JPS61189649A - Formation of deposited film - Google Patents

Abstract

PURPOSE:To facilitate the control of deposited-film formation, by a method wherein a deposited film is formed over the substrate by introducing two specific compounds which are raw materials for forming the deposited film and an activation seed chemically reacting with at least one of them to the film-forming space to form the deposited film over the substrate. CONSTITUTION:In the film-forming space to form a deposited film over a substrate, compounds serving as raw materials for forming the deposited film, which are expressed each by general formulas I and II [(m) indicates positive integers equal to or integral multiples of the valence numbers of R; (n) positive integers equal to or integral multiples of the valence numbers of M; M elements belonging to the II group of the periodic table; and R hydrogen H, halogen X, or hydrogen carbide radicals; besides, (a) indicates positive integers equal to or integral multiples of the valence numbers of B; (n) positive integers equal to or integral multiples of the valence numbers of A; X elements belonging to the VI group of the periodic table; and B hydrogen H, halogen X, or hydrogen carbide radicals.] and an activation seed chemically reacting with at least one of these compounds are introduced, thereby forming a deposited film over the substrate.

Description

[Detailed Description of the Invention] [Prior Art] The present invention relates to non-quality or crystalline functional thin films such as semiconductor films, insulator films, and conductor films, especially active or passive semiconductor devices, optical The present invention relates to a method for forming deposited films useful for applications such as semiconductor devices, solar cells, and photosensitive devices for electrophotography.

Vacuum evaporation method, plasma CVD method, thermal CVD method, photo CVD method 1 reactive sputtering method, ion blating method, etc. have been tried to form the deposited film, and in general, plasma CVD method is widely used. It has become a corporate entity.

As the deposited films obtained by these deposited film formation methods are required to be applied to electronic devices and optoelectronic devices that require higher functionality, it is difficult to improve electrical and optical properties and fatigue due to repeated use. Characteristics or usage environment characteristics, and even uniformity.

There is room for further improvement in overall characteristics in terms of productivity and mass production, including reproducibility.

The reaction process in forming a deposited film by the conventional plasma CVD method is the conventional so-called thermal carbon
It is considerably more complicated than the VD method, and the reaction mechanism is still unclear. In addition, there are many formation parameters for the deposited film (for example, substrate temperature, flow rate and ratio of introduced gas, pressure during formation, high frequency power, electrode structure 1 reaction vessel structure, pumping speed, plasma generation method, etc.). Because it depends on a combination of many parameters.

At times, the plasma becomes unstable, which often has a significant negative effect on the deposited film. Furthermore, the actual situation is that parameters unique to each device must be selected for each device, making it difficult to generalize manufacturing conditions.

Among these, for example, in the case of amorphous silicon films, it is currently considered best to form them using the plasma CVD method, since it is possible to develop electrical and optical properties that fully satisfy each application. ing.

According to Heigo et al., depending on the application of the deposited film, it is necessary to fully satisfy the requirements of large area, uniformity of film thickness, and uniformity of film quality, and mass production with reproducibility.
Forming a deposited film by the method requires a large amount of equipment investment for mass production equipment, the control items for mass production are complicated, the control tolerance is narrow, and the adjustment of the equipment is delicate. These have been pointed out as problems that should be improved in the future.

On the other hand, the conventional technique using the normal CVD method requires high temperatures and has not been able to provide a deposited film with characteristics that are necessarily satisfactory at a commercial level.

These problems remain as a bigger problem, especially when forming a thin film of n-vt group compounds.

As mentioned above, in forming a functional film, there is a strong desire to develop a method for forming a deposited film that can be mass-produced using low-cost equipment while ensuring practical properties and maintaining uniformity.

〔the purpose〕

The present invention eliminates the drawbacks of the conventional deposited film forming methods described above, and at the same time provides a novel deposited film forming method that does not rely on conventional forming methods.

The purpose of the present invention is to be able to easily control the characteristics of a monofunctional membrane,
A method for forming a deposited film that maintains at least the characteristics of a high-quality film obtained by conventional methods, improves the deposition rate, simplifies the management of film formation conditions, and facilitates mass production of films. The goal is to provide the following.

〔composition〕

In the deposited film forming method of the present invention, the following general formula (
Forming a deposited film on the substrate by introducing a compound (A) and a compound (B) represented by A) and CB), respectively, and an active species that chemically reacts with at least one of the compounds. It is characterized by・Rn M m・・・・・・・・・(A)A a
B b -1----------(B) However, m is R
n is a positive integer equal to or an integral multiple of the valence of M, M is an element belonging to Group Ⅰ of the periodic table, R is hydrogen (H), halogen (X) each represents a hydrocarbon group.

a is a positive integer equal to or an integral multiple of the valence of B, and n is a positive integer equal to or an integral multiple of the valence of A.

A is an element belonging to Group Ⅰ of the periodic table, B is hydrogen (H),
Each represents a halogen (X) and a hydrocarbon group.

In the method of the present invention, when forming a deposited film with desired functionality, the formation parameters of the deposited film are set such that the compound (A) represented by the general formulas (A) and (B), respectively, and (
B) and the amount of introduced active species that chemically reacts with at least one of these compounds, the temperature in the substrate and film-forming space, and the internal pressure in the film-forming space, thus making it easier to control the deposited film formation. , it is possible to form a functional deposited film that is reproducible and mass-producible.

The "active species" as used in the present invention refers to the compound (A)
and chemically interacts with the compound (B) to give energy to the compound (A) or/and (B), or chemically reacts with the compound (A) or/and (B). In other words, a substance that plays a role in bringing the compound (A) and/or CB) into a state in which a deposited film can be formed.

Therefore, the "active species" may include constituent elements constituting the deposited film to be formed, or may not include such constituent elements.

The above general formulas (A) and (B) used in the present invention
Compounds (A) and (B) represented by each of these compounds are formed on the substrate by causing a chemical reaction by molecular collision with the above-mentioned active species in the space where the substrate on which the film is to be formed exists. It is more desirable to select a chemical species that spontaneously generates chemical species that contribute to the formation of a deposited film; If the activity is not that great, compounds (A) and (
B) applying excitation energy strong enough to prevent the compounds (A) and (B) from completely dissociating M and A in the general formulas (A) and (B) before or during film formation, Compound (A
) and CB) are required to be brought into an excited state capable of chemically reacting with the active species, and the compounds capable of bringing them into such an excited state are the compounds (A) and (B) used in the method of the present invention.
) is adopted as one of the types.

In the present invention, a compound in the above-mentioned excited state will hereinafter be referred to as an "excited species".

In the present invention, the compound (A) RnMm and the compound (B) AaBb respectively represented by the above general formulas (A) and (B)
The following compounds can be mentioned as those which can be effectively used.

That is, an element belonging to group Ⅰ of the periodic table as rlldJ,
Specifically, elements belonging to group B of Zn, Cd, and Hg r
AJ is an element belonging to Group Ⅰ of the periodic table, specifically, 0. Compounds containing elements belonging to Group ⅠB of S, Se, and Te can be cited as compounds (A) and (B), respectively.

rH4 and rf3J include monovalent, divalent and trivalent hydrocarbon groups derived from linear and side chain saturated hydrocarbons and unsaturated hydrocarbons, or saturated or unsaturated monocyclic and Mention may be made of monovalent, divalent and trivalent hydrocarbon groups derived from polycyclic hydrocarbons.

Unsaturated hydrocarbon groups include not only a single type of carbon-carbon bond but also those having at least two types of bonds among - double bonds, double bonds, and triple bonds. If it is different from achieving the purpose of the invention, it can be effectively adopted.

Further, in the case of an unsaturated hydrocarbon group having a plurality of double bonds, it does not matter whether the double bonds are non-integrated double bonds or integrated double bonds.

Examples of acyclic hydrocarbon groups include alkyl groups, alkenyl groups,
Alkynyl group, alkylidene group, alkenylidene group, alkynylidene group, alkylidine group, alkenylidine group,
Preferred examples include alkynylidine groups, and in particular, those having 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and most preferably 1 to 5 carbon atoms.

In the present invention, the compounds (A) and (B) to be effectively used are selected from those that are gaseous under standard conditions or that can be easily vaporized under the usage environment.
In the selection of rRJ and "M" and "A" and "B" listed above, combinations of "R" and "M" and rAJ and rBJ are selected as desired.

In the present invention, specific compounds that can be effectively used as compound (A) include Z n Me 3 ,
Cd M e 3 , Z n E t 3 .

A specific example of CdEt3 etc. that can be effectively used as the compound (B) is Me2O.

Me2S, Me2Se, Me2Te, Et20゜Et
2 S, Et2 Se, Et2 Te, X20°SX2
, SXa, SX6.5eX2.5eXa.

5eX6, TeX6H20, H2S, H2Se.

Examples include H2Te.

In the above, X is halogen (F, C1°Br, I),
Me represents a methyl group, and Et represents an ethyl group.

The lifetime of the active species used in the present invention is preferably shorter in consideration of reactivity with compound (A) and/or (B), ease of handling during film formation, transportation to the film formation space, etc. In consideration of this, the longer the better, and the lifetime of the active species also depends on the internal pressure of the film forming space.

Therefore, the active species used should be selected and determined in such a way that a functional film with the desired properties can be effectively obtained, taking production efficiency into account. An active species having the following properties is appropriately selected and used.

The active species used in the present invention has a lifetime of:
The active species with a lifespan appropriately selected in view of the above points is selected from within the compatible range of chemical affinity with the compound (A) or/and CB) to be specifically used. It is selected as appropriate, but preferably, its life is 1×10−4 seconds or more, more preferably I×10−3 seconds or more, and optimally 1×10−3 seconds or more in an environment within the scope of the present invention.
It is desirable that the time is L2 seconds or more.

The active species used in the present invention can minimize its function as a so-called initiator when a chemical reaction with compound (A) or/and (B) occurs in a chain reaction. The amount introduced into the film forming space may be such that a chemical reaction can occur efficiently in a chain reaction.

The active species used in the present invention are simultaneously introduced into the film forming space (A) when forming a deposited film in the film forming space (A),
The compound (A) and (B) or/and the compound (A)G containing a component that will be the main component of the deposited film to be formed
Excited species (A) or/and excited species (B) of compound (B)
is easily formed.

According to the present invention, a more stable CVD method can be achieved by arbitrarily controlling the ambient temperature and substrate temperature of the film forming space (A) as desired.

One of the differences between the method of the present invention and the conventional CVD method is that the activation space (C) is different from the film forming space (A).
] The method is to use active species activated in ]. As a result, the deposition rate can be dramatically increased compared to the conventional CVD method, and in addition, the substrate temperature during the formation of the deposited film can be further lowered, resulting in stable film quality. Deposited films with controlled film properties can be provided industrially in large quantities at low cost.

In the present invention, the active species generated in the activation space (C) are not only excited and activated by energy such as electric discharge, light, heat, etc., or a combination thereof, but also by contact with a catalyst, etc., or by addition. It may be generated by

In the present invention, the raw material introduced into the activation space (C) to generate active species is preferably a gaseous or easily vaporizable substance, and can include a substance that generates hydrogen radicals. Specific examples thereof include H2, D2, HD, and other rare gases such as He and Ar.

In addition to the above, heat and light are applied in the activation space (C).

Activated species are generated by applying activation energy such as electric discharge. This active species is introduced into the film forming space (A). At this time, the lifespan of the active species is preferably I x 10-
It is necessary to have such a long life to promote the increase in deposition efficiency and deposition rate, and to increase the efficiency of the chemical reaction with the compound (A) introduced into the film forming space (A). increase.

Specifically, the activation energy that causes an activation effect on the active species generating substance in the activation space (C) includes thermal energy such as resistance heating and infrared heating, and light such as laser light, mercury lamp light, and halogen lamp light. Energy, microwave, RF, low frequency, electric energy using discharge such as DC, etc. can be mentioned, and these activation energies are applied alone to the active species generating substance in the activation space (C). A compound (A) introduced into the film-forming space (A), which may also be used in combination of two or more,
The compound (B) and the active species are selected from those listed above, which can cause a chemical reaction by mutual collision at the molecular level even as they are, and can deposit a functional film with the desired gas. However, depending on the selection of the compound (A), the compound (B), and the active species, the above chemical reactivity may be poor, or the chemical reaction may be carried out more effectively to achieve efficient deposition. When a film is formed on a gas, reaction promoting energy acting on the compound (A), the compound (B), or/and the active species in the film formation space (A), for example, in the activation space (C) described above, The activation energy used is acceptable. Or, before introducing the compound (A) and the compound (B) into the film forming space (A), in another activation space (B), in order to bring the compound (A) and the compound (B) into the above-mentioned excited state. Excitation energy may also be applied.

In the present invention, the compound (A) introduced into the film forming space (A)
) and the total amount of compound (B) and the amount of active species introduced from the activation space (C) is determined according to the deposition, but preferably 1000:1 to 1:10 (introduction flow rate ratio) is appropriate. , more preferably 500:1 to 1:5.

If the active species does not cause a chain chemical reaction with compound (A) or/and compound (B), the above introduction amount ratio is
Preferably lo:1-1:10, more preferably 4:l
It is desirable that the ratio is ~2:3 in the film forming chamber f! 1 The internal pressure of (A) is appropriately determined according to the selected types of compound (A), compound (B) and active species, deposition conditions, etc., but is preferably 1X10-2 to 5X
103Pa, more preferably 5X10-2 to 1X103
Pa, preferably 1X10" to 5X102Pa, and if it is necessary to heat the substrate during film formation, the substrate temperature is preferably 50 to 1000
°C, more preferably 100-900 °C, optimally ioo
It is desirable that the temperature be 750°C.

The compound (A), the compound (B), and the active species may be introduced into the film forming space (A) through a transport pipe connected to the film forming space (A); Alternatively, the transport pipe may be installed in the film forming space (A) and extended to near the film forming surface of the substrate, and the tip may be introduced with a nozzle shape, or the transport pipe may be doubled. one side with the inner tube,
The other may be transported into the film forming space (A) using the outer pipe, for example, the active species may be transported using the inner pipe, and the compound (A) and the compound (B) may be transported using the outer pipe.

In addition, three wooden nozzles connected to the transport pipe are prepared, and the tips of the three wooden nozzles are placed near the surface of the substrate already installed in the film forming space (A). Compound (A) and compound (B) discharged from respective nozzles in
) and the active species may be mixed and introduced.

In this case, it is possible to selectively form a functional film on the substrate, which is advantageous because patterning can be performed at the same time as film formation.

The present invention will be specifically explained below using examples.

Example 1 200 SCC of H2 gas was supplied from the gas introduction pipe 102 in Fig. 1.
M is introduced into an activation chamber 103 made of a quartz glass tube, and a 280 W microwave is applied to the activation chamber 103 from a waveguide placed above the activation chamber 103 as an activation source 5 to activate it. 0 that generated H radicals in the reaction chamber 103
The generated H radicals were introduced into the film forming chamber 104 from a nozzle l00-3 via a transport pipe 102-2 made of a quartz glass tube.

At the same time, (C2H5) 2Zn was bubbled with He gas through gas introduction pipe Lot-2.
It was introduced into the film forming chamber 104 through the nozzle 100-2 at a ratio of smol/win. On the other hand, H2S gas was introduced into the film forming chamber 104 from the nozzle 100-10 at a ratio of 1 Ommol/win (7) through the gas introduction pipe tot-t. In this case, (C2H5)2 Zn and H2S are activated by the action of H radicals to decompose Zn and S, and are heated to about 220° C. by a substrate heater 109 on an Al2O3 substrate, and a 30 cm x 30 cm in 1.5 hours is added to lO8. A ZnS film with a thickness of about 2.2 μm was formed over an area of .

When the film characteristics of this ZnS film were evaluated, the film thickness fJF
It was confirmed that the film was of good quality and had no locational dependence in semiconductor properties.

Example 2 In place of the smell of Example 1 (C2Hs)2Zn+ and H2S, the raw material gases shown in Table 1 were used as compounds (, A
) and Compound (B), the amounts of Compound (A) and Compound (B) introduced were each 1 ■■ ol view/win, and the conditions other than those listed in Table 1 were as follows:
When the film was formed in substantially the same manner as above, the thin film shown in Table 1 was formed.

When we evaluated the film properties of these thin films, the average
It was confirmed that the film had an IMI thickness, was uniform, had good quality, and had excellent properties.

Example 3 In Example 1, R installed around the film forming chamber 104
F discharge device 106 13.56MHzc7) high frequency 3
Power of W was applied to the film forming chamber 104 to form a plasma atmosphere within the reaction chamber 104. In this case, the base 106 was placed at a position lam on the downstream side of the plasma atmosphere so as not to directly touch the plasma atmosphere. Approximately 2.5 hours after starting film formation.
51J, a ZnS film with a thickness of m was formed. The substrate temperature at this time was maintained at 200°C. Except for the above, the process was carried out in the same manner as in Example 1. When the film characteristics of this ZnS film were evaluated in the same manner as in Example 1, it was confirmed that the film was of good quality.

Furthermore, the film was mechanically excellent without peeling from the substrate.

〔Effect of the invention〕

According to the deposited film forming method of the present invention, the desired electrical, optical, photoconductive, and mechanical properties of the formed film are improved, the reproducibility in film formation is improved, and the film quality is improved. In addition to making it possible to improve the film quality and make the film uniform, it is also advantageous for increasing the area of the film, and it is possible to easily achieve improvement in film productivity and mass production.

Furthermore, since it is possible to form films at low temperatures, it is possible to form films even on substrates with poor heat resistance, and the process can be shortened by low-temperature processing. The effect is that the composition ratio and properties can be controlled.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a manufacturing apparatus that embodies the method of the present invention. t o 1----1 introduction pipe, 102----1 transport pipe, 103----1 activation chamber, 104----1 film formation chamber.

Claims (1)

[Claims] A compound (A) and a compound represented by the following general formulas (A) and (B), respectively, which are raw materials for forming a deposited film, are placed in a film forming space for forming a deposited film on a substrate. (B) and an active species that chemically reacts with at least one of these compounds to form a deposited film on the substrate. RnMm・・・・・・・・・(A) AaBb・・・・・・・・・(B) However, m is a positive integer equal to or an integral multiple of the valence of R, n
is a positive integer equal to or an integral multiple of the valence of M, M is an element belonging to Group II of the periodic table, R is hydrogen (H), halogen (
X) and each represent a hydrocarbon group. a is a positive integer equal to or an integral multiple of the valence of B, n is a positive integer equal to or an integral multiple of the valence of A, and X is a positive integer equal to or an integral multiple of the valence of A.
Elements belonging to group VI, B is hydrogen (H), halogen (X),
The hydrocarbon groups are shown respectively.