JPS60126823A - Plasma vapor growth apparatus - Google Patents

Abstract

PURPOSE:To prevent exfoliation of adhered substance due to high frequency power source and the like by a method wherein a heating mechanism is provided on the circumference of the reaction gas introducing pipe located in the vicinity of the entrance of a chamber, and heated reaction gas is introduced. CONSTITUTION:The reaction gas introducing pipe 5, provided at the upper part in the center of a chamber 3 through the intermediary of a seal packing 4, is connected to the internal part of said chamber 3 provided on a chamber base 1 using an O-ring 2. A tabular and hollow upper high frequency electrode 6, having a plurality of gas jetting holes 6b on the bottom face 6a, is arranged. A lower high high frequency electrode 7, which performs an additional function as a substrate placing stand is opposingly arranged at the lower part of said electrode 6, and a heater 8 to be used for heating of the substrate is provided at the bottom part of said electrode 7. Besides, an exhaust pipe 10 and doors 11 and 12, to be used for insertion and pick-up of a sample, are provided. A heating mechanism, consisting of the heater unit 21 equipped with a temperature regulator 20, is provided in the vicinity of the inlet of the reaction gas introducing pipe 5 provided at the upper part in the center of the chamber 3 through the intermediary of a seal packing 4. According to this constitution, reaction gas is heated up by the heater 21 immediately before the chamber 3, and the exfoliation of adhered substance can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a plasma vapor deposition (CVD) apparatus, and particularly to an improvement of a parallel plate type plasma CVD apparatus 4.

(b) Conventional waves Advantages and problems Parallel plate type plasma vapor phase epitaxy devices are generally arranged in a chamber under reduced pressure with vertically facing ridges.
There are n. A structure in which a hollow flat plate-shaped upper high-frequency electrode connected to a reaction gas inlet pipe and having multiple gas ejection holes on the lower surface and a lower high-frequency electrode on which a substrate is placed are placed vertically opposite each other in a depressurized chamber. This device generates plasma between the upper and lower electrodes by applying a high-frequency voltage between the two electrodes, and in the presence of this plasma, a chemical reaction of the reactive gas is caused to cause a chemical reaction on the substrate. A vapor grown film is formed.

Figure 1 shows, for example, silane (SiH4), ammonia (
2 is a schematic diagram showing a conventional plasma vapor phase epitaxy apparatus for forming a silicon nitride film (Si3N4) using NH3, and shows the inside of a chamber 3 installed on a chamber base 1 via an O-ring 2. A flat upper high-frequency electrode 6 is disposed, which is connected to a reaction gas introduction pipe 5 provided at the upper center of the chamber 3 via a seal backing 4, and is hollow and has a plurality of gas ejection holes 6b on a bottom surface 6a. A lower high-frequency electrode 7, which also serves as a substrate mounting table, is disposed opposite to the lower part of the upper high-frequency electrode 6, and the lower high-frequency electrode'
A heater 8 for heating the substrate is provided at the bottom of the substrate 2 . Sho 9
is a semiconductor substrate (sample) on which a silicon nitride film is formed, and is placed on the lower electrode 7. Also, 10 is the exhaust pipe,
Reference numerals 11 and 12 indicate sample insertion and sample extraction doors provided on the sides of the chamber 8, respectively.

Silane (SiH+) and ammonia (NIi3) are deposited on the semiconductor substrate 9 using a plasma vapor phase epitaxy apparatus having such a structure.
When forming a nitride film (S a-3N4) using
f' as a pole? A vacuum pump (not shown) is driven to evacuate the inside of the chamber 3 to a vacuum level from the exhaust v]0, and the semiconductor substrate 9 is heated to a desired temperature of several hundred degrees by the heater 8.

Next, desired silane (SiH4) is introduced through the reaction gas introduction pipe 5.
and ammonia (NH3) together with nitrogen (N2) or argon (Ar) gas as a gear, and is ejected into the chamber from the gas ejection hole 6b at the bottom of the upper electrode. The internal pressure in the chamber is a number 'i'
o r r, apply a high frequency voltage to the upper and lower high frequency electrodes, turn the reaction gas into plasma, and form a nitride film (Si, 3N) on the substrate 9 through a chemical reaction represented by the following reaction formula. 4) is formed.

3Sili4+NH3→5j-3N4+12H2 In this case, most of the reaction gas becomes 5j-3N4 due to the above chemical reaction and is deposited on the semiconductor substrate 9, and by-products are exhausted from the exhaust pipe 10, but some of them are stored in the low-temperature part of the chamber, such as the upper high-frequency electrode. 6. It also deposits and adheres to the inner wall of the chamber 3.

However, in the conventional device, the reaction gas introduced into the chamber 3 is introduced into the chamber at room temperature, which causes the temperature inside the chamber to drop temporarily, causing the upper high frequency The deposited grown film peels off due to the temperature change, and the deposits peeled off from the upper electrode 6 etc. adhere to the semiconductor substrate 9, causing film and blurring. There were some problems when forming the .

(C) Purpose of the Invention The purpose of the present invention has been made in view of the above problems, and is to prevent the peeling of deposits from the upper high-frequency electrode, etc., and to form a high-quality vapor-grown film on a semiconductor substrate. The purpose of the present invention is to provide a plasma vapor phase growth apparatus ff that can absorb water.

(d-) Structure of the Invention In order to achieve the object, the plasma vapor phase growth apparatus a of the present invention uses a heating mechanism around the reactant gas introduction pipe of the hook near the chamber population to inject the heated reactant gas. It is characterized by the fact that it has been introduced.

(e) Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

Figure 2 shows a plasma qi (eye growth device d) of an embodiment of the wooden invention.
FIG. 1 is a schematic diagram of the configuration of FIG. 1, in which the same parts as in FIG.

As is clear from the figure, the present invention is particularly different from the conventional one. The structure is such that a heating mechanism consisting of a heater unit 21 equipped with a temperature regulator 20 is attached around the periphery of the heating mechanism. That is, a reaction gas introduction pipe 5 and a hollow flat plate-shaped upper high frequency electrode 6 connected to the introduction pipe.
The reaction gas entering the chamber 8 through the heating mechanism is heated by the heating mechanism immediately before the chamber, and the reaction gas heated to a desired temperature of several hundred degrees is pumped into the chamber from the gas jet hole 6b of the two-part high-frequency electrode 6. This was done so that it would gush out inside.

With this structure, it is possible to prevent the temperature inside the chamber from decreasing at the time when the reaction gas is introduced into the chamber,
Therefore, the peeling off of deposits due to the stress caused by the temperature change described above is prevented, and it is possible to prevent foreign matter from adhering to the semiconductor substrate 9 caused by the peeling of deposits from the upper high frequency electrode 6, etc. It becomes possible to form a high quality vapor phase growth film on the film 9 without pinholes or flakes.

Furthermore, by eliminating temperature changes within the chamber, good results can be achieved in improving the uniformity of the distribution of vapor phase growth.

The heating mechanism of the heater unit equipped with the temperature regulator 20 is structured so that it can be easily attached to a conventional device, and the effects of the present invention can also be achieved by attaching the heating mechanism to a conventional device. It is possible to obtain

(In the Buchsma vapor phase growth apparatus invented by Kotogi, detailed explanation of the invention,
The reaction gas introduced into the chamber is
By preheating and preventing the temperature inside the chamber from dropping, it is possible to prevent the generation of foreign matter due to the peeling off of deposits caused by temperature changes, and it is possible to form a high quality vapor phase growth film on the semiconductor substrate. Furthermore, it has a great effect on improving the quality of the vapor-phase grown film, such as improving the uniformity of the distribution of the vapor-phase grown film.

Although the present invention has been explained by taking as an example the plasma vapor phase growth of silicon nitride H onto a semiconductor substrate, the plasma vapor phase growth apparatus of the present invention is not limited to the above-mentioned films; Alternatively, the same effect can be obtained by using it as an apparatus for forming +1J of polycrystalline silicon or the like. Further, the shape of the parallel Heisei electrodes is not limited to the rectangular shape shown in the embodiment, but may be circular, for example.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional apparatus, and FIG. 2 is a schematic diagram of a plasma vapor deposition apparatus according to an embodiment of the present invention. In the figure, 1 is a chamber base, 2 is an O-ring, 3 is a chamber, 4 is a seal backing, 5 is a reaction gas introduction pipe,
6 is an upper high-frequency electrode, 7 is a lower high-frequency electrode, 8 is a heater for heating the substrate, 9 is a semiconductor substrate, 10 is an exhaust pipe, ]]・]
Reference numeral 2 indicates a door for sample insertion and extraction, respectively, 20 a temperature controller, and 21 a heater unit.

Claims (1)

[Claims] 1. A plasma vapor phase growth apparatus characterized in that a heating mechanism is attached around a reactant gas introduction pipe near a chamber population so that a heated reactant gas is introduced.