JPH04299532A - Atmospheric cvd device - Google Patents

Abstract

PURPOSE:To prevent a reaction product from adhering on a semiconductor wafer by a method wherein an atomospheric CVD device is provided with nozzles for spraying raw gases subjected to temperature control so that the raw gases mix with each other and react to each other in the part of a constant area on the wafer. CONSTITUTION:An atmospheric CVD device is provided with nozzles 4 consisting of raw gas introducing tubes 6, which are individually provided in each raw gas and are made to incline their respective tips toward the direction of one point, a temperature control device 8, which makes these tubes 6 heat by raw gas heating heaters 7 and controls raw gas at a prescribed temperature, and exhaust vents 5, which are arranged alternately with the tubes 6 and exhaust unreacted gas and a reaction product.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an atmospheric pressure CVD apparatus.
In particular, the present invention relates to an atmospheric pressure CVD apparatus with an improved nozzle for spraying a reaction gas onto a wafer.

0002

[Prior Art] Conventionally, as a method for forming oxide films, PSG films, etc., monosilane (S
A vapor phase growth method is used in which a source gas such as iH4) or oxygen (O2) is supplied and a thermal decomposition reaction of the source gas occurs on the semiconductor wafer. The cross-sectional view of FIG. 3 shows an example of this type of atmospheric pressure CVD apparatus. In this example,
A semiconductor wafer 1 is loaded on a semiconductor wafer loading belt 2, heated to a predetermined temperature while moving on a heater 3, and introduced below a nozzle 4. The raw material gas ejected from the nozzle 4 undergoes a thermal decomposition reaction to form an oxide film and an insulating film on the semiconductor wafer 1. This nozzle 4 sprays raw material gases such as oxygen, monosilane, etc. mixed in a raw material gas introduction pipe 6 onto the semiconductor wafer 1 to form a film. The air is exhausted from an exhaust port 5 provided on the outer periphery of the air.

0003

[Problem to be solved by the invention] The above-mentioned conventional normal pressure C
In VD equipment, the raw material gases oxygen and monosilane are mixed in advance and sprayed onto the semiconductor wafer from a nozzle, so it is impossible to predict at what stage the raw material gas will undergo a thermal decomposition reaction before it reaches the semiconductor wafer. However, it is very difficult to properly control film formation on semiconductor wafers. Further, part of the mixed gas reacts inside the nozzle, and reaction products adhere to the nozzle, increasing the frequency of cleaning the nozzle and reducing the operating rate of the device. Furthermore, since the raw material gas is blown onto the semiconductor wafer at approximately room temperature, there is a drawback that the temperature of the semiconductor wafer decreases, making it difficult to control the film-forming temperature.

0004

[Means for Solving the Problems] The atmospheric pressure CVD apparatus of the present invention sprays oxygen and monosilane, which are raw material gases, onto a semiconductor wafer from separate raw material gas introduction pipes, and the oxygen and monosilane are sprayed onto the semiconductor wafer. The nozzle has its tip tilted toward one point so that only the raw materials are mixed, and the raw material gas introduction pipe that constitutes this nozzle is equipped with a raw material gas heating heater that heats the raw material gas to a predetermined temperature. It is equipped with a temperature control device that controls the heater and the heater that heats the semiconductor wafer to a predetermined temperature, and exhaust ports that are provided alternately with the nozzles and exhaust unreacted raw material gas and reaction products from the vicinity of the nozzles.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of the vicinity of a nozzle of an atmospheric pressure CVD apparatus according to a first embodiment of the present invention.

[0007] The nozzle 4 for blowing out the source gas onto the semiconductor wafer 1 has a structure in which oxygen and monosilane source gas introduction tubes 6 are separated from each other, and the oxygen and monosilane are separated before the source gas is blown out from the nozzle. reacts to form SiO
It is designed so that reaction products such as 2 are not generated. Also,
A raw material gas heating heater 7 is provided in a part of a raw material gas introduction pipe 6 for introducing raw material gas into the nozzle 4 so as to cover the outer periphery thereof. When the raw material gas reaches the semiconductor wafer 1 by the raw material gas heating heater 7, it is heated so as not to lower the temperature of the surface of the semiconductor wafer 1 and to cause a thermal decomposition reaction immediately. 7
is controlled by a temperature control device 8 together with a heater 3 that heats the semiconductor wafer 1 from the bottom. In addition, the tips of the nozzles 4 are each tilted toward a single point, so that oxygen and monosilane are mixed and reacted only on the semiconductor wafer 1, and the thermal decomposition reaction occurs on areas other than the surface of the semiconductor wafer 1. The structure is such that it does not occur. In addition, unreacted gas and S
Reaction products such as iO2 are quickly exhausted and do not adhere to the semiconductor wafer 1.

FIG. 2 is a sectional view of the vicinity of the nozzle of an atmospheric pressure CVD apparatus according to a second embodiment of the present invention.

In this embodiment, the raw material gas introduction pipe 6 itself is made of a resistance heating element. In this example, the entire source gas introduction pipe 6 can be heated, and rapid heating of the source gas can be avoided, making temperature control more stable. Furthermore, since there is no need to cover the outer periphery with a heater, it becomes easier to process the raw material gas introduction pipe 6 into any desired shape, and the overall size can be reduced, and the atmospheric pressure CVD apparatus itself can be expected to be smaller and lighter. Furthermore, during maintenance of the raw material gas introduction pipe 6, it is possible to save the man-hours of removing the heater on the outer periphery, and it is also possible to reduce the working hours of the equipment operator.

0010

Effects of the Invention As explained above, the present invention heats oxygen and monosilane to predetermined temperatures and then heats them at one point on the tip of the semiconductor wafer so that the raw material gases mix and react in a certain area of the semiconductor wafer. Because the source gas is angled in the direction and sprayed onto the semiconductor wafer from independent nozzles, the raw material gas does not undergo a decomposition reaction on its way to the semiconductor wafer surface, and only occurs on the semiconductor wafer surface. becomes possible. As a result, it is possible to suppress the adhesion of reaction products inside the nozzle, etc., and the raw material gas does not lower the surface temperature of the semiconductor wafer.
It is easier to control the film forming temperature, and reaction products such as SiO2 are quickly exhausted from the exhaust ports provided on the outside of the nozzle and between the nozzles, reducing the amount of reaction products adhering to the semiconductor wafer surface and improving yield. It has the effect of

[Brief explanation of drawings]

FIG. 1 is a sectional view of the vicinity of a nozzle according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the vicinity of a nozzle according to a second embodiment of the present invention.

FIG. 3 is a sectional view of the vicinity of a nozzle of a conventional atmospheric pressure CVD apparatus.

[Explanation of symbols]

1 Semiconductor wafer 2 Semiconductor wafer loading belt 3 Heater 4 Nozzle 5 Exhaust port 6 Raw material gas introduction pipe 7 Raw material gas heater 8 Temperature control device

Claims (1)

[Claims] Claim 1: In an atmospheric pressure CVD apparatus that is equipped with a nozzle for spraying raw material gas onto a semiconductor wafer and performs vapor phase growth through a thermal decomposition reaction, each raw material gas is provided separately, and each tip is directed toward a single point. A nozzle consisting of a raw material gas introduction pipe tilted toward the direction of the gas, a temperature control device that heats this introduction pipe with a heater and controls the raw material gas to a predetermined temperature, and a nozzle that is arranged alternately with the raw material gas introduction pipe to remove unreacted gas and reacted gas. An atmospheric pressure CVD apparatus characterized by having an exhaust port for exhausting products.