JP2009218430A - Film formation method, method of manufacturing semiconductor device, and method of manufacturing electronic equipment - Google Patents

Abstract

A film forming apparatus and a film forming method capable of improving the film forming atmosphere are provided. In addition, a film having favorable characteristics is formed by the apparatus and method.
A film forming apparatus of the present invention is a film forming apparatus that solidifies a liquid material by subjecting the liquid material (3) disposed on the substrate (S1) in the processing chamber (11) to a heat treatment. The processing chamber has a stage (15) on which the substrate is mounted, a heating means (15a) for heating the substrate, and a cover (17) that covers the substrate, and an inert gas (N ₂ ) inside the cover. ). For example, the inert gas supplied to the cover is discharged from the space at the bottom of the side wall of the cover. According to such an apparatus, it is possible to perform the heat treatment while limiting the atmospheric gas with which the liquid material on the substrate can come into contact with the cover. Further, a heat treatment can be performed while always supplying a clean inert gas onto the liquid material on the substrate and discharging impurities such as a reaction gas (decomposed gas) generated by heating out of the cover.
[Selection] Figure 1

Description

  The present invention relates to a film forming apparatus and a film forming method, and more particularly to a film forming method using a liquid material and a film forming apparatus used therefor.

  For film formation and patterning of a silicon (Si) film constituting a semiconductor device, a film formation method such as CVD (Chemical Vapor Deposition) or a photolithography method is employed. However, these methods require devices such as a high-vacuum and high-energy device and an exposure / development device, which are high in cost and use efficiency of materials.

  Thus, a technique for forming a Si film by using a liquid material of a silicon precursor, applying only to a desired region, and baking (solidifying) is drawing attention.

For example, Patent Document 1 below discloses a technique for forming all or part of a thin film such as a silicon film using a liquid material.
International Publication WO00 / 59040

  The present inventors are examining a technique for forming a constituent film of a semiconductor device such as a Si film using a liquid material. During film formation using this liquid material, processing is performed in an inert atmosphere in order to prevent deterioration and deterioration of the liquid.

However, according to the study by the present inventors, in the case where the Si liquid material is fired in a low oxygen atmosphere with an oxygen concentration of 1 ppm (parts per million, 1/10 ⁶ ) or less, as will be described in detail later. However, the oxygen concentration in the film was high, for example, about 10 ⁴ ppm, and it was found that further improvement of the film characteristics was necessary.

  A specific aspect of the present invention aims to provide a film forming apparatus and a film forming method capable of improving the film forming atmosphere. It is another object of the present invention to form a film with good characteristics by the apparatus and method.

  A film forming apparatus according to the present invention is a film forming apparatus that solidifies the liquid material by subjecting the liquid material disposed on the substrate in the processing chamber to a heat treatment, and the substrate is mounted in the processing chamber. A heating unit that heats the substrate; a cover that covers the substrate; and a supply unit that supplies an inert gas to the inside of the cover.

  According to such an apparatus, the heat treatment can be performed while limiting the atmospheric gas with which the liquid material on the substrate can come into contact with the cover, so that a film with reduced impurities (for example, oxygen) taken into the film can be formed. Can be membrane.

  For example, the inert gas supplied to the cover is discharged from the space at the bottom of the side wall of the cover.

  According to such an apparatus, it is possible to perform heat treatment on a liquid material on a substrate while always supplying a clean inert gas, and to cover impurities such as reaction gas (decomposition gas) generated by heating. Since the heat treatment can be performed while discharging to the outside, reattachment of impurities (for example, a reaction gas, oxygen, or a compound thereof) into the film can be prevented. Thus, a film with reduced impurities taken into the film can be formed.

  For example, the space is a gas discharge hole provided at the bottom of the side wall of the cover.

  According to such an apparatus, heat treatment can be performed while efficiently discharging impurities such as reaction gas (decomposition gas) generated by heating.

  For example, a gas discharge hole is provided around the substrate, and the inert gas inside the cover is discharged outside the processing chamber.

  According to such an apparatus, heat treatment can be performed while efficiently discharging impurities such as reaction gas (decomposition gas) generated by heating. In addition, impurities such as reaction gas (decomposition gas) can be prevented from entering the processing chamber.

  For example, the supply means has a filter in the flow path of the inert gas.

  According to such an apparatus, heat treatment can be performed while supplying an inert gas having a low impurity (eg, oxygen) concentration onto the liquid material on the substrate.

  Preferably, the oxygen concentration in the processing chamber is 1 ppm or less, and the oxygen concentration of the inert gas is 1 ppm or less. As described above, the oxygen concentration of the processing chamber and the supplied inert gas is preferably adjusted to a state in which the oxygen concentration is suppressed to 1 ppm or less.

  For example, a discharge device for the liquid material is provided in the processing chamber.

  According to such an apparatus, the discharge process and the heat treatment can be performed quickly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or related code | symbol is attached | subjected to what has the same function, and the repeated description is abbreviate | omitted.

<Embodiment 1>
FIG. 1 is a cross-sectional view of an essential part showing a film forming apparatus (a heating apparatus, a baking apparatus, and a semiconductor apparatus manufacturing apparatus) according to the present embodiment. 2A and 2B are a top view and a cross-sectional view illustrating a configuration example of a bell jar used in the film forming apparatus of the present embodiment. FIG. 3 is a cross-sectional view of an essential part showing a film forming process using the film forming apparatus of the present embodiment.

  As shown in FIG. 1, a film forming apparatus 10 of the present embodiment includes a processing chamber (chamber) 11 with a stage (mounting table) 15 in which a heater (heating means) 15a is built, and a bell jar (perger, cover, A lid member (cover) 17.

The bell jar 17 has a supply hole 17a, and the supply hole 17a is connected to an inert gas cylinder (not shown) (here, a nitrogen cylinder) via a gas line (gas supply pipe, tube, gas supply means) 19. Yes. As the inert gas, in addition to nitrogen (N ₂ ), argon (Ar), helium (He), or the like may be used.

  For example, as shown in FIG. 2, the bell jar 17 has a cylindrical side wall, and the ceiling portion has the supply hole 17 a described above. Furthermore, the ceiling portion has a handle portion 17b for conveying the bell jar 17. As a constituent material of the bell jar 17, for example, quartz glass, SUS (stainless steel, iron alloy) can be used. The shape of the bell jar 17 is not limited to the cylindrical shape, and may be a bell shape or a box shape (box shape). The opening bottom surface of the bell jar 17 is larger than the processing substrate (for example, a circular substrate having a diameter of 4 inches), the height is, for example, about 0.5 cm to 30 cm, and the capacity is, for example, about 1 L (liter) to 2 L. . Hereinafter, the unit “liter” is indicated by “L”. A to B indicate a range from A to B.

In the processing chamber 11, an inert gas is purged by a control unit (not shown), and the inert gas is circulated and purified to have an oxygen concentration of 1 ppm or less and a moisture (water vapor, H ₂ O) concentration of −60 at a dew point. It is adjusted to be below ℃. This moisture concentration means that the inside of the processing chamber 11 has a moisture amount that allows water to condense when it reaches −60 ° C. More preferably, the inside of the processing chamber 11 is preferably adjusted so that the oxygen concentration is 1 ppm or less and the moisture concentration is -65 ° C. or less at the dew point.

  The transfer chamber 13 has a substrate insertion door and a connecting door to the processing chamber 11, and the inside thereof is configured to be purged with an inert gas as in the processing chamber 11. After inserting the substrate S1 into the transfer chamber 13 and purging the transfer chamber 13 with nitrogen, the connecting door is opened and the substrate S1 is transferred onto the stage 15 in the processing chamber 11. With this configuration, it is possible to carry in the substrate S1 while preventing intrusion of outside air.

  For example, as shown in FIG. 3A, the silicon precursor liquid material 3 is ejected onto the substrate S1 in a desired shape by using a droplet ejection head 14a. Next, the substrate S <b> 1 is transferred onto the stage 15 through the transfer chamber 13. At this time, the bell jar 17 is disposed in the vicinity of the stage 15 in the processing chamber 11 (see the broken line portion in FIG. 1). Thereafter, the bell jar 17 is disposed on the stage 15 by the bell jar transport mechanism so as to cover the substrate S1. The bell jar transport mechanism, for example, lifts after gripping the handle portion 17b of the bell jar 17, moves horizontally to the stage 15, then descends, and places the bell jar 17 on the stage 15 (see FIG. 1).

  Next, while supplying an inert gas (in this case, nitrogen gas) into the bell jar 17 through the gas line 19, the substrate S1 is heated by the heater 15a, and the silicon precursor liquid material 3 is baked (solidified). A silicon film is formed. The inert gas supplied has an oxygen concentration of 1 ppm or less. The supply flow rate is preferably about 2 to 10 L / min when, for example, a 4 inch substrate is used at 0.5 L / mim or more. As an inert gas supplied into the bell jar 17, Ar, He, or the like may be used in addition to nitrogen. Further, when the bell jar capacity V [L] and the supply flow rate v [L / min] are satisfied, V / v ≦ 2, that is, the inert gas in the bell jar 17 is replaced at a rate of once or more every two minutes. It is preferable to adjust the supply flow rate v.

Here, as shown in FIG. 3B, the supplied inert gas (N ₂ ) is a space generated between the bottom of the side wall of the bell jar 17 and the stage 15 due to the pressure of the supply of the inert gas. It is discharged from (gap) 17c. That is, the inert gas is supplied from above the bell jar 17 and discharged into the processing chamber 11 from the bottom.

  Thus, according to the present embodiment, the film forming atmosphere can be controlled well. Specifically, the atmospheric gas that can be contacted by the silicon precursor liquid material 3 is limited by the bell jar 17, and impurities such as oxygen taken into the film during heating can be reduced. In addition, a clean inert gas having a low oxygen-containing concentration is always in contact with the liquid material 3 of the silicon precursor. Further, since impurities such as reaction gas (decomposition gas, volatile gas, generated gas, calcination gas) generated by heating are discharged out of the bell jar 17, for example, reaction gas, volatile gas, oxygen, or these compounds Impurity reattachment can be prevented.

  In particular, in the firing (heating) step of the liquid material 3 of the silicon precursor, a reaction gas (decomposition gas, volatile gas) such as silane or a silane compound is generated. These gases are easily bonded to oxygen, and can be reattached to the treatment film, take in oxygen, or reattach to the treatment film in a state of being combined with oxygen. Therefore, by exhausting these gases to the outside of the bell jar 17, a silicon film having a low oxygen content can be formed. Further, by reducing the reattachment of impurities as described above, the flatness of the film surface can be improved, for example, within ± 2 nm. Further, the uniformity of the film thickness can be improved.

  In the film forming step, the bell jar 17 to which an inert gas is supplied in advance may be disposed on the substrate S1. Further, the substrate S1 may be transferred onto the stage 15 that has been heated by the heater 15a in advance. Thus, the timing of supplying the inert gas and heating the heater can be adjusted as appropriate.

  In the film forming apparatus, a filter may be disposed in the gas line 19, that is, in the flow path of the inert gas, and the inert gas may be filtered and then supplied into the bell jar 17.

  As the filter, a filter (gas purifier) that removes (traps) gas such as oxygen is preferable. An oxygen / water trap filter manufactured by Agilent Technologies, an oxygen trap filter manufactured by Osaka Chemical Co., and a fine pure manufactured by Liquid Gas. Or a gas purification filter (Mat / Sen) manufactured by Shimadzu DLC or a Click-On gas filter SGT can be used.

(Example)
Next, characteristics of various silicon films formed using the film formation apparatus of this embodiment will be described. FIG. 4 is a table summarizing the processing conditions of various silicon films, and FIG. 5 is a graph showing the oxygen concentration of various silicon films.

  As a liquid material for the silicon precursor, a solution obtained by dissolving a silane compound (hydrogenated silane polymer: molecular weight 2800) in an organic solvent (toluene) is used. Quartz having an outer diameter of 115.8 mm, a height of 103.2 mm, and a thickness of about 5 mm Using a glass bell jar, an amorphous silicon film was formed by processing at a heater temperature of 540 ° C. and a nitrogen flow (nitrogen supply flow rate) of 2 L / mim to 5 L / min.

  The samples (a) to (e) in FIG. 4 will be described. The sample (a) was fired using the bell jar while performing a nitrogen flow of 5.0 L / min. In sample (b), the nitrogen flow was not performed, but the baking was performed in the bell jar. Moreover, in the sample (c), it baked using the said bell jar, performing the flow of 2.0 L / min filtered nitrogen. In the sample (d), the above bell jar was used for firing while performing a filtered nitrogen flow of 5.0 L / min. Sample (e) was fired in a bell jar with a height of about 5 mm without nitrogen flow. Sample (f) is a comparative example in which firing was performed in a processing chamber without using a bell jar.

FIG. 5 shows the analysis results of each sample film by SIMS (Secondary Ion-microprobe Mass Spectrometer), where the vertical axis is the oxygen concentration (Concentration, atoms / cc), and the horizontal axis is the depth of the film. (Depth, nm). Since each sample film has a different film thickness after firing and a film thickness of a natural oxide film formed on the surface of the film, the minimum value Cmin of the oxygen concentration in the film is compared here. The minimum value Cmin (f) of the oxygen concentration in the film of the sample (f) is about 5 × 10 ²⁰ (atoms / cc), and about 10,000 ppm of oxygen exists in the film. On the other hand, Cmin (a) of sample (a) was about 9 × 10 ¹⁹ (atoms / cc), and the oxygen concentration in the film was reduced. Further, in the filtered sample (d), Cmin (d) is about 2.1 × 10 ¹⁹ (atoms / cc), and the oxygen concentration in the film is further improved.

In the samples (d) and (c) subjected to filtering, Cmin (d) is about 2.1 × 10 ¹⁹ (atoms / cc) and Cmin (c) is about 4 × 10 ¹⁹ (atoms / cc). cc), the higher the flow rate of nitrogen, the lower the oxygen concentration in the film.

Further, in the sample (b) in which the nitrogen flow was not performed, Cmin (b) is about 4 × 10 ¹⁹ (atoms / cc), and even if it is covered with a bell jar, an effect of reducing oxygen in the film can be obtained. found. Further, in the sample (e) covered with a small capacity bell jar without performing nitrogen flow, Cmin (e) was about 3 × 10 ¹⁹ (atoms / cc).

  In this way, it is confirmed that the oxygen concentration in the film is reduced by firing while the silicon precursor liquid material is covered with a bell jar, and the oxygen concentration in the film is further reduced by performing nitrogen flow. did it. It was also confirmed that the oxygen concentration in the film was further reduced by performing the filtered nitrogen flow.

  Such analysis results can be considered as follows. As described above, the liquid material and the reaction gas at the time of firing thereof easily combine with oxygen, and have a reactivity capable of absorbing oxygen in the processing chamber as needed. Therefore, it is considered that the oxygen concentration in the film could be reduced only by limiting the amount of the atmospheric gas that can be contacted with the silicon precursor liquid material.

  Furthermore, by performing the nitrogen flow, the reaction gas at the time of firing the liquid material of the silicon precursor could be discharged, the oxygen uptake by the reaction gas and the reattachment to the film were reduced, and the oxygen concentration in the film could be reduced. Seem.

  In addition, it is considered that the oxygen concentration in the film could be reduced by reducing the amount of oxygen that can come into contact with the liquid material of the silicon precursor by flowing nitrogen with a low oxygen content by filtering.

  As described above in detail, according to the film forming apparatus and the film forming method of the present embodiment, a film having good characteristics can be formed.

  FIG. 6 is a side view showing another configuration example of the bell jar used in the film forming apparatus of the present embodiment. In the above embodiment (FIGS. 1 and 3B), the supplied inert gas is generated between the bottom of the side wall of the bell jar 17 and the stage 15 by the pressure of the supply of the inert gas. Although exhausted from the space (gap) 17c, as shown in FIG. 6, a hole (notch, gas exhaust hole) 17d may be provided at the bottom of the side wall of the bell jar 17, and the inert gas may be exhausted from this hole. .

  FIG. 7 is a cross-sectional view of an essential part showing another configuration of the film forming apparatus of the present embodiment. In the above embodiment, the liquid material is discharged (applied) onto the substrate and then loaded into the film forming apparatus (FIG. 1). However, as shown in FIG. May be provided. 21a is a droplet discharge head, and 23 is a stage. Further, the transfer chamber 25 may be provided as the carry-in side chamber and the carry-out side chamber as the carry-out side chamber. That is, after the discharge and firing processes, the substrate S1 is stored in a transfer chamber 25 that has been purged with nitrogen in advance, the connecting door between the processing chamber 11 and the transfer chamber 25 is closed, and these spaces are isolated. The substrate S1 is taken out. In addition, the same code | symbol is attached | subjected to what has the same function as FIG. 1, and the repeated description is abbreviate | omitted. In addition, you may use various printing apparatuses, such as a spin coat apparatus, a roll coat apparatus, a convex printing apparatus, and an intaglio printing apparatus, as a discharge part.

  FIG. 8 is a diagram illustrating an example of a transport mechanism of the film forming apparatus according to the present embodiment. The substrate transport mechanism for transporting the substrate S1 from the transport chamber 13 to the stage (discharge unit) 23 to the stage (heating unit) 15 to the transport chamber 25 is not particularly limited. For example, the transport mechanism (transport unit) shown in FIG. ) Can be used. In this mechanism, a substrate elevating mechanism 23a is prepared in advance inside the stages 23, 15, and the substrate S1 is lifted. The arm 28a of the robot 28 is inserted into the space on the back surface of the substrate S1, and is transferred onto the stage 15 by the rotation or movement of the shaft 28b. In addition, a transport mechanism such as a belt conveyor may be used. Further, the transport mechanism may be changed in each transport process between the transport chamber 13 → the stage (discharge unit) 23 → the stage (heating unit) 15 → the transport chamber 25.

  In the above embodiment, the heater 15a in the stage 15 is used as the heating means. However, a lamp (infrared ray, far infrared ray) or a laser may be used. For example, a lamp or a laser device may be installed on the inner wall (for example, the ceiling) of the bell jar, and the substrate S1 may be heated by these. In addition, heating may be performed by an energy beam such as plasma, electron beam, ion beam, or microwave. Also in this case, an energy beam irradiation device is installed on the inner wall (for example, the ceiling) of the bell jar to heat the substrate S1.

  Further, for example, the film formed by the baking treatment of the above embodiment is an amorphous film. The amorphous film formed by the above film formation method may be subjected to laser annealing to form a polycrystalline silicon film. Of course, it is also possible to bake the liquid material of the silicon precursor into polycrystalline silicon by adjusting conditions such as temperature.

The silicon precursor liquid material used in the above embodiment is not particularly limited, but as a specific example, for example, a liquid material in which hydrogenated polysilane is dissolved in a solvent can be used. A solution in a dispersed state may be used instead of a dissolved state. This hydrogenated polysilane is formed by polymerizing a silane compound (silicon hydride compound). Such a silane compound is represented by, for example, a general formula Si _n H _m (where n and m are each an independent integer). As the solvent, hydrocarbon solvents such as hexane, octane, cyclohexane, cyclooctane, decalin, and toluene can be used. The hydrogenated polysilane solution can be generated by irradiating the silane compound solution with, for example, ultraviolet rays and polymerizing the solution. A silicon film is formed by subjecting this hydrogenated polysilane solution to the above baking treatment.

  Moreover, in the said embodiment, although the liquid material of the silicon precursor was demonstrated to the example, it is applicable also to another solution process. When the solution process is used, a volatile component such as a solvent or a gas due to heating is easily generated from the liquid material, and an improvement in film forming characteristics can be expected by the film forming apparatus (film forming method).

(Manufacture of semiconductor devices)
Next, a manufacturing process of a semiconductor device using the film forming apparatus and the film forming method will be described. FIG. 9 is a cross-sectional view showing the configuration of the HIT type solar cell. FIG. 10 is a cross-sectional view showing the structure of the thin film transistor.

  As shown in FIG. 9, a HIT (Heterojunction with Intrinsic Thin-layer) solar cell (photoelectric conversion device) includes a lower electrode 113, a first conductive silicon film (substrate) 115, and an intrinsic amorphous silicon film. 117, a second conductivity type silicon film 119, an upper electrode 121, and an auxiliary electrode 123.

  The first and second conductivity types are n-type or p-type. In the case of n-type, n-type impurities such as phosphorus are included, and in the case of p-type, p-type impurities such as boron are included. Intrinsic (i-type) is a semiconductor film that is not doped with impurities and has a lower impurity concentration than an n-type or p-type semiconductor film (layer).

  An example of the manufacturing process of such a HIT type solar cell will be described. For example, a conductive film such as aluminum (Al) is formed on the back surface of the p-type silicon substrate 115 by a sputtering method or the like, and the lower electrode 113 is formed by patterning. Next, a liquid material of a silicon precursor is applied in a desired shape over the silicon substrate 115 (see FIG. 3A). Next, the film is transferred into the film forming apparatus 10 shown in FIG. 1, the silicon substrate 115 is covered with the bell jar 17, and heated (fired) while performing a nitrogen flow as described above to form an amorphous silicon film 117. Next, an n-type silicon film 119 is formed on the amorphous silicon film 117. In forming the n-type silicon film 119, the liquid material of the silicon precursor in which a dopant such as phosphorus is dissolved may be baked as described above using the film forming apparatus 10 shown in FIG. Next, an upper electrode 121 made of indium tin oxide (ITO) or the like and an auxiliary electrode 123 made of Al or the like are formed on the n-type silicon film 119. These conductive films can be formed by patterning after being formed using a sputtering method or the like. Note that a liquid in which conductive fine particles are dispersed may be used in forming the conductive film. Thus, it is also possible to form all the constituent films of the apparatus by using a liquid process.

  As shown in FIG. 10, the thin film transistor has a stacked structure of an insulating substrate 213, a silicon film 215, a doped silicon film 217, a gate insulating film 219 and a gate electrode 221, and the gate electrode 221 is covered with an interlayer insulating film 223. The doped silicon film 217 located on both sides of the gate electrode 221 is connected to the wiring (source electrode and drain electrode) M1 through the contact hole C1 on the upper side.

  An example of a manufacturing process of such a thin film transistor will be described. For example, a liquid material of a silicon precursor is applied in a desired shape over an insulating substrate 213 such as a glass substrate (see FIG. 3A). Next, the film is transferred into the film forming apparatus 10 shown in FIG. 1, the silicon substrate 213 is covered with the bell jar 17, and heated (fired) while performing a nitrogen flow as described above to form a polycrystalline silicon film 215. Next, a doped silicon film 217 is formed on both ends of the silicon film 215. Also in the formation of the silicon film 217, the liquid material of the silicon precursor in which the dopant is dissolved may be baked and formed as described above using the film forming apparatus 10 shown in FIG. Next, a gate insulating film 219 is formed in a region excluding the contact region (C1 portion). The gate insulating film 219 is also formed by baking the silicon precursor liquid material as described above using the film forming apparatus 10 shown in FIG. 1 to form a silicon film and then oxidizing the film. Also good. Next, a conductive film such as tantalum (Ta) is deposited on the gate insulating film 219 and patterned to form the gate electrode 221. Thereafter, an interlayer insulating film 223 is formed in a region excluding the contact region (C1 portion), and a wiring (source electrode and drain electrode) M1 made of a conductive film such as Al is formed inside and above the contact hole C1. . The interlayer insulating film 223 may be formed in the same manner as the gate insulating film 219. The wiring M1 can be formed by forming a conductive film using a sputtering method or the like and then patterning the conductive film. Note that a liquid in which conductive fine particles are dispersed may be used in forming the conductive film. Thus, it is also possible to form all the constituent films of the apparatus by using a liquid process.

  Thus, the film characteristics can be improved by using the film formation apparatus and the film formation method of this embodiment for forming a film (especially a silicon film) included in the semiconductor device. The performance of the apparatus can be improved.

  Note that, in the above, a solar cell or a thin film transistor is applied as an example of a semiconductor device using the film formation apparatus and the film formation method of the present embodiment, but the present invention is not limited thereto, and the film formation apparatus of the present embodiment and The film formation method can be widely applied to semiconductor devices having a semiconductor film (particularly, a silicon film).

(Electronics)
The semiconductor device such as the solar cell or the thin film transistor can be incorporated into various electronic devices. There is no limitation on applicable electronic devices, but semiconductor devices such as solar cells and thin film transistors can be incorporated in electronic devices such as a calculator, a mobile phone, an electronic notebook, an electronic dictionary, a wristwatch, and a clock.

  The thin film transistor can be used as a pixel circuit or a drive circuit of an electro-optical device (display device). For example, the thin film transistor can be incorporated in an electro-optical device (display portion) such as a video camera or a television.

<Embodiment 2>
In the first embodiment, the inert gas supplied into the bell jar 17 is discharged from the gap 17c or the hole 17d at the bottom of the side wall of the bell jar 17, but the inert gas is discharged outside the processing chamber 11 by the exhaust mechanism. It may be discarded.

  FIG. 11 is a cross-sectional view of an essential part showing a film forming apparatus (a heating apparatus, a baking apparatus, a semiconductor apparatus manufacturing apparatus) according to the present embodiment. FIG. 12 is a top view of the stage of the film forming apparatus of the present embodiment. Note that components having the same functions as those in FIGS. 1 and 7 are denoted by the same reference numerals, and repeated description thereof is omitted.

  The difference from the first embodiment is that an exhaust mechanism 30 is provided. The exhaust mechanism 30 includes an exhaust pipe 30 b connected to an exhaust hole 30 a provided at the bottom of the processing chamber 11. Reference numeral 30c provided in the exhaust pipe 30b is an exhaust shutter (valve) that prevents the backflow of exhaust gas. On the other hand, an exhaust hole 15b is provided in the outer periphery of the mounting area of the substrate S1 on the stage 15. The shape and number of the exhaust holes 15b are not particularly limited. For example, as shown in FIG. 2, a plurality of substantially circular exhaust holes 15b are provided on the outer periphery of the mounting region of the substrate S1. The plurality of exhaust holes 15 are connected, for example, inside the stage 15 and extend to the exhaust hole 30 a at the bottom of the processing chamber 11. From the exhaust pipe 30b, natural exhaust may be performed, or suction exhaust may be performed by connecting to a decompression pump or the like. Reference numeral 17e denotes a resin member (for example, an O-ring) adhered to the entire bottom surface of the side wall of the bell jar 17 and improves the adhesion between the stage 15 and the bell jar 17. With this configuration, the airtightness in the bell jar 17 is improved. Further, with this configuration, exhaust (suction) efficiency can be improved. Further, the intrusion of the exhaust gas into the processing chamber 11 can be reduced.

Note that reference numeral 24 in FIG. 11 denotes a filter, which clearly indicates the filter described in the first embodiment. Reference numeral 26 denotes a flow meter. Note that a flow meter may be arranged in the film formation apparatus of the first embodiment (FIGS. 1 and 7). Reference numeral 27 denotes a dry pump, which adjusts the pressure (depressurized state) in the transfer chamber 13 and the bell jar 17 to, for example, about 10 ⁻¹ Toll ( ¹ Toll = (101325/760) Pa).

  The film formation process using the film formation apparatus of this embodiment is the same as that of Embodiment 1. That is, the substrate S1 is carried in, and the liquid material 3 of the silicon precursor is discharged into a desired shape using the droplet discharge head 21a thereon, and then the substrate S1 is transferred onto the stage 15. At this time, the pelja 17 is disposed in the vicinity of the stage 15 in the processing chamber 11. Thereafter, the bell jar 17 is arranged on the stage 15 by the bell jar transport mechanism so as to cover the substrate S1 and the exhaust hole 15b, and an inert gas (here, nitrogen gas) is supplied into the bell jar 17 through the gas line 19. While heating the substrate S1 with the heater 15a, the silicon precursor liquid material 3 is baked to form a silicon film. At this time, the supplied inert gas is discharged out of the processing chamber 11 by the exhaust mechanism 30 described above. Also in this embodiment, the same effects as those of the first embodiment are obtained.

  FIG. 13 is a cross-sectional view of an essential part showing another configuration of the film forming apparatus of the present embodiment. In addition, the same code | symbol is attached | subjected to what has the same function as FIG. 11, and the repeated description is abbreviate | omitted. In FIG. 11, the exhaust holes 15 b are provided in the stage 15. However, the exhaust holes 30 a are arranged on the bottom surface of the processing chamber 11 on the outer periphery of the stage (substrate S 1 mounting region) so as to cover the stage 15 and the exhaust holes 30 a. It is good also as a structure which arrange | positions the bell jar 17. FIG. Also in such a film forming apparatus, an inert gas (here, nitrogen gas) is supplied into the bell jar 17 through the gas line 19 and is discharged out of the processing chamber 11 by the above-described exhaust mechanism 30, while being heated by the heater 15 a. The substrate S1 can be heat-treated.

<Embodiment 3>
In the second embodiment, only the inert gas is supplied into the bell jar 17, but a mechanism capable of supplying other gases may be used.

  FIG. 14 is a cross-sectional view of an essential part showing a film forming apparatus (heating apparatus, baking apparatus, semiconductor device manufacturing apparatus) of the present embodiment. In addition, the same code | symbol is attached | subjected to what has the same function as FIG. 11, and the repeated description is abbreviate | omitted.

  The difference from Embodiment 1 is that two supply holes 17a are provided in the bell jar 17, one side is supplied with an inert gas via a gas line 19, and the other side is supplied with a gas line (gas supply pipe, tube, gas supply). Means) Another gas is supplied through 40. Examples of other gases include a dopant gas used when doping impurities into the silicon film, and a gas containing oxygen or an oxygen compound (oxidizing gas) used when oxidizing the silicon film. . Reference numeral 41 denotes a flow meter. Three or more gas lines (supply holes 17a) may be provided.

  A film forming process using the film forming apparatus of this embodiment will be described. For example, in forming the n-type silicon film 119 of the solar cell in “Manufacturing the semiconductor device” in the first embodiment, a liquid material of a silicon precursor is applied and added to the nitrogen flow similar to that in the second embodiment. And baking while supplying an n-type dopant gas. Further, the doped silicon film 217 of the thin film transistor can be formed similarly.

Further, when forming the gate insulating film 219 and the interlayer insulating film 223, similarly to the second embodiment, the silicon precursor film was formed by heating at 100 to 200 ° C., more preferably 180 to 200 ° C. while flowing nitrogen. Thereafter, the silicon precursor film can be changed to a silicon oxide film by heating while supplying an oxidizing gas (for example, air). The heating condition is, for example, about 400 hours at 400 ° C. Thereafter, an inert gas (N ₂ ) is supplied into the bell jar 17 and the oxidizing gas in the bell jar 17 is discharged.

  As described above, in the film forming apparatus and the film forming method of the present embodiment, by increasing the number of gas lines connected to the bell jar 17, not only the silicon film forming process but also the dopant mixing process and the oxidizing process are performed. be able to. Further, these various films can be continuously formed, and are effective for use in manufacturing a semiconductor device having a laminated structure of these films.

  Furthermore, by having the exhaust mechanism 30 described in detail in the second embodiment, it is possible to prevent the dopant gas and the oxidizing gas from entering the processing chamber 11 from the bell jar 17, and the inside of the processing chamber 11. Can reduce pollution.

  In FIG. 14, a plurality of gas lines are connected to one bell jar 17. However, a plurality of bell jars 17 are prepared such as providing a bell jar for each line, and the bell jar 17 used according to the gas to be supplied is prepared. It may be divided.

  In addition, the Example and application example demonstrated through the said Embodiment 1-3 can be combined suitably according to a use, or can be used by adding a change or improvement, and this invention is a thing of embodiment mentioned above. It is not limited to the description.

FIG. 3 is a cross-sectional view of a main part showing the film forming apparatus (heating apparatus, baking apparatus, semiconductor device manufacturing apparatus) of the first embodiment. 3A and 3B are a top view and a cross-sectional view illustrating a configuration example of a bell jar used in the film forming apparatus according to Embodiment 1. FIG. 3 is a cross-sectional view of a main part showing a film forming process using the film forming apparatus of the first embodiment. 4 is a table summarizing processing conditions for various silicon films in Examples of the first embodiment. 3 is a graph showing oxygen concentrations of various silicon films in the example of the first embodiment. It is a side view which shows the other structural example of the bell jar used for the film-forming apparatus of Embodiment 1. FIG. FIG. 6 is a cross-sectional view of a main part showing another configuration of the film forming apparatus of the first embodiment. 3 is a diagram illustrating an example of a transport mechanism of the film forming apparatus according to Embodiment 1. FIG. It is sectional drawing which shows the structure of a HIT type solar cell. It is sectional drawing which shows the structure of a thin-film transistor. FIG. 5 is a main part sectional view showing a film forming apparatus (a heating apparatus, a baking apparatus, a semiconductor device manufacturing apparatus) according to a second embodiment. 6 is a top view of a stage of a film forming apparatus according to Embodiment 2. FIG. FIG. 10 is a main part cross-sectional view showing another configuration of the film forming apparatus of the second embodiment. FIG. 10 is a main-portion cross-sectional view illustrating a film forming apparatus (a heating apparatus, a baking apparatus, and a semiconductor apparatus manufacturing apparatus) according to a third embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Liquid material, 10 ... Film-forming apparatus, 11 ... Processing chamber, 13 ... Transfer chamber, 14a ... Droplet discharge head, 15 ... Stage, 15a ... Heater, 15b ... Exhaust hole, 17 ... Berja, 17a ... Supply hole, 17b ... handle part, 17c ... space, 17d ... resin member, 19 ... gas line, 21 ... discharge part, 21a ... droplet discharge head, 23 ... stage, 23a ... substrate lifting mechanism, 24 ... filter, 25 ... exhaust chamber, 26 ... Flow meter, 27 ... Dry pump, 28 ... Robot, 28a ... Arm, 28b ... Shaft, 30 ... Exhaust mechanism, 30a ... Exhaust hole, 30b ... Exhaust pipe, 30c ... Exhaust shutter, 40 ... Gas line, 41 ... Flow rate 113 ... Lower electrode, 115 ... Silicon film (substrate), 117 ... Amorphous silicon film, 119 ... Silicon film, 121 ... Upper electrode, 123 ... Auxiliary electrode, 2 3 ... insulating substrate, 215 ... silicon film, 217 ... doped silicon film, 219 ... gate insulating film, 221 ... gate electrode, 223 ... interlayer insulation film, C1 ... contact hole, M1 ... wiring, S1 ... substrate

Claims (8)

A film forming apparatus that solidifies the liquid material by performing a heat treatment on the liquid material disposed on a substrate in a processing chamber,
In the processing chamber,
A stage on which the substrate is mounted;
Heating means for heating the substrate;
A cover that covers the substrate,
A film forming apparatus comprising supply means for supplying an inert gas into the cover.   The film forming apparatus according to claim 1, wherein the inert gas supplied to the cover is discharged from a space at a bottom portion of a side wall of the cover.   The film forming apparatus according to claim 1, wherein the space is a gas discharge hole provided in a bottom portion of a side wall of the cover.   The film forming apparatus according to claim 1, further comprising a gas discharge hole around the substrate, and discharging an inert gas inside the cover to the outside of the processing chamber.   The film forming apparatus according to claim 1, wherein the supply unit includes a filter in the flow path of the inert gas.   6. The film forming apparatus according to claim 1, wherein the oxygen concentration in the processing chamber is 1 ppm or less.   The film forming apparatus according to claim 1, wherein an oxygen concentration of the inert gas is 1 ppm or less.   The film forming apparatus according to claim 1, further comprising a discharge device for the liquid material in the processing chamber.

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