JPH031379B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to an improved vacuum evaporation method and apparatus, and more particularly to a vacuum evaporation method and apparatus for supplying a vapor of evaporation material in a pulsed manner to a vacuum evaporation apparatus. [Prior art] Conventionally, in a vapor deposition method called chemical vapor deposition method,
The evaporation material was deposited on the material to be evaporated under reduced pressure by introducing, or while introducing, the vapor of the evaporation material under a relatively high pressure of about 10 ^-3 to 10T ^-4 orr into the evaporation container of the evaporation equipment. . However, in such a chemical vapor deposition method, it takes time to introduce and stop the vapor of the vapor deposition material into the vapor deposition container, and it is difficult to precisely control the vapor deposition conditions. Moreover, since the average degree of vacuum in the vapor deposition container is lowered by introducing the vapor deposition material gas, it has been impossible to analyze the vapor deposited film each time. [Object of the Invention] The present invention solves the above-mentioned conventional drawbacks, can quickly cut off the supply of a vapor deposition material gas flow to a vacuum evaporation apparatus, and allows precise control of evaporation conditions.
Moreover, it is an object of the present invention to provide a vapor deposition method and an apparatus for the same, which can analyze a vapor-deposited film in situ. [Structure of the Invention] The pulsed molecular beam evaporation method of the present invention achieves the above object by injecting a gas flow of the evaporation material in a pulsed manner onto the material to be evaporated in a vacuum evaporation apparatus. It is characterized by vapor-depositing. Further, the pulsed molecular beam evaporation apparatus of the present invention is composed of a combination of a pulsed molecular beam generation apparatus and a vacuum evaporation apparatus, and the pulsed molecular beam generation apparatus includes a container containing a vapor of a vapor deposition material, and an inner side of the ejection port of the container. The device is characterized in that it comprises a high-speed cutoff means for the ejected gas flow, and a pulse voltage generation source connected to the means. First, the pulsed molecular beam evaporation apparatus of the present invention will be explained based on the drawings. FIG. 1 shows an embodiment of a pulsed molecular beam generator that is combined with a vacuum evaporation apparatus in the present invention. The pulsed molecular beam generator 1 includes a container 2 containing the gas of the evaporation material, a high-speed blocking means 4 for the ejected gas flow provided inside a gas flow jetting port 3 formed in the container 2, and this high-speed blocking means 4. The container 2 normally contains a vapor deposition material gas of 10 atmospheres or less, and this gas 2 is introduced through a valve 8 and a pipe 9. Here, the gas flow in the present invention refers to not only normal gas flow but also all forms of things that can move in the gas phase, such as metal vapor, metal clusters, ultrafine particles, and ions. It also includes flow. Therefore, in this sense, the present invention is not limited to molecular beams, but is directed to beams in a wide range of gas phases. The high-speed cutoff means 4 for the ejected gas flow includes, for example, a piezoelectric element 6, an electromagnetic solenoid element, or an element having a similar function, and a gas flow outlet closing member 7 bonded to the tip of the element 6. It is formed. The gas outlet closing member 7 is made of a highly hard material, such as tungsten carbide, or a resin, such as Viton, and the surface thereof in contact with the gas outlet 3 is polished smooth. This closing member 7 is normally pressed against the spout 3 by the vapor deposition material gas contained in the container 2, and prevents the vapor deposition material gas from leaking from the spout 3. From the pulse voltage source, the piezoelectric element 6 receives 80~
A pulse voltage of 140 V is applied, the piezoelectric element 6 contracts, and the vapor deposition material gas contained in the container 2 is ejected from the ejection port 3. When the application of the pulse voltage is stopped, the piezoelectric element 6
The shape of is restored to its original state, and the closing member 7 comes into contact with the spout 3 again to close the spout 3. By repeating application and termination of the pulse voltage to the piezoelectric element 6 in this manner, the vapor deposition material gas is ejected from the ejection port 3 in a pulsed manner. A cooling mechanism, such as a coolant circulation pipe, is attached to the outer wall of the container 5 in order to prevent performance deterioration of the piezoelectric element 6 due to radiant heat from the vapor deposition material. The vapor deposition material gas ejected in a pulsed manner from the ejection port 3 is guided to a vacuum evaporation device (not shown) combined with a pulsed molecular beam generator and irradiated onto the material to be evaporated. It is vapor-deposited on the material to be vapor-deposited according to the same process as above. Here, in the present invention, the vacuum evaporation device combined with the pulsed molecular beam generator is not particularly limited, and for example, in addition to a normal vacuum evaporation device,
Examples include a cluster ion beam device, a vapor deposition device using a Knudsen cell, an ionization vapor deposition device, an ion sputtering device, a magnetron sputtering device, and the like. The amount of vapor deposition material gas irradiated onto the material to be vaporized by one pulse is determined by the duration Δt of the pulse voltage applied to the piezoelectric element body, the pressure of the vapor deposition material gas introduced into the container 2, and the pulse voltage. It can be changed depending on the number of times. Furthermore, in the present invention, although it is possible to form a thin film of the evaporation material on the material to be evaporated using only the above-mentioned pulsed molecular beam generation device, the evaporation material gas flow formed by the pulsed molecular beam generation device can be used in any other evaporation method. It can also be used in combination with a gas stream generated by a gas generator. In this case, evaporation is performed by supplying the gas flow generated by the pulsed molecular beam generator to the material to be evaporated, either in combination with the gas flow from other evaporation material gas flow generators, or alternately. Furthermore, two or more of the pulsed molecular beam generators can be incorporated into the same vapor deposition apparatus at the same time. In this case, vapor deposition is performed by operating two or more pulsed molecular beam generators simultaneously or alternately. Furthermore, the pulsed gas flow from the pulsed molecular beam generator can be activated by electrons, ions, or light to promote deposition on the material to be deposited. Next, the functions of the pulsed molecular beam evaporation apparatus of the present invention will be described in the case where the pulsed molecular beam generation apparatus is combined with a vacuum evaporation apparatus having an electron beam heating evaporation source. In FIG. 2, the pulsed molecular beam generator 1 is combined with two electron beam heating evaporation sources 11 and 12 to form a vacuum evaporation apparatus 13. The electron beam heating evaporation sources 11 and 12 can control the evaporation speed using crystal film thickness gauges 14 and 15, respectively, and when a predetermined film thickness is reached, they are independently controlled by shutter mechanisms 16 and 17, respectively. It is possible to block the beam from the deposition source. In this way, the electron beam heating evaporation sources 11, 12
Vapor deposition is performed by irradiating the beam generated by the heating device 18 onto a material 19 to be vapor-deposited, such as a vapor deposition substrate, which is maintained at a predetermined temperature. On the other hand, the pulsed evaporation material gas generated by the pulsed molecular beam generator 1 is evaporated simultaneously with the beams from the evaporation sources 11 and 12, or after the evaporation is performed with the beams from the evaporation sources 11 and 12, the pulsed molecular beam generator 1
The operation of injecting a pulsed gas flow from 2 to 3 is alternately repeated a predetermined number of times until the total film thickness on the deposition substrate 19 reaches a predetermined value. The film thickness, composition, and structure on the vapor deposition substrate 19 were determined by high-speed electron diffraction devices 20 and 21.
This can be determined by analyzing the analysis pattern from the surface of the deposited film from time to time. [Effects of the Invention] As described above, according to the present invention, a pulsed vapor deposition material gas flow is formed by the high-speed gas jet flow blocking means, and this gas flow is supplied to the vacuum vapor deposition apparatus. Only the gas pressure near the material to be evaporated can be controlled at high speed without significantly changing the vacuum atmosphere of the entire vacuum evaporation apparatus. Further, the degree of vacuum can be maintained at a degree sufficient to operate a high-speed electron beam diffraction device or a mass spectrometer, and a deposited film can be analyzed on the spot during thin film production. Therefore, a thin film whose composition and structure are well controlled can be formed on the material to be deposited. Examples of the present invention will be described below. [Example] A thin film of titanium oxide was formed on a substrate using the pulsed molecular beam evaporation apparatus shown in FIG. Titanium vapor generated by the electron beam heating evaporation sources 11 and 12 is deposited at a deposition rate of 0.5 Å/sec to 2.25 Å on a quartz substrate 19 maintained at 700°C, and then applied to the back pressure of the pulsed molecular beam generator 1. oxygen gas
0.34 atm was introduced and a pulsed gas flow was applied to the substrate 1 N times under the conditions of a pulse applied voltage of 120 V and a pulse width of 3 msec.
9 was sprayed on top. This cycle was repeated 600 times to obtain the titanium oxide thin films shown in Table 1 below.

[Table] The composition of each titanium oxide was confirmed to be a single phase by X-ray diffraction method. The pulsed gas flow from the pulsed molecular beam generator 1 is ejected into the vacuum evaporator 13 with a half width of 3 msec, and after the ejection ends, the degree of vacuum in the container of the vacuum evaporator returns to the base vacuum level within 10 msec. . Moreover, since the pulsed oxygen flow from the pulsed molecular beam generator is injected onto the substrate 19 as a directional molecular beam beam, it is possible to maintain the average degree of vacuum inside the vacuum evaporation device container at a low level. It is possible to increase the effective gas partial pressure above. In addition, in FIG. 2, two electron beam heating evaporation sources 1
1 and 12 and the shutter mechanisms 16 and 17, it is possible to fabricate a multilayer thin film, but by using two or more pulsed molecular beam generators,
Multilayer thin films such as TiO/TiN can be created. In this case, N ₂ gas can be used as the nitrogen source, but in some cases, the reaction can also be promoted by ionizing the N ₂ beam. With the conventional method of introducing gas into the container of a vapor deposition apparatus using a gas introduction valve, it was difficult to exchange or exhaust the atmospheric gas at high speed, so it was necessary to create a multilayer structure film with a large number of repetition cycles. was almost impossible.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory view showing an aspect of a pulsed molecular beam generator used in the pulsed molecular beam vapor deposition apparatus of the present invention, and FIG. 2 is an explanatory view of the pulsed molecular beam vapor deposition apparatus of the present invention. DESCRIPTION OF SYMBOLS 1...Pulse molecular beam generator, 2...Deposited material gas storage device, 3...Ejection port, 4...Ejected gas flow high-speed cutoff means, 6...Pulse voltage generation source.

Claims (1)

[Scope of Claims] 1. A pulsed molecular beam evaporation method characterized by injecting a gas flow of the evaporation material in a pulsed manner onto a material to be deposited in a vacuum evaporation apparatus to deposit the evaporation material onto the material to be deposited. . 2 Consisting of a combination of a pulsed molecular beam generator and a vacuum evaporation device, the pulsed molecular beam generator includes a container containing the vapor of the evaporation material, and a high-speed blocking means for the ejected gas flow provided inside the ejection port of the container. , and a pulsed voltage generation source connected to the means.