JPH0776427B2 - Low pressure vapor phase growth equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reduced pressure vapor phase growth apparatus, and in particular, it has a high process throughput in a film forming process and has good uniformity in film thickness, film quality, and the like. The present invention relates to a reduced pressure vapor phase growth apparatus with little particle generation.

[Prior Art] Conventionally, as a reduced pressure vapor phase growth apparatus of this type, there is a mode as shown in FIGS. 3 (a) and 3 (b). 301 is a front lid, 302 is a reaction furnace, 303 is a rear lid, 304 is a semiconductor substrate, 305 is a boat for mounting the semiconductor substrate 304, 306 is a gas inlet, 30
7 is a gas discharge port, 308 is a cylindrical gas introduction pipe, 309 is a gas ejection port, 310 is a cylindrical gas exhaust pipe, and 311 is a gas exhaust port.

In FIG. 3 (a), gas is introduced into the reaction furnace 302 through the gas introduction port 306 and is discharged through the gas discharge port 307 so as to maintain a constant pressure. As a result, a uniform gas flow was created from the gas inlet 306 toward the gas outlet 307, and a thin film was formed on the semiconductor substrate 304 in the regions shown as A, B, and C.

On the other hand, in FIG. 3 (b), the gas is introduced into the gas introduction pipe 308.
After being introduced into the reaction furnace 302, the gas outlet 309
It is introduced into the reaction furnace 302 more. The introduced gas is
The gas passes through the gas exhaust port 311, the gas exhaust pipe 310, and is discharged from the gas exhaust port 307 to the outside of the reaction furnace 302. In this case, a gas flow is generated from the gas introduction pipe 308 in the direction of the gas exhaust pipe 310, and the semiconductor substrate 3 is generated in the regions shown as D, E, and F.
A thin film was formed on 04.

[Problems to be Solved by the Invention] The conventional low pressure vapor phase growth apparatus described above has various drawbacks as described below.

First, in the manner shown in FIG. 3 (a), in order to make the gas flow perpendicular to the plane of the semiconductor substrate 304, in the regions shown as A, B, C, A
Because of the large gas consumption in B, C that is behind A
Then it is easy to run out of gas. Therefore, it is difficult to improve or maintain the uniformity of the film thickness and film quality in the batch and the surface of the semiconductor substrate 304.

Second, in the mode shown in FIG. 3 (b), in order to make the gas flow parallel to the surface of the semiconductor substrate 304, the problem of the mode shown in FIG. 3 (a), That is, there is little problem of non-uniformity in the batch depending on the position where the semiconductor substrate is installed. However, although the gas concentration in the vicinity of the gas introduction pipe 308 or the gas exhaust pipe 310 is high, the gas concentration becomes thin in a place far from the gas introduction pipe 308 or the gas exhaust pipe 310. As a result, even if a thin film is grown on the semiconductor substrate 304, a phenomenon such as an increase in the film thickness occurs in a place where the gas concentration is high near the gas introduction pipe 308 and the gas exhaust pipe 310, and the film thickness and the film quality are uniform. It has the disadvantage of poor sex.

Thirdly, SiH ₄ and O ₂ are used for gases that contribute to the deposition of a thin film, for example, a silicon oxide film (SiO ₂ ), which is a common drawback of the modes shown in FIGS. 3 (a) and 3 (b). However, if this gas is mixed before being introduced into the reactor 302, SiH
Before reacting on the surface of the semiconductor substrate 304, ₄ and O ₂ react in the gas phase to become SiO ₂ , and some of them adhere to the surface of the semiconductor substrate as particles. Since SiH ₄ and O ₂ are extremely reactive, mixing SiH ₄ and O _{2 for} a long time has a problem that particles are often generated. These particles cause generation of pinholes and the like during the deposition of the thin film, which is one of the causes for lowering device reliability and lowering product yield.

An object of the present invention is to provide a reduced pressure vapor phase growth apparatus that solves the above problems.

[Differences from the Prior Art of the Invention] In contrast to the above-described conventional low pressure vapor phase growth apparatus, the present invention can independently introduce a gas that contributes to the deposition of a thin film into a reaction furnace,
Furthermore, since gas can be uniformly supplied and exhausted uniformly in the reaction furnace, the gas concentration in the reaction furnace is extremely uniform, resulting in the generation of particles due to unnecessary reaction of gas in the reaction furnace. The difference is that the film thickness and film quality of the film deposited on the semiconductor substrate can be improved while being suppressed.

[Means for Solving the Problems] In order to achieve the above object, a reduced pressure vapor phase growth apparatus according to the present invention is a reduced pressure vapor phase growth apparatus having a reaction furnace, a pair of partition plates, and a gas introduction pipe. Therefore, the reaction furnace has a single-layer structure, and film formation processing is performed on the semiconductor substrate inside. The pair of partition plates has a large number of openings, and the inner wall of the reaction furnace is One of the pair of partition plates is used for introducing a reaction gas into the reaction furnace, and the other partition plate is used for processing in the reaction furnace. The exhaust gas is used to exhaust the exhausted reaction gas to the outside of the reaction furnace, and the gas introduction pipe has a large number of openings and is formed between the partition plate in the gas introduction and the inner wall of the reaction pipe. It was installed in a closed space.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

(Example 1) FIG. 1 (a) is a sectional view of a reaction furnace in a reduced pressure vapor phase growth apparatus of the present invention. Further, FIG. 1 (b) is shown in FIG. 1 (a).
2 is a cross-sectional view taken along line XY of FIG. 101 is a front lid, 102 is a reactor, 10
3 is a rear lid, 104 is a semiconductor substrate, 105 is a boat for mounting the semiconductor substrate 104, 106 is a gas introduction pipe provided with a large number of openings which is a feature of the present invention, and 107 is a gas introduction of a part of the reaction gas. A gas inlet port leading to the pipe 106, 108 is a partition plate provided with a gas jet port 109, which is a feature of the present invention, 110 is a gas inlet port of a reaction gas, 111 is a feature of the present invention, a gas exhaust port 112 is A partition plate provided, 113 is a gas outlet, and 114 is a heater.

In order to deposit a silicon oxide film by the low pressure vapor phase epitaxy method, generally, SiO ₂ is produced on a semiconductor substrate by the reaction of monosilane gas (SiH ₄ ) and oxygen gas (O ₂ ). Also in this embodiment, the case of depositing a silicon oxide film with SiH ₄ and O ₂ will be described. The semiconductor substrate 1 installed on the boat 105 in FIG.
04 is heated by the heater 114. A region in which monosilane gas (SiH ₄ ) is shown as M in FIG. 1B from the gas introduction port 107 into the gas introduction pipe 106, that is, the gas introduction pipe 10
Install inside 6. On the other hand, the space portion formed by the partition plate 108 and the reaction furnace 102 from another gas inlet 110, that is, the region shown as N in FIG. 1B, that is, the reaction furnace 10.
Oxygen gas (O ₂ ) is independently introduced into the space formed by 2 and the partition plate 109. As a result, monosilane gas (SiH ₄ )
It is possible to suppress unnecessary reaction between oxygen and oxygen gas (O ₂ ). These two kinds of gases are independently introduced from the gas inlets 107 and 110, respectively, but they are uniformly mixed in the region shown as N in FIG. Can be supplied uniformly over the entire area. Therefore, the gas in the reaction furnace 102 diffuses in a state where the components and the density are uniform, and the monosilane gas (SiH ₄ ) and oxygen gas (O ₂ )
Since it is possible to suppress unnecessary reactions with
A uniform thin film with few particles is deposited on the surface of 104.

Reactor 102, boat 105, partition plates 108, 111, gas inlet pipe 106
Quartz glass is desirable as the material of, but the material of other parts does not matter. Further, the shape of the partition plates 108 and 111 is not limited to a flat surface, and may have an appropriate curvature.

Next, the gas in the reaction furnace 102 is exhausted through a gas exhaust port 112 provided in the partition plate 111, and the reaction furnace 10 is exhausted through a gas exhaust port 113.
2 Discharged to the outside.

In the present embodiment, the case where the silicon oxide film (SiO ₂ ) is deposited by using monosilane gas (SiH ₄ ) and oxygen gas (O ₂ ) has been described. However, monosilane gas (SiH ₄ ) and phosphine gas (PH ₃ ) are mixed. If used, it can also be used for depositing a phosphorus glass (PSG) film, and in this case as well, generation of particles is small and the uniformity of film thickness and film quality is good.

(Embodiment 2) FIG. 2 is a sectional view showing Embodiment 2 of the present invention. The reduced pressure vapor phase growth apparatus of the present invention is shown in FIG.
If a high frequency power can be applied to the portion shown in the figure, it can be used as a plasma CVD apparatus. In FIG. 2, 201 is a fixture for fixing the boat 202 and the electrode 203, 204 is a semiconductor substrate, and 205 is a high frequency power source. Plasma is generated at a pressure of about 1 torr and a frequency of 50 KHz to 13.56 MHz to deposit a thin film on the semiconductor substrate 204.

When a plasma silicon oxide film was deposited using monosilane gas (SiH ₄ ) and oxygen gas (O ₂ ) according to this example, particles were few and film thickness and film quality could be deposited with good uniformity. In this embodiment, since the plasma is used, the deposition temperature can be lowered (about 250 ° C. to 350 ° C.), and aluminum is used in the manufacturing process of the semiconductor integrated circuit device.
It has an advantage that it can be used for depositing an interlayer insulating film between aluminum wirings.

EFFECTS OF THE INVENTION As described above, according to the present invention, a space formed by a partition plate provided with a gas ejection port and a gas exhaust port in each of two places in the reaction furnace, a gas ejection port partition plate, and a reactor side wall. By having a gas introduction pipe for independently introducing the reaction gas inside, it is possible to suppress the generation of particles and improve the non-uniformity of the film thickness and film quality in the batch and the semiconductor substrate surface. The yield and cost can be reduced. In addition, the stability and reliability of the manufactured semiconductor device can be improved.

[Brief description of drawings]

FIG. 1 (a) is a sectional view of a reaction furnace in a reduced pressure vapor phase growth apparatus of the present invention, FIG. 1 (b) is a sectional view taken along the line XY of FIG. 1 (a), and FIG. 2 is of the present invention. FIG. 3A and FIG. 3B are cross-sectional views of a boat portion in Example 2, which are cross-sectional views of a reaction furnace of a conventional reduced pressure vapor phase growth apparatus. 101 ... Front lid, 102 ... Reactor 103 ... Rear lid, 104 ... Semiconductor substrate 105 ... Boat, 106 ... Gas inlet pipe 107 ... Gas inlet, 108 ... Partition plate 109 ... Gas injection Outlet, 110 ... Gas inlet 111 ... Partition plate, 112 ... Gas outlet 113 ... Gas outlet, 114 ... Heater 201 ... Fixing device, 202 ... Boat 203 ... Electrode, 204 ... Semiconductor Substrate 205 …… High frequency power source, 301 …… Front lid 302 …… Reactor, 303 …… Rear lid 304 …… Semiconductor substrate, 305 …… Boat 306 …… Gas inlet, 307 …… Gas outlet 308 …… Gas Introducing pipe, 309 ... Gas outlet 310 ... Gas exhaust pipe, 311 ... Gas exhaust port

Claims (1)

[Claims] 1. A reduced pressure vapor phase growth apparatus having a reaction furnace, a pair of partition plates, and a gas introduction tube, wherein the reaction furnace has a single-layer structure, and a film forming process on a semiconductor substrate is internally performed. The pair of partition plates have a large number of openings and are provided parallel to the inner wall of the reactor, and one of the pair of partition plates is , The reaction gas is introduced into the reaction furnace, and the other partition plate is used to exhaust the treated reaction gas in the reaction furnace to the outside of the reaction furnace. A reduced pressure vapor phase growth apparatus having an opening of 1. and being installed in a space formed between the partition plate and the inner wall of the reaction tube in the gas introduction.