JPH07172982A - Cell for introducing pulse-like raw material - Google Patents

Abstract

PURPOSE:To make it possible to precisely control vapor feed amount of a raw material having very high vapor pressure, e.g. sulfur. CONSTITUTION:A heater 22 for heating is wound around a raw material container 21 and a nozzle 23 is attached through a seal mechanism 24 to the top part. A sealing member 25 each having a flange projection 25b in a groove (passage) in the axial direction at the lower part of the groove is fitted into the inside of the nozzle 23 and the sealing member 25 is subjected to high speed piston motion by a magnetic body 27 in the lower end, a magnet 28 and a spring 29 through a rod 26. A raw material vapor vaporized by heating a solid raw material having high vapor pressure in the raw material container 21 with a heater 22 is fed from a closable nozzle opening 23a into a vacuum chamber in a pulse state by the sealing member 25 which carries out high-speed piston motion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition device for depositing a metal or oxide on a surface of a substrate provided in a high vacuum,
The present invention relates to a raw material introduction cell used for a molecular beam epitaxy (MBE) apparatus, a crystal growth apparatus such as a CVD (chemical vapor deposition method) apparatus, an organic vapor deposition apparatus having an introduction system of a monomer for vapor deposition polymerization, and the like. .

[0002]

2. Description of the Related Art Conventionally, when a thin film is formed on the surface of a substrate in a vacuum, K cell (Knudsen cell), which is one of evaporation sources, and an evaporation boat (sample There was a boat-shaped container made of platinum, ceramic, etc. used for supporting the sample by putting it in a combustion tube or the like so as not to touch the tube wall when heating and burning.

FIG. 5 is a cross-sectional explanatory view of a main part showing a conventional example of the K cell. In the figure, a heater 2 is wound around a crucible 1 and is surrounded by a heat reflection plate 3 on the outside, and is attached to a vacuum flange 5 via a support 4. In the figure, 6 is a thermocouple. When the raw material is put in the crucible 1 at the time of use and the raw material is heated to a predetermined temperature by the heater 2, the heat reflection plate 3 and the thermocouple 6, the raw material in the crucible 1 is evaporated and a molecular beam (beam) is emitted from the upper opening 1a. It pops out in the form of and supplies raw materials.

FIG. 6 is a conceptual diagram of a conventional molecular beam epitaxy apparatus, as an example, in which the above-described conventional K cell or the like is attached. In the figure, a vacuum chamber 1 evacuated to a high vacuum
The evaporation source 12 composed of a K cell or the like as shown in FIG.
Are arranged in a ring shape, the surroundings of these evaporation sources 12 are filled with liquid nitrogen 13, and metallic materials such as Ga and As housed in the evaporation sources 12 are heated by a heater (2 in FIG. 5). Then, it is ejected from the cell in the form of a molecular beam (beam) 16, and the molecular beam 16 is made to collide with a substrate 18 placed in the vacuum chamber 11 and heated by a heater 17, and the adhesion coefficient of each material is Is utilized to maintain the stoichiometric composition ratio for epitaxial growth. In the figure, 19 is a shutter attached near the outlet of the evaporation source 12, and the molecular beam 16 traveling from the evaporation source 12 to the substrate 18 is mechanically blocked by the shutter 19 so that the growth can be interrupted. Therefore, each evaporation source is attached independently. The vacuum chamber 11 communicates with the preheat chamber and the substrate exchange chamber in the arrow direction.

[0005]

In the evaporation source 12 in the above-mentioned conventional example (FIG. 6), when vaporizing a raw material having a very high vapor pressure such as sulfur (S) or an organic material, the vapor pressure is low at a low temperature. Is too high, and it is difficult to control the evaporation amount for forming a thin film.

The present invention solves the above-mentioned problems of the prior art, and provides a raw material introduction cell capable of precisely controlling the vapor supply amount of a raw material such as sulfur having a very high vapor pressure. Is intended.

[0007]

In order to achieve the above object, the present invention provides a raw material supply device for supplying a raw material into a vacuum chamber for vacuum deposition or the like, in which a raw material is supplied from a raw material container to a tip portion thereof. A rod having a nozzle for performing a piston movement in which the opening of the nozzle is repeatedly closed from the inside and a means for driving the rod at high speed are provided, and raw material vapor is introduced into the vacuum chamber from the nozzle in a pulsed manner. It is characterized by doing so.

In addition, the rod which performs the piston movement driven by the high speed driving means is provided through a raw material container for heating and evaporating a solid raw material such as sulfur having a very high vapor pressure, and It is characterized in that a rod for performing a piston motion driven by the high speed driving means is provided so as to penetrate a raw material container for introducing a raw material gas from the outside.

A raw material introduction cell for introducing raw material into the vacuum chamber in a pulsed manner from a nozzle at the tip is installed on a flange connectable to the vacuum chamber, and the nozzle attached to the tip is provided with a sealing mechanism. It is characterized in that it is attached so as to be sufficiently isolated from the vacuum chamber and exchangeable.

[0010]

Since the present invention is constructed as described above,
During operation, by heating the evaporation source consisting of the K cell to heat and evaporate the raw material with a very high vapor pressure in the raw material container, and to open and close the nozzle at the tip of the cell by the rod that makes a piston motion by the high speed driving means. The raw material is supplied from the nozzle in a pulsed manner into the vacuum chamber. At this time, by controlling the opening / closing speed, the number of opening / closing, etc. of the nozzle by the high-speed driving means, it becomes possible to precisely control the raw material supply.

Also, when the raw material gas is introduced into the raw material container from the outside, the same operation is performed.

The raw material introduction cell, which is supplied in a pulsed manner into the vacuum chamber, is connected to the vacuum chamber via a flange, and the nozzle at the tip is mounted sufficiently isolated from the vacuum chamber via a sealing mechanism. Therefore, it can be easily replaced.

[0013]

EXAMPLE FIG. 1 is a vertical sectional view of a raw material introduction cell showing an example of the present invention. In the drawing, a heater 22 for heating is wound around a raw material container 21, and a nozzle (member) 23 is provided at a tip portion of the raw material container 21 and a metal sheet 24b is sandwiched between opposing knife-edge type seal portions 24a. The nozzle 23 is mounted via a sealing mechanism 24 that is configured by fastening with a bolt 21a. Inside the nozzle 23, as shown in FIG. Is fitted with a rod-shaped sealing member 25 having a lower end notch 23b of the nozzle 23 and a flange-shaped projection 25b that abuts, and the tip of the sealing member 25 seals the opening 23a of the nozzle 23. It has become.

The sealing member 25 is integrally connected to a rod 26 penetrating the raw material container 21.
Has a magnetic body 27 formed at its lower end, and is provided with an electromagnet 28 that drives the magnetic body 27 so as to attract the magnetic body 27 downward and a spring 29 that biases the magnetic body 27 upward. The raw material container 21 is supported by a vacuum chamber (not shown) via a support 30a and a flange 30.

Next, the operation will be described. When a solid material such as sulfur having a very high vapor pressure is contained in the material container 21 and heated by the heater 22, the solid material evaporates. On the other hand, when the electromagnet 28 is driven, the rod 26
By the attraction force of the electromagnet 28 acting on the magnetic body 27 at the lower end and the pushing force of the spring 29, the rod 2
6 Therefore, the sealing portion 25 repeats the piston movement at a high speed, and accordingly, the vapor in the raw material container 21 causes the sealing member 25 to move downward as shown in FIG. 2B. , The nozzle member 23 is ejected into the vacuum chamber through the groove 25a from the lower end notch 23b of the nozzle member 23 and the lower brim-shaped protrusion 25b of the sealing member 25, and then into the vacuum chamber. When 25 is in the ascending stroke as shown in FIG. 2 (a), the nozzle opening 23a is sealed, so that the raw material vapor is supplied in pulses. At this time, the ejection amount of the raw material vapor from the nozzle opening 23a can be precisely controlled by adjusting the opening time of the nozzle opening 23a by the electromagnet 36 and the number of repeating cycles.

FIG. 3 is a conceptual diagram of an epitaxy apparatus as an example in which the above-mentioned raw material introduction cell of the present invention is attached to the vacuum chamber 11 and raw material vapor is deposited on the substrate.
In the figure, the same reference numerals as those shown in FIG. 6 indicate the same or similar parts. In the figure, the substrate 18 installed in the vacuum chamber 11 is often heated by the substrate heating heater 17 to improve the film quality of the film forming material, and the K cell 12 and the pulse of the present invention are directed toward the substrate 18. The raw material vapor radiated from the raw material introduction cell 31 is deposited on the substrate 18. In the figure, 13 is a cooling liquid nitrogen, 19 is a shutter, and although not shown, an evacuation system required for the vapor deposition chamber, a substrate holding mechanism, and other evaporation sources for doping are normally provided. ing.

During operation, for example, zinc is contained in the K cell 12, sulfur is contained in the pulsed material introduction cell 31 of the present invention, and a GaAs substrate is installed on the substrate 18. In the normal K cell 12, it is not possible to precisely control the amount of sulfur with high vapor pressure,
In the raw material introduction cell 31 of the present invention, the above vapor amount control can be performed.

As a result of the experiment, the substrate 18 was heated to 250 ° C., the K cell 12 was radiated with zinc vapor at 300 ° C., the raw material introduction cell 31 of the present invention was set to 150 ° C., and pulse control of 100 ms (millisecond) was performed. As a result, a zinc sulfide thin film having a good composition ratio could be obtained.

FIG. 4 is a vertical cross-sectional view of a raw material introduction cell showing another embodiment of the present invention. In the figure, the same reference numerals as those shown in FIG. 1 indicate the same or similar parts. This embodiment differs from the previous embodiment (FIG. 1) in that the raw material container 21 is connected to a gas introduction mechanism (not shown) via a gas supply pipe 32, and other points are the same. There is. According to this embodiment, not only solid raw materials such as sulfur and organic materials but also gas can be introduced.

In addition, two kinds of monomers are used and can be applied to a vapor deposition polymerization apparatus and the like.

[0021]

As described above, according to the present invention,
In a raw material supply device for supplying a raw material into a vacuum chamber for vacuum deposition or the like, a piston movement having a nozzle for supplying a raw material from a raw material container at a tip portion and repeating the opening of the nozzle from the inside to the sealing opening By providing a rod for performing the above and a means for driving the rod at a high speed, and introducing the raw material vapor from the nozzle into the vacuum chamber in a pulsed manner, the evaporation source such as the conventional K cell has a very high vapor content such as sulfur. When vaporizing a high pressure raw material, the problem that the vapor pressure was too high at low temperature and it was difficult to control the vaporization amount for thin film formation was solved, and the vapor pressure of sulfur etc. It is possible to precisely control the supply amount of the raw material vapor even with a high raw material, and it is possible to obtain a good thin film of zinc sulfide, which was difficult in the past.

Further, by providing a rod which is driven by a high speed driving means and which performs a piston motion, through a raw material container for introducing the raw material gas from the outside, it is possible to adapt to the introduction of the gas.

Further, since the above-mentioned raw material introducing cell of the present invention is connected to the vacuum chamber through the flange, the cell body can be easily attached and detached, and the nozzle at the tip of the cell is vacuumed through the sealing mechanism. Since the nozzle is mounted so as to be sufficiently isolated from the chamber, the nozzle can be removed by the seal mechanism portion and can be easily replaced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a pulsed raw material introduction cell showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of FIG. 1, where (a) shows a closed state of a nozzle opening and (b) shows an open state.

FIG. 3 is a conceptual diagram of a molecular beam epitaxy apparatus in which the pulsed raw material introduction cell of the present invention is attached to a vacuum chamber.

FIG. 4 is a vertical sectional view showing another embodiment of the present invention.

FIG. 5 is an explanatory diagram of a K cell that is an evaporation source showing a conventional example.

FIG. 6 is a conceptual diagram of a molecular beam epitaxy apparatus showing a conventional example.

[Explanation of symbols]

 21 Raw Material Container 22 Heater 23 Nozzle 23a Nozzle Opening 23b Nozzle Notch 24 Sealing Mechanism 24a Knife Edge Sealing Part 24b Metal Sheet 25 Sealing Member 25a Groove 25b Collar-like Projection 26 Rod 27 Magnetic Material 28 Electromagnet 29 Spring 30 Mounting Flange 31 pulsed raw material introduction cell 32 gas supply pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location // C30B 29/48 8216-4G (72) Inventor Bonsu Kim Saigo, Myodaiji Town, Okazaki City, Aichi Prefecture Naka 38 Okazaki National Institute for Collaborative Research, Institute for Molecular Science (72) Inventor, Yasuki Endo, 3-8-1, Komaba, Meguro-ku, Tokyo, Faculty of Arts and Sciences, University of Tokyo (72) Hiroyuki Fukasawa, 2500, Hagien, Chigasaki, Kanagawa Incorporated (72) Inventor Toshio Negishi 2500 Hagien, Chigasaki, Kanagawa Japan Vacuum Technology Co., Ltd. (72) Inventor Tatsuhiko Koshida 2500 Hagien, Chigasaki City, Kanagawa Nihon Vacuum Technology Co., Ltd.

Claims (4)

[Claims] 1. A raw material supply apparatus for supplying a raw material into a vacuum chamber for vacuum deposition or the like, which has a nozzle for supplying a raw material from a raw material container at a tip portion, and the opening of the nozzle is provided with a sealing opening from the inside. A pulsed raw material introduction cell, characterized in that a rod for performing repeated piston movements and a means for driving the rod at high speed are provided, and raw material vapor is introduced into the vacuum chamber from the nozzle in a pulsed manner. 2. A rod, which is driven by a high-speed driving means and carries out a piston motion, is provided through a raw material container for heating and evaporating a solid raw material such as sulfur or an organic material having a very high vapor pressure. The pulsed raw material introduction cell according to claim 1. 3. The pulsed raw material introduction cell according to claim 1, wherein a rod for performing a piston movement driven by a high speed driving means is provided through a raw material container for introducing a raw material gas from the outside. 4. A raw material introduction cell in which a raw material is introduced into the vacuum chamber in a pulsed manner from a nozzle at the tip is installed on a flange connectable to the vacuum chamber, and the nozzle attached to the tip is provided with a sealing mechanism. The vacuum chamber is sufficiently isolated from the vacuum chamber to be replaceable.
The pulsed raw material introduction cell described.