JPS60251195A - Process and device for preparing compound crystal film - Google Patents

Abstract

PURPOSE:To prepare a compound crystal film having high purity easily and with high efficiency by forming the compound crystal film consisting of each material for vapor deposition on a substrate in a vacuum chamber and at least one of the vapor deposition material is fed from outside of the vacuum chamber in the form of gas. CONSTITUTION:Gas cylinders are used as the source 10, 24 for gases, wherein gaseous H2S is filled in the first gas cylinder 10, and gaseous ZnCl2 is filled in the second gas cylinder 24. An opening 3 at the top end on a film forming chamber 2 is closed by a shutter 26 on a substrate holder 25. By heating a peripheral wall of the film forming chamber 2 in the closed condition of the top end opening 3, feeding materials for vapor deposition simultaneously to the film forming chamber 2 and sliding the substrate holder 25 to a position described in Fig.B under a thermally equilibrium condition, a crystal film of ZnCl2 is formed to a rear side of the substrate 29 placed to a position covering the top end opening 3 of the film forming chamber 2. If the substrate holder 25 is returned to a state as shown in the Fig.A during a state for prepg. the compound crystal film so as to expose the substrate 29 to the vacuum in the vacum chamber 1, an extremely good compound crystal film is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel compound crystal film manufacturing method and apparatus. Specifically, a highly pure compound crystal film can be easily formed using a simple device, impurities can be easily added, the manufacturing efficiency is extremely high, and the substrate temperature can be kept lower than conventional The object of the present invention is to provide a novel method and apparatus for producing a compound crystal film, which can produce a compound crystal film without increasing the cost.

Background technology and its problems With the development of microelectronics and optical communication technology, the demand for photoelectric conversion elements such as semiconductor lasers, light emitting diodes, EL, etc., infrared sensors, and photoelectric conversion elements such as solar cells is rapidly increasing. It is coming. However, in order to manufacture these devices, highly pure crystal films are required.
Furthermore, it is necessary to add impurities to the crystal film under sufficient control.

However, the current situation is that conventional compound crystal film manufacturing methods cannot sufficiently meet these demands.

For example, the MBE method (molecular beam epitaxy) is currently the only method that allows the formation of various compound crystal films, but it requires an ultra-high vacuum, and the equipment is large and expensive. There are problems such as a large amount of material loss and difficulty in processing large substrates.

In addition, the LPE method (liquid phase epitaxy method) is a high-temperature process and has drawbacks such as not being applicable to materials with high vapor pressure and difficulty in processing large substrates.
VPE methods (vapor phase epitaxy) such as LE, sputtering, and vacuum evaporation have high substrate temperatures, limitations on the raw material gases that can be used, and limitations on compound combinations.
It has drawbacks such as being prone to becoming amorph and ass.

As described above, each of the conventional methods for manufacturing compound crystal films has its advantages and disadvantages, and it is possible to easily obtain a variety of highly pure compound crystal films, and it is also possible to add impurities under sufficient control. There is nothing that can be done, and what's more, the equipment is simple and cheap. In particular, only the MBE method can produce a ZnS crystal film, and there have been no reports yet of production examples using other methods.

Purpose of the Invention Therefore, the present invention solves the problems of the conventional methods by using the HWE method (hot wall epitaxy method), and forms a highly pure compound crystal film easily and with a simple device. It is an object of the present invention to provide a novel method and apparatus for manufacturing a compound crystal film, which can easily add impurities, and furthermore, can be manufactured with extremely high efficiency.

Invention #1! Essential A method and apparatus for producing a crystalline film of the compound of the present invention.

In order to achieve the above object, the method includes heating the peripheral wall of a film forming chamber with its top opening sealed in a vacuum chamber, and supplying evaporated molecules of a plurality of vapor deposition materials to the film forming chamber, In a method for manufacturing a compound crystal film, the heated substrate is placed in the upper end opening of the film formation chamber when the vapor pressure in the film formation chamber has increased, and a compound crystal film made of each of the materials is formed on the substrate. At least one of the vapor deposition materials is supplied in gaseous form from outside the vacuum chamber, and the apparatus for manufacturing a compound crystal film of the present invention includes a film forming chamber with an open upper end disposed within the vacuum chamber, A plurality of evaporated atom or molecule supply ports are provided which are open in the film forming chamber, and at least one of the evaporated atom or molecule supply ports is connected to a gaseous vapor deposition material supply source outside the vacuum chamber. A shutter is provided to open and close the upper end opening of the film forming chamber, a means is provided for arranging a compound crystal film forming substrate over the upper end opening of the film forming chamber when the upper end opening is opened, and a wall surface of the film forming chamber is provided. and a heating means for heating the compound crystal film forming substrate.

EXAMPLES Below, details of the method for manufacturing a crystalline film of the compound of the present invention and the apparatus thereof will be explained according to illustrated examples.

First Embodiment FIGS. 1 and 2 show an example of an apparatus for producing a compound crystal film of binary materials according to the present invention.

Reference numeral 1 denotes a vacuum chamber, which is connected to a pump (not shown) to control the internal air pressure.

Reference numeral 2 denotes a film forming chamber disposed within the vacuum chamber 1, which has an opening 3 at its upper end, and other portions are completely cut off from the inside of the vacuum chamber 1. This film forming chamber 2 has a substantially cylindrical shape,
For example, it is made of quartz glass. 24 is a heater arranged so as to surround the film forming chamber 2 at a phase interval from the outer circumferential surface of the film forming chamber;
It is made by winding heater wires 6 such as tantalum wires at equal intervals.

Reference numeral 7 denotes an evaporated molecule supply pipe made of, for example, quartz glass, which extends vertically through the bottom of the film forming chamber 2, and the evaporated molecule supply port 8° at the upper end is in the vertical direction of the film forming chamber 2. The lower end extends to the outside of the vacuum chamber 1. The outer end (lower end) of the vaporized molecule supply pipe 7 is connected to a gas supply source 10 via a control valve 9.

Reference numeral 11 denotes a heater, and the quartz tube 12 is placed so as to surround the intermediate portion of the vaporized molecule supply tube 7 in the vacuum chamber 1. ! It is made up of 13 windings.

Reference numeral 14 denotes a vapor deposition material heating section, which includes a bottom 15 of the film forming chamber 2, a continuous section 16 extending from the periphery of the bottom 15 to a position approaching the vaporized molecule supply pipe 7, and a continuous portion 16 of the vaporized molecule supply pipe 7. It is formed as a space surrounded by a protrusion inside the film forming chamber 2. Note that the continuous portion 16 is also made of, for example, quartz glass. The upper end of the continuous portion 16 extends with a slight distance from the outer peripheral surface of the evaporated molecule supply pipe 7, and a gap 17 between the upper end and the evaporated molecule supply pipe 7 serves as an evaporated molecule supply port. The position of this evaporated molecule supply port 17 in the downward direction is the evaporated molecule supply pipe 7.
It is located approximately in the middle of the protrusion in the film forming chamber 2 and has an annular opening.

Reference numeral 18 denotes a heater, which is constructed by winding a heater wire 20 similar to that described above around a quartz tube 19 arranged so as to surround the vapor deposition material heating section 14.

Reference numeral 21 denotes an evaporated molecule supply pipe, the upper end of which opens 22 into the bottom 15 of the evaporation material heating section 14, and the lower end extending to the outside of the vacuum chamber l. And this evaporated molecule supply pipe 2
The outer end (lower end) of 1 is connected to a gas supply source 24 via a control valve 23 .

Reference numeral 25 denotes a substrate holder that also serves as a shutter, in which a shutter part 26 and a substrate holding part 27 are integrally formed. It is arranged so that it can be slid in any direction.

Reference numeral 28 denotes a substrate heater, which is arranged in the substrate holding portion 27 of the substrate holder 25 so as to be located on the back side of the substrate.

29 is a substrate held by the substrate holding portion 27 of the substrate holder 25. As shown in FIG. When the substrate holder 25 is in the state shown in FIG. 2(A), the upper opening 3 of the film forming chamber 2 is closed by the shutter part 26 of the substrate holder 25, and the substrate holder 25 is In the state shown in B), the substrate 29 faces the film forming chamber 2. The substrate holder 25 is slidably movable between the position shown in FIG. 2(A) and the position shown in FIG. 2(B).

Next, the production of a compound crystal film using the above-described apparatus will be explained. First, manufacturing of the ZnS film will be explained.

A gas pump is used as the gas supply source 10.24.

First, the first gas pump 10 is filled with H2S gas, and the second gas pump 24 is filled with ZnCL2 gas.

First, as shown in FIG. 2(A), the upper end opening 3 of the film forming chamber 2 is closed with the shutter part 26 of the substrate holder 25. As shown in FIG. Then, the control valves 9 and 23 are opened, and the heater wires 6.13 and 2 of each heater 4.11 and 18 are opened.
0, the pressure Pd in the film forming chamber 2, the pressure PS in the vaporized molecule supply pipe 7, and the pressure PZn in the vapor deposition material heating section 14 will have the following relationships: Pd<PZn, Pd<PS. The wall temperature TW of the film forming chamber 2, the temperature TS of the substrate 29, and the temperature of the evaporated molecule supply pipe 7 are adjusted as follows.

The temperature TH1 and the temperature TH2 of the vapor deposition material heating section are set to TS<TW and TH1<TH2, respectively. For example, TW=
400@C, TS: 300°C, THL: 150°C
,TH2#370''C.

Therefore, under thermal equilibrium as described above, the substrate holder 25 is slid to the position shown in FIG. A ZnS crystal film is formed on the lower surface of the substrate 29 positioned to cover the upper end opening 3 of the chamber 2 .

In the manufacturing process of the compound crystal film described above, if the substrate holder 25 is returned to the state shown in FIG. 2(A) and the substrate 29 is exposed to the vacuum inside the vacuum chamber 1, an extremely good compound crystal film can be obtained. can get.

That is, unstable molecules that do not become the nucleus of a single crystal may adhere to the substrate 29, but as described above, such unstable molecules can be removed by exposing the substrate 29 to a vacuum. reevaporated. At this time, as shown in FIG. 3, if a heater 30 is provided to heat the surface of the substrate 29 on which the compound crystal film is formed while the substrate 29 is exposed to a vacuum, the instability described above can be avoided. Re-evaporation of molecules is promoted. The heater 30 shown in FIG. 3 has an opening on the substrate 29.
It consists of a paraboloid of revolution reflecting mirror 31 facing toward the side and a light source (heat source) such as a halogen lamp or a laser beam, the light source of which is placed approximately at the focal point of the reflecting mirror.

As described above, the substrate 29 exposed to vacuum is again brought into the state shown in FIG. 2(B) to obtain a compound crystal film with a required thickness. Note that exposing the substrate 29 to a vacuum is -
It is not limited to once, but may be performed several times as necessary.

In addition, when forming a compound crystal film using the above-mentioned apparatus, the vapor deposition material may be placed in the vapor deposition material heating section 14. That is, when forming the aforementioned ZnS film, Zn is stored in the vapor deposition material heating section 14, and Ct gas is supplied from the gas pump 24 to the vapor deposition material heating section 14.
ZnCL gas may be generated within the chamber.

Furthermore, when forming Zn5ell* using the above-mentioned apparatus, a gas cylinder filled with HSe gas may be used as the gas supply source 10. In this case, THl is set at about 220@C and TH2 is set at about 390°C. It should be set to a certain degree.

Second Embodiment FIG. 4 shows a second embodiment of an apparatus for producing a compound crystal film of binary materials according to the present invention.

1 is a vacuum chamber similar to the vacuum chamber 1 in the first embodiment. 2 is also a film forming chamber similar to the film forming chamber 2 in the first embodiment, and has a substantially cylindrical shape with an opening 3 at the upper end and a closed lower end. 25 is also the first
This is a substrate holder similar to the substrate holder 25 in the embodiment. 4 is a heater for heating the film forming chamber 2;
This is also similar to the heater 4 in the first embodiment.

32 and 33 are vaporized molecule supply pipes, and both are formed in substantially the same shape. That is, the upper end is substantially constricted to form the vaporized molecule supply ports 34 and 35, and is located at the lower end within the film forming chamber 2. Further, the lower ends of the vaporized molecule supply pipes 32 and 33 extend outside the vacuum chamber 1 and are connected to gas supply sources 38 and 39 via control valves 36 and 37. Moreover, intermediate portions of the vaporized molecule supply pipes 32 and 33 within the vacuum chamber 1 are gas heating portions 40 and 41 having a larger diameter than other portions.

42 and 43 are heaters, which are arranged so as to surround the gas heating parts 40 and 41. The heaters 42 and 43 are constructed by winding heater wires 46 and 47 around quartz tubes 44 and 45, respectively.

In such an apparatus, the necessary gases are supplied to each of the gas supply sources 38 and 39 (for example, when forming a ZnS film, ZnCL2 gas is supplied to one and H2S gas is supplied to the other, and when forming a Zn5e film, (inject ZnCL2 gas into one side and H3e gas into the other side), and then drive the substrate holder 25 and each heater 4, 28, 42, and 43 in the same manner as explained in the first embodiment to generate the desired compound. It forms a crystalline film.

Embodiment 3 FIGS. 5 to 7 show the manufacturing apparatus for the compound crystal film of the present invention.
This shows a third embodiment.

FIG. 5 is an explanatory diagram of the layout of the entire device viewed from above.

Depl and Dep2 are film forming positions, Rev, Rev, Rev are re-evaporation positions, and Dop is an impurity doping position.

A substrate holder 48 is placed in the vacuum chamber 1 and is intermittently rotated by a rotation control section 49. Then, the substrate holding parts 50 are arranged at equal intervals along the rotation direction.
．． 50.50 is formed, and the substrate holding portion 50.5
At 0.50, a substrate heater 51.51.51 is arranged to heat the substrate 29.29.29 held there from above. Then, such a substrate holding section 5
Each interval between 0.50 and 50 functions as a part of the shutter.

At the film forming positions Depl and Dep2, a film forming chamber 2, a heater 4. An evaporated molecule supply pipe 7, a control valve 9, a gas supply source IO, a heater 11, a evaporation material heating section 14, a heater 18, an evaporated molecule supply pipe 21, a control valve 23, and a gas supply source 24 are arranged.

Reference numeral 52 denotes an evaporation port located within the vacuum chamber 1, and is located below the substrate holder 48 at the impurity addition position Dop. A material to be added as an impurity is placed on the evaporation port 52, and the substrate 29 on which the crystal film has been grown is moved to the position directly above the evaporation port 52.
Therefore, crystals of the material placed on the evaporation port 52 are grown by vacuum evaporation, thereby making it possible to add impurities to the compound crystal film.

For example, the substrate 29 at the film forming positions Depl and Dep2
Z'n5lll is grown on top, and Mn is deposited by normal vacuum evaporation.
(the material is placed on the evaporation port 52).

In such a compound crystal film manufacturing apparatus shown in FIGS.
Hold 9.29.29 and move each substrate 29.29.29 to film formation position Depl- + re-evaporation position Rev → impurity addition position Dop → re-evaporation position Rev →
The film forming position De p2 is intermittently moved to each position in the order of re-evaporation position Rev, and each film forming position Dep1. In Dep2, a compound crystal film is grown on the substrate 29, unstable molecules are reevaporated at each reevaporation position, and the impurity doping position Do
In p, impurities are added to obtain a desired compound crystal film on the substrate 29.

Note that if addition of impurities is not required, driving of the evaporation port 52 may be stopped.

Further, the same compound crystal film may be grown at the film forming positions Depl and Dep2, or separate compound crystal films may be grown at the film forming positions Depl and Dep2. For example, the ZnS film is deposited at the deposition position Depl, and the ZnS film is deposited at the deposition position Depl.
If you grow Zn5e films in step 2 and repeat this process alternately, ZnS/ZnS
e superlattice film can be formed.

Effects of the Invention As is clear from the above description, the method for producing a compound crystalline film of the present invention involves heating the peripheral wall of a film forming chamber with its top opening sealed in a vacuum chamber, and forming the film. Evaporated atoms or molecules of a plurality of vapor deposition materials are supplied to the chamber, and when the vapor pressure in the film formation chamber increases, a heated substrate is placed at the upper end opening of the film formation chamber, and the vaporized atoms or molecules of each of the materials are placed on the substrate. In the method for manufacturing a compound crystal film forming a compound crystal film, at least one of the vapor deposition materials is supplied in a gaseous state from outside the vacuum chamber,
In addition, the apparatus for producing a crystalline film of the compound of the present invention includes a film forming chamber with an open top end disposed in a vacuum chamber, a plurality of evaporated atom or molecule supply ports opened in the film forming chamber, and evaporated atoms or molecules・At least one of the knots is connected to a gaseous vapor deposition material supply source outside the vacuum chamber, and a shutter is provided to freely open and close one end of the film forming chamber. Providing means for arranging a compound crystal film forming substrate over the opening when the upper end opening is opened, and
The present invention is characterized in that heating means for heating the wall surface of the film forming chamber and the compound crystal film forming substrate are respectively provided.

Therefore, the method and apparatus for manufacturing a compound crystal film of the present invention have the following advantages.

That is, although a compound crystal film with extremely good crystallinity can be obtained, the equipment is very simple compared to other conventional methods, such as MBE, and only requires modification of the vacuum evaporation equipment. The manufacturing equipment can be obtained, the degree of vacuum in the vacuum chamber is only about 1O-6 Torr, and ultra-high vacuum is not required.
It has many advantages, such as being able to process large substrates and reducing material loss. In addition, impurities can be easily added to any part, crystal films with a crystalline structure can be easily manufactured, and the state of crystal film formation can be observed in-process. It can be controlled with a process monitor (temperature control), has many advantages such as good reproduction, no need for post-processing such as heat treatment, less contamination of the vacuum equipment, and low substrate temperature. have Furthermore, the range of application is extremely wide, and various combinations such as GaAs, In
A compound crystal film can be produced using multi-component materials such as Sb, Zn5e, Pd5nTe, HgCde, etc.

Moreover, since at least one type of vapor deposition material is supplied in gaseous form from outside the vacuum chamber, if the vapor deposition material used in large quantities is supplied from outside the vacuum chamber, the vapor deposition material can be replenished without opening the vacuum chamber. Therefore, the manufacturing efficiency of the compound crystal film is extremely good.

In addition, in the description of the above embodiment, a ZnS film is used.

We have described an apparatus for forming a compound crystal film made of binary materials such as a Zn5e film, or an apparatus for forming a multilayer film thereof, but when forming a compound crystal film made of ternary or more materials, evaporation is required in the film forming chamber. Supply device that supplies molecules (
This objective can be easily achieved by increasing the number of vaporized molecule supply tubes (such as vaporized molecule supply pipes).

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the compound crystal film manufacturing apparatus according to the present invention, in which FIG. 1 is an overall vertical cross-sectional view, FIG. 2 is an operation explanatory diagram, and FIG. 4 is a longitudinal sectional view showing a modification of the first embodiment, FIG. 4 is a longitudinal sectional view showing a second embodiment of the compound crystal film manufacturing apparatus according to the present invention, and FIGS. 5 to 7 are A third embodiment of the compound crystal film manufacturing apparatus according to the present invention is shown. FIG. 5 is a conceptual diagram showing the overall arrangement in a plan view, and FIG. 6 is an apparatus having the arrangement shown in FIG. 5. FIG. 7 is a cross-sectional view taken along the line vr-vt, and FIG. 7 is a cross-sectional view taken along the line ■-■ of the device having the arrangement shown in FIG. Explanation of symbols 1...Vacuum chamber, 2...Film forming chamber, 3...Top opening, 4...Heating means. 8... Evaporated atom or molecule supply port, lO... Gaseous vapor deposition material supply source, 17... Evaporated atom or molecule supply port 24... Φ Gaseous vapor deposition material supply source, 26... Shutter . 28φ: heating means, 2911: compound crystal film forming substrate, 34: vaporized atom or molecule supply pipe, 35: vaporized atom or molecule supply pipe, 51φ: heating means Applicant: Koito Seisakusho Co., Ltd.

Claims (2)

[Claims] (1) In a vacuum chamber, heat the peripheral wall of a film forming chamber with its top opening sealed, and supply vaporized atoms or molecules of a plurality of vapor deposition materials to the film forming chamber, so that the vapor pressure inside the film forming chamber is When the temperature is high, a heated substrate is placed in the upper opening of the film forming chamber, and a compound crystal film made of the above-mentioned materials is formed on the substrate, and at least one of the evaporation materials is kept in a gaseous state in the vacuum. A method for producing a compound crystal film characterized by supplying it from outside. (2) A film forming chamber with an open top end is placed in the vacuum chamber,
A plurality of evaporated atom or molecule supply ports are provided in the film forming chamber, and at least -
is connected to a gaseous vapor deposition material supply source located outside the vacuum chamber, and is further provided with a shutter that closes the upper end opening of the film forming chamber so that the upper end opening of the film forming chamber is opened. An apparatus for manufacturing a compound crystal film, characterized in that a means for arranging a compound crystal film forming substrate thereon is provided, and heating means for heating the wall surface of the film forming chamber and the compound crystal film forming substrate are respectively provided.