JPH033228A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PURPOSE:To grow an epitaxial film favorable in film thickness uniformity without performing substrate rotation by arranging a substrate obliquely to the direction of a gas nozzle which irradiates a substrates with gas, and so arranging the opening to become the outlet, through which gas is jetted, of the gas nozzle as to be parallel to the surface of the substrate. CONSTITUTION:The opening 1a to become the outlet, through which gas is jetted, of a gas nozzle 1 is so arranged as to be parallel to the surface of a substrate 33 being arranged obliquely to the direction of the gas nozzle 1. For that reason, the irradiation gas densities at point A3 and point B3, on the outsides of the surface 33a of the substrate and at point C3 at the center become almost equal, and the particle densities viewed on the substrate also become equal, so the film thickness uniformity of an epitaxial film being grown becomes favorable.

Description

[Detailed Description of the Invention] [Summary] An object of the present invention is to provide a semiconductor manufacturing device capable of growing an epitaxial thin film with good film thickness uniformity without rotating a substrate, and to provide a semiconductor manufacturing device that uses a gas as a raw material. In semiconductor manufacturing equipment having a gas cell for source MBE, a substrate is arranged obliquely to the direction of a gas nozzle that irradiates gas, and an opening that serves as an exit for irradiating gas from the gas nozzle is parallel to the surface of the substrate. Configure it so that

[Industrial application field]

The present invention relates to semiconductor manufacturing equipment, and can be applied to semiconductor manufacturing equipment having a gas cell used in a gas source MBE method using an organometallic gas or the like as a raw material. The present invention relates to a semiconductor manufacturing apparatus capable of growing epitaxial thin films.

In recent years, gas sources M using metal gases etc. as raw materials have been developed.
In semiconductor manufacturing equipment having a gas cell used in the BE method, it is necessary to develop a gas cell that can uniformly irradiate gas onto a substrate, especially in order to improve the film thickness uniformity of the resulting epitaxial thin film.

[Conventional technology]

FIGS. 3(a) and 3(b) are diagrams illustrating a conventional semiconductor manufacturing apparatus. The illustrated example is a case where the present invention is applied to a semiconductor manufacturing apparatus using a gas cell for gas source MBE.

In this figure, 31 is a gas nozzle made of metal, for example, and 31a is an opening at the tip of the gas nozzle 31. A raw material gas 32 such as an organometallic gas is irradiated from this opening 31a. 33 is the substrate, 33a is the substrate surface, 34 is the substrate 33
This is a substrate holder that supports the.

Note that here, the gas concentration within the gas nozzle 31 is uniform. The gas irradiated from the opening 31a of the gas nozzle 31 reaches the substrate surface 33a while expanding slightly in vacuum.

As shown in FIGS. 3(a) and 3(b), in conventional semiconductor manufacturing equipment, the opening 31a at the tip of the gas nozzle 31 is aligned in the direction of the gas flow of the gas nozzle 31 (as shown in FIGS. 3(a) and 3(b)). It is arranged perpendicularly to the arrow G) shown.

Specifically, the opening 31a of the gas nozzle 31 shown in FIG. 3(a) is parallel to the substrate surface 33a (a IA
1=blBl), when the gas nozzle 31 (also the gas flow direction arrow G) is arranged perpendicularly to the substrate surface 33a, points A1 and B on the outside of the substrate surface 33a
1 point, the irradiation gas density (number of gas molecules per unit cross-sectional area light N) at the central point C1 is NA 1 = NB 1 = NC1
Thus, the thickness uniformity of the grown epitaxial thin film is good.

That is, the gas nozzle 3 shown in FIG.
1, one type of raw material gas 32
Since one gas nozzle 31 is arranged perpendicularly to the substrate surface 33a and the opening 31a of the gas nozzle 31 is arranged parallel to the substrate surface 33a, the thickness of the grown epitaxial thin film can be made uniform. It has the advantage of being possible. However, in reality, several types of raw material gas 3
2 must be used, and one gas nozzle 31 is required for one type of gas. For this reason, a plurality of gas nozzles 31 have been arranged for several types of gases, and the gases have been irradiated to cause epitaxial growth. In this case, the third
As shown in Figure (b), it is not possible to arrange a plurality of gas nozzles 31 perpendicularly to the substrate surface 33a, but it is possible to arrange the gas nozzles 31 obliquely to the substrate surface 33a. τ end). For this reason, the opening 3 of the gas nozzle 31
1a was not parallel to the substrate surface 33a but was disposed obliquely. Note that FIG. 3(b) shows a case where one gas nozzle 31 is arranged for convenience.

[Problem to be solved by the invention]

However, in a semiconductor manufacturing apparatus having such a gas nozzle 31 shown in FIG. 3(b), since the opening 31a of the gas nozzle 31 is arranged obliquely to the substrate surface 33a, A2 points and 82
The irradiation gas density at the central point 02 becomes smaller as NA2>NC2>NB2 as the distance from the opening 31a of the gas nozzle 31 increases, and the concentrations at each point are not equal and are significantly different, resulting in growth. Epitaxial thin film W
There was a problem in that the film thickness uniformity deteriorated as the i thickness was A2>C2>B2.

When the irradiation gas concentration is far from the opening 31a of the gas nozzle 31 (
The reason why NA 2 >NC2>NB 2 is satisfied is considered to be because the gas released into the vacuum from the opening 31a is more likely to collapse as the distance from the opening 31 increases.

As a means for solving the above problem, it is known that uniformity in film thickness can be improved by rotating the substrate 33 at a constant rotational speed around the center. However, the substrate 33 must be rotated with high precision, which requires a high-performance motor, etc., which makes the growth apparatus mechanically complex, leading to frequent failures of the motor, etc.
A problem has arisen in that metal particles are generated, which can cause deterioration in the yield of devices manufactured from the grown epitaxial thin film.

For example, Ga particles generate metal particles.
When growing an As film, As tends to adhere to the substrate holder, etc., and is emitted into the vacuum during rotation, resulting in the substrate surface 33a.
This is thought to be due to the particles adhering to the surface. Therefore, it is desired to grow an epitaxial thin film without rotating the substrate 33 as much as possible.

Therefore, an object of the present invention is to provide a semiconductor manufacturing apparatus that can grow an epitaxial thin film with good film thickness uniformity without rotating the substrate.

[Means to solve the problem]

In order to achieve the above object, a semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus having a gas cell for gas source MBE using gas as a raw material, in which a substrate is arranged obliquely to the direction of a gas nozzle that irradiates gas, and the gas nozzle The opening, which serves as an outlet for irradiating the gas, is arranged parallel to the surface of the substrate.

[Effect]

As shown in FIGS. 1 and 2, the present invention provides a substrate 33
are arranged obliquely with respect to the direction of the gas nozzle 1, and the opening 1a, which serves as an exit to which the gas from the gas nozzle 1 is irradiated, is arranged parallel to the substrate surface 33a.

Therefore, compared to the conventional irradiation gas density explained in FIG.
The thickness of the grown epitaxial thin film can now be made almost equal, and the particle density seen on the substrate can also be made more uniform than in the conventional case explained in FIG. 3(b). It becomes possible to improve the uniformity. Details will be explained in Examples.

Further, since the process is performed without rotating the substrate 33, the problem of adverse effects on the epitaxially grown film due to the generation of metal particles, which occurs when the substrate 33 is rotated in the conventional art, does not occur.

〔Example〕

1 and 2 are diagrams for explaining one embodiment of a semiconductor manufacturing apparatus according to the present invention, FIG. 1 is a schematic diagram of the apparatus showing the configuration of one embodiment, and FIG. 2 is an effect of one embodiment. FIG. The illustrated example is a case where the present invention is applied to a semiconductor manufacturing apparatus using a gas cell for gas source MBE.

In these figures, the same reference numerals as in FIGS. 3(a) and 3(b) indicate the same or corresponding parts, 1 is a gas nozzle made of stainless steel, and la is a gas nozzle made of stainless steel, and la is a source gas such as an organometallic gas in the gas nozzle l that is irradiated. It is an opening that serves as an exit for the liquid, and is formed parallel to the substrate surface 33a. 2 is a vacuum chamber, 3 is a heater, 4 is a thermocouple, 5 is a flange 1, which has an outer diameter φ of 114 n, for example, according to the ICF standard; 7 is a barrier pull leak valve, and 8 is a bottle containing organic metal as a raw material.

Note that here, the gas concentration within the gas nozzle 1 is uniform. The gas irradiated from the opening 1a of the gas nozzle 1 is discharged into a chamber 2 which is evacuated. The opening 1a of the gas nozzle 1 is directed toward the gas nozzle 1 (the same applies to the gas flow arrow G shown in FIGS. 1 and 2), whereas the conventional gas nozzle 31 shown in FIGS. In contrast to the vertical arrangement in the opening 31a,
In the above embodiment, they are arranged diagonally. Further, the substrate 33 is arranged obliquely with respect to the direction of the gas nozzle 1, as in the conventional case shown in FIG. 3(b).

First, the principle of operation will be explained using FIG.

Here, triethyl gallium, which is liquid at room temperature and filled in a bottle 8, is used as the raw material gas.This triethyl gallium is introduced in gaseous form into the chamber 2, which is kept in a high vacuum, and the triethyl gallium gas is (100) Ga
A case is shown in which crystal growth is performed by irradiating a substrate 33 made of As. The gas cell is attached to the chamber 2 by a flange 5, and a gas line is connected via a minicon flat flange 6. The gas line is shown in the simplest configuration in which the gas flow rate is controlled by a barrier pull leak valve 7. The gas cell is broadly divided into a gas nozzle 1 and a heater 3 surrounding the gas nozzle 1. The heater 3 is heated at a temperature of about 100°C (monitored by a thermocouple 4) to prevent triethyl gallium gas from adhering to the inner wall of the gas nozzle 1. It's heating up.

That is, in the above embodiment, as shown in FIGS. 1 and 2, the opening 1a of the gas nozzle 1, which serves as the exit to which the gas is irradiated, is set with respect to the gas flow direction G (in the direction of the gas nozzle 1). Because it was arranged parallel to the surface of the substrate 33, which was arranged diagonally, the irradiation gas density at points A3 and 83 on the outside of the substrate surface 33a, and point 03 in the center was as shown in Fig. 3(b). Compared to the conventional gas nozzle 31b, NA3=NB 3=NC3 are almost equal at each point, and the particle density as seen on the substrate 33 is also lower than that of the conventional gas nozzle 31b as shown in FIG.
Since the thickness is more uniform than in the case described in b), the thickness uniformity of the grown epitaxial thin film is improved.

Here, the reason why the irradiation gas densities at points A3 and 83 on the outside of the substrate surface 33a and at point 03 in the center are almost equal than in the case of the conventional gas nozzle 31b shown in FIG. 3(b) is because
This is thought to be due to the fact that the opening 1a of the gas nozzle 1 is made parallel to the substrate surface 33a, so that the difference in distance b3B3-a 3A3 is smaller than the difference in distance b2B2-a2A2 in the prior art. As shown in FIG. 2, instead of making the opening la and the substrate surface 33a parallel to each other, the opening 11a is made more inclined with respect to the substrate surface 33a than the opening 1a, as shown by the dotted line. and a1
By making 3Δ3=b3B3, A3.
It may be possible to achieve film thickness uniformity by equalizing the irradiation gas concentration at 83 points, but in this case, the gas in gas nozzle 1 was reflected between a13 and a23 and was irradiated. Since the object is not irradiated to the substrate surface 33a as shown by arrow X but is irradiated to the outside, the influence of gas leakage is large and the irradiation density at point A3 is not equal to the irradiation density at point 83 and becomes extremely small. There is a problem with this. Therefore, the opening 1a and the substrate surface 33a must be parallel to each other.

Furthermore, since the substrate 33 is not rotated, the problem of adverse effects on the epitaxial growth layer due to the generation of metal particles, which occurred when the substrate 33 was conventionally rotated, does not occur.

In the above embodiment, as shown in FIGS. 1 and 2, one gas nozzle 1 using one type of gas is used, and the substrate surface 33a is arranged obliquely with respect to the direction of the gas nozzle 1. However, the present invention is not limited to this, and may include a plurality of gas nozzles using several types of gas.
It can also be applied to a case where the substrate 33 is arranged obliquely with respect to the direction of each gas nozzle 1.

〔Effect of the invention〕

According to the present invention, there is an effect that an epitaxial thin film with good film thickness uniformity can be grown without rotating the substrate.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining one embodiment of a semiconductor manufacturing apparatus according to the present invention. FIG. 1 is a schematic diagram of the apparatus showing the configuration of one embodiment, and FIG. FIG. 3 is a diagram explaining a conventional example. 1... Gas nozzle, 1a... Opening, 2... Vacuum chamber, 3... Heater, 4... Thermocouple, 5. ...Flange, 6...Minicon flat flange, 7...
...Barrier pull leak valve, 8...Bottle. Diagram explaining the effect of one embodiment Diagram Distance from the gas nozzle opening (a) Diagram explaining the conventional example

Claims (1)

[Claims] In a semiconductor manufacturing apparatus having a gas cell for gas source MBE using gas as a raw material, the substrate is arranged obliquely with respect to the direction of a gas nozzle that irradiates the gas, and an outlet that is irradiated with the gas of the gas nozzle is provided. A semiconductor manufacturing apparatus characterized in that an opening is arranged parallel to the surface of the substrate.