JPS6350394A - Molecular beam crystal growth device - Google Patents

Abstract

PURPOSE:To monitor the thickness, etc., of the crystal on a substrate and to control the epitaxy of the crystal by connecting an electron beam generating chamber to a molecular beam crystal growth chamber through a partition wall, projecting the generated electron beam on the substrate arranged in the molecular beam crystal growth chamber, and detecting the reflected electron beam from the substrate with a detector. CONSTITUTION:The molecular beam crystal growth device is provided with the molecular beam crystal growth chamber 2, wherein the substrate 1 is arranged and a crystal is epitaxially grown on the substrate 1, and an evacuation pump 4 for evacuating the chamber. The device has the following structure. Namely, (a) the electron beam generating chamber 12 furnished with an electron beam source 13 is connected to the molecular beam crystal growth chamber 2 through the partition wall 11, (b) the evacuation pump 15 for evacuating the chamber is connected to the electron beam generating chamber 12, (c) an electron beam transmitting hole 17 for radiating an electron beam 16 from the electron beam source 13 on the substrate 1 is provided to the partition wall 11, and (d) an electron beam detector 17' for detecting the electron beam 16' obtained by the diffraction and reflection of the electron beam 16 on the substrate 1 is furnished in the molecular beam crystal growth chamber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a molecular beam crystal growth apparatus for epitaxially growing crystals on a substrate using molecular beams, and particularly relates to a process of epitaxially growing crystals on a substrate. The present invention relates to a molecular beam crystal growth system that can monitor the thickness of a crystal epitaxially grown on a substrate, and furthermore, can control the epitaxial growth of a crystal on a substrate.

BACKGROUND OF THE INVENTION Conventionally, a molecular beam crystal growth chamber is provided with a substrate and epitaxially grows a crystal on the substrate using molecular beams.
The molecular beam crystal growth chamber is evacuated using the exhaust pump, and the molecular beam is introduced into the molecular beam crystal growth chamber. A molecular beam crystal growth apparatus has been proposed in which an epitaxy layer of crystals is grown on a substrate by irradiating the molecular beam onto the substrate.

Problems to be Solved by the Invention By the way, conventionally, in the process of epitaxially growing a crystal on a substrate in such a molecular beam crystal growth apparatus, the thickness of the crystal epitaxially grown on the substrate has to be on the order of atomic layer thickness. It would be desirable to be able to monitor and further control the epitaxial growth of crystals on a substrate.

For this reason, it has been proposed to place an electron beam generation source in the molecular beam crystal growth chamber, irradiate the substrate with the electron beam, and detect the resulting foul electron beam that is diffracted and reflected from the substrate. It will be done.

However, in this case, since the electron beam generation source is placed inside the molecular beam crystal growth chamber, the inside of the molecular beam crystal growth chamber is suitable for growing crystals on the substrate using molecular beams. In a pressurized state, the function of the electron beam source decreases or deteriorates due to the low pressure.
It had the following drawback.

By means of solving and overcoming the problems, the present invention seeks to propose a novel molecular beam crystal growth apparatus free of such drawbacks.

Molecular beam crystal growth according to the present invention 1! As in the case of conventional molecular beam crystal growth equipment, the i' position is a molecular beam crystal growth chamber in which a substrate is arranged and crystals are epitaxially grown on the substrate using molecular beams, and a chamber for molecular beam crystal growth. It has an exhaust pump for evacuating the chamber.

However, in the molecular beam crystal growth apparatus according to the present invention having such a configuration, an electron beam generation source is arranged in the molecular beam growth chamber through a partition. The generation chambers are connected and can also be used for electron beam generation! An evacuation pump separate from the evacuation pump for the molecular beam crystal growth chamber is connected to evacuate the chamber, and further,
The partition wall is provided with an electron beam passage hole through which the electron beam from the electron beam generation source passes into the molecular beam growth chamber in order to irradiate the substrate, and the molecular beam growth chamber is provided with an electron beam passage hole. An electron beam detector is provided for detecting the reflected electron beam obtained by diffraction and reflection from the substrate.

Effects and Effects According to the molecular beam crystal growth apparatus according to the present invention, as in the case of conventional molecular beam crystal growth apparatuses, while evacuating the molecular beam crystal growth apparatus using its exhaust pump,
By introducing molecular beams into the molecular beam crystal growth chamber, crystals can be epitaxially grown on the substrate.

However, in the case of the molecular beam crystal growth apparatus according to the present invention, in the process of epitaxially growing a crystal on a substrate, by moving the electron beam generation source, the thickness of the crystal epitaxially grown on the substrate is determined by an electron beam detector. etc., or the epitaxial growth of the crystal can be controlled by the output of an electron beam detector.

In addition, since the electron m generation chamber can be evacuated using a pump separate from that for the molecular beam crystal growth chamber, the function of the electron beam generation chamber and electron beam source is not required. It is possible to maintain high pressure without causing any drop or deterioration. Therefore, when the pressure in the molecular beam crystal growth chamber is set to a level suitable for growing crystals on the substrate, the function of the electron beam source is that the pressure of the atmosphere in which the electron beam source is placed is low. By doing so, the disadvantage of reduction or deterioration can be effectively avoided.

Embodiment Next, an embodiment of the molecular beam crystal growth apparatus according to the present invention will be described with reference to the drawings.

In the embodiment of the molecular beam crystal growth apparatus according to the present invention, as in the case of a conventional molecular beam crystal growth apparatus, a substrate 1 is arranged, and a crystal is grown epitaxially on the substrate 1 using molecular beams. It has a chamber 2 and an exhaust pump 4 connected thereto via an opening/closing means 3 for evacuating the chamber for molecular beam crystal growth.

In this case, the molecular beam crystal growth chamber 2 includes molecular beam ejectors 7 and 8 that receive the source gases from source gas sources 5 and 6 outside the molecular beam crystal growth apparatus, respectively, and eject them, respectively. Nozzles 9 and 10 are extended.

Further, an electron beam generation chamber 12 is connected to the molecular beam crystal growth chamber 2 via a barrier 11.
A well-known scale electron beam source 13 is disposed therein, and the molecular beam crystal growth chamber 12 is connected to another exhaust pump 15 via an opening/closing means 14 . In this case, the barrier 11 allows the electron beam 16 from the electron beam generation source to pass through the molecular beam crystal growth chamber 2 in order to irradiate the substrate 1 arranged in the molecular beam crystal growth chamber 2. It has a hole 17 for electron beam passage.

On the other hand, based on the electron beam 16 being irradiated onto the substrate 1, the molecular beam crystal growth chamber 2 receives the reflected electron beam 16 obtained by diffraction and reflection from the substrate 1, and the intensity of the reflected electron beam is A fluorescent screen 17 that emits light with an intensity corresponding to the brightness is provided, and a monitoring window 18 for visually monitoring the intensity of light emitted from the fluorescent screen 17 is provided.

The above is the configuration of the embodiment of the molecular beam crystal growth apparatus according to the present invention.

According to such an embodiment of the molecular beam crystal growth apparatus according to the present invention, the substrate 2 is disposed in the molecular beam crystal growth chamber 2, and the substrate 2 is heated by the heating means shown in FIG. While evacuating the chamber 2 using the exhaust pump 4, a source gas source 5 is introduced into the molecular beam crystal growth chamber 2.
For example, phosphine is introduced through the molecular beam jetter 7 and its nozzle 9, and triethyl indium, for example, is introduced through the molecular beam jetter 8 and its nozzle 10, and then inside the molecular beam crystal growth chamber 2. For example, 5X
10-'T.

By maintaining the pressure at rr, I
A crystal made of nP can be grown epitaxially well.

In addition, during or before the process of epitaxially growing a crystal on the substrate 1, the electron beam generation chamber 12 is evacuated using the exhaust pump 15, and the electron beam generation source 13 is evacuated using the evacuation pump 15. When the electron beam 16 is moved, the substrate 1 is irradiated with the electron beam 16, and the electron beam 16' obtained by diffraction and reflection from the substrate 1 is reflected on the fluorescent screen 1.
7, the fluorescent screen 17 emits light according to the intensity of the reflected electron beam, and the emitted light intensity can be monitored through the monitoring window 18. Therefore, by controlling the amount of phosphine and triethyl indium introduced into the molecular beam crystal growth chamber 2 from the raw material gas sources 5 and 6, epitaxial growth of a crystal made of np is epitaxially grown on the substrate 1. can be controlled.

Further, the electron beam generation II! generates the electron beam 16 used for monitoring and control as described above! The electron beam generation chamber 12 in which the electron beam generation chamber 13 is located can be evacuated using an evacuation pump 15 that is different from the evacuation pump 4 for molecular beam crystal growth V2. 17 into a relatively small hole, for example, 5 mm in diameter, the inside of the electron beam generation chamber 2 is made into a 5×1 hole, for example.
The molecular beam crystal growth chamber 2 does not unnecessarily lower or deteriorate the function of the electron beam generation source 13 such as 0' Torr.
It is possible to maintain a higher pressure than the

In the above description, a case has been described in which a crystal made of InP is epitaxially grown on a substrate, but crystals made of various other materials can also be grown epitaxially.

In addition, although the fluorescent screen 17 is used as an electron beam detector, the reflected electron beam 1
6' and outputs an electrical output, using various well-known electron beam detectors, and the electrical output automatically detects the amount of gas introduced into the molecular beam crystal growth chamber 2. 1 or 11, and various other modifications and changes may be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

The figure is a linear cross-sectional view showing an embodiment of the molecular beam crystal growth apparatus according to the present invention. １・・・・・・・・・・・・・・・Substrate 2・・・・・・
・・・・・・Molecular beam crystal growth chamber 4.15...
... Exhaust pump 5.6 ... Raw material gas source 7.8 ... Molecular beam ejector 9.10 ...
···nozzle

Claims (1)

[Claims] A molecular beam comprising a molecular beam crystal growth chamber in which a substrate is arranged and a crystal is epitaxially grown on the substrate using a molecular beam, and an exhaust pump for evacuating the molecular beam crystal growth chamber. In the crystal growth apparatus, an electron beam generation chamber in which an electron beam generation source is arranged is connected to the molecular beam growth chamber via a partition wall, and the electron beam generation chamber is evacuated to the electron beam generation chamber. An evacuation pump different from the evacuation pump is connected, and the partition wall has an electron beam passage hole for passing the electron beam from the electron beam generation source into the molecular beam growth chamber in order to irradiate the substrate with the electron beam. The molecular beam growth chamber is provided with an electron beam detector for detecting a reflected electron beam obtained by diffraction and reflection from the substrate based on the electron beam. Crystal growth equipment.