JPH03194918A - Apparatus for epitaxial growth - Google Patents

Abstract

PURPOSE:To eliminate loss in stable growth due to releasing a reaction system to an atmosphere accompanying change in a nozzle position by providing a mechanism for changing and adjusting from outside a reaction vessel a distance from a nozzle for supplying material gas for growing a deposited material to an object where deposition occurs. CONSTITUTION:In an epitaxial growth apparatus housing in a reaction vessel a nozzle 102 provided for the purpose of supplying material gas for growing deposited materials in the vicinity of an object 101 where deposition occurs, a mechanism for changing and adjusting a distance from the nozzle 102 to the object 101 where the deposition occurs from outside the reaction vessel is provided. For example an adjusting mechanism is provided wherein a hollow male screw 106 is provided through a flange 104 attached to the reaction vessel 110, a female screw 107 to be engaged with the male screw 106 is attached to the flange 104 so that it can be slid and rotated, and a nozzle 103 is placed at the lower end of the male screw 106 via a supporting jig 103, while the supporting jig 103 is connected to the flange 104 via bellows 108.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vapor phase growth apparatus used for the purpose of obtaining a semiconductor thin film by a vapor phase growth method. The present invention relates to a vapor phase growth apparatus suitable for achieving highly uniform properties.

[Conventional technology]

Not limited to elemental semiconductors such as Sl, but also GaAs, Al1 GaA
s.

Alternatively, as one method for growing a thin film of a ■-v group compound semiconductor such as InP, a vapor phase growth method is used.
Epltaxy (VPE method) is known. In this VPE method, raw materials for thin film growth,
Alternatively, molecular species involved in the growth as well as impurities intentionally added to obtain desired electrical characteristics, so-called dopants, are also introduced in gaseous form into the vicinity of the substrate on which the thin film is deposited. As described above, one of the characteristics of the VPE method is that chemical species involved in thin film growth are introduced in gaseous form near the substrate, but on the other hand, it also achieves uniformity of film thickness, electrical properties, etc. In order to achieve this, it is necessary to supply these gas species to the substrate as uniformly as possible. For this reason, in order to uniformly supply these gas species to the substrate, it has been conventionally practiced to provide a jig such as a nozzle near the substrate.

[Problem that the invention seeks to solve]

However, even when a nozzle is provided as described above, for example, when it becomes necessary to change the total amount of gas supplied onto the substrate, which is the deposited material, in the actual work of thin film growth. In order to obtain uniform characteristics, it is sometimes necessary to change the nozzle or the like having a corresponding shape. Furthermore, even in the case where the temperature at which the thin film is grown is changed, for example, in order to obtain desired electrical characteristics, as the temperature is changed, the volume expansion of the gas species supplied to the vicinity of the substrate, or In consideration of phenomena such as thermal diffusion, complicated measures have been taken, such as newly providing a nozzle or the like having a shape suitable for the phenomenon, or changing the distance between the nozzle and the base.

For this reason, in the past, in order to obtain thin films with uniform properties in response to changes in growth conditions, frequent and complicated operations were required, such as repeatedly attaching and detaching nozzles, etc., according to the conditions. Ta. In addition, in carrying out this work, the reaction system must be temporarily decomposed, thus exposing the reaction system to the atmosphere, which may hinder subsequent thin film growth, especially if it contains easily oxidizable elements. , or when growing a thin film made of additives, the above-mentioned decomposition operation may invade the reaction system and cause serious hindrance to the stable growth of the film due to the effects of adsorbed oxygen, water, etc. There was a problem.

[Means for solving problems]

The present inventors have solved the frequent and troublesome work associated with attaching and detaching nozzles, etc., as seen in conventional examples, and thereby preventing outside air from entering the reaction system and contamination caused by the attaching and detaching devices such as nozzles. As a result of intensive studies to provide a method that suppresses this and thereby contributes to the stability of thin films containing easily oxidizable elements, we have developed a mechanism that allows the position of the nozzle relative to the substrate to be changed by operating from outside the reaction system. This led to the discovery that the above-mentioned drawbacks associated with the conventional method can be eliminated, leading to the present invention.

That is, the present invention provides a gas phase system in which a nozzle jig, which is provided for the purpose of supplying raw material gases for deposit growth near a deposit, is housed in a reaction vessel provided for carrying out the growth. in the growth apparatus, freely changing the distance M (position) of the nozzle with respect to the deposited material from the outside of the reaction vessel;
This vapor phase growth apparatus is characterized by being equipped with an adjustment mechanism.

〔Example〕

Hereinafter, a detailed description will be given based on one embodiment of the present invention.

FIG. 1 shows a mechanism for changing the nozzle position from outside the reaction system according to the present invention. In the figure, 101 is a substrate on which a desired thin film is deposited, and 102 is a nozzle that supplies a reactive gas as a raw material to the substrate 101. This nozzle 102 is supported by a support 103. A male threaded portion 106 is connected to the support 103 and extends through a flange 104 attached to the reaction vessel 110 to reach the outside of the reaction system 105. This male thread part 1
06 is adapted to operate in conjunction with a female threaded portion 107 connected to the flange 104. Female thread part 1
07 is rotatably and slidably fixed to the flange 104 via a sliding fixture 111 attached to the flange 104. Further, the male threaded portion 106 is configured to be hollow, and a reaction gas vibrator 112 for supplying a reaction gas passes through the inside thereof, and one end is connected to the nozzle 102 and the other end is connected to a gas supply system (not shown). has been done. 108 is a bellows, one end of which is connected to the support 103,
The other end is connected to the flange 104 to prevent raw material gases from entering the male threaded portion 10B, thereby preventing leakage of raw material gases to the outside of the reaction system 105, and conversely, preventing outside air from entering the reaction system 105.
It is responsible for preventing intrusion into 5.

With the above configuration, in order to change the distance (position) of the nozzle 102 with respect to the base body lot, the female threaded portion 1
07 in the desired direction, and then the male threaded part 10B
By moving the nozzle 102 upward and downward, the distance of the nozzle 102 can be easily and quickly changed from outside the reaction system 105.

Further, in order to grasp the position of the nozzle 102 with respect to the base body 101, for example, if a scale 109 or the like is provided on a part of the flange portion 104 to indicate the positional relationship, the positional relationship can be easily recognized.

[For production]

According to the present invention, the distance of the nozzle to the base can be freely changed from the outside without breaking the airtightness of the reaction system. Therefore, for example, even if it becomes necessary to change the flow rate of gas supplied to the reaction system during growth, the distance of the nozzle to the substrate can be quickly and easily changed, thereby improving the electrical properties of the resulting thin film. This has the advantage that equalization of the numbers can be easily achieved.

〔effect〕

As described above, the present invention has the advantage that the position of the nozzle relative to the substrate can be easily and simply changed without any complicated operations or without the need to decompose the reaction system. Therefore, as seen in the conventional example, a practical effect is provided in that the stable growth of the thin film is not impaired due to the release of the reaction system to the outside air as the position of the nozzle is changed.

Moreover, by using the mechanism according to the present invention, it is possible to quickly change the positional relationship between the nozzle and the substrate, which makes it necessary to rapidly change the source gases in the middle of thin film growth. Even in such cases, it is possible to quickly correct the positional relationship in order to quickly obtain a thin film with uniform properties, which greatly contributes to the growth of a highly uniform thin film.

In this embodiment, the position of the nozzle was made variable by converting the rotational movement into vertical movement using the male and female screws. This can also be achieved when using a mechanism that allows the positional relationship of the nozzles to be varied from outside the reaction system.

[Brief explanation of drawings]

FIG. 1 schematically shows a mechanism for changing the position of a nozzle with respect to a substrate constructed according to the present invention.
02 is a nozzle, 103 is a support for the nozzle, 104
105 is a flange, 105 is a reaction system, 106 is a male threaded portion, 107 is a female threaded portion, 108 is a bellows, and 109 is a scale.

Claims (1)

[Scope of Claims] 1) In a vapor phase growth apparatus in which a nozzle provided for the purpose of supplying raw material gases for deposit growth near a substance to be deposited is housed in a reaction vessel, A vapor phase growth apparatus comprising a mechanism for changing and adjusting the distance of the nozzle to the object to be deposited from outside the reaction vessel. 2) A hollow male screw is provided through the flange attached to the reaction vessel, a female screw that engages with the male screw is attached to the flange so as to be slidable and rotatable, and a support is attached to the lower end of the male screw. 2. The vapor phase growth apparatus according to claim 1, further comprising an adjustment mechanism in which a nozzle is installed through the adjustment mechanism.