JPS59253B2 - Kisouhan no Souchi - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a gas phase reactor.

[Technical background of the invention and its problems]

An example of an apparatus for subjecting a semiconductor substrate to a vapor phase reaction such as vapor phase growth is shown in FIG.

Fig. 1a is a partial cross-sectional view, and the same figure also shows a cross-sectional view of a part of Fig.
A substrate mounting heating table 3 for placing and heating the semiconductor substrate 2 is attached to the base inside the envelope, and the inside of the envelope is divided into a reaction chamber A and a heating chamber. Divide into B.

The reaction chamber is provided with a reaction gas introduction pipe 4 for introducing a reaction gas for vapor phase growth, such as silane and oxygen together with nitrogen as a carrier gas, and an exhaust pipe 5 for discharging exhaust gas.

In addition, a high-purity quartz plate is suitable for the substrate mounting heating table, and the semiconductor substrate 2 placed thereon is heated to 400° C., for example, by a heating element 6 made of carbon attached to a heating chamber at the bottom of this plate to cause a reaction. Then, a low-temperature oxide film (not shown) is formed.

The heating chamber and the reaction chamber in the above gas phase reactor are isolated by attaching a 01J ring 8 to the quartz plate holder T, as shown in Figure 1.
A quartz plate 3 is installed on this 01J ring, and a stainless steel tightening ring 9 is placed from above the quartz plate 3 via a Teflon ring 10 for preventing damage to the quartz plate. The periphery was fastened with a plurality of bolts 11.

However, with this method, the quartz plate will be damaged if the bolts are over-tightened or if they are not tightened uniformly around the circumference.

Furthermore, if the tightening is too weak, oxygen and other reactive gases may enter the heating chamber through the O-ring 8, causing contamination or deterioration of the carbon heater 6, which is the heating source.

If the reaction is repeated several more times, S io 2 will accumulate on the quartz plate, causing the wafer to become contaminated, so the quartz plate must be washed, and the quartz plate must be removed each time.

However, there is a serious drawback in that the quartz plate must be repeatedly attached and removed, which is difficult as described above.

[Purpose of the invention]

The object of the present invention is to provide a gas phase reactor that overcomes the above-mentioned drawbacks.

[Summary of the invention]

That is, the gas phase reaction apparatus of the present invention includes an envelope, a substrate-mounted heating table that divides the inside of the envelope into a reaction chamber and a heating chamber, and a The envelope includes a plurality of isolation rings on the inner wall of the envelope or an extension thereof, a isolation chamber formed by a part of the surface of the substrate mounting heating table, and an exhaust device connected to the isolation chamber. It is characterized by this.

[Embodiments of the invention]

The gas phase reaction apparatus of the present invention uses a substrate mounting heating table, that is, a quartz plate is fastened without using bolts, but a quartz plate holder is provided with a plurality of blocking rings, such as O rings, and the quartz plate is placed on the quartz plate holder.

Furthermore, by reducing the pressure in the isolation chamber surrounded by the isolation ring, quartz plate, and quartz plate holder, the quartz plate can be brought into close contact with the isolation ring and the reaction chamber and heating chamber can be completely isolated, making it possible to install and remove the quartz plate. Reduce frequency.

Therefore, there is no damage to the quartz plate, and workability is greatly improved without any tightening work.

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

As shown in FIG. 2, an outer O-ring 22a is attached to the quartz plate holder 21 along the outer edge of the quartz plate 3 on which the semiconductor substrate 2 is placed.
A groove 23 is made so that the inner O-ring 22b and the inner O-ring 22b can be installed with a distance of about 10 mm, and the two O-rings are installed.

A suitable OIJ song hardness is a soft one with a rubber hardness of about 20 to 30.

At least one hole 24 is made along the circumferential direction on the surface of the quartz plate holder narrowed by the two OIJ songs and connected to an external vacuum device, and a cutoff chamber C' surrounded by the O-rings is formed. is evacuated using a vacuum device (not shown).

FIG. 3 shows another embodiment. That is, instead of the evacuation hole 24 shown in FIG. 2, a slit 25 having a width of about 0.5 mm is provided around the circumference, and a reservoir 26 is provided below the slit 25 in order to equalize the evacuation.

In this way, the connection between the external vacuum device and the quartz plate holder can be made by one or several pieces, which is simpler than the method shown in FIG. 2.

When removing the quartz plate, install a valve in a part of the piping between the external vacuum device and the quartz plate holder, and introduce air or nitrogen into the cutoff chamber to bring it to atmospheric pressure.The quartz plate can be easily removed. .

〔Effect of the invention〕

As described above, according to the present invention, the quartz plate is in close contact with the OIJ song, and there is no leakage from the reaction chamber side to the heating chamber.

For example, if you use a 500φ quartz plate and set the outer 0 ring along the outer edge and the inner 01 ring 10 mm inside of it, the quartz plate will be approximately 60K if the isolation chamber is evacuated to 500 Torr.
The force of g will hold down the surrounding area, and the rubber hardness is 20 to 30.
If it is a 0 ring of about 100 degrees, you can get enough crushing margin.

Even if leakage occurs from the reaction chamber side through the outer edge, it will not leak into the heating chamber side as it will be evacuated in the cutoff chamber.

Furthermore, according to this method, there is no need for a Teflon ring attached to the quartz plate, there is no need for tightening errors, and differences in thermal expansion can be avoided, so there is a remarkable effect that damage to the quartz plate is eliminated.

[Brief explanation of drawings]

FIG. 1a is a partial cross-sectional view showing an embodiment of a semiconductor vapor phase reaction device; FIG. FIG. 3 is an enlarged partial sectional view showing another embodiment of the present invention. Note that the same reference numerals in the drawings indicate the same or corresponding parts, respectively. A...Reaction chamber, B...Heating chamber, C...
...Break chamber, 1...Envelope, 3...
- Substrate mounting heating table, 22a. 22b......Shutoff ring.

Claims (1)

[Claims] 1. An envelope, a substrate mounting heating table that divides the inside of the envelope into a reaction chamber and a heating chamber, and an inner wall of the envelope or an extension thereof to isolate between the reaction chamber and the heating chamber. A gas phase reaction device comprising: a cutoff chamber formed by a plurality of cutoff rings and a part of the surface of the substrate-mounted heating table; and an exhaust device connected to the cutoff chamber. .