JPH0713941B2 - Method of forming deposited film - Google Patents

Description

The present invention relates to a deposited film forming method in which heat is used as excitation energy to form a photoconductive film, a semiconductor or an insulating film on a predetermined support, and more specifically, thermal energy The source gas is excited and decomposed by the addition of the above, and amorphous silicon (hereinafter a) is formed on a predetermined support.
-Si) and a method for forming a deposited film.

Conventionally, as a method of forming a-Si deposited film, SiH ₄ or Si
Glow discharge deposition method and thermal energy deposition method using ₂ H ₆ as a raw material are known. That is, these deposition methods are
This is a method in which SiH ₄ or Si ₂ H ₆ as a source gas is decomposed by electric energy or thermal energy (excitation energy) to form a deposited film of a-Si on a support. It is used for various purposes as a conductive film, a semiconductor, an insulating film, or the like.

However, in the glow discharge deposition method, in which a deposited film is formed under high-power discharge, it is difficult to control reproducible and stable conditions such as the fact that a uniform discharge distribution state cannot always be obtained. The influence of high-power discharge on the film inside is large, it is difficult to secure the uniformity of the electrical and optical characteristics of the formed film and the stability of quality, the surface of the film is disturbed during deposition, and the inside of the deposited film Is likely to cause defects. In particular, it was very difficult to uniformly form a thick deposited film by this method in terms of electrical and optical characteristics.

On the other hand, also in the thermal energy deposition method, since a high temperature of 400 ° C. or higher is usually required, the support material used is limited, and in addition, useful bonded hydrogen atoms in desired a-Si are released. Since the probability increases, it is difficult to obtain the desired characteristics.

So, as one method to solve these problems,
A-Si made of a silicon compound other than SiH ₄ and Si ₂ H ₆ as a raw material
Low energy calorific energy deposition method (thermal CVD) is attracting attention.

This low calorific thermal energy deposition method uses low-temperature heating instead of glow discharge or high-temperature heating in the above-described method as excitation energy, and a-Si deposited film is produced at a low energy level. It enables you to do it. Further, the lower the temperature, the easier it is to uniformly heat the raw material gas, and it is possible to perform high-quality film formation while maintaining uniformity, with lower energy consumption than the deposition method described above. Is easy to control and stable reproducibility can be obtained. Further, it is not necessary to heat the support to a high temperature, and there is an advantage that the selectivity to the support is widened.

The present invention has been made in view of the above points, and by performing film formation without generating plasma in the deposition chamber by using low-level thermal energy as excitation energy, high quality is maintained while maintaining high quality. It is an object to provide a thermal energy deposition method capable of forming a deposited film containing silicon atoms at a film rate.

Another object of the present invention is to form a high-quality deposited film that secures stable quality of uniformity of electrical and optical characteristics even when forming a large-area, thick-film deposited film. To provide a way to do it.

As a result of earnest studies, the present invention has found that these objects can be achieved by the general formula; (Si _n H
It has been completed by finding out what is achieved by using a linear silane compound represented by _{2n + 2} (n ≧ 1) in a mixed state with a halogen compound.

That is, the method for forming a deposited film according to the present invention is carried out by using the general formula; Si _n H in a deposition chamber in which a support maintained at 150 ° C to 300 ° C is arranged.
_A linear silane compound represented by _{2n + 2} (n ≧ 1),
A gaseous atmosphere of a halogen gas selected from I ₂ , Cl ₂ and Br ₂ and a compound containing an atom belonging to Group III or Group V of the periodic table is formed, and plasma is generated in the deposition chamber. The heat energy is supplied without supplying the obtained electric energy to excite the compound to form a deposited film containing silicon atoms and atoms belonging to Group III or Group V of the periodic table on the support. Characterize.

In the method of the present invention, a silicon compound as a raw material for supplying Si and a compound containing these atoms for introducing an atom belonging to Group III or V of the periodic table are used as the raw material, The deposited film is a deposited film containing silicon atoms and atoms belonging to Group III or Group V of the periodic law, and can be used for various purposes as a functional film such as a photoconductive film or a semiconductor film.

The raw material for supplying Si used in the method of the present invention is a linear silane compound represented by the general formula: Si _n H _{2n + 2} (n ≧ 1), and a good quality a-Si deposited film is obtained. To form
It is desirable that n in the above formula is 1 to 15, preferably 2 to 10, and more preferably 2 to 6.

However, when such a linear silane compound uses heat energy as excitation energy, efficient excitation and decomposition cannot be obtained, and a good film formation rate cannot be obtained.

Therefore, in the method of the present invention, a halogen compound is mixed with the linear silane compound in order to more efficiently promote the excitation and decomposition of the linear silane compound by thermal energy.

The halogen compound mixed with the linear silane compound in the method of the present invention is a compound containing a halogen atom, and it is possible to more efficiently promote the excitation and decomposition of the linear silane compound by thermal energy. It can be done. Examples of such halogen compounds include Cl ₂ , B
Examples thereof include halogen gases such as r ₂ , I ₂ , and F ₂ .

The proportion of the halogen compound mixed with the a-Si forming raw material compound in the method of the present invention varies depending on the kind of the a-Si film forming raw material compound and the halogen compound used, but is 0.001 Vol% to 95Vol%, preferably 0.1Vol%
Used within the range of ~ 70Vol%.

In the deposited film formed by the method of the present invention, for example, B, A
As a raw material used for introducing an atom belonging to Group III of the periodic table such as l, Ga, In and Tl or Group V such as N, P, As, Sb, Bi, etc., a raw material containing these atoms, A compound that is easily excited and decomposed by thermal energy is used, and examples of such a compound include PH ₃ , P ₂ H ₄ , PF ₃ , PF ₅ , PCl ₃ , and A.
sH ₃ , AsF ₃ , AsF ₅ , AsCl ₃ , SbH ₃ , SbF ₅ , BiH ₃ , BF ₃ , BCl
₃ , BBr ₃ , B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₆ H ₁₀ , B ₆ H ₁₂ , AlCl _{3 and the} like.

In the method of the present invention, a silicon compound as described above in a gas state and a compound containing an atom belonging to Group III or Group V of the periodic table are introduced into a deposition chamber, and thermal energy is applied to these compounds. When applied, these are excited and decomposed, and a deposited film (a-Si film) containing silicon atoms and atoms belonging to Group III or Group V of the periodic table is formed on the support placed in the deposition chamber.

Next, the application of heat energy to the silicon compound gas introduced into the battlefield deposition chamber is performed by Joule heat generation element,
It is performed using a high frequency heating means or the like.

The Joule heat generating element may be a heater such as a heating wire or an electric heating plate, and the high frequency heating means may be induction heating or dielectric heating.

Explaining an embodiment using the Joule heat generating element, the heater is brought into contact with or close to the back surface of the support to conductively heat the surface of the support to thermally excite and thermally decompose the raw material gas in the vicinity of the surface to decompose the decomposition product into the support. Deposit on the surface. Alternatively, the heater can be placed near the surface of the support.

Hereinafter, the method of the present invention will be described in detail with reference to FIG.

FIG. 1 is a schematic configuration diagram of a deposited film forming apparatus for forming a functional film such as a photoconductive film made of a-Si, a semiconductor film, or an insulator film on a support.

The deposited film is formed inside the deposition chamber 1.

Reference numeral 3 which is placed inside the deposition chamber 1 is a support table on which a support is arranged.

Reference numeral 4 is a heater for heating the support, and the conductor 4 supplies power to the heater 4. A gas introducing pipe for introducing a raw material gas of a-Si and a gas such as a carrier gas used as necessary into the deposition chamber 1 is connected to the deposition chamber 1. The other end of the gas introduction pipe 17 is connected to gas forming sources 9, 10, 11, 12 for forming a raw material gas for forming a-Si and a gas such as a carrier gas used as necessary. Corresponding flow meters 15-1, 15-2, 15-3, 15-4 correspond to measure the flow rate of each gas flowing from the gas forming sources 9, 10, 11, 12 toward the deposition chamber 1. The gas introduction pipes 17-1, 17-2, 17-3, 17-4 are branched. Before and after each flow meter, valves 14-1, 14-
2,14-3,14-4,16-1,16-2,16-3,16-4 are provided,
By adjusting these valves, a predetermined flow rate of gas can be formed. Reference numerals 13-1, 13-2, 13-3, 13-4 are pressure meters for measuring the pressure on the high pressure side of the corresponding flow meter.

The respective gases that have passed through the flow meter are mixed and introduced into the deposition chamber 1 under reduced pressure by an exhaust device (not shown). The pressure meter 18 measures the total pressure of the mixed gas.

A gas exhaust pipe 20 is connected to the deposition chamber 1 to reduce the pressure inside the deposition chamber 1 and to exhaust the introduced gas. The other end of the gas exhaust pipe is connected to an exhaust device (not shown).

In the present invention, the number of gas supply sources 9, 10, 11, 12 is appropriately set.
It can be increased or decreased.

That is, when using a single source gas, one gas supply source is sufficient. However, when two kinds of raw material gases are mixed and used, two or more are required when mixing a single gas (catalyst gas or carrier gas).

Since some raw materials do not become gas at room temperature but remain liquid, a vaporizer (not shown) is installed when using a liquid raw material. Vaporizers include those that utilize heating and boiling, and those that allow a carrier gas to pass through a liquid raw material. The raw material gas obtained by vaporization is introduced into the deposition chamber 1 through a flow meter.

A typical PIN using the device shown in FIG.
Using an example of the method of forming a diode-type diode device,
The a-Si deposited film forming method of the present invention will be described in more detail.

FIG. 2 is a schematic cross-sectional view for explaining the structure of a typical PIN diode device obtained by the present invention.

21 is a support, 22 and 26 are thin film electrodes, 23 is a P-type a-Si
A layer, 24 is an I-type a-Si layer, 25 is an N-type a-Si layer, 27 is a semiconductor layer, and 28 is a conducting wire. Semi-conductive as the support 21,
An electrically insulating material is preferably used. Examples of the semiconductive support include a plate made of a semiconductor such as Si or Ge.

As the electrically insulating support, a film or sheet of synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and polyamide, glass, ceramics, paper and the like are usually used. .

Particularly, in the method of the present invention, the temperature of the support is 150 to 3
Since the temperature can be set to a relatively low temperature of about 00 ° C., it is made of a material having low heat resistance, which cannot be applied to the conventional glow discharge deposition method or thermal energy deposition method among the materials forming the support. It has also become possible to use a support.

The thin film electrode 22 is, for example, NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, P
It can be obtained by providing a thin film of t, Pd, In ₂ O ₃ , SnO ₂ , ITO (In ₂ O ₃ + SnO ₂ ) or the like on a support using a method such as vacuum deposition, electron beam deposition, or sputtering.

The thickness of the electrode 22 is 30 to 5 × 10 ⁴ Å, more preferably 1
It is desirable to set it to 00-5 × 10 ³ Å.

In order to make a predetermined layer among the layers forming the a-Si semiconductor layer 27 N-type or P-type as desired, N-type impurities or P-type impurities are formed during layer formation. It suffices to dope the layer while controlling its amount.

Examples of P-type impurities doped in the semiconductor layer include atoms belonging to Group III of the periodic table, among which, for example, B, Al, G
Preferred examples thereof include a, In, Tl, and the like. Examples of the N-type impurities include atoms belonging to Group V of the periodic table, among which, for example,
N, P, As, Sb, Bi and the like are mentioned as preferable ones, but especially
B, Ga, P, Sb, etc. are optimal.

Semiconductor layer for imparting desired conductivity type in the present invention
The amount of impurities doped in 27 is appropriately determined according to desired electrical and optical characteristics.
In the case of group III impurities, doping should be carried out so as to be in the range of 3 × 10 ^{−2 to 4} atomic%, and in the case of group V impurities of the periodic table, it should be in the range of 5 × 10 ^{−3 to 2} atomic%. Doping so that

In order to dope the above-mentioned impurities into a predetermined layer in the layers forming the semiconductor layer 27, a raw material for introducing impurities may be introduced into the deposition chamber in a gas state when the layer is formed. As such a raw material for introducing impurities, those which can be easily gasified at room temperature and atmospheric pressure in a gas state or at least under layer forming conditions or by a vaporizer are adopted.

As the raw material substance (impurity gas) for introducing such impurities, specifically, PH ₃ , P ₂ H ₄ , P for introducing N-type impurities.
F ₃ , PF ₅ , PCl ₃ , AsH ₃ , AsF ₃ , AsF ₅ , AsCl ₃ , SbH ₃ , Sb
F ₅ , BiH ₃ , while BF ₃ , BCl ₃ , B for introducing P-type impurities
_{Br 3, B 2 H 6,} B 4 H 10, B 5 H 9, B 6 H 10, B 6 H 12, AlCl 3 and the like.

Next, the method for forming the semiconductor layer 27 will be described more specifically.

First, the support 21 having a thin layer of the electrode 22 attached to the surface thereof is placed on the support base 3 in the deposition chamber 1, and the gas in the deposition chamber is exhausted through a gas exhaust pipe 20 by an exhaust device (not shown) to reduce the pressure. . The pressure in the deposition chamber under reduced pressure is preferably 5 × 10 ^-5 Torr or less, and more preferably 10 ^-6 Torr or less.

When the pressure inside the deposition chamber 1 is reduced, the heater 4 is energized to heat the support 3 to a predetermined temperature. The temperature of the support at this time is 150 to 300 ° C, preferably 200 to 250 ° C.

As described above, since the support temperature is relatively low in the method of the present invention, the support as in the glow discharge deposition method or the thermal energy deposition method using SiH ₄ , Si ₂ H ₆ as a raw material is used. Since no high temperature heating of the body is required, the energy consumption required for this can be saved.

Next, in order to stack the P-type a-Si layer on the thin layer electrode 22 on the support 21, the valve 14-1 of the forming source 9 filled with the Si forming source gas as listed above. , 16-1 and valves 14-2, 16 of the formation source 10 in which the P-type impurity gas is stored
2 is opened, and a mixed gas in which the Si supply source gas and the P-type impurity gas are mixed at a predetermined mixing ratio is fed into the deposition chamber 1.

At this time, the flow rate is adjusted while measuring with the corresponding flow meters 15-1 and 15-2. The flow rate of the raw material gas is preferably 10 to 1000 SCCM, more preferably 20 to 500 SCCM.

The flow rate of the P-type impurity gas is determined by the flow rate of the source gas × the doping concentration.

However, since the amount of the impurity gas mixed in is extremely small, in order to easily control the flow rate, the impurity gas is usually added.
It is used after being stored in a state of being diluted with H ₂ gas or the like to a predetermined concentration.

The pressure of the mixed gas into the deposition chamber 1, 10 ^-2 ~100Torr, preferably it is desirable that maintained in the range of 10 ^-2 ~1Torr.

In this way, thermal energy is applied to the raw material gas flowing near the surface of the support 2, thermal excitation and thermal decomposition are promoted, and a-Si as a product substance and a trace amount of P-type impurity atoms are present on the support. Be deposited on.

Decomposition products other than a-Si and P-type impurity atoms and surplus raw material gas not decomposed are discharged through the gas exhaust pipe 20, while new raw material gas is continuously formed through the gas introduction pipe 17. , P-type a-Si layer 23 is formed.
P-type a-Si 100~10 ⁴ Å as the layer thickness, preferably 30
A range of 0 to 2000Å is desirable.

Next, the valves 14-1, 16-1, 14 connected to the gas supply sources 9, 10 are connected.
-2, 16-2 are all closed, and the introduction of gas into the deposition chamber 1 is stopped. After the gas in the deposition chamber is removed by driving an exhaust device (not shown), the valves 14-1 and 16-1 are opened again to introduce the Si supply source gas into the deposition chamber 1. Suitable flow rate conditions and pressure conditions in this case are the same as the conditions when forming the P-type a-Si layer 23.

In this way, the undoped or I-type a-Si layer 24 is formed.

The layer thickness of the I-type a-Si layer is 500 to 5 × 10 ⁴ Å, preferably 10
A range of 00 to 10,000Å is desirable.

Next, the valves 14-3 and 16-3 connected to the gas supply source 11 in which the N-type impurity gas is stored are opened to introduce the N-type impurity gas into the deposition chamber 1.

The flow rate of the N-type impurity gas is determined from the flow rate of the Si supply source gas × the doping concentration, as in the case of determining the flow rate of the P-type impurity gas.

In the same manner as when the P-type a-Si layer 23 is formed, thermal energy is applied to the Si-supplying raw material gas and the N-type impurity gas flowing near the surface of the support 2, and thermal excitation and thermal decomposition are promoted to decompose them. The product a-Si is deposited on the support, and a trace amount of N-type impurity atoms of the decomposition product is mixed into the deposit to form N.
A mold a-Si layer 25 is formed.

The thickness of the N-type a-Si layer 25 is 100 to 10 ⁴ Å, preferably 300
A range of up to 2,000Å is desirable.

In forming the P-type and N-type a-Si layers as described above, the Si-supplying raw material gas and the impurity-introducing gas used in the method of the present invention are, as described above, thermal energy. Is easily excited and decomposed, so that a high layer formation rate of about 5 to 45 Å / sec can be obtained.

Finally, the thin-layer electrode 26 is formed on the N-type a-Si layer 25 in the same layer thickness as the thin-layer electrode 22 by the same method as that for forming the thin-layer electrode 22 to complete the PIN diode device. .

The PIN diode device formed in this manner satisfied the predetermined characteristics and quality.

According to the method of the present invention, in addition to the formation of the semiconductor layer of the PIN diode device described above, a single-layer or multi-layer a-Si layer having desired electrical and optical characteristics is formed. Can be formed. Further, in the example described above, the deposited layer was formed under reduced pressure, but the present invention is not limited to this, and the method of the present invention can be carried out under normal pressure or under increased pressure as desired.

According to the method of the present invention as described above, the heat energy of a low calorie is used as the excitation energy, and the raw material gas that is easily excited and decomposed by the heat energy is used. Level of a-Si
It becomes possible to form a deposited layer, and it has become possible to form an a-Si deposited layer excellent in uniformity of electrical and optical characteristics and stability of quality. Therefore, in the method of the present invention, a support made of a material having low heat resistance, which cannot be applied to the conventional glow discharge deposition method or thermal energy deposition method, can be used, and the high temperature of the support can be used. It has become possible to save the energy consumption required for heating.

Further, although heat energy is used as the excitation energy, since the low heat quantity is applied instead of the high heat quantity, the energy can always be uniformly applied to the predetermined space occupied by the source gas to which the energy is applied, and therefore the deposited film It has become possible to form the film accurately and uniformly.

Hereinafter, the present invention will be specifically described with reference to examples.

Example 1 Using the apparatus shown in FIG. 1, disilane was used as a raw material for supplying Si, I ₂ was used as a halogen compound, and B ₂ H ₆ was used as a P-type impurity introduction gas to dope B atoms. The P-type a-Si layer was formed as follows.

First, a support (polyethylene terephthalate) is set on the support base 3 in the deposition chamber 1, the pressure inside the deposition chamber 1 is reduced to 10 ⁻⁶ Torr by an exhaust device (not shown) through the gas exhaust pipe 20, and the heater 4 is energized. To maintain the support temperature at 225 ° C,
Next, the valves 14-1, 16 of the raw material supply source 9 filled with Si ₂ H ₆
-1 and I ₂ filled raw material supply source valve 14-5,16-5 further diluted by H ₂ (1000ppm H ₂ dilution) are P-type impurity introduced gas B ₂ H ₆ was filled source 29 10 valves 14-
2, 16-2 were opened, and the raw material mixed gas was introduced into the deposition chamber 1.

At this time, measure disilane to 150 SCCM and PH ₃ gas to 40 SCCM while measuring with the corresponding flow meters 15-1, 15-2, 15-5.
Then, the flow rate of I ₂ was adjusted to ₂₀ SCCM.

Next, the pressure in the deposition chamber was kept at 0.1 Torr, and the P thickness of 400 Å was used.
The type a-Si layer 3 (B atomic content 5 × 10 ⁻³ atomic%) is
It was deposited on the support 2 at a film forming rate of Å / sec. The thermal energy was uniformly applied to the gas flowing near the entire surface of the support 2 arranged in the deposition chamber 1. At this time, the decomposition products other than the a-Si and B atoms and the surplus raw material gas that has not been decomposed are discharged through the gas exhaust pipe 20, while the new raw material mixed gas is continuously discharged through the gas introduction pipes 17 and 30. Was supplied to.

Thus formed by the method of the present invention, a-Si
The evaluation of the layers was performed by further forming a comb-shaped Al gap electrode (length: 250 μ, on each of the a-Si layers formed on the substrate).
Width 5mm), dark current is measured, and dark conductivity σ
This was done by determining d.

The gap electrode is a formed as described above.
-The Si layer is put in a vapor deposition tank, the pressure of the tank is once reduced to 10 ^-6 Torr, the vacuum degree is adjusted to 10 ^-5 Torr, the vapor deposition rate is 20 Å / sec, and the layer thickness is 1500 Å. , Al was vapor-deposited on the a-Si layer, and this was etched and patterned using a pattern mask having a predetermined shape.

The obtained dark conductivity σ _p is shown in Table 1.

Examples 2 and 3 A P-type a-Si film was formed in the same manner as in Example 1 except that Br ₂ (Example 2) or Cl ₂ (Example 3) was used as the halogen compound. The obtained a-Si film was used in Example 1.
It evaluated similarly to. The evaluation results are shown in Table 1.

Examples 4 to 12 As a raw material and a halogen compound for forming an a-Si deposited film,
Linear silane compounds listed in Table 1 and Table 2 and I ₂ , Br
₂ and Cl ₂ were used individually in combination, and the a-Si film was deposited in the same manner as in Example 1 except that the support temperature and the halogen gas flow rate were set as shown in Tables 1 and 2. did. The obtained a-Si film was evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 1 and 2.

Comparative Examples 1 to 4 The linear silane compounds listed in Tables 1 and 2 were used as raw materials for supplying a-Si, and the support temperature was set as shown in Tables 1 and 2, and the halogen compounds were used. An a-Si film was deposited in the same manner as in Example 1 except that it was not used. The obtained a-Si film was evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 1 and 2.

Examples 13 to 24 As a raw material for supplying a-Si and a halogen compound, the linear silane compounds and I ₂ , Br ₂ and Cl ₂ listed in Table 1 and Table 2 were individually used in combination to introduce impurities. An a-Si film was deposited in the same manner as in Example 1 except that N-type PH ₃ was used as the working gas and the halogen gas flow rates were set as shown in Tables 3 and 4. The obtained a-Si film was evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 3 and 4.

Comparative Examples 5 to 8 The linear silane compounds listed in Tables 3 and 4 were used as raw materials for forming the a-Si deposited film, no halogen compound was used, and N-type PH ₃ was used as the impurity introduction gas. An a-Si film was deposited in the same manner as in Example 1 except for the above. The obtained a-Si layer was evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 3 and 4.

Comparing the corresponding examples using the same kind of a-Si film source, when the halogen compound was mixed, when it was doped with B ₂ H ₆ and when it was doped with PH ₃ , Also, the film forming rate was increased by about 2 to 4 times. The rate of acceleration of the deposition rate depending on the type of halogen is generally Cl ₂ , B
r ₂ and I ₂ are larger in that order.

Also, the electrical characteristics were good.

Example 25 Using the apparatus shown in FIG. 1, using disilane as a raw material for supplying Si and setting the support temperature to 225 ° C.
The PIN diode device shown in the figure was formed as follows.

First, a support 21 [polyethylene naphthalate transparent conductive film having 1000 liters of ITO (Indium Tin Oxide) deposited thereon] was set on the support 3 in the deposition chamber 1, and the raw material was supplied under the same operating conditions as in Example 1. Disilane, B ₂ from sources 9 and 29
Introducing H ₆ gas and I ₂ gas into the deposition chamber 1 to form a P-type a-Si layer
Formed 23.

Next, when the thickness of the P-type a-Si layer 23 reaches 400 Å, the valves 14-1 and 16 connected to the gas supply sources 9, 10 and 29 are connected.
-1,14-2,16-2,14-5,16-5 are all closed, and the introduction of gas into the deposition chamber 1 is stopped. After exhausting the gas in the deposition chamber by driving an exhaust device (not shown), the valves 14-1 and 16 are restarted.
-1,14-5,16-5 are opened and disilane for Si supply is 150SCC
M and I ₂ gases were introduced into the deposition chamber 1 at a flow rate of 20 SCCM, and a non-doped, ie, I-type, a-Si layer 24 (layer thickness, 5000Å) was added to
It was formed at the same speed as when forming the mold a-Si layer 23.

Next, the valves 14-3 and 16-3 connected to the gas supply source 11 storing the N-type impurity introduction gas PH ₃ diluted with H ₂ (dilution rate 0.05 mol%) are opened, and the inside of the deposition chamber 1 is opened. At PH ₃
A gas was introduced and the N-type a-Si layer 25 (layer thickness 400 Å) doped with P atoms was formed at the same rate as the P-type a-Si layer 23 by using the operating conditions in Example 13. A semiconductor layer which is deposited on the I-type a-Si layer 24 and is composed of three a-Si layers 23, 24, 25.
Created 27.

A vacuum deposition method (pressure of 1 × 10 ⁻⁵⁾ was further performed on the PIN type a-Si semiconductor layer 27 thus formed by the method of the present invention.
Torr) is used to stack Al thin film electrodes with a thickness of 1000Å
Completed N-type diode device.

Rectification characteristics (ratio of forward current and reverse current at a voltage of 1 V) of a PIN diode device (area: 1 cm ² ) formed in the present embodiment, n value (current formula of PN junction J = J
Each of {n values in {exp (eV / nkT) -1}) was evaluated. The results are shown in Table 5.

Examples 26 to 36 As the a-Si supply gas and the halogen compound, the linear silane compounds listed in Table 1 and Table 2 and I ₂ , Br ₂ and Cl ₂ were individually used in combination, and the halogen gas flow rate was used. A PIN type a-Si semiconductor layer having a three-layer structure was formed in the same manner as in Example 25 except that the values were set as shown in Tables 5 and 6 to prepare a PIN type diode device. The rectification characteristics, n value, and light irradiation characteristics of the created PIN diode device were evaluated in the same manner as in Example 25. The results are shown in Tables 5 and 6.

Comparative Examples 9 to 12 A PIN type having a three-layer structure was used in the same manner as in Example 25 except that the linear silane compounds listed in Tables 6 and 7 were used as the a-Si deposition film supply gas and no halogen compound was used. a-S
An i semiconductor layer was formed to create a PIN diode device. The rectification characteristics, n value, and light irradiation characteristics of the created PIN diode device were evaluated in the same manner as in Example 25. The results are shown in Tables 5 and 6.

Summarizing the results of Examples 25 to 36 and Comparative Examples 9 to 12 described above, the rectification characteristics of the PIN diode devices formed in Examples 25 to 36 are the same at the low support temperature of 225 ° C. With the a-Si feed gas, the use of halogen gas was better than that without.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an example of a deposited film forming apparatus used in the method of the present invention, and FIG. 2 is a schematic cross-sectional view of a PIN diode device that can be formed by the method of the present invention. 1: Deposition chamber, 2, 21: Support 3: Support, 4: Heater, 5: Conductor 6-1, 6-2, 6-3: Gas flow 9,10, 11, 12, 29: Gas supply Source 13-1, 13-2, 13-3, 13-4, 18: Pressure meter 14-1, 14-2, 14-3, 14-4, 16-1, 16-2, 16-3, 16 −4,2
9: Valve 15-1, 15-2, 15-3, 15-4: Flow meter 17,17-1, 17-2, 17-3, 17-4: Gas inlet pipe 20: Gas exhaust pipe 22,26 : Thin film electrode 23: P-type a-Si layer, 24: I-type a-Si layer 25: N-type a-Si layer 27: Semiconductor layer, 28: Conductor wire

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masahiro Haruta 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Hirai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Ken Eguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Nakagiri 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 56) References Japanese Patent Laid-Open No. 58-158646 (JP, A) Proceedings of the 43rd Society of Applied Physics (1982-9-28), p. 356, 30a-X-5, 30a-X-6

Claims (1)

[Claims] 1. A linear silane compound represented by the general formula; Si _n H _{2n + 2} (n ≧ 1) and I ₂ in a deposition chamber in which a support maintained at 150 ° C. to 300 ° C. is placed. Which can generate plasma in the deposition chamber by forming a gaseous atmosphere of a halogen gas selected from Al, Cl ₂ and Br ₂ and a compound containing an atom belonging to Group III or Group V of the periodic table. Heat energy is supplied without supplying energy to excite the compound, and silicon atoms and periodic table II are provided on the support.
A method of forming a deposited film, which comprises forming a deposited film containing atoms belonging to Group I or Group V.