JPH0415911A - Substrate heating device of molecular beam epitaxy system - Google Patents

Abstract

PURPOSE:To obtain an epitaxially developed film with few foreign matters by installing shielding plates to prevent foreign matters from falling or scattering between a substrate and foreign matter generation parts of power transmissions in a substrate heating device for preventing foreign matters from attaching the substrate which is developed epitaxially or from mixing into the source of molecular beam. CONSTITUTION:Foreign matter shielding plates 9 and 10 are installed between foreign matter generation parts of power transmissions and a substrate 1. Foreign matter generated at gears a7 and b8 installed in a rotary introducer 6 and at a bearing 11 is caught by the shielding plates 9 and 10 while it falls in the gravity direction. Because of the projected shape of the shielding plate toward the gravity direction, the foreign matter which falls upon the shielding plates 9 and 10 does not scatter in a vacuum chamber. With the foreign matter kept from falling on the substrate 1 which is epitaxially developed, a good- quality epitaxially developed film can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a substrate heating device for a five-molecular beam epitaxy device, and is particularly suitable for reducing defects caused by adhesion of foreign matter on a growing substrate. The present invention relates to a substrate heating device for a single molecular beam epitaxy device.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 62-73706, the conventional device focuses on automation and high precision in board delivery, and the mechanical parts for board delivery and rotation are constructed using gears and bearings. ing. That is, the conventional equipment is in vacuum without using oil lubrication.

Accurate board supports have been devised to allow for hand-over and rotational movements. However, little consideration was given to foreign matter generated from parts such as springs, rollers, gears, etc. that slide in a vacuum, and no foreign matter shielding plates were installed. In addition, regarding a mechanism for preventing the diffusion of foreign matter generated from a substrate heating device, as described in Japanese Patent Application Laid-Open No. 1-114679, the screw portion where foreign matter is likely to be generated is covered with a bellows, and the foreign matter is scattered outside. I was trying not to let it happen. It is thought that this method reduced the number of defects caused by foreign matter generated from the neck portion of the substrate holder. However, no consideration is given to bearings and gears, which have a high possibility of generating foreign matter in the substrate heating device. In addition, if the substrate heating device is equipped with a mechanism to prevent foreign matter from scattering, such as a bellows, it can be applied to a mechanism that moves linearly, but it cannot be applied to a sliding part such as a hair ring used to rotate the substrate. , difficult to apply. Further, when a bellows or the like is introduced into a vacuum device and moved, foreign matter may be generated from this part.

[Problem to be solved by the invention]

The substrate heating device of the molecular beam epitaxy device according to the above-mentioned conventional technology places emphasis on a mechanism for receiving and passing the substrate with high precision and a mechanism for uniformly heating the substrate, and the power transmission devices contact each other when the substrate is rotated. Not much consideration was given to defects occurring in the grown GaAs film, which are thought to be caused by foreign matter generated from the parts. That is, in the conventional substrate heating device, a heat shield plate is attached to prevent the heat from the heater that heats the substrate from being transmitted to the power transmission device that rotates the substrate. but,
Abrasion particles are generated from parts of gears and bearings used in power transmission devices that come into contact with each other, and fall in the direction of gravity. Conventional devices do not give any consideration to these foreign substances, and the foreign substances may adhere to the substrate. As a result, a defect occurred in the grown epitaxial film, which was thought to be caused by foreign matter.

Furthermore, in the conventional substrate heating apparatus, there was a possibility that foreign matter generated from the power transmission device would fall into the crucible of the molecular beam source of Ga, As, or the like. As a result, impurities caused by foreign substances are incorporated into the epitaxially grown film, resulting in a problem of deterioration of crystal quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate heating device for a molecular beam epitaxy apparatus that prevents foreign matter generated from mutually contacting parts of a power transmission device from reaching a substrate to be epitaxially grown or a molecular beam source.

[Means to solve the problem]

In order to prevent foreign matter generated from the power transmission device from adhering to the substrate or entering the molecular beam source, in the temporary heating device of the molecular beam epitaxy device according to the present invention, the power of the power transmission devices that come into contact with each other is A shielding plate was installed below the transmission mechanism to prevent foreign objects from falling or scattering due to their convex shape in the direction of gravity. The purpose of preventing foreign matter from falling or scattering can also be achieved by attaching this shielding plate to the outer circumference of the substrate holder or to the shroud.

[Effect]

In the present invention, a shielding plate is provided between the foreign matter generation part of the power transmission device in the substrate heating device and the substrate to prevent foreign matter from falling or spreading, so foreign matter generated when the substrate rotates on its axis, etc. can be collected on the shielding plate, thereby preventing it from falling and adhering to the substrate or falling into the crucible of the molecular beam source.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

First, FIG. 1 shows an example of the substrate heating device of the present invention, and is a longitudinal sectional view when foreign material shielding plates 9 and 10 are provided between the foreign material generating part of the power transmission device and the substrate 1. It is.

In this embodiment, the gear a attached to the rotation introducing machine 6 is
7. Foreign matter generated from gear b8 and bearing 11 is
When the foreign matter falls in the direction of gravity, it is collected by the shielding plates 9 and ]O, and since the shielding plates 9 and 10 are convex in the direction of gravity, the foreign matter that falls onto the shielding plates 9 and 10 is collected. The structure is such that it can prevent it from scattering into the vacuum chamber. As a result, foreign matter will not fall onto the substrate 1 on which epitaxial growth is to be performed, and a high-quality epitaxial growth film can be obtained.

FIG. 2 shows another embodiment of the present invention, in which a shielding plate c1 having a convex shape with respect to the gravity direction is provided on the outer peripheral part of the substrate holder 3.
5 is arranged. As a result.

Gravity transmission gear gear a7. Gear b8 and bearing 11
When falling in the direction of gravity, foreign matter generated from the substrate holder 3 is collected by the shielding plate c15 disposed on the substrate holder 3, and does not enter the substrate 1 to be epitaxially grown.

In FIG. 3, convex shielding plates d16 are arranged in the liquid nitrogen cylindrical chamber 5 surrounding the substrate heating device in five gravity directions. As a result, gear a7 of the power transmission device
．． When foreign matter generated from gear b8 and bearing 11 falls in the direction of gravity.

It is collected by this shielding plate d16 and does not enter the substrate 1 to be epitaxially grown.

In FIG. 4, the shield plate e17 is electrically insulated from the ground potential, and a potential is applied to the shield plate e17 from the current introduction terminal 12. This allows the charged foreign matter to be removed from the shielding plate e.
17, so the gear a of the power transmission device
7. When foreign substances generated from the gear b8 and the bearing 11 fall in the direction of gravity, they are collected by the shielding plate e17 and do not enter the substrate 1 on which epitaxial growth is to be performed.

In addition, in this embodiment, the shielding plate a, which is convex in the direction of gravity,
Although the cross-sectional shapes of b, c, d, e9, 10, 15, and 16°17 are semicircular, shielding plates a and b may also be used if the peripheral portion is L-shaped, such as a rectangular cross section.

Valid as c, d, e9, 10, 15, 16.17.

In addition, the shielding plates a, b, c, and d described in this embodiment.

By magnetizing e9.10, 15, and 16.17, magnetized wear particles can be collected by magnetic force, and the effect of preventing scattering of foreign matter is further enhanced.

〔Effect of the invention〕

According to the present invention, foreign matter generated from the parts of the power transmission device that come into contact with each other is prevented from adhering to the epitaxially grown substrate or being mixed into the single molecule beam source, so there are no defects caused by the foreign matter in the epitaxially grown film. It will no longer occur. Furthermore, since there is no deterioration of crystal quality due to impurity contamination, a high quality thin film with few defects can be grown.

As a result, it becomes possible to obtain an epitaxially grown film with very low defects.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a substrate heating device of a molecular beam epitaxy apparatus according to an embodiment of the present invention, Fig. 2 is a sectional view of a substrate heating device in which a foreign matter shielding plate is provided on a substrate holder, and Fig. 3 is a sectional view of a substrate heating device in which a foreign matter shielding plate is provided on a substrate holder. FIG. 4 is a sectional view of a substrate heating apparatus provided with a shielding plate for foreign matter. FIG. 4 is a sectional view of a substrate heating apparatus provided with a shielding plate for foreign matter that can be electrostatically attracted. 1... Board, 2... Heater, 3... Board boulder,
4. Boulder support, 5. Shroud, 6. Rotating introduction machine. 7... Gear, 8... Gear, 9... Shielding plate, 10.
Shield. 1. Bearing, 12.. Support, 13. Terminal, 1.
4-- Current introduction terminal, 15... Shielding plate, 16... Shielding plate, 17 Shielding plate. Agent: Patent attorney Katsuo JX, 1st review 2nd ■ z 15-JL 歎玖C Imozukan/Lk forgiveness

Claims (1)

[Scope of Claims] 1. Consists of a substrate holder for holding a substrate, the substrate held by the substrate holder, a heater for heating the substrate, and a power transmission device for rotating the substrate; In a substrate heating device of a molecular beam epitaxy apparatus, with the epitaxy growth surface of the substrate in the direction of gravity, when the substrate is rotated, a portion of the power transmission device that contacts each other and the substrate is provided between the substrate and the substrate. 1. A substrate heating device for a molecular beam epitaxy apparatus, characterized in that a shielding plate is provided with a shielding plate having a function of collecting foreign matter generated from mutually contacting portions of the power transmission device.