JPH0513373B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method of forming a thin film on a substrate by photochemically decomposing a reactive gas.
vapor deposition (hereinafter referred to as photoexcitation CVD method)
The present invention relates to semiconductor manufacturing equipment that forms thin films using.

[Conventional technology]

The CVD method is an important technology for forming thin films in integrated circuit devices, but the conventional CVD method
The reaction gas is mainly heated to cause a chemical reaction, and therefore the reaction temperature becomes high, and the thin film formed thereby is easily damaged.

Therefore, recently, photo-excited CVD has been developed as a low-temperature CVD technology.
The law is attracting attention. This photoexcitation CVD method is
Light is used as the energy source for CVD, which allows the reaction temperature to be lower than that of conventional thermally excited CVD methods, plasma CVD methods, etc.
Damage to the thin film can also be reduced.

In general, in photo-excited CVD methods, it is known that the intensity of light has a large effect on the rate of thin film formation. It is known that the rate of formation of is proportional to the intensity of light irradiation.

Figure 2 shows the basic configuration of a conventional thin film forming apparatus using such a photo-excited CVD method. In the figure, 1 is a reaction chamber whose inside is reduced to a high vacuum state during film formation, and 2 is a linear lamp. 3 is a heater for heating the substrate; 4 is a reactive gas such as silane;
6 is a substrate on which a thin film is formed, 6 is a light entrance window made of a light-transmitting material, 7 is a reaction gas supply port, 8 is a gas discharge port for discharging the gas 4a after the reaction, and 9 is a substrate 5
It is a fixed stand on which to place.

Incidentally, the pressure inside the reaction chamber 1 is generally reduced to a high vacuum state, and the walls of the reaction chamber 1 and the light entrance window 6 made of a light-transmitting material are of course constructed with a structure and plate thickness capable of withstanding this pressure.

In this apparatus, when a reaction gas 4 is introduced into the reaction chamber 1 through a supply port 7, the reaction gas 4 is excited and decomposed by a light beam projected from an entrance window 6. The resulting reaction product is deposited on the substrate 5 heated at a low temperature by the heater 3, and a thin film is formed on the substrate 5. Gas 4a after reaction is discharged from outlet 8
is discharged from.

[Problem that the invention seeks to solve]

In this conventional semiconductor manufacturing apparatus, the light entrance window 6 is provided in the reaction chamber 1 as described above, and light is projected from the light source 2 provided outside the reaction chamber 1. In order to increase the speed, it is necessary to increase the illuminance of the light on the substrate 5, and for this purpose, it is necessary to use a light source with a higher output, or to connect the substrate 5 and the light source 2.
It is necessary to shorten the distance and increase the illuminance on the substrate 5. However, it is currently difficult to find a practical light source with a long life and high output, and it is also possible to shorten the distance between the substrate 5 and the light source 2 with the conventional structure by using a light-transmitting material between them. The light entrance window 6 is arranged in the reaction chamber 1 with a structure that can withstand high vacuum pressure.
This was extremely difficult as it had to be attached to the

In addition, reaction products from photochemical reactions accumulate on the light entrance window 6, resulting in so-called clouding, which makes it difficult for ultraviolet rays to pass therethrough, making continuous operation of the apparatus impossible.

The present invention was made to solve these problems, and aims to provide a semiconductor manufacturing apparatus that can increase the illuminance of light on a substrate and can be operated continuously.

[Means for solving problems]

A semiconductor manufacturing apparatus according to the present invention uses as a light source a plurality of linear lamps arranged in a rotatable quartz glass tube in a reaction chamber, and near the outer surface of the quartz glass tube on the opposite side from the substrate. A plasma discharge device is provided for generating plasma and etching away reaction products adhering to the surface of the quartz glass tube.

[Effect]

In this invention, since the light source is provided in the reaction chamber, the light source approaches the substrate, increasing the illuminance of the light on the substrate, and forming a thin film quickly. Further, reaction products adhering to the outer peripheral surface of the quartz glass tube move upward as the quartz glass tube rotates, and are removed by plasma etching there.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor manufacturing apparatus according to an embodiment of the present invention. In the figure, 1 is a reaction chamber, 1
3 is a cylindrical quartz glass tube provided in the reaction chamber 1 and rotatable clockwise in the figure, and is driven by a motor (not shown). 12 is a light source formed by a plurality of linear lamps arranged along the inner wall of the quartz glass tube 13; 5 is a substrate; 14 is a vicinity of the outer surface of the cylindrical quartz glass tube 13 on the side opposite to the substrate 5; That is, a plasma discharge device that generates plasma above, 11a and 11b are both electrodes thereof, and 10 is a seal plate provided to cover both sides of the cylindrical quartz glass tube 13 and partition the reaction chamber 1 into a substrate side and a non-substrate side. be. 3 is a heater for heating the substrate, 4 is a reactive gas,
7 is a reaction gas supply port, 8 is a gas discharge port for discharging the gas 4a after the reaction, and 9 is a table on which the substrate 5 is placed.

Next, the effects will be explained.

In this apparatus, a reaction gas 4 is supplied into the reaction chamber 1 through a supply port 7, and light is projected from a cylindrical quartz glass tube 13 serving as a light source 12 to cause a photochemical reaction in the reaction gas 4. A thin film is formed on the substrate 5 which is being heated by.

In this apparatus, a plurality of linear lamps arranged in a cylindrical quartz glass tube 13 is used as a light source, and since the light source 12 is installed in the reaction chamber 1, the light source 12 can be extended to any desired distance from the substrate. 5, and the illuminance of the light on the substrate 5 can be increased. Therefore, the speed of forming a thin film on the substrate 5 can be increased without increasing the output of the light source 12 more than necessary.

Further, during the formation of the thin film, reaction products adhere to the surface of the quartz glass tube 13, but as the quartz glass tube 13 rotates, the reaction products move upward and are exposed to the plasma generated by the plasma discharge device 14. By etching it away, the device can be operated continuously while the linear lamp remains lit.

In addition, in this embodiment, the reactive gas supply port 7 and the gas discharge port 8 are provided close to each other below the glass tube 13 with the cylindrical quartz glass tube 13 in between, so that the reactive gas 4 is supplied to the cylindrical quartz glass tube. The light flows where the distance between the light source 13 and the substrate 5 is narrow and the illuminance of the light on the substrate 5 is strong, allowing the reaction gas 4 to quickly undergo a photochemical reaction. In addition, by providing such a reaction gas supply port 7 and a gas discharge port 8, the reaction gas 4 only needs to flow over a short distance, so that the reaction gas 4 can be placed in an unnecessary part of the reaction chamber 1.
can be prevented from flowing. In addition, since the reactive gas can be efficiently flowed over a short distance, the concentration of the reactive gas can be made uniform, and a sufficient amount of the reactive gas can be flowed onto the substrate 5 in accordance with the speed of the photochemical reaction of the reactive gas. Thin film formation speed can be increased.

Moreover, the glass tube 1 is placed inside the cylindrical quartz glass tube 13.
Since the linear lamps are arranged at appropriate intervals along the inner wall of the glass tube 13, the illuminance distribution of the light on the substrate 5 can be made uniform to some extent in the direction perpendicular to the axis of the glass tube 13.

〔Effect of the invention〕

As described above, according to the semiconductor manufacturing apparatus according to the present invention, a plurality of linear lamps incorporated in a quartz glass tube is used as a light source, and the light source is provided in the reaction chamber, so that the illuminance of the light on the substrate is In addition, since a plasma discharge device is provided that generates plasma near the outer circumferential surface of the upper part of the rotatable quartz glass tube, reaction products adhering to the outer circumferential surface are removed by plasma. It can be removed by etching, which has the effect of allowing continuous operation of the device.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of a semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional side view of a conventional semiconductor manufacturing apparatus. DESCRIPTION OF SYMBOLS 1... Reaction chamber, 12... Light source, 4... Reaction gas, 5... Substrate, 13... Quartz glass tube, 14...
...Plasma discharge device. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1 In a semiconductor manufacturing apparatus that projects light from a light source onto a reaction gas in a reaction chamber to cause a photochemical reaction and form a thin film on a substrate placed in the reaction gas, the light source is rotatably installed in the reaction chamber. A plurality of linear lamps are arranged in a quartz glass tube, and a plasma discharge device for generating plasma is provided near the outer surface of the quartz glass tube on the side opposite to the substrate. Features of semiconductor manufacturing equipment.