JPH01132769A - Atmospheric pressure cvd device - Google Patents

Abstract

PURPOSE:To blow a sufficient reaction gas to a step part and to improve step coverage by providing plural reaction gas blow ports of different blow directions to a dispersion head and providing an inert gas blow port and discharge port to the outside thereof. CONSTITUTION:A mixing chamber 5a for mixing gaseous silane 3 and gaseous oxygen and a distributing chamber 5b for distributing a gaseous mixture to a susceptor 1 side are provided to the dispersion head 5 installed right above the susceptor 1. The distributing chamber 5b is divided to the plural distributing chambers 5b1-5bn by partition plates 10a, 10b of different angles of inclination and ejection ports 6- are provided toward the specific regions of a wafer mounting part on the extension line thereof to blow the reaction gas to the step 2a of a semiconductor device 2 from a diagonal direction. An inert gas ejection port 9 is opened to enclose the outside circumference of the gas ejection ports 6- and the discharge port 7 is provided on the outside thereof to partition the reaction gas and the atm. air by the inert gas 8, by which the abnormal growth of the film and the adhesion of the rubber onto the semiconductor device 2 are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a CVD apparatus under normal pressure, and particularly to an improvement of a dispersion head.

[Conventional technology]

Conventional atmospheric pressure CVD equipment has a temperature of approximately 400°C as shown in Figure 2.
Semiconductor device 1i is placed on susceptor 1 which is heated back and forth! 2 is placed on the semiconductor device, and the susceptor 1 is moved horizontally by a belt to deposit an insulating film such as an oxide film on the semiconductor device. To grow the oxide film, diluted silane gas 3 and oxygen 4 are introduced into the dispersion head 5. The reactant gases were mixed in the head 5 and ejected from the reactant gas outlet 6 perpendicularly to the semiconductor device 2 .

[Problem that the invention seeks to solve]

The conventional atmospheric pressure CVD apparatus described above mixes the reaction gas (SiH4゜0□, etc.) in the dispersion head 5,
It has a structure in which gas is ejected perpendicularly to the semiconductor device 2 on the heated susceptor 1 through a plurality of reaction gas ejection ports 6,6, which are opened in the same direction with respect to the susceptor 1, In consideration of safety, the structure is such that excess reactive gases 3 and 4 from the head 5 are exhausted through the exhaust lower, so in the semiconductor device v:12 with a step, the reactive gas is injected diagonally to the step 2a. The insulating film cannot be sprayed uniformly, resulting in poor step coverage.Also, since the air is drawn in by the exhaust lowers on both sides, there are areas where the insulating film grows abnormally thick, causing in-plane The uniformity deteriorates, causing problems such as the dust remaining on the susceptor 1 being thrown up and being deposited on the semiconductor device, which has a large effect on the characteristics and appearance of the semiconductor device.

An object of the present invention is to provide a normal pressure CVO device that solves the above problems.

[Differences between the invention and the prior art]

In contrast to the conventional atmospheric pressure cvo yi system described above, the present invention shields the reaction gas blowing area from the atmosphere, blows the reaction gas into the area, and blows the reaction gas to the semiconductor device from mutually different directions. have differences.

[Means for Solving the Problems] The present invention provides a dispersion head in a normal pressure CvO apparatus having a susceptor on which a wafer is mounted, and a dispersion head located directly above the susceptor and spraying a reaction gas onto the wafer. A plurality of reaction gas blow-off ports are formed to direct the reaction gas in different directions and concentrate the reaction gas toward a specific area of the wafer mounting portion of the susceptor, and an inert gas flow surrounding the area is formed. It has an inert gas outlet that shields the region from the atmosphere, and an exhaust port that sucks and exhausts the inert gas and excess reaction gas blown out from each outlet to prevent them from flowing out of the region. This is a characteristic atmospheric pressure CVD device.

〔Example〕

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

FIG. 1 is a sectional view showing one embodiment of the present invention.

In FIG. 1, 5 is a dispersion head installed directly above the susceptor 1. The dispersion head 5 includes a mixing chamber 5a for mixing silane (Sil14) gas 3 and oxygen (02) gas 4, and a distribution chamber 5b for guiding and distributing the mixed gas mixed in the mixing chamber 5a to the susceptor 1 side. has. The distribution chamber 5b is divided into front and rear parts by a partition plate IO installed perpendicularly in the center, and partition plates 10a, 10a, 10a, 10a, 10a, 10a, 10a, 10a, 10a, 20a, 30b, 30b, 30b, 30b, 30b, 30b, and 5b, which have mutually different inclination angles in the front and rear direction, centering on the partition plate 10. . . , 10b, 10b, . The reactant gas ejection ports 6, 6, .

Further, in the dispersion head 5, partition plates 10 are provided in front and behind the outer periphery of each reactant gas outlet 6, 6...
c and 10d form an inert gas introduction chamber 5C.

An inert gas outlet 9 is opened at the bottom of the inert gas introduction chamber 5C.

In addition, the dispersion head 5 is a bottomless hollow flj1
a, and between the outer edge of the lower surface of the dispersion head 5, the inert gas and excess reaction gas blown out from each outlet 9.6 are sucked and exhausted, and prevented from flowing out of the area. Forms the exhaust lower.

In the embodiment, the atmospheric pressure CVD apparatus deposits a semiconductor device I! on a susceptor 1 heated to about 400°C. ! The susceptor L is moved left and right by a belt, and the thickness of the film deposited on the semiconductor device 2 is controlled by the belt speed.In the case of an oxide film, silane (Si
H,) gas 3 and oxygen (0□) gas 4 are mixed in the dispersion head 5, and the reaction gases 3 and 4 are ejected to the semiconductor device 2 through a plurality of reaction gas ejection ports 6.6... It has become.

By the way, if there is a step in the semiconductor device 2, the step coverage is poor and the air is drawn in by the exhaust lowers on both sides, resulting in abnormal growth of the oxide film, and the oxide film grows thick in some areas, drawing in the air.

The deposits and dust remaining on the susceptor 1 are rolled up and deposited on the semiconductor device 2, resulting in poor appearance and poor characteristics. In the CVD apparatus of the present invention, the plurality of reaction gas injection ports 6 in the dispersion head 5 have different blowing directions with respect to the semiconductor device @ 2 on the susceptor 1. The gas is sufficiently blown obliquely onto the step 2a of the semiconductor device 2, and as a result, the step coverage of the semiconductor device 2 can be improved. In addition, nitrogen gas 8 is provided on both sides of the reaction gas outlet 6.
By providing an inert gas outlet 9 through which an inert gas such as the like can flow, and by providing an exhaust lower on the outside thereof, the inert gas 8 separates the reaction gas from the atmosphere, thereby preventing air from being drawn into the reaction section. As a result, abnormal growth is eliminated, and adhesion of dust and the like on the semiconductor device 2 can be prevented.

In the embodiment, if the susceptor 1 is formed into a disk shape and the disk-shaped susceptor 1 is rotated directly below the dispersion head 5, the reaction gas can be sufficiently sprayed onto the steps of the semiconductor device 2.

Step coverage can be further improved.

〔Effect of the invention〕

As explained above, in the present invention, since a film is formed by flowing a reactive gas obliquely to a semiconductor device, a sufficient amount of reactive gas can be sprayed onto the steps, and step coverage in the semiconductor device can be improved. In addition, since the reaction gas blowout area is shielded from the atmosphere, the atmosphere is not drawn in, which has the effect of preventing abnormal growth of the film and preventing dust from adhering.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a conventional device. 1... Susceptor 2... Semiconductor device 3... Silane gas 4... Oxygen gas 5
... Dispersion head 6 ... Reactant gas blowout lower ... Exhaust port 8 ... Nitrogen gas 9 ... Inert gas blowout port

Claims (1)

[Claims] (1) In an atmospheric pressure CVD apparatus having a susceptor on which a wafer is mounted and a dispersion head located directly above the susceptor and spraying a reaction gas onto the wafer,
The dispersion head has a plurality of reactive gas jetting ports that direct the reactive gas in different directions and concentrate it toward a specific area of the wafer mounting portion of the susceptor, and forms an inert gas flow surrounding the area. an inert gas outlet that shields the region from the atmosphere, and an exhaust port that sucks and exhausts the inert gas and excess reaction gas blown out from each outlet to prevent them from flowing out of the area. An ordinary pressure CVD apparatus comprising: