JPS5843225Y2 - The best way to know - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor phase growth apparatus, and more particularly to an improvement in an apparatus for chemically vapor growing an insulating film on a semiconductor substrate.

Conventionally, phosphosilicate glass or borosilicate glass was used as a multilayer insulating film or element surface protection film on a semiconductor substrate.
As an apparatus for vapor phase growth as a diffusion source, for example, an apparatus as shown in FIG. 1 is known.

That is, the heater plate 1 heated to 400 to 450°C
The semiconductor substrate 2 is placed on top with its surface (the surface on which the semiconductor element is formed) facing up, and set in the Pelger 3.

To this, from the upper reactive gas population 4, a reactive gas, for example, a mixed gas of SiH4, PH3,02 and N2 (carrier gas) in the case of phosphosilicate glass, SiH4, B2. A mixed gas of Hs, 02 and N2 (carrier gas) is charged.

These reaction gases react at high temperature and heat the heater plate 1.
Transparent phosphosilicate glass (P
SG) or borosilicate glass (BSG) is grown and suctioned and exhausted from the exhaust port 5.

However, in such conventional devices, a white powder (an amorphous material having almost the same composition as phosphosicate glass or borosilicate glass) produced by the reaction of the reaction gas at room temperature to relatively low temperature is deposited on the inner wall of the Pelger. Then, the white powder may fall onto the substrate due to vibration or impact, or the reaction gas may react in the gas phase and the white powder may float in the gas and be deposited on the substrate, causing phosphosilicate glass or There was a problem that the borosilicate glass did not become stable.

Therefore, the purpose of the present invention is to improve the drawbacks of the conventional vapor phase growth apparatus, and to drop and deposit the amorphous white powder, which is generated by the reaction of the reaction gas on the inside wall of the Pelger or in the gas phase, onto the semiconductor substrate. It is an object of the present invention to provide a vapor phase growth apparatus capable of chemically effectively and efficiently growing an insulating film on a semiconductor substrate in a vapor phase without causing any problems.

According to the present invention, the device comprises a Pel jar having a reactant gas exhaust port and a reactant gas inlet provided at the bottom thereof, and a heater plate for heating a semiconductor substrate provided on the outside of the Pel jar 7 above the Pel jar in the direction of gravity; A Pelger-type reaction device is provided for chemically vapor-growing an insulating film on a semiconductor substrate, the semiconductor substrate being set between a Pelger and the heater plate with its vapor growth surface facing downward. Ru.

Hereinafter, the present invention will be explained in detail with reference to FIG. 2, which shows a preferred embodiment of the present invention apparatus.

In a preferred embodiment of the vapor phase growth apparatus according to the present invention, as shown in FIG. ) is placed face down, and a heater plate 9 is placed above and outside.

By configuring the vapor phase growth apparatus in this manner, the reaction gas charged from the reaction gas population 6, for example, the reaction mixture gas for phosphosilicate glass or borosilicate glass as described above, is heated by the heater plate 9 at a temperature of usually 400 to 450°C. Phosphorsilicate glass or borosilicate glass is grown in a vapor phase on the surface of the semiconductor substrate 8, and the white amorphous powder produced as a side reaction product at room temperature or relatively low temperature is deposited on the inner wall of the Pelger. Unlike conventional devices, there is no risk of the white amorphous powder generated in the gas phase falling onto the semiconductor substrate 8 due to vibration or impact.
There is no risk of it falling or depositing on top.

Exhaust gas is exhausted from the exhaust port 10.

A heater plate with a glass cover is installed on the underside of the substrate inside the Pelger. A reactive gas supply port is provided in the gas phase space inside the Pelger between the heater plate and the substrate to apply a coating onto the lower surface of the substrate in the vapor phase. There is also a known growth device, but in the Gagaru device, the reaction gas contained in the gas phase space below the substrate inside the Pelger and the reaction gas supply port are heated together with the substrate, so the thermal decomposition reaction proceeds in the gas phase. This prevents film growth on the substrate surface.

For example, when growing a film of phosphosilicate glass or borosilicate glass on the surface of a substrate, it is usually done by supplying gases such as SiH4 and PH3 or B2H6 in a high-purity dry 02 atmosphere as described above, but SiH4 gas is generally used. does not react in high-purity dry 02 gas, so a certain amount of thermal energy must be applied.

In this case, the growth rate of the film increases as the temperature rises to a certain level, but decreases after a certain peak.

This is because when the temperature rises above a certain level, decomposition in the gas phase becomes active and a large amount of white amorphous powder is formed, reducing the absolute amount of reaction gas that should be used for film growth, and as a result, the growth rate decreases. It becomes smaller.

From the above points, in order to achieve the most efficient growth, it is ideal to use an apparatus that does not apply thermal energy to the reactant gas in the gas phase, but only applies thermal energy near the surface of the semiconductor substrate.

In this regard, in the reaction apparatus according to the present invention described above, the heater 9 is provided above the substrate 8 on the outside above the Pel jar 7, and the reactant gas is supplied from the reactant gas port 6 provided at the bottom of the Pel jar 7. Since only the substrate 8 is heated and thermal energy is given to the reactive gas near the substrate surface without heating the reactive gas in the gas phase as much as possible, almost no white amorphous powder is formed and the reactive gas is not wasted. It is used for film growth, and the film growth rate is significantly improved.

FIG. 2 also shows a mode in which the semiconductor substrate 8 is physically or mechanically fixed to the upper part of the Pelger 7 and the semiconductor substrate 8 is indirectly (non-contact) heated from above using a heater plate 9 such as an infrared heater. However, in other embodiments, for example, the heater plate 9 is provided with a through hole, and the semiconductor substrate 8 is fixed thereon by suction with its surface facing downward, that is, in the direction of the Pelger 7 (so-called vacuum chuck), by resistance heating, etc. Direct (contact) heating is also possible as in conventional devices.

As an example, using a heater plate with a diameter of 300 cm, a heater plate with a diameter of about 76 m was used at a temperature of 450°C using the apparatus shown in Figure 2.
Phosphorsilicate glass was grown in vapor phase on a semiconductor substrate of m.

The reaction gas used was 100ml/min of 5iH4,1
0ml/min PH3, 1017mln(7)02
It was confirmed that an insulating film of phosphosilicate glass was formed on the substrate at a rate of 800 A/min using a mixed gas of 101/min of N2 as a carrier gas, and the white amorphous powder produced as a by-product from this reaction gas was deposited on the substrate. It was confirmed that no deposits were deposited on the top.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an example of a conventional vapor phase growth apparatus, and FIG. 2 is a schematic explanatory diagram showing a preferred embodiment of the vapor phase growth apparatus according to the present invention. 1.9... Heater plate, 2,8...
...Semiconductor substrate, 3.7...Pelger, 4,
6...Reaction gas inlet, 5゜10...Exhaust port.

Claims (1)

[Scope of utility model registration request] In a Pelger type reactor for chemical vapor phase growth of an insulating film on a semiconductor substrate, a Pelger 7 having a reactive gas exhaust port 10 and a reactive gas population 6 provided at the bottom;
A semiconductor substrate 8 is set between the Pel jar 7 and the heater plate 9 with its vapor growth surface facing downward. A vapor phase growth apparatus characterized by comprising: