JPH01139767A - Reduced-pressure vapor growth apparatus - Google Patents

Abstract

PURPOSE:To control the generation of particles and to uniformize the thickness and quality of a film by providing a partition plate furnished with a gas injection port and a gas outlet and a gas inlet pipe for introducing a gas into the space formed by a gas injection partition plate and the side wall of a reaction furnace in the reaction furnace. CONSTITUTION:A semiconductor substrate 104 set on a boat 105 is heated by a heater 114 in the reaction furnace 102, and a gas M is introduced into the gas inlet pipe 106 pierced with many holes from a gas inlet 107. Meanwhile, gaseous oxygen is introduced into the space N formed by the partition plate 108 provided with a gas injection port 109 and the reaction furnace 102 from a gas inlet 110. As a result, the gases respectively introduced from the inlets 107 and 110 are uniformly mixed and uniformly supplied over the whole requisite region in the reaction furnace 102, and a uniform thin film is formed on the substrate 104. The gas in the reaction furnace 102 is discharged from a gas outlet 112 provided in the partition plate 111, and further discharged from a gas outlet 113 to the outside of the reaction furnace 102.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reduced-pressure vapor phase growth apparatus, which has high process throughput especially in the film forming process, has good uniformity in film thickness, film quality, etc. , relates to a reduced pressure vapor phase growth apparatus that generates few particles.

[Prior Art] Conventionally, this type of reduced pressure vapor phase growth apparatus is shown in Fig. 3 (a).
), (b). 301 is a front lid, 302 is a reactor, 303 is a rear lid, 304 is a semiconductor substrate, 305 is a boat on which the semiconductor substrate 304 is installed, 30
6 is a gas inlet, 307 is a gas outlet, 308 is a cylindrical gas inlet pipe, 309 is a gas outlet, 310 is a cylindrical gas exhaust pipe, and 311 is a gas exhaust port.

In FIG. 3(a), the reactor 3 is connected to the gas inlet 306.
Gas is introduced into the chamber 02 and is discharged from the gas outlet 307 so as to maintain a constant pressure. As a result, from the gas inlet 306 to the gas outlet 307 -
A.

In the regions illustrated as B and C, the semiconductor substrate 30
A thin film was formed on 4.

On the other hand, in FIG. 3(b), gas is introduced into the gas introduction pipe 30.
After the gas is introduced into the reactor 302 through the gas outlet 309, the gas is introduced into the reactor 302 through the gas outlet 309.

The introduced gas flows through the gas exhaust port 311. gas exhaust pipe 31
0 and is discharged from the reactor 302 through the gas discharge port 307. In this case, a gas flow was created from the gas inlet pipe 308 toward the gas exhaust pipe 310, and a thin film was formed on the semiconductor substrate 304 in regions shown as D, E, and F.

[Problems to be Solved by the Invention] The conventional reduced 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, and C, Since the amount of gas consumed at A is large, B and C, which are tangential to A, tend to run out of gas. Therefore, it is difficult to improve or maintain the uniformity of film thickness and film quality within the batch and within the surface of the semiconductor substrate 304.

Second, in the format shown in FIG. 3(b), in order to make the gas flow parallel to the surface of the semiconductor substrate 304, there is a problem in the format shown in FIG. 3(a). That is, there is little problem of intra-batch non-uniformity caused by the placement position of the semiconductor substrate. However, although the gas concentration near the gas introduction pipe 308 or the gas exhaust pipe 310 is high, the gas introduction pipe 308. The gas concentration becomes thinner at a location far from the gas exhaust pipe 310. As a result, even if a thin film is grown on the semiconductor substrate 304, the gas introduction tube 308. In areas where the gas concentration is high near the gas exhaust pipe 310, phenomena such as an increase in film thickness occur, and there is a drawback that the uniformity of both film thickness and film quality is poor.

Third, a common drawback of the systems shown in FIGS. 3(a) and 3(b) is that in a gas that contributes to the deposition of a thin film, such as a silicon oxide film (Si02), S! If H4 and 02 are used and the gases are mixed before being introduced into the reactor 302, S i H4 and 02 are
Before reacting on the surface of 4, Si reacts in the gas phase.
This becomes O2, and some of it adheres to the surface of the semiconductor substrate as particles. Since SiH4 and 02 are very reactive, S! There is a problem in that the coexistence of H4 and 02 for a long time increases the generation of particles. These particles cause pinholes and the like to occur during thin film deposition, which is one of the causes of lower device reliability and product yield.

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

[Differences between the invention and the prior art] In contrast to the above-mentioned conventional reduced pressure vapor phase growth apparatus, the present invention can independently introduce a gas that contributes to thin film deposition into the reactor.
Furthermore, since gas can be supplied uniformly and exhausted uniformly within the reactor, the gas concentration within the reactor is extremely uniform, and as a result, the generation of particles due to unnecessary gas reactions within the reactor is prevented. The difference is that the film thickness and quality of the film deposited on the semiconductor substrate can be improved in uniformity at the same time.

Means for Solving the Problem] The present invention provides means for installing a semiconductor substrate on which a thin film is to be deposited, means for introducing a gas containing an element for forming a thin film into a reactor, and means for exhausting the gas. and a means for heating the reactor, wherein a pair of partition plates having a large number of openings are provided in the reactor in parallel with the side wall of the reactor, and the - side partition plate is The other partition plate is used for gas introduction, and the other partition plate is used for gas exhaust, and a gas introduction pipe having a large number of holes is provided in the space formed by the gas introduction partition plate and the side wall of the reactor. This is a reduced pressure vapor phase growth device.

[Examples] Examples of the present invention will be described below with reference to the drawings.

(Example 1) FIG. 1(a) is a sectional view of a reactor in a reduced pressure vapor phase growth apparatus of the present invention. Also, Fig. 1(b) is similar to Fig. 1(a).
FIG. 101 is a front lid, 102 is a reactor, 103 is a rear lid, 104 is a semiconductor substrate, 105 is a boat on which the semiconductor substrate 104 is installed, 106 is a gas introduction pipe provided with a large number of holes, which is a feature of the present invention, Reference numeral 107 denotes a gas introduction port for introducing a portion of the reaction gas into the gas introduction pipe 106;
08 is a partition plate provided with a gas outlet 109, which is a feature of the present invention; 110 is a gas inlet for a reaction gas; 111 is a partition plate provided with a gas exhaust port 112, which is a feature of the present invention; The gas outlet 114 is a heater.

Depositing a silicon oxide film by low pressure vapor phase growth is generally done by producing SiO2 on a semiconductor substrate through a reaction between monosilane gas (S!H4) and oxygen gas (02), but this method In the example, S
The case of depositing a silicon oxide film using iH4 and 02 will be explained. In FIG. 1(a), the boat 105
The semiconductor substrate 104 placed on the substrate is heated by a heater 114. Monosilane gas (S!H4) is introduced from the gas inlet port 107 into the gas inlet pipe 10B as shown in FIG. 1(b).
The gas is introduced into the region shown in the figure, that is, into the interior of the gas introduction pipe 106. On the other hand, from another gas inlet 110, the space formed by the partition plate 10B and the reaction furnace 102, that is, the area shown as N in FIG. Oxygen gas (0
2) is introduced independently. This makes it possible to suppress unnecessary reactions between the monosilane gas (S!H4) and the oxygen gas (02). These two types of gas each have gas inlet 1.
Although introduced independently from 07.110, Fig. 1(b)
By uniformly mixing in the area shown as N in the figure, it is possible to uniformly supply the entire necessary area in the reactor 102.

Therefore, the gas in the reactor 102 diffuses with uniform composition and density, and the monosilane gas (S!
Since unnecessary reactions between H4) and oxygen gas (02) can be suppressed, a uniform thin film with fewer particles is deposited on the semiconductor substrate 104.

Reactor 102. Boat 105. Partition plate 108.111
゜The material of the gas introduction pipe 106 is preferably quartz glass, but
The materials of other parts do not matter. In addition, the partition plate 108°1
The shape of 11 is not limited to a plane, but may have an appropriate curvature.

Next, the gas in the reactor 102 is exhausted from the gas exhaust port 112 provided on the partition plate 111, and then
It is discharged to the outside of the reactor 102.

In this example, a case has been described in which a silicon oxide film (SiO2) is deposited using monosilane gas (S!H4) and oxygen gas (02).
! If a mixture of phosphine gas (PH3) and H4) is used, it can also be used to deposit phosphor glass (PSG) films, and in this case too, there are fewer particles, and the film thickness and thickness can be reduced.
The uniformity of the film quality etc. is good.

(Example 2) FIG. 2 is a sectional view showing a second embodiment of the present invention.

The low-pressure vapor phase growth apparatus of the present invention can be used as a plasma CVD apparatus if high-frequency power can be applied to the portion shown as boat 105 in FIG. 1(a). Second
In the figure, 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. Pressure is approximately 1 torr, frequency is 50K
llZ~13.56) Generate plasma at iHz and deposit a thin film on the semiconductor substrate 204.

According to this example, when a plasma silicon oxide film was deposited using monosilane gas (SiHa) and oxygen gas (02), there were few particles and the film thickness and quality were deposited with good uniformity. In this example, since plasma is used, the deposition temperature can be lowered (approximately 250°C to 350°C), and in the manufacturing process of semiconductor integrated circuit devices,
It has the advantage that it can be used for interlayer insulating film deposition between aluminum and aluminum wiring.

[Effects of the Invention] As explained above, the present invention provides a space consisting of a partition plate provided with a gas outlet and a gas exhaust port at two locations in a reactor, respectively, and a gas outlet partition plate and a side wall of the reactor. By having a gas introduction tube to independently introduce reactive gases into the film, it is possible to suppress particle generation and improve the non-uniformity of film thickness and quality within the batch and on the surface of the semiconductor substrate, thereby increasing the yield in the film forming process. This will improve performance and reduce costs. Further, there is an effect that the stability and reliability of the manufactured semiconductor device can be improved.

[Brief explanation of the drawing]

FIG. 1(a) is a cross-sectional view of a reactor provided in the reduced pressure vapor phase growth apparatus of the present invention, FIG. 1(b) is a cross-sectional view taken along the X-Y line of FIG. 1(a), and FIG. FIGS. 3(a) and 3(b) are cross-sectional views of a boat portion in Example 2, and FIGS. 3(b) are cross-sectional views of a reactor of a conventional reduced pressure vapor phase growth apparatus. 101...Previous i 102...Reactor 1
03... later! 104...Semiconductor substrate 105...Boat 106 Gas introduction pipe 107...Gas introduction port 10B...Partition plate 1
09...Gas outlet 110...Gas inlet 1
11... Partition plate 112... Gas exhaust port 1
13... Gas discharge port 114... Heater 20
1... Fixture 202... Boat 203.
・Electrode 204 ・Semiconductor substrate 205 ・
...High frequency power supply 301...Front cover 302...Reactor 303...Rear cover 304...Semiconductor substrate 305...Boat 306...Gas inlet
307...Gas outlet 308...Gas inlet pipe
309...Gas outlet 310...Gas exhaust pipe
311... To gas exhaust port (b) = "1 - Figure 2 (a) (b) Figure 3

Claims (1)

[Claims] (1) means for installing a semiconductor substrate on which a thin film is to be deposited;
In a reduced pressure vapor phase growth apparatus having a means for introducing a gas containing an element that forms a thin film into a reactor, a means for exhausting the gas, and a means for heating the reactor, A pair of partition plates having a large number of openings are provided parallel to the reactor side wall, one partition plate is used for gas introduction and the other partition plate is used for gas exhaust, and the partition plate for gas introduction and the reactor side wall are provided. 1. A reduced pressure vapor phase growth apparatus characterized in that a gas introduction pipe having a large number of openings is provided in a space consisting of.