped bodies, and the two electrodes are opposed to each other. An apparatus for producing a DLC film, wherein the tip side is rounded. A DLC film manufacturing apparatus for forming a DLC film by plasma enhanced chemical vapor deposition,
  The substrate on which the DLC film is formed and a pair of opposing electrodes that perform plasma discharge are arranged in parallel, and the two electrodes are plate-shaped, and the tips of the two plate-shaped electrodes are opposed to each other An apparatus for producing a DLC film, wherein the side corners are rounded. Using the DLC film manufacturing apparatus according to claim 1 or 2,
The substrate was placed in the raw material gas by a plasma chemical vapor deposition method using a pulsed discharge, a method of forming a DLC film to form a diamond-like carbon (DLC) film on a surface of the substrate,
A method for forming a DLC film, comprising cooling the base material and forming the DLC film by the plasma enhanced chemical vapor deposition method. 4. The method for forming a DLC film according to claim 3 , wherein a gas pressure of the source gas is set to 300 Torr or more. The method for forming a DLC film according to claim 3 or 4 , wherein a gas containing hydrogen gas and a hydrocarbon-based gas is used as the source gas. 6. The method for forming a DLC film according to claim 5 , wherein a mixing ratio of the hydrocarbon-based gas in the source gas is controlled to 1% to 50%. The method for forming a DLC film according to claim 3 or 4 , wherein a gas containing an argon gas and a hydrocarbon-based gas is used as the source gas. 5. The method for forming a DLC film according to claim 3 , wherein a gas containing argon gas, hydrogen gas, and hydrocarbon-based gas is used as the source gas. 5. The DLC film formation according to claim 3, wherein a gas containing an argon gas, a nitrogen gas, and a hydrocarbon-based gas is used as the source gas to form an n-type semiconductor DLC film. Method. 5. The DLC film according to claim 3, wherein an n-type semiconductor DLC film is formed using a gas containing hydrogen gas, argon gas, nitrogen gas, and hydrocarbon-based gas as the source gas. Method for forming a film. Wherein as the raw material gas, using a gas containing hydrogen gas and trimethyl boron gas and hydrocarbon-based gas, a DLC film according to claim 3 or 4, characterized in that the DLC film is formed of a p-type semiconductor Forming method. An N step of forming the n-type semiconductor DLC film by the method of claim 9 or 10 ;
In the formation method of claim 11 , a P step of forming the DLC film of the p-type semiconductor;
The DLC film is formed by laminating the n-type semiconductor DLC film and the p-type semiconductor DLC film to form a pn junction semiconductor DLC film. In the formation method of claim 11 , a P step of forming the DLC film of the p-type semiconductor;
An I step of forming an i-layer DLC film as an intrinsic layer by the formation method according to any one of claims 3 to 8 ;
An N step of forming the DLC film of the n-type semiconductor by the formation method according to claim 9 or 10 ,
The p-type semiconductor DLC film and the n-type semiconductor DLC film are stacked so as to sandwich the i-layer DLC film, thereby forming a pin junction semiconductor DLC film. A method of forming a DLC film.