JPH03285078A - Chemical vapor deposition device - Google Patents

Abstract

PURPOSE:To obtain the chemical vapor deposition device capable of forming a good-quality film without increasing O2 supply by controlling the heating means for a substrate while the film is formed and providing a control means for changing the substrate temp. between the two preset temps. several times. CONSTITUTION:The substrate 10 is heated to about 300 deg.C by a lit lamp 14, and O2 is supplied 19a to an O3 generator 18 to generate O3 which is supplied to a gas supply passage 7a. Meanwhile, gaseous N2 is introduced 19b into a reaction vessel 20 for tetraethoxysilane(TEOS), and the formed TEOS is supplied to a gas supply passage 7b. The gaseous O3 and TEOS are blown from a gas blowoff port 5, and a film is formed on the surface of the substrate 10 by a CVD reaction. The lamp 14 is then turned on and off at the time intervals of several to several ten sec while the film is formed, and the substrate is repeatedly heated to about 400 deg.C and cooled to about 300 deg.C. After the lapse of the specified time required to form the film, the supply of gaseous TEOS and O3 is stopped, and a silicon oxide film is formed on the substrate 10.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a gas phase chemical reaction for forming an oxide film or the like on a substrate made of a semiconductor substrate using a gas phase chemical reaction, for example in a semiconductor manufacturing process. (hereinafter abbreviated as CVO device).

[Prior Art] In the manufacturing process of semiconductor devices, for example, when forming an oxide film on a substrate, an atmospheric pressure CVO apparatus is used.

Such an atmospheric pressure CvD device is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-19
:1129. Figure 6 shows this normal pressure C.
It is a sectional view of a VD device. In the figure, (1) is loading 1
．． -1 (la) and a closed container having an exhaust port (lb), (2) is placed within this container (1) and has an exhaust IN (
: l) is an exhaust hood with an open exhaust hood, (4) is installed inside this exhaust hood (2), and has a plurality of hollow gas passages (6) connected vertically from the elongated gas outlet (5). Individually formed gas blowing head, (7a) (7
b) is configured inside the gas blowing head (4).
Adjacent gas passages (6) in the gas supply path of the system
are connected alternately.

(8) is an exhaust path formed between the gas blowing head (4) described in 1- and the exhaust hood (2), and (9) is a substrate (10) which is disposed opposite to the gas blowing head (4) and is a base body. ), a turntable (11) is placed under the turntable (IO), and a heater (11) is a heating means for heating the substrate (lO) via the turntable (IO); (12) stores the substrate (lO) carried into the container (1) through the loading port (la), and also stores the substrate (10) which is discharged from the container (1) through the discharge port (1b). This is the cassette that will be used.

In the atmospheric pressure CVD apparatus configured in this way, one
A board (lO) is carried in from the loading entrance (1a) in a timely manner,
It is transferred onto the turntable (9). When the substrate (10) is placed on the turntable (9), the turntable (9) rotates and the substrate (10) is placed on the turntable (9).
9) The lower heater (11) uniformly heats the entire area. On the other hand, a desired raw material gas is fed into the gas supply channels (7a) and (7b), and is supplied to the connected gas channels (6), respectively, and the substrate on the turntable (9) from the gas outlet (5). Each is blown out toward (lO). At this time, the gas blown out from the gas outlet (5) flows as if being sucked into an exhaust path (8) provided around the blowing head (4). The gas blown out from the gas outlet (5) is
A film is formed by causing a gas phase chemical reaction on the heated substrate (lO). The substrate (lO) on which a film has been formed by the gas-phase chemical reaction is lowered from the turntable (9), carried out from the carry-out port (Ib), and placed in the aerodynamic set (
12).

In addition, in recent years, atmospheric pressure CVD methods using ozone (03) and organic scum as raw material gases have been used to form oxide films on semiconductors using such CVD equipment, due to the fact that they have good step filling properties and do not cause plasma damage. This method is attracting attention as a promising method for the future.

In such a normal pressure CVD method, ozone generated by an ozone generator is supplied to one gas supply path (7a) in the above-described CVD apparatus, and ozone is supplied to the other gas supply path (7a).
b) contains tetraethoxysilane (Si (OC2H5)
4) (hereinafter abbreviated as TE01) is supplied. Then, TEOS scum and ozone gas flow out alternately at every - point of gas blowout 0 (5), and each gas is mixed on the heated surface of the substrate (10) to cause a chemical vapor phase reaction and oxidize. A film is formed on the surface of the substrate (IO).

In this way, using the conventional CVD apparatus, the above-mentioned 1
'The film formation characteristics of the film formation method using EO5-ozone gas are as follows.
It is shown in FIG. At this time, the TE01-ozone scum flow rate is constant. As shown here, 'rEO5-
The deposition rate of silicon oxide film using ozone system is
It increases as the temperature rises, but it decreases with a peak value of about 300°C. In other words, at high temperatures of about 300° C. or higher, ozone on the surface of the substrate (10) decomposes quickly and the amount of ozone required for the gas phase chemical reaction is insufficient. On the other hand, the film quality of the silicon oxide film is that the film with fewer 011 groups is
The i-0 bonnetwork is now more perfect,
Although a film of good quality or a film formed at a temperature of the substrate (]0 of about 300° C. has a high film formation rate, a high quality film cannot be obtained due to the large number of 011 groups contained in the film. Therefore, in forming a TE01-ozone film using a conventional CVD device, the temperature of the substrate (lO) is set at 400°C, and in order to compensate for the ozone that decomposes, the capacity of the ozone generator is increased, and the gas blowout [ Film formation was performed by increasing the amount of ozone blown out from i.

[Problems to be Solved by the Invention] However, in the CVD apparatus as described above, in order to obtain a high quality film without reducing the film formation rate, the capacity of the ozone generator (18) must be increased. First, as CVD equipment becomes larger and the amount of ozone supplied increases, running costs increase, which leads to cost savings for semiconductors.

The present invention has been made to solve the problem of JAx as described above, without increasing the amount of ozone supply.
The objective is to obtain a gas phase chemical reaction device that can form high-quality films at high speed.

[Means for Solving the Problems] The gas phase chemical reaction apparatus according to the present invention includes a container for supplying gas for forming a film on the surface of a substrate, and a heating means for heating the body. The heating means is provided with a control means for controlling the heating means during film formation and for reciprocating a plurality of times between two temperatures set to be equal to the temperature of the substrate.

[Function] In the gas phase chemical reaction apparatus configured as described above, the control means controls the heating means and keeps the temperature of the substrate during film formation at two temperatures: the temperature at which the film formation rate is high and the humidity at which the film properties are good. Make the user go back and forth between the two locations multiple times.

[Example] Hereinafter, an atmospheric pressure CVD apparatus which is an example of the present invention will be described. Further, here, a case will be described in which a silicon oxide film is formed using ozone gas and TEOS gas as raw materials. FIG. 1 is a block diagram of an atmospheric pressure CvD apparatus according to an embodiment of the present invention. In the figure, (13) indicates a substrate (lO) suspended in a container (1), (14) is a heating means for heating the substrate (10), such as a halogen lamp;
(15) converts the light from this lamp (14) into a substrate (lO)
(16) a transparent window provided in the container for illumination;
is a temperature sensor for measuring the temperature of the substrate (lO), (
17) is a control means consisting of a microcomputer that controls the light intensity of the lamp (14) so that the temperature of the substrate (lO) can be instantaneously changed between two temperatures. When the temperature information indicating 300° C. is obtained from the temperature sensor (16), the lamp (14)
) is turned on. (18) is an ozone generator connected on one side to a mass float controller (19a) where the oxygen inflow rate is controlled and on the other side connected to a gas supply path (7a), and (20) is an organic source, such as a high-purity source. One side is connected to a mass float controller (+9b) that controls the amount of nitrogen gas inflow for generating TEOS gas, and the other side is connected to a gas supply path.

A method for forming a silicon oxide film using the atmospheric pressure CvD apparatus configured as described above will be described with reference to FIGS. 2(a) and 2(b). Figure 2 (a) and (b) show this normal pressure CV.
It is a figure for explaining operation of D device. First, the lamp (14) is turned on, and the lamp light causes the substrate (lO
) begins to be heated, and the temperature sensor (16) monitors the substrate temperature until the substrate temperature reaches approximately 300°C. When the substrate temperature reaches approximately 300°C, oxygen is supplied to the ozone generator (18) via the mass float controller (19a), and ozone gas is generated by the ozone generator (18), and the gas supply path is (7a). On the other hand, TEO5 reaction vessel (20
) is fed with nitrogen gas via a mass float controller (19b), and this nitrogen gas bubbles high-purity TE01 in the reaction vessel to generate TEOS gas, and the gas supply to which the ozone gas is supplied The gas is supplied to a gas supply path (7b) different from the path (7a).

Then, the ozone gas and TEOS gas are led separately to the gas outlet (5), and the TEOS gas and ozone gas are blown out from the gas outlet (5) at various locations, causing a CVO reaction on the substrate surface, and the film formation is completed. will be started. Then, when the film formation begins, as shown in FIG. 2(a),
During film formation, the lamp (14) is turned on and off at intervals of several seconds to several tens of seconds. That is, when the lamp (14) is turned on and the lamp light is irradiated onto the substrate (10) for several seconds to several tens of seconds, the substrate temperature rapidly rises and reaches about 400°C. After that, when the lamp (14) is turned off for a few seconds to several tens of seconds, the substrate temperature is rapidly cooled down by a large amount of gas blown out from the gas outlet (5), and the substrate temperature drops to about 300°C. . Then, the lamp (1
4) is lit, and the substrate temperature rises to 400t. The control operation of such a lamp (14) is as follows:
The edges are turned over during film formation. After a predetermined time required for film formation has elapsed, the supply of TEOS gas and ozone gas is stopped, and film formation on the substrate is completed.

The control means for such a heating means will be explained in more detail. As shown in FIG. 7, the substrate temperature is 300℃.
At temperatures around 0.degree. C., there are many ON groups in the film, but the film is formed at a high speed. In addition, when the substrate temperature is around 400°C, although the film formation rate is slow, the number of old films in the previously formed film 11 is reduced, improving the film quality, and the number of films formed is 5i-1 with fewer old films. A high quality film with nearly perfect zero bonnet work is formed. Therefore, at intervals of several seconds to several tens of seconds, the above 300°C
By varying the temperature between ~400℃ and 400℃, the substrate temperature during film formation can be improved. This enables high-speed film formation. Therefore, as explained above, by changing the temperature between 300°C and 400°C many times during film formation, the capacity 11t of the ozone generator (18) can be increased without increasing the ozone supply amount. Good quality 11
q can be formed at high speed.

FIG. 3(a) is a block diagram of another embodiment of the present invention, in which (21) is a mass float controller (
19c), a cooling nitrogen supply path for spraying nitrogen onto the back surface of the substrate (10); (22) is a motor; (22) is a motor;
23) is a chopper to which rotational force is applied by the motor (22) and adjusts the amount of light emitted from the lamp (14) to the substrate (lO); (24) is the motor (21);
For example, it is a control unit consisting of a microcomputer that controls the importance of nitrogen gas, rotation speed, etc. In this embodiment, a mass float controller (+9) is used to control the importance of nitrogen gas.
c) and the signal from the temperature sensor (16), the lamp (
14) is also controlled by a control unit (24), and this control unit (24), the motor (22) and the chopper (23) can instantly change the temperature of the substrate (IO) between two temperatures. A control means for making the change is configured. Figure 3 (
b) is a top view of this chopper (23), and (25
) is provided on this chopper (23), and a lamp (14)
A fully transparent area (2δ) that transmits light from the lamp (23) is a semi-transparent area that blocks part of the light from the lamp (14), and (27) is a semi-transparent area provided on the chopper (23).
This is a shielding area that completely blocks the light from the lamp (14).

By rotating the chopper (23) configured in this manner by the motor (22) during film formation, the light from the lamp (14) is partially or completely blocked at regular intervals. . Therefore, the amount of light irradiated onto the substrate (10) and the temperature of the substrate (10) are as shown in FIG. 2(c) and FIG. 2(d). This period corresponds to half a revolution of the chopper (22). That is, by increasing the intensity of the lamp (14) compared to the above embodiment, the amount of light irradiated onto the substrate (lO) is large in the total transmission region (25) of the chopper (23), and the substrate The temperature is set to 400°C.

Thereafter, in the semi-transparent region <26), the amount of light irradiated onto the substrate (10) decreases, preventing the substrate temperature from exceeding 400° C. and improving the film quality. Then, the chopper (23) becomes a shielding area (27), the lamp light is completely shielded, the substrate (10) is no longer irradiated with light, the substrate temperature suddenly drops to 300°C, and the film formation rate increases. Become. By controlling the lamp light in this way,
The same effect as in the above embodiment can be obtained, and since the lamp (14) is not turned on and off as in the above embodiment, the life of the lamp (14) is extended. In addition, in this embodiment, the surface of the substrate (lO) is provided with a gas outlet (5).
) is cooled by the gas blown out,
Shielding area (27) of chopper (22) on substrate (10)
When this happens, as shown in Figure 3(e) and (f), by flowing nitrogen gas or the like from the cooling nitrogen supply path (2I) to the back side of the substrate (10), the substrate temperature can be further rapidly reduced. Can be cooled.

Further, in the above embodiment, the amount of light from the lamp (14) is constant, and the amount of light irradiated onto the substrate (10) is controlled by the chopper (23). The same effect as in the above embodiment can also be obtained by changing the current flowing through the lamp (14) and changing the amount of light from the lamp (14).

In addition, in the above embodiment, the light irradiation to the substrate (lO) is performed at various times.
Although the lamp light is controlled based on the temperature sensor provided near the substrate (10), the lamp light can also be controlled based on a signal from a temperature sensor provided near the substrate (10).

FIG. 4 shows still another embodiment of the present invention, which differs from the above embodiment in that the heating means for the substrate (lO) is not a lamp (14), but has a small heat capacity. The electric heating M (28) is provided on the back side of the substrate (30). By using the heating wire (2B) with a small heat capacity as the heating means, the heating wire (2B) can also be heated.
28) When a current is passed through it, the heat capacity is small, so the temperature rises rapidly, and when the current is stopped, the temperature drops suddenly.
- It exhibits the same effect as the lamp (14) of the embodiment described above, and the same effects as the above embodiment can be obtained.

In the embodiment of the invention described hereafter, the substrate (10
) to make the temperature and formation uniform in the substrate (10).
It is possible to configure it so that it rotates or revolves.
It's no good.

In the above embodiment, ozone gas is continuously supplied from the ozone generator (18) to the gas supply path (7a) during film formation.
) was blown out from the gas outlet (5) through the substrate temperature, but when the substrate temperature was 400°C, by stopping the ozone scum, 011 groups could be removed from the film formed at the substrate temperature of 300°C, and the ozone supply (Low IL,
A film of even better quality than the above example can be formed.

Furthermore, although the above embodiment describes the formation of a silicon oxide film using TEOS gas and ozone gas, the present invention is not limited to this and can be applied to other film formations.

For example, it can also be used in forming a tungsten (1) film from tungsten carbonyl (W(CO)a) gas. That is, this film formation is as shown in FIG. 5(a) (
As shown in b), when the substrate temperature is low, the film formation rate is slow, CO in the film is difficult to escape, and there are many impurities.
A very dense and uniform film is formed. Furthermore, as the substrate temperature increases, the film formation rate increases and the amount of impurities decreases.

However, if the substrate temperature becomes too high, components decomposed in the gas phase will be incorporated into the film, and the amount of impurities such as oxygen and carbon in the film will increase. Therefore, conventional CV
In apparatus D, film formation was performed using an intermediate temperature (T2) with the least amount of impurities, but the film formed at this substrate temperature was rough and uneven. However, the CV explained above
Using D equipment, the substrate temperature (T
1) and the substrate temperature (T2) at which a film with few impurities can be formed.
By moving back and forth between the two, impurities in the film formed at a substrate temperature that allows formation of a dense film can be removed by raising the temperature to a temperature where there are fewer impurities. A dense film with fewer impurities than a film can be formed.

[Effects of the Invention] As mentioned above, in the gas phase chemical reaction apparatus of the present invention, the control means controls the heating means during film formation to cause the temperature of the substrate to cycle back and forth between two preset temperatures a plurality of times. Therefore, during film formation, the temperature of the substrate goes back and forth between these two temperatures, and the film is formed while taking advantage of the characteristics of the film that is formed at these two temperatures, resulting in a good film. It has the effect of being able to form a film.

[Brief explanation of drawings]

Figure 'dIJ1 is a sectional view showing a gas phase chemical reaction apparatus according to an embodiment of the present invention, Figure 2 is a diagram for explaining a method of controlling the gas phase chemical reaction apparatus of this invention, and Figure 3 (a) is a cross-sectional view showing a gas phase chemical reaction apparatus according to an embodiment of the present invention. 3(b) is a top view showing the chopper of FIG. 3(a), and FIG. 4 is a sectional view showing a gas phase chemical reaction apparatus according to another embodiment of the present invention. 5(a) and 5(b) are diagrams for explaining the relationship between substrate temperature and film characteristics in another embodiment of the present invention, and FIG. 6 is a partial cross-sectional view of a gas phase chemical reaction apparatus. FIG. 7, a cross-sectional view showing a phase chemical reaction device, is a diagram for explaining the relationship between substrate temperature and film characteristics using a conventional gas phase chemical reaction device. In the figure, (1) is a container, (7a) (7b) is a waste supply means, (1O) is a substrate, (13) is a support, (+4
), (28) are heating means (17), (22)
, (2:l), (24) is a control means. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A container into which gas is supplied to form a film on the surface of the substrate, a support for supporting the substrate within the container, a heating means for heating the substrate, and controlling the heating means during film formation. and a gas phase chemical reaction apparatus comprising a control means for reciprocating the temperature of the substrate between two set temperatures a plurality of times.