JPS63148617A - Molecular beam epitaxy apparatus - Google Patents

Abstract

PURPOSE:To realize the miniaturization of a system by a method wherein a delivery mechanism of a molecular beam source is installed at the tip of a conveyance mechanism and on the side of a growth chamber and a reserve chamber is made detachable. CONSTITUTION:A molecular beam source 3 having a crucible 4 containing a source substance is installed in the air at a delivery mechanism 14 at the tip of a conveyance mechanism 7 inside a reserve chamber 6; the reverse chamber 6 is connected to a gate valve 8; after the inside of the reserve chamber 6 has been evacuated to produce a vacuum, the gate valve 8 is opened. Then, the molecular beam source 3 is shifted to the side of a growth chamber 1 by means of the conveyance mechanism 7, and the molecular beam source 3 is delivered to the delivery mechanism 14; the molecular beam source 3 is supported by a positioning device. After that, the conveyance mechanism 7 is returned to its initial position; after the gate valve 8 has been closed, the reserve chamber 6 is detached from the gate valve 8. It is possible to supply the source substance for the molecular beam source 3 without exposing the growth chamber 1 to the atmospheric pressure, to execute this operation in the single reserve chamber 6 and, furthermore, to detach the reserve chamber 6 during the growth of a film; as a result, it is possible to miniaturize a system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a single-molecular beam epitaxy apparatus, and particularly relates to a single molecular beam epitaxy system that is capable of replenishing a source material, which is a vapor deposition material, for growing a high-quality epitaxy layer with high productivity. The present invention relates to a molecular beam epitaxy device that can easily perform epitaxy without opening a chamber to the atmosphere.

(Prior Art) As shown in FIG. 3, the main components of a commonly used molecular beam epitaxy apparatus are as follows: A wafer is placed inside a growth chamber 1 maintained at an ultra-high vacuum by an exhaust device 5. A plurality of molecular beam sources 3 each having a crucible 4 containing a source material to be a thin film material are provided at positions facing the wafer 2, and the molecular beam sources 3 grow a film on the surface of the wafer 2. If this film growth continues for a certain period of time, the source material will be depleted, and it will be necessary to supply new source material.

This fund includes opening growth chamber 1 to atmospheric pressure and molecular beam source 3.
is removed from the growth chamber 1 and the crucible 4 is replenished with the source material. In order to be able to perform film growth again after that, it is necessary to bake the growth chamber 1, which has been released to atmospheric pressure, including baking the source material, to remove impurities attached to the walls, etc. become. Once the growth chamber 1 is released to atmospheric pressure in this manner, it takes a long time to start up the chamber, and the thin films grown several times immediately after the start-up usually fail to produce a good quality film.

Therefore, it has been proposed to replenish the source material without releasing the growth chamber to atmospheric pressure when the source material is depleted. This method can be broadly divided into two methods: one is to replenish only the source material or the crucible containing the source material while keeping the growth chamber in vacuum, and the other is to remove the molecular beam source and replenish the source material while keeping the growth chamber in vacuum. There is a way to do this.

Conventional devices using these methods will be explained below with reference to FIGS. 4 to 7.

FIG. 4 shows an apparatus described in Japanese Patent Application Laid-open No. 58-33825, in which a preliminary chamber 6 is provided with an exhaust device 9 via a gate bulk 8 separately from the growth chamber 1, and the preliminary chamber 6 A transport mechanism 7 is provided inside the chamber, and the transport mechanism 7 is used to transport the preliminary chamber 6.
A crucible containing a source material is supplied to a crucible 4 in the growth chamber 1 from inside.

FIG. 5 shows an apparatus described in Japanese Patent Application Laid-Open No. 58-194796, in which a preliminary chamber 6 having an exhaust device i'19 is installed separately from the growth chamber 1 via a gate bulk 8. A transport mechanism 7 for supplying only the source material to the crucible 4 is provided in the preliminary chamber 6.

FIG. 6 shows the apparatus described in Japanese Unexamined Patent Publication No. 60-27118, in which a tubular body L3 having an exhaust port 11 is provided separately from the growth chamber 1 via a gate bulk.
The metal tubular body 13 has a telescopic iJ for moving the molecular beam source 3.
Connect the functional bone tubular body 0 and connect the molecular beam source 3 to the metal tubular body 1.
3 through the expandable tubular body 10 and taken out to the outside.

The apparatus shown in FIG.
is provided with an exhaust port 11 and a transport mechanism 7 for moving the molecular beam source 3.

[Problem that the invention seeks to solve]

In the above-mentioned prior art, there was a particular problem with the structure of the preliminary chamber attached to the growth chamber via the gate bulk. That is, in the apparatus shown in FIGS. 4 and 5, the preliminary chamber occupies a large space, and a plurality of preliminary chambers are required in order to supply source materials to the plurality of molecular beam sources.

Furthermore, in order to supply source material to a plurality of molecular beam sources using only one preparatory chamber and a transport mechanism, the transport mechanism becomes very complicated.

The same applies to the devices shown in FIGS. 6 and 7.
Multiple extensible tubular bodies are required for multiple molecular beam sources, and these extensible tubular bodies are always connected to the growth chamber, which increases the size and complexity of the device. There was a problem.

The object of the present invention is to supply one p.
It is an object of the present invention to provide a molecular beam epitaxy apparatus in which a molecular beam source can be attached and removed using a preliminary chamber, and the preliminary chamber can be removed when replenishment work is completed.

[Means for solving problems]

In order to achieve the above object, the molecular beam epitaxy apparatus of the present invention has a wafer placed in a growth chamber kept in an ultra-high vacuum,
a molecular beam source that irradiates the wafer with a molecular beam of a source material to form a thin film on the wafer surface; a preliminary chamber connected to the growth chamber via a gate bulk; In a molecular beam epitaxy apparatus equipped with a transport mechanism capable of moving a radiation source, a delivery mechanism for the molecular beam source is provided at the tip of the transport mechanism and on the side of the growth chamber, and the preliminary chamber is made detachable. It is something.

[Operation] According to the configuration described in Section 2, source material is supplied by first installing a molecular beam source containing the source material in the delivery mechanism installed at the tip of the transport mechanism in the preliminary chamber in the atmosphere.
The preliminary chamber is connected to the gate bulk.The preliminary chamber is then evacuated and the gate bulk is opened. Next, the molecular beam source is moved in the axial direction by a transport mechanism, and the molecular beam source is delivered to a delivery mechanism in the growth chamber. As a result, the molecular beam source is installed at a predetermined position in the growth chamber.6 Afterwards, the transport mechanism is returned to the initial position, the gate bulk is closed, and the preliminary chamber is removed from the gate bulk. With the above steps, the source material replenishment work is completed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Note that components having the same functions as known components are given the same reference numerals.

As shown in FIG. 1, the overall configuration of an embodiment of the present invention is as follows.
A removable preliminary chamber 6 having an exhaust port 11 is provided in the growth chamber 1 via a gate bulk 8 . A transport mechanism 7 for the molecular beam source 3 is installed in the preliminary chamber 6, and at the tip of the transport machine 4i17, the molecular beam source 3 having the crucible 4 is held, and the single molecular beam source 3 is moved to the growth chamber 1 side. A delivery mechanism 12 is provided for delivery to. On the other hand, growth chamber 1
On the side, there is a delivery mechanism 14 for supporting, positioning, and receiving the molecular beam source 3 transported by the transport mechanism 7, a heater for heating the source material of the molecular beam source 3, and a thermocouple for measuring its temperature. A current introduction terminal 15 for a lead wire is provided. In this case, the method of positioning and supporting the molecular beam source 3 on the side of the growth chamber 1 has a close relationship with the transport mechanism and delivery mechanism of the molecular beam source 3, and has a structure that can be supported in the vacuum growth chamber with one touch. shall be. Also.

When the molecular beam source 3 is supported on the side of the growth chamber 1, the lead wire for heating the source material and the lead wire for the thermocouple for measuring its temperature are taken out of the apparatus through the current introduction terminal 15. The structure has electrical contact points on the single molecule beam source 3 side and on the support mechanism side of the molecular beam source 3 in the growth chamber 1, respectively, and the electrical connection is made in vacuum by a pressing or rotating mechanism, etc. do.

Next, the operation of the above embodiment will be explained. Regarding the case of replenishing the source material, first, the molecular beam source 3 having the crucible 4 containing the source material is installed in the delivery mechanism 12 provided at the tip of the transport mechanism 7 in the preliminary chamber 6 in the atmosphere. The preliminary chamber 6 is connected to the gate bulk 8 by bolting or the like, and then the preliminary chamber 6 is evacuated by exhausting air through the exhaust port 11, and then the gate bulk 8 is opened. Next, the molecular beam source 3 is moved to the growth chamber 1 side by the transport mechanism 7, and the molecular beam source 3 is delivered to the delivery mechanism 14, whereby the molecular beam source 3 is positioned and supported by the delivery mechanism 14. After that, the transport mechanism 7 is returned to the initial position, and then the gate bulk 8 is closed, and the preliminary chamber 6 is moved to the gate bulk 8.
Removal and replenishment work is complete. In addition, molecular beam VA3
Normally, a plurality of molecular beam sources are required, but according to this embodiment, source materials for a plurality of molecular beam sources can be supplied in one preliminary chamber.

FIG. 2 shows another embodiment of the present invention, the basic configuration of which is the same as that of FIG. 1, except that a heater 16 for heating is provided around the preliminary chamber 6. That's what happened. According to this embodiment, the molecular beam source 3 can be prebaked before being transported to the growth chamber 1, and a thin film of better quality can be grown.

〔Effect of the invention〕

As described above, according to the present invention, the source material for a single molecule beam source can be replenished without opening the growth chamber to atmospheric pressure, and these operations can be performed in one preparatory chamber. Since the preliminary chamber can be removed during growth, it is possible to downsize the device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main components of a molecular beam epitaxy apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing main components of another embodiment of the present invention, and FIGS. 3 to 7 are 1 is a cross-sectional view of a conventional molecular beam epitaxy apparatus. 1...Growth chamber, 3...Molecular beam source,
4... Crucible, 6... Preliminary room, 7
...Transport mechanism, 8...Gate bulk, 11...Exhaust port, 12.14...
Delivery mechanism, 15... Current introduction terminal, 16... Heater for heating.

Claims (2)

[Claims] (1) A wafer is placed in a growth chamber kept in an ultra-high vacuum, a molecular beam source that irradiates the wafer with a molecular beam of a source material to form a thin film on the wafer surface, and a gate bulk is placed in the growth chamber. In a molecular beam epitaxy apparatus equipped with a prechamber connected to the prechamber and a transport mechanism capable of moving a molecular beam source in the axial direction of the prechamber, a molecular beam source is provided at the tip of the transport mechanism and on the side of the growth chamber, respectively. A molecular beam epitaxy apparatus characterized in that a delivery mechanism is provided and the preliminary chamber is detachable. (2) The molecular beam epitaxy apparatus according to claim 1, characterized in that a heater is disposed around the outer periphery of the preliminary chamber.