JPH03287770A - Single wafer processing atmospheric cvd device - Google Patents

Abstract

PURPOSE:To form a thin film on the entire surface of a substrate in uniform thickness in the single wafer processing atmospheric CVD device by providing a raw gas flow straightening plate pierced with many through-holes at a specified inclination on the substrate. CONSTITUTION:A susceptor 14 carrying a substrate 18 is fixed to a rotary plate 64 by plural legs 62 in the single wafer processing atmospheric CVD device consisting of an upper chamber 10 and a lower chamber 12 and made rotatable and vertically movable. The substrate 18 is heated by a heater 68, and SiH4 and O2 as the raw gas are supplied from a gaseous reactant supply means 16 into the upper chamber 10 respectively with gaseous N2 as the carrier gas. A flow straightening plate 30 pierced with many throughholes 40 at an inclination of 20-45 deg. is placed above the substrate, the raw gas is passed through the holes 40 to form a uniform film on the substrate 18, and the film of SiO2 formed by the reaction of SiH4 with O2 is deposited on the entire surface in uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a CVD thin film forming apparatus. More specifically,
The present invention relates to a single-wafer atmospheric pressure CVD apparatus that can improve the uniformity of film thickness.

[Prior Art] One of the methods widely used in the semiconductor industry for forming thin films is chemical vapor deposition (CVD).
Chemical Vapor Depos it
1on). CVD refers to turning a gaseous substance into a solid substance through a chemical reaction and depositing it on a substrate.

Characteristics of CVD are that various thin films can be obtained at deposition temperatures considerably lower than the melting point of the thin film to be grown;
Because the grown thin film has high purity (and its electrical characteristics are stable even when grown on Si or a thermal oxide film on Si), it is widely used as a passivation film on semiconductor surfaces.

Thin film formation by CVD is performed at a temperature of approximately 400°C to 500°C, for example.
A reactive gas (for example, SiH++
02. Or SiH4+PH3+02) is supplied. The above reaction gas is blown onto the wafer in a reactor (belljar) to form a thin film of 5i02 or phosphorus silicate glass (PSG) or porosilicate glass (BSG) on the surface of the wafer. Also, 5i0
In some cases, two-layer film formation of 2 and PSG or BSG is performed. Furthermore, it can also be used to form metal thin films such as molybdenum, tungsten or tungsten silicide.

There are three types of CVD film-forming processing operations: single-wafer method that deposits film on each wafer, batch method that deposits film on more than ten wafers at once, and continuous method that deposits film while continuously transporting wafers. be. The single-wafer type is suitable for forming a uniform CVD film on a large-diameter Ueno film.

As shown in FIG. 2, in a conventional single-wafer atmospheric pressure CVD apparatus, a susceptor 14 that can rotate and move up and down is arranged inside a reaction chamber consisting of an upper chamber 10 and a lower chamber 12. Reaction gas supply means 1 on the top surface of the chamber
6 are arranged.

This gas supply means is configured so that SiH+ and 02 can be supplied from separate pipes. The upper chamber 10 and the lower chamber 12 are connected by a hinge member 20,
The upper chamber 10 is configured to be openable and closable. With such a configuration, the inside of the reaction chamber can be cleaned regularly.

[Problem to be solved by the invention] However, in the apparatus shown in FIG.
Since the film flows down from directly above the wafer 18, the film thickness tends to be thicker at the center of the wafer 18 and thinner at the periphery.

Therefore, an object of the present invention is to provide a single-wafer atmospheric pressure CVD apparatus that can improve film thickness uniformity.

[Means for Solving the Problems] As a means for solving the above-mentioned problems and also achieving the object of the present invention, the present invention provides a system for rotating and raising/lowering a reaction chamber consisting of an upper chamber and a lower chamber. In a single-wafer atmospheric pressure CVD apparatus in which a susceptor is disposed, a reactant gas supply means is disposed on the upper surface of the upper chamber, and the supplied reactant gas is disposed inside the upper chamber. A rectifying plate having a large number of through slits for making the flow uniform is fixed to the upper chamber, and the gas outlet near the lower end of the through slit is inclined by 20 to 45 degrees toward the gas flow direction. Provided is a single-wafer atmospheric pressure CVD apparatus characterized by:

[Function] As described above, in the CVD apparatus of the present invention, the gas outlet of the through-slit is inclined at a predetermined angle toward the gas flow direction, so that a uniform flow can be achieved over the entire surface of the wafer, and the film thickness can be reduced. Uniformity is improved.

[Example] Hereinafter, an example of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a conceptual diagram of an embodiment of a single-wafer atmospheric pressure CVD apparatus of the present invention.

Components in the apparatus shown in FIG. 1 that are the same as those in the conventional apparatus shown in FIG. 2 are designated by the same reference numerals as used in FIG.

The single-wafer CVD apparatus of the present invention shown in FIG. 1 also consists of an upper chamber 10 and a lower chamber 12, similar to the conventional apparatus. The upper chamber 10 and the lower chamber 12 are connected by a hinge member 20, and the upper chamber 10 is configured to be openable and closable. Although not shown, while the device is in operation,
The upper chamber 10 and the lower chamber 12 are clamped together by a suitable ramp mechanism or the like.

A current plate 30 is disposed inside the upper chamber 10. A gas diffusion space 32 is formed on the upper surface side of the current plate 30.

The gas diffusion space 3 is located in the same portion of the rectifying plate 30 as the wafer.
A large number of through holes 40 extending from the reaction space 2 to the reaction space 38 are provided. Further, an exhaust port 42 is provided at a suitable location on the lower end of the current plate 30. This exhaust port 42 is preferably located adjacent to the exhaust duct 44 of the device. The air outlet of the baffle plate shall be connected to the equipment exhaust duct and shall not be integrated with it.

Further, the through hole 40 is oriented 20 mm toward the exhaust port 42.
Tilt at an angle of ~45'. If the inclination angle is less than 20 degrees, the gas will flow horizontally and may not come into contact with the wafer surface. Further, if the inclination angle exceeds 45°, the spraying becomes like vertical spraying, and no improvement in film thickness uniformity can be expected. When the blowing angle of the through hole is within the range of 20 to 45@, a uniform gas flow is formed over the entire surface of the wafer, and not only the generation of foreign matter is suppressed, but also the deposition rate can be increased.

In order to allow gas to smoothly flow inside the reaction space 38 toward the exhaust port 42, a surrounding plate 4 surrounding the susceptor 14 is provided.
6 and 48 are preferably provided. There is a very small gap between the surrounding plate 46 and the susceptor 14, and there is no problem in raising and lowering the susceptor 14.

The susceptor 14 is configured to be able to be raised and lowered by a commonly used raising and lowering mechanism such as an air cylinder 50. For example, the air cylinder 50 is preferably disposed on the lower surface of the support column 60. When carrying out a film forming reaction, the susceptor is raised, and after the film forming reaction is completed, it is lowered. When the upper surface of the susceptor reaches a gate portion (not shown), the lowering is stopped.

The susceptor 14 is configured to be rotatable. For example, the susceptor 14 is fixed to a rotary plate 64 by legs 62, and a rotation bearing 66 is inserted between the rotary plate 64 and the column 60. The susceptor 14 is rotated when the rotating plate 64 is rotated by an appropriate driving source (not shown). Susceptor 14
is rotated only during the film forming reaction process.

When forming a CVD film using the apparatus of the present invention, the susceptor 14 is raised as described above, and the surrounding plate 46 of the rectifying plate 30 is
It will be stopped at a height of . Gas is sent from the reaction gas supply means 16 to the reaction gas diffusion space 32 and flows down from the through hole 40 to the wafer 18 placed on the upper surface of the susceptor. The wafer 18 is heated to a predetermined temperature by the heater 68 of the susceptor 14, and a film forming reaction is performed on the heated wafer surface.

During the film deposition process, the wafer is rotating together with the susceptor.

[Effects of the Invention] As explained above, the CVD! of the present invention! In tIiF, the gas outlet of the through-slit is inclined at a predetermined angle toward the gas flow direction, so that a uniform flow can be achieved over the entire surface of the wafer, improving the uniformity of the film thickness.

When a film is formed using the apparatus of the present invention, the film quality is improved because a thin film is vertically deposited over the entire surface of the wafer.

Further, since a uniform laminar flow is generated over the entire surface of the wafer and no turbulent flow or eddy flow is generated, not only the generation of foreign matter is suppressed, but also the deposition rate can be increased.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a single wafer type normal pressure CVD apparatus of the present invention, and FIG. 2 is a conceptual diagram of an example of a conventional single wafer type normal pressure CVD apparatus. 10... Upper chamber, 12... Lower chamber. 14... Susceptor, 16... Reaction gas feeding means. 18... Wafer, 30... Rectifying plate, 40... Through hole. 42...Exhaust port, 46 and 48...Surrounding plate 6 Fig. 2

Claims (1)

[Claims] (1) In a single-wafer atmospheric pressure CVD apparatus in which a rotatable and movable susceptor is disposed in a reaction chamber consisting of an upper chamber and a lower chamber, a reaction gas supply means is disposed on the upper surface of the upper chamber. and a baffle plate having a large number of through slits for uniformizing the flow of the supplied reaction gas is fixed to the inside of the upper chamber, and the lower end of the through slit is fixed to the upper chamber. The side gas outlet is 20~ towards the direction of gas flow.
Single-wafer atmospheric pressure CVD characterized by a 45° inclination
Device.