JP2907403B2 - Deposition film forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deposited film forming apparatus for forming a functional deposited film useful on a substrate, such as a semiconductor device, an in-line sensor for image input, an image pickup device, and a photoreceptor for electrophotography. The present invention relates to a deposited film forming apparatus for continuously forming a semiconductor element composed of a large-area thin film such as a photovoltaic element on a long strip-shaped substrate.

[0002]

2. Description of the Related Art Conventionally, when a functional deposited film, especially a semiconductor thin film is formed, an appropriate film forming method and an appropriate film forming apparatus are used according to the electrical or physical characteristics required for the functional deposited film and the application. Was used. For example, a vacuum deposition method, a plasma CVD method, a reactive sputtering method, an ion plating method, an optical CVD method, and the like are applied for forming a functional deposition film such as an amorphous silicon film used for a photovoltaic element or the like. In general, the plasma CVD method is widely used and commercialized.

[0003] However, the functional deposited film formed by these methods is not suitable for productivity / mass productivity including electrical / optical characteristics, fatigue characteristics during repeated use, use environment characteristics, or uniformity / reproducibility. In view of the above, there is room for further improving the overall characteristics. In order to obtain a functional deposited film that can sufficiently satisfy each of the electrical / optical properties, photoconductive properties, and mechanical properties, at present, plasma CV
The best method is to use Method D. In addition, depending on the application of the functional deposited film, it is necessary to perform reproducible mass production while increasing the film deposition rate while further improving the film quality while increasing the area and uniforming the film thickness. It has been pointed out that these are also issues to be improved in the future also in the plasma CVD method.

One of the means for solving the above-mentioned problems in the plasma CVD method is disclosed in US Pat.
No. 79455 describes a roll-to-roll (Ro)
In the (llto Roll) method, a more uniform semiconductor film is deposited by making the flow direction of the source gas anti-parallel to the transport direction of the substrate with respect to the substrate continuously transported in the longitudinal direction. A system is disclosed that can reduce waste when manufacturing a photovoltaic device and improve the efficiency of the manufactured photovoltaic device. Also, U.S. Pat.
No. 943 describes that when a deposited film is formed on a substrate that is continuously moving by a roll-to-roll method, a concentration gradient of a specific element is provided in the deposited film in the thickness direction of the deposited film. For this purpose, a large number of gas discharge holes for discharging the source gas of the specific element are provided on the cathode electrode facing the substrate, and the flow rate of the source gas released from the gas discharge holes is determined by the position of the gas discharge holes in the substrate transport direction. A method and an apparatus for changing according to are disclosed.

[0005]

In the above-mentioned plasma CVD apparatus in which a large number of gas emission holes are provided in the cathode electrode,
Since a large number of gas inlets are provided for one film formation space, control of composition change in the film thickness direction tends to be complicated, and reproducibility of conditions when forming a deposited film is poor. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily control a composition change in a film thickness direction uniformly over a large area on a continuously moving belt-like substrate, and to obtain a higher-quality functional deposited film. An object of the present invention is to provide a deposited film forming apparatus which can be mass-produced.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a vacuum vessel, a transport means for continuously transporting a strip-shaped substrate in the vacuum vessel in a longitudinal direction thereof, At least a part of the boundary is constituted by the band-shaped substrate, and has a film forming space into which a raw material gas and plasma forming energy are introduced, and the band-shaped by forming plasma in the film forming space. In a deposited film forming apparatus for forming a deposited film on the surface of a substrate, a partition plate for controlling a flow of the source gas is provided in a direction intersecting a transport direction of the strip-shaped substrate inside the film forming space. It is characterized by having.

It is preferable that high-frequency power is used as the plasma forming energy so that high-frequency plasma is formed in the film forming space. Further, introduction portions for supplying the raw material gas to the film formation space may be provided on both sides of the partition plate.

[0009]

A partition plate for controlling the flow of the raw material gas is provided in the film forming space so as to be substantially perpendicular to the transport direction of the strip-shaped substrate. As a result, a difference occurs in the pressure, and on the other hand, since the strip-shaped substrate continuously moves across the partition plate, the composition of the film deposited on the strip-shaped substrate changes in the thickness direction. In addition, since the film forming space is partitioned by the partition plate, the distribution of the source gas in the partitioned space becomes uniform, and the deposited film is more uniformly formed in the width direction of the band-shaped substrate. become.

In addition, if introduction portions for supplying a raw material gas to the film formation space are provided on both sides of the partition plate, respectively, when the type and flow rate of the gas introduced from each introduction portion into the film formation space are different. Since the different gases are more effectively divided on both sides of the partition plate, the composition of the film deposited on the strip-shaped substrate in the thickness direction becomes steeper.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic sectional view showing the structure of a deposited film forming apparatus according to an embodiment of the present invention. The arrows in the figure schematically show the gas flow.

This deposition film forming apparatus has two internal containers 1
It comprises a vacuum vessel 101 having therein 02a and 102b. The vacuum container 101 includes each of the internal containers 102a, 102
Two exhaust pipes 111a and 111b, each of which has the other end connected to an exhaust pump (not shown) corresponding to b, are connected. Vacuum gauges 110a and 110b are provided in the middle of the exhaust pipes 111a and 111b, respectively.

The strip-shaped substrate 103 on which the deposited film is formed is
It is supplied from the feed roll 114 outside the vacuum vessel 101, is introduced into the vacuum vessel 101 through the gas gate 113a attached to the illustrated left side wall of the vacuum vessel 101, and is attached to the illustrated right side wall of the vacuum vessel 101. It is wound around a take-up roll 115 outside the vacuum vessel 101 through the gas gate 113b. By rotating the take-up roll 115 with a drive motor (not shown), the base 103 is continuously supplied from the feed roll 114 into the vacuum vessel 101, and
1 continuously moves along the longitudinal direction of the base 103,
It will be wound up by the winding roll 115. That is, the base 103 is continuously conveyed from the left side to the right side in the figure. Each gas gate 113a, 113b
Can continuously evacuate the substrate 103 without breaking the vacuum.
The vacuum vessel 101 is configured to be transported into the chamber 1 and to introduce a gate gas, and also serves as a connecting portion when the vacuum vessel 101 is connected to another vacuum vessel. Also, the feed roll 11
4. The take-up roll 115 includes the gas gates 113a, 1
The base 103 is stored in a vacuum chamber (not shown) connected to each of the bases 13b so that the base 103 is not exposed to the atmosphere.

Each of the inner containers 102a and 102b has a hollow rectangular parallelepiped shape having an opening on one side, and is provided such that the opening is close to and opposed to the base 103. Each of the inner vessels 102a and 102b is provided with an exhaust opening facing the attachment section of the exhaust pipe 111a and 111b on the vacuum vessel 101 side, and an open tubular projection 117a from the opening toward the attachment section. , 1
17b are provided respectively. Adjustment plates 108a and 108b are attached to the openings, respectively. Tip portions of the protrusions 117a and 117b and each exhaust pipe 11
Adjusting plate 1 is also provided on the mounting portions 1a and 111b.
09a and 109b are attached. These adjusting plates 108a, 108b, 109a, 109b adjust the exhaust conductance, and form the film forming spaces 102a, 102b.
It is a member that can change the area of the opening to generate a differential pressure inside and outside the member, for example, a slit-shaped or throttle-shaped member. By changing the area of the opening, the differential pressure can be appropriately selected.

Each of the inner containers 102a and 102b has a gas heater 106a for heating a raw material gas.
106b, electrode 105 for generating plasma discharge
a and 105b are provided. The gas heaters 106a and 106b heat the source gas to prevent the generation of polysilane and the like, and the electrodes 105a and 105b.
b to remove residual air and moisture adsorbed on the surfaces of the electrodes 105a and 105b.

Each of the electrodes 105a and 105b has a flat plate shape, and may be divided into several portions.
It is provided so as to be opposed to and parallel to the base 103. Each of the electrodes 105a and 105b is
Two high-frequency power supplies 112a, 112 provided outside
b is electrically connected to one end via a matching box (not shown). Each high frequency power supply 112
The other ends of the terminals a and 112b are grounded. By arranging the electrodes 105a and 105b in this manner, the vacuum vessel 1
01, a predetermined raw material gas is introduced, and high-frequency power is supplied from each of the high-frequency power sources 112a and 112b to the electrode 105.
a when applied to the electrodes 105a, 105b.
5b and the substrate 103, plasma discharge occurs in a space between the substrate 103 and the substrate 103.
04a and 104b. That is, each internal container 102
a, 102b corresponding to the film formation spaces 104a, 104b, respectively.
104b will be formed.

A rectangular partition plate 116 for controlling the flow of the raw material gas in the film forming space 104a is provided in the film forming space 104a formed in the inner container 102a on the left side in the figure. The partition plate 116 is used for the base 103.
In the direction intersecting the conveying direction of the left inner container 10
2a is attached to the electrode 105a. Partition plate 11
The height of 6 is slightly smaller than the distance between the base 103 and the electrode 105a, so that a gap is formed between the upper side of the partition plate 116 and the base 103. Also,
The width of the partition 116 is larger than at least the width of the base 103, and the partition 116 partitions the film forming space 104a. The partition plate 116 may be either conductive or non-conductive, but is preferably non-conductive, and examples thereof include quartz, alumina ceramics, and aluminum nitride.

In the film forming space 104a, where the partition plate 116 is provided in the transport direction of the substrate 103 is appropriately determined according to a change in the composition of the film to be deposited on the substrate 103 in the film thickness direction. . The partition plate 116 may be moved in the direction of the thick arrow in the figure by an external operation using a moving means such as an actuator (not shown).

Further, first and second gas supply pipes 107a and 107b for supplying a source gas from a gas supply source such as a gas cylinder provided outside the vacuum vessel 101 to each of the internal vessels 102a and 102b. Penetrate through the wall of the vacuum vessel 101 and each of the internal vessels 102a, 10a
2b. Source gas is supplied to each gas supply pipe 1
07a, 107b to the corresponding inner containers 102a, 10b
2b, heated by the gas heaters 106a, 106b, and introduced into the film forming spaces 104a, 104b, and then the projections 117a, 117b, the exhaust pipe 11
Air is exhausted through 1a and 111b. In this case, the raw material gas introduced from the first gas supply pipe 107a attached to the left inner container 102a is supplied to the partition plate 11 in the film forming space 104a of the left inner container 102a.
6 to be introduced from one side. Therefore, a third gas supply pipe 107c for directly supplying a source gas is provided on the other side of the film forming space 104a partitioned by the partition plate 116. Third gas supply pipe 1
07c is provided through the wall of the vacuum vessel 101. These three gas supply pipes 107a, 107b, 10
7c is a gas for heating the substrate 103 and a gas for cleaning the vacuum vessel 101 in addition to the raw material gas.
It is also used when introducing into.

A group of lamp heaters 118 for generating radiant heat for heating the base 103 is provided on the back side of the base 103 in the vacuum chamber 101 (the side not facing the internal vessels 102a and 102b).

Next, the operation of the deposited film forming apparatus will be described.

First, the inside of the vacuum vessel 101 is evacuated by an exhaust pump (not shown), and a predetermined source gas is introduced into the vacuum vessel 101 from each of the gas supply pipes 107a, 107b, 107c while operating the exhaust pump.
Further, the gas heaters 105a and 105b and the lamp heater 118 are operated, and the winding roll 115 is rotationally driven by a drive motor (not shown) to continuously move the belt-shaped base 103. By doing so, the substrate 103 moving continuously in the vacuum vessel 101 is heated, and the source gas introduced into the film formation spaces 104a, 104b from the first and second gas supply pipes 107a, 107b is also heated. Is done.

In this state, each of the high-frequency power supplies 112a, 112
When high-frequency power is applied to each of the electrodes 105a and 105b by 2b, a high-frequency discharge is generated in each of the film forming spaces 104a and 104b to generate plasma, and the raw material gas is decomposed by the action of the plasma and moves continuously. A deposited film is formed on the surface of the base 103 which is being formed. Here, a film forming space 104a formed in the inner container 102a on the left side in the figure.
Note that the partition plate 11 is provided in the film forming space 104a.
6, the raw material gas supplied from the first gas supply pipe 107a is first introduced into the space on the right side of the film forming space 104a partitioned by the partition plate 116, and is mainly decomposed in the space. It will be deposited on the base 103. The raw material gas introduced from the third gas supply pipe 107c is introduced only into the space on the left side of the partition plate 116, is decomposed in this space, and is deposited on the base 103.

Since the substrate 103 is continuously conveyed from the left side to the right side in the drawing, a deposited film is first formed on the left side of the partition plate 116, and then the deposited film is formed on the right side of the partition plate 116. Will be formed. By adjusting the type and flow rate of the source gas introduced from the first and third gas supply pipes 107a and 107c, the partition plate 1
Since the composition of the film deposited on the base 103 is different on both sides across the substrate 16, the composition eventually changes in the thickness direction of the film deposited on the base 103. The less the degree of mixing of the source gases across the partition plate 116, the steeper the change in the above-described composition in the film thickness direction.

Since the partition plate 116 is provided, the pressure distribution in the film forming space 104a is
6, the distribution is such that it changes abruptly and hardly changes in other places, and since the partition plate 116 extends in the width direction of the base 103, the distribution of the raw material gas in the lateral direction of the base 103 is more uniform. As a result, the uniformity of the film deposited on the base 103 in the width direction is improved, and the film quality is improved.

In the above description, the film forming space 104a
The third gas supply pipe 107c for directly introducing the raw material gas is provided in the space on the left side of the drawing partitioned by the partition plate 116, but the partition plate 11 can be provided without providing the gas supply pipe 107c.
Since the gas concentration, pressure, etc., are different on both sides of
03, a deposited film having a composition changed in the thickness direction can be formed satisfactorily.

(Embodiment 2) FIG. 2 shows a photovoltaic element in which a vacuum vessel for forming a deposited film is further connected in cascade on both sides of the vacuum vessel 101 in the above-described deposited film forming apparatus. FIG. 2 is a schematic cross-sectional view showing a structure of a deposition film forming apparatus that can be used.

Three vacuum vessels 201 to 203 are connected in series via gas gates 204 and 205, respectively. The strip-shaped substrate 211 is fed from a feed roll 212 provided inside the first vacuum vessel 201, passes through a first gas gate 204, a second vacuum vessel 202, a second gas gate 205, and passes through the third gas gate 205. Is wound up by a take-up roll 213 provided inside the vacuum vessel 203. The winding roll 2 is driven by driving means (not shown).
When the substrate 13 is driven to rotate in the direction of the arrow shown in the figure,
It is fed out from the feed roll 212 and is continuously conveyed. When an amorphous photovoltaic element having a pin junction is formed on the base 211, the first vacuum vessel 201 is an n-type semiconductor layer, the second vacuum vessel 202 is an i-type semiconductor layer, and the third vacuum vessel is Reference numeral 203 denotes a film forming chamber for forming each of the p-type semiconductor layers.

The first vacuum vessel 201 has a feed roll 21
An internal container 221 provided integrally with the vacuum chamber 214 in which the vacuum chamber 2 is housed and opposed to the substrate 211 fed from the feed roll 212; a gas supply pipe 222 for supplying a raw material gas to the internal container; A gas heater 223 provided in the inner container 221 for heating the gas, an electrode 224 connected to a high-frequency power supply (not shown) provided in the inner container 221, and a base 211 provided opposite the inner container 221 with the base 211 interposed therebetween. Lamp heater 22 for heating
Five. The configuration of the internal container 221 is the same as the internal container 102b on the right side in the first embodiment described above. Further, the vacuum vessel 201 is connected to one end of an exhaust pipe 226 whose other end is connected to an exhaust pump (not shown).

First vacuum vessel 201 and second vacuum vessel 2
02 is connected to a first gas gate 204 to which a gate gas is introduced. The configuration of the second vacuum vessel 202 is the same as that of the vacuum vessel 101 in the first embodiment described above. Further, a second gas gate 205 connecting the second vacuum vessel 202 and the third vacuum vessel 203 is connected to a gate gas introduction pipe 207 for introducing a gate gas. The third vacuum vessel 203 is provided integrally with a vacuum chamber 215 that houses the take-up roll 213, and has a structure that has a mirror image relationship with the first vacuum vessel 201. Each vacuum chamber 214,
An exhaust pipe 216 connected to an exhaust pump (not shown) is connected to 215.

Next, the operation of the deposited film forming apparatus will be described.

First, the vacuum vessels 201 to 203 and the vacuum chambers 214 and 215 are evacuated, and the gas gates 204 and 20 are evacuated.
The gate gas for preventing the source gas in each of the vacuum vessels 201 to 203 from flowing into the adjacent vacuum vessel is introduced from the gate gas introduction pipes 206 and 207 of No. 5. continue,
While supplying a predetermined raw material gas to each of the vacuum vessels 201 to 203, the take-up roll 213 is rotationally driven by a driving unit (not shown), and the belt-shaped substrate 211 is continuously conveyed in its longitudinal direction. By generating plasma discharge in each of the vacuum containers 201 to 203 in this state, a deposited film is formed on the base 211. At this time, since the substrate 211 is continuously transported in the direction from the first vacuum container 201 to the third vacuum container 203, the surface of the substrate 211
From the main body side of the base body 211, a deposited layer in the first vacuum vessel 201, a deposited layer in the second vacuum vessel 202, and a deposited layer in the third vacuum vessel 203 are sequentially laminated.

In particular, since the same vacuum vessel 101 as that of the first embodiment is used for the second vacuum vessel 202, the film deposited on the substrate 211 by the second vacuum vessel 202 is the same. The composition changes favorably in the thickness direction, and the uniformity of the film in the width direction of the substrate 211 is further improved.
Therefore, if this deposited film forming apparatus is used for producing an amorphous photovoltaic device having a pin-type junction, it is possible to give the i-type semiconductor layer a change in the composition in the thickness direction and to form the i-type semiconductor layer. The film quality is improved. It is known that the characteristics of the amorphous photovoltaic element are determined substantially by the characteristics of the i-type semiconductor layer, and therefore, a more excellent amorphous photovoltaic element can be obtained by this deposited film forming apparatus.

Next, the result of actually forming a deposited film using the deposited film forming apparatus shown in each of the above embodiments will be described with reference to a comparative example.

(Experimental Example 1) An amorphous silicon germanium film was formed on a belt-like substrate 103 using the deposition film forming apparatus of Example 1 shown in FIG. The base 103 is made of stainless steel (SUS430BA, width 12 cm × length 50 m × thickness 0.2 mm), and a rotary pump, a mechanical booster pump, and a turbo molecular pump (TMP-150 manufactured by Shimadzu Corporation) are used as the exhaust pump of the vacuum vessel 101. Was used.
Adjusting plates 108a and 108b attached to the exhaust openings of the inner containers 102a and 102b;
7a, 117b and each exhaust pipe 111a, 11b
Adjustment plate 109 attached to the attachment portion 1b
The aperture ratio of a and 109 was set to 1:18. Further, the partition plate 116 is arranged at a place where the film forming space 104a formed in the inner container 102a on the left side in the drawing is divided into 1: 2 when viewed from the exhaust side (the left side in the drawing).

First, the feed roll 114, the take-up roll 1
The vacuum chamber 101 and two vacuum chambers (not shown) each containing a vacuum pump 15 are roughly evacuated by a rotary pump, and then a pressure of about 10 ^-3 To
Exhaust until rr. The surface temperature of the substrate is maintained at 300 ° C. by the lamp heater 118.
06a and 106b were maintained at 330 ° C., and then evacuated to 2 × 10 ⁻⁵ Torr or less using a turbo molecular pump.

When the degree of vacuum falls below 2 × 10 ⁻⁵ Torr,
Through a mass flow controller (not shown) from the gas cylinder, not shown, the first H ₂ gas of 400sccm as the purge gas, the second gas supply pipe 107a, 107b and the two
Butterfly valves (not shown) which are introduced from conduits (not shown) provided in the vacuum chambers and attached to the respective exhaust pipes (111a, 112b) so that the readings of the respective vacuum gauges 110a, 110b become 1.0 Torr. Was adjusted, and the mixture was evacuated with a turbo molecular pump for 2 hours.

Thereafter, from a gas cylinder (not shown) through a mass flow controller (not shown), the first and second gas supply pipes 107a and 107b are used to obtain Si ₂ gas under the conditions shown in Table 1.
Each gas of H ₆ , GeH ₄ and H ₂ is introduced, and each vacuum gauge 110
The rotation speed of the mechanical booster pump was adjusted so that the readings of a and 110b became 1.0 Torr. First, the above-mentioned gas was supplied for 0.5 hour, and then the high-frequency power having the effective value of 13.56 MHz shown in Table 1 of 13.56 MHz was supplied from each of the high-frequency power supplies 112a and 112b while the gas was supplied.
5b to each of the film forming spaces 104a, 104
b, a plasma discharge is generated, and a length of 40 μm
m was formed. At this time, the base 103
Was 14 cm / min.

[0040]

[Table 1]

After forming the deposited film, the substrate 103 is cooled and then cooled.
Was taken out, and the film thickness distribution of the deposited film was measured in the longitudinal direction and the width direction of the base 103 using a film thickness meter (Alpha Step 100 manufactured by Tokyo Electron Limited). As a result, the variation in the film thickness was within 2.5%, and the calculated deposition rate was 8 ° / s on average. Next, a part of the substrate 103 on which the deposited film is formed is optionally 35
Cut out, secondary ion mass spectrometer (SIMS) (CAM
The composition of the deposited film in the depth direction was analyzed using ECA (imf-3f). As a result, the dispersion of the germanium content at an arbitrary film thickness was within ± 3% for 35 cut-out samples.

Comparative Example 1 A deposited film was formed on a substrate in the same manner as in Experimental Example 1 except that the partition plate 116 was removed. Thereafter, the distribution of the germanium content in the depth direction was examined in the same manner as in Experimental Example 1. As a result, the variation in the germanium content at an arbitrary film thickness was ± 6%.

When the experimental example 1 and the comparative example 1 are compared,
It has been found that by using the deposited film forming apparatus of the present invention, when a deposited film is formed on a continuously moving strip-shaped substrate, a change in composition in the film thickness direction can be accurately controlled. This indicates that the band gap adjuster can be distributed as desired with good reproducibility in the production of an amorphous photovoltaic device, for example.

(Experimental Example 2) Using the deposited film forming apparatus of Example 2 shown in FIG. 2, a solar cell single cell having a pin type junction provided on a substrate and having an inclined band gap profile was prepared. As the substrate 211, the same one as in the above-described experimental example was used.

While continuously transporting the substrate 211 at a transport speed of 15 cm / min, the first vacuum vessel 2 is placed on the substrate 211.
01, an n-type semiconductor layer was sequentially deposited in the second vacuum vessel 202, and a p-type semiconductor layer was deposited in the third vacuum vessel 202. At this time, in order to prevent mixing of the source gases between the vacuum vessels 201 to 203, the gate gas introduction pipes 206, 2
From 07, Ar gas and H ₂ gas were supplied at 300 sccm and 3 respectively.
50 sccm was introduced. The conditions for depositing the n-type semiconductor layer and the p-type semiconductor layer were as shown in Table 2, and the conditions for depositing the i-type semiconductor layer were the same as those shown in Table 1 in Experimental Example 1 above. Other operations are the same as those in the first experimental example.

[0046]

[Table 2]

The amorphous silicon germanium solar cell thus produced is irradiated with simulated sunlight having an AM value of 1.5 and a light intensity of 100 mW / cm ² , and an arbitrary 40 places of the amorphous silicon germanium solar cell are irradiated. When the photoelectric conversion efficiency was measured, the variation in the photoelectric conversion efficiency was within ± 4%.

(Comparative Example 2)
A solar cell single cell having an inclined band gap profile was prepared in the same manner as in Experimental Example 2 except that the partition plate provided in the film formation space in the vacuum vessel 202 was removed. Then, when the photoelectric conversion efficiency of the produced solar cell single cell was measured in the same manner as in Experimental Example 2, the variation in the photoelectric conversion efficiency was ± 8%.

When the experimental example 2 was compared with the comparative example 2, the variation in the photoelectric conversion efficiency was reduced by half by providing the partition plate in the film formation space. From the above results, by using the deposited film forming apparatus of the present invention, it is possible to obtain a good solar cell with good reproducibility over a large area when producing the solar cell on a continuously moving strip-shaped substrate. I understood.

(Experimental Example 3) In the deposited film forming apparatus used in Experimental Example 2 described above, one partition plate was used for the second vacuum vessel 202. A solar cell single cell having an inclined band gap profile was produced in the same manner as in Experimental Example 2.

Here, the details of the arrangement of the partition plates in this experimental example will be described. Since the second vacuum vessel 202 in Experimental Example 2 has the same configuration as the vacuum vessel 101 described in Embodiment 1 with reference to FIG.
No. 01 describes the arrangement of the two partition plates.

In the vacuum vessel 101, the partition plate 116 is formed in the film forming space 1 formed in the inner vessel 102a on the left side in the figure.
04a is provided at a position internally dividing 1: 2 from the exhaust side. In this experimental example, a second partition plate having the same configuration as the partition plate 116 is further provided at a point where the film forming space 104a is internally divided into 2: 1 from the exhaust side. As a result, the film forming space 104a is divided into approximately three equal parts along the transport direction of the base 103 by these two partition plates.

When the photoelectric conversion efficiency was measured at arbitrary 35 places of the solar cell produced in the same manner as in Experimental Example 2, the variation in the photoelectric conversion efficiency was within ± 3%. Further, the FF (fill factor) was improved by about 2% as compared with the solar cell of Experimental Example 2.

From the above results, in the deposited film forming apparatus of the present invention, by increasing the number of the partition plates provided in the film forming space, a solar cell with higher reproducibility and more excellent characteristics over a large area can be obtained. I understand.

(Experimental Example 4) Using the deposited film forming apparatus of the second embodiment, the source gas was also supplied from the gas forming pipe to the exhaust side of the film forming space of the second vacuum vessel 202 where the partition was provided. , A solar cell single cell having an inclined band gap profile was prepared in the same manner as in Experimental Example 2. As described above, since the second vacuum vessel 202 has the same configuration as the vacuum vessel 101 in the first embodiment, FIG.
This will be described below.

The inner container 10 on the left side of the vacuum container 101 shown in the figure.
A third gas supply pipe 107c for introducing gas to the exhaust side of the partition plate 116 provided in the film forming space 104a is attached to the film forming space 104a formed in the film forming space 2a. From this gas supply pipe 107c, Si
₂ H ₆ and H ₂ gases were introduced into the film forming space 104a.
The conditions for forming the solar cell single cell at this time are summarized in Table 3 below.

[0057]

[Table 3]

The photovoltaic conversion efficiencies of the thus prepared solar cells were measured at arbitrary 35 locations in the same manner as in Experimental Example 2. As a result, the variation in photoelectric conversion efficiency is ±
It was within 3.5%. In addition, the above-mentioned comparative example 2
(Factor) and V _oc (open circuit voltage) were each increased by 1.5% as compared with the solar cell according to the above.

From the above results, in the deposition film forming apparatus of the present invention, by introducing the raw material gas also into the film forming space on the exhaust side from the partition plate, the solar cell having better reproducibility and more excellent characteristics over a large area. It turned out that a battery was obtained.

[0060]

As described above, according to the present invention, the partition plate for controlling the flow of the raw material gas is provided in the film forming space in a direction intersecting the transport direction of the strip-shaped substrate. There is a difference in the concentration and pressure of the raw material gas on both sides of the film, and it is possible to easily and satisfactorily control the change in the composition in the film thickness direction of the film deposited on the belt-like substrate. Is deposited, so that the deposited film is formed uniformly over a large area in the width direction of the strip-shaped substrate, and there is an effect that a high-quality functional deposited film can be mass-produced with good reproducibility. In particular, there is an effect that it is suitable for producing a high-quality semiconductor thin film having a band gap that continuously changes in the film thickness direction with high productivity. Further, by providing the source gas introduction portions in the film forming spaces on both sides separated by the partition plate, respectively, the source gas is divided more effectively on both sides of the partition plate. The composition change can be made steeper, and the composition can be easily and accurately controlled in the film thickness direction.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a structure of a deposited film forming apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the structure of a deposited film forming apparatus according to another embodiment of the present invention.

[Explanation of symbols]

101, 201-203 Vacuum vessels 102a, 102b, 221 Internal vessels 103, 211 Bases 104a, 104b Film formation spaces 105a, 105b, 224 Electrodes 106a, 106b, 223 Gas heaters 107a, 107b, 107c, 222 Gas supply pipes 108a, 108b , 109a, 109b Adjustment plate 110a, 110b Vacuum gauge 111a, 111b, 216, 226 Exhaust pipe 112a, 112b High frequency power supply 113a, 113b, 204, 205 Gas gate 114, 212 Feed roll 115, 213 Winding roll 116 Partition plate 117a, 117b Projections 118, 225 Lamp heaters 206, 207 Gate gas introduction pipe 214, 215 Vacuum chamber

Claims (4)

(57) [Claims] 1. A vacuum container, and conveying means for continuously conveying a band-shaped substrate in the vacuum container in a longitudinal direction thereof;
A film forming space provided in the vacuum vessel, at least a part of a boundary of which is formed by the band-shaped substrate, and into which a raw material gas and plasma forming energy are introduced; and forming plasma in the film forming space. In the deposited film forming apparatus for forming a deposited film on the surface of the band-shaped substrate, a partition plate for controlling a flow of the source gas is intersected in the film forming space with respect to a transport direction of the band-shaped substrate. A deposited film forming apparatus provided in a direction in which the deposited film is formed. 2. The deposited film forming apparatus according to claim 1, further comprising moving means for reciprocating the partition plate in a direction parallel to the direction in which the strip-shaped substrate is transported. 3. The deposited film forming apparatus according to claim 1, wherein the plasma forming energy is high frequency power. 4. The deposited film forming apparatus according to claim 1, wherein introduction portions for supplying a source gas to the film forming space are provided on both sides of the partition plate.