JPS6227725B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] A vertical heating furnace is used, and a substrate holding jig with a substrate to be processed horizontally mounted inside the furnace core tube of the heating furnace is held without touching the inner wall of the furnace core tube. A device that performs high-temperature reaction processing of the substrate to be processed by inserting the substrate holding jig into the center of the furnace core tube and fixing it almost vertically without touching the inner wall of the furnace core tube. Since the inner wall of the tube is not rubbed, generation of friction powder on the furnace core tube and jig material is prevented, and a decrease in yield in high temperature reaction treatment due to burning of the friction powder is prevented.

[Industrial application field]

The present invention relates to a high-temperature reaction processing apparatus, and more particularly to a high-temperature reaction processing apparatus for semiconductor substrates used in the manufacturing process of semiconductor devices.

In the manufacturing process of semiconductor devices, various high-temperature reaction treatments such as oxidation, diffusion, and vapor phase growth are performed.

[Conventional technology]

Conventionally, a horizontal heating device is used for these high-temperature reaction treatments. A substrate holding jig made of transparent quartz, etc., on which multiple semiconductor substrates to be processed are mounted,
A commonly used method is to place it on a boat loader made of transparent quartz or the like, insert it, and heat it.

[Problem that the invention seeks to solve]

However, in the above conventional method, the boat loader slides on the inner surface of the furnace core tube when inserting the substrate to be processed into the furnace core tube and when removing the substrate to be processed from the furnace core tube. As semiconductor substrates become larger in diameter and moreover a large number of substrates are processed at the same time to increase mass production, for example, when processing 100 semiconductor substrates with a diameter of 100 mm at the same time, the load on the boat loader becomes approximately 1 kg. Therefore, the friction between the boat loader and the inner surface of the furnace core tube becomes extremely large, and a large amount of quartz (SiO ₂ ) powder is generated when the boat loader slides.

Then, during high-temperature processing, the quartz powder is blown up by the reaction gas flowing into the furnace core tube, adheres to the semiconductor substrate to be processed, and burns, reducing the yield of high-temperature reaction processing, that is, the manufacturing yield of semiconductor devices. It was hot.

Therefore, the furnace core tube must be frequently cleaned with hydrofluoric acid (HF), etc. to reduce the yield loss, which requires a large amount of cleaning man-hours, shortens the life of the furnace core tube, and Problems also occurred, such as the operating rate of the heating device, including the start-up time after pipe cleaning, was significantly reduced.

[Means for solving problems]

The above-mentioned problem is caused by a vertical heating furnace 16 having a furnace core tube 17 with a gas introduction tube 19 connected to the lower end via a tapered portion 20 and an open upper portion, and the inner wall of the furnace core tube 17 not touching the inner wall of the furnace core tube 17. has an outer diameter that can hang down into the furnace core tube 17 and supports the substrate to be processed almost horizontally;
The substrate holding jig 10 has a centering tube 9 at its lower end and an exhaust port 5, and is fixed to the upper end of the substrate holding jig 10 and placed over the opening of the furnace core tube 17. In this state, the substrate holding jig 10 is attached to the furnace core tube 17.
The furnace core tube lid 6 is supported almost vertically at the center of the furnace core tube, and the substrate holding jig 10 is suspended almost vertically onto the tube axis of the furnace core tube 17 via the furnace core tube lid 6, and the substrate is Substrate holding jig vertical mechanism 1 for moving the holding jig 10 in and out of the furnace core tube 17 along the central axis of the furnace core tube 17
5, the substrate holding jig 10 is placed in the furnace core tube 17 by the substrate holding jig vertical mechanism 15, and the furnace core tube lid 6 is brought into contact with the open end of the furnace core tube 17. The substrate holding jig 10 is inserted into the furnace core tube 17 until the centering tube 9 contacts the tapered portion 20 of the furnace core tube 17, and the furnace core tube lid 6 is placed over the opening of the furnace core tube 17.
This problem is solved by the high-temperature reaction processing apparatus according to the present invention, which performs high-temperature reaction processing on a substrate to be processed while supporting the furnace core tube 17 substantially vertically at the center thereof.

[Effect]

That is, in the high temperature reaction processing apparatus of the present invention, a substrate holding jig having an outer diameter smaller than the inner diameter of the furnace core tube is suspended perpendicularly onto the tube axis of the furnace core tube by the substrate holding jig vertical mechanism. There is. Therefore, the substrate holding jig can be taken in and out of the furnace core tube without touching the inner wall of the furnace core tube, and generation of friction powder between the furnace core tube and the substrate holding jig at this time is avoided.

In addition, the substrate holding jig inserted into the furnace core tube is fixed to the centering tube, which is arranged at the lower end of the substrate holding jig and touches the tapered part of the lower end of the furnace core tube, and to the upper end of the substrate holding jig. Since the substrate holding jig is supported in the center of the furnace core tube without touching the tube wall by the furnace core tube cover having the exhaust port, when the substrate holding jig is placed in the furnace core tube, There is no significant friction between the substrate holding jig and the furnace core tube when it is lifted from a stationary position or during high-temperature reactions; Powder generation is prevented.

As a result, there is almost no sticking of friction powder of the furnace core tube material and jig material to the substrate to be processed during the high temperature reaction treatment, and the yield of the high temperature reaction treatment is improved.

〔Example〕

Embodiments will be specifically described below with reference to drawing examples.

1A and 1B are schematic side sectional views of an embodiment of the present invention according to each step, FIG. FIG. 4 is a perspective view of the substrate holding jig used in the same embodiment, and FIG. 4 is a side view of the substrate holding jig when the substrate holder is mounted in the same embodiment.

Identical objects are indicated by the same reference numerals throughout the figures.

As shown in FIGS. 1a and 1b, for example, the high-temperature reaction treatment apparatus of the present invention has a furnace core tube 17 made of transparent quartz, which has a gas introduction tube 19 connected to its lower end via a tapered portion 20, and whose upper portion is open. A vertical heating furnace 16 is vertically held, and has an outer diameter that allows it to hang down into the furnace core tube 17 without touching the inner wall of the furnace core tube 17. A substrate holding jig 10 made of transparent quartz, which is held substantially horizontally on the tube axis of the furnace core tube 17, and is equipped with a centering tube 9 made of quartz that also serves as a gas passage at the center of the lower end, and an exhaust port 5. is welded and fixed to the upper part of the substrate holding jig 10, and supports the substrate holding jig 10 perpendicularly to the center of the furnace core tube 17 while covering the open end of the furnace core tube 17. A furnace core tube lid 6 made of transparent quartz and the substrate holding jig 10 are suspended vertically onto the tube axis of the furnace core tube 17 via a hanger 4 provided on the furnace core tube lid 6. It has a function of moving the substrate holding jig 10 in and out of the furnace core tube 17 without touching the inner wall of the furnace core tube 17.
For example, the tip is fixed to the above-mentioned hanger 4 and the pulley 23
It is constructed by having a substrate holding jig up and down mechanism such as a stainless steel wire 15 whose tip is moved up and down via a substrate holding jig.

First, as shown in FIG.
The tube is suspended vertically via a pulley 23 directly above the opening (on the axis of the tube).

During high-temperature reaction treatment, as shown in Figure b,
A desired reaction gas 18 flows into the furnace core tube 17 from the lower gas introduction tube 19 and is heated to a predetermined temperature.
The substrate holding jig 10 is
gradually lower the furnace core tube lid 6 of the substrate holding jig 10.
cover the opening of the furnace core tube 17. At this time, the centering tube 9 disposed at the lower end of the substrate holding jig 10 is guided by the tapered part 20 at the bottom of the furnace core tube 17, and the substrate holding jig 10 is approximately perpendicular to the center of the furnace core tube 17. is maintained.

In the high-temperature reaction process, the opening of the furnace core tube 17 is covered by the furnace core tube lid 6, the inside of the furnace core tube 17 is maintained in a uniform atmosphere of the reaction gas 18, and the substrate holding jig 10 is kept stationary. It is done in a restrained state.

The reaction gas 18 that has passed through the reaction area is transferred to the furnace core tube lid 6.
The gas is discharged through the exhaust port 5 into, for example, the clean bench 21 containing the high-temperature reaction apparatus, and is exhausted outside through an exhaust duct.

After the substrate to be processed is subjected to the high temperature reaction treatment for the desired time in the above state, the substrate holding jig vertical mechanism, that is, the stainless steel wire 15 is gradually pulled up via the pulley 23, and the substrate is held again as shown in FIG. The jig 10 is pulled up to the top of the furnace core tube 17 to complete the high temperature reaction treatment.

Note that it is possible to take in and out the substrate holding jig 10 without touching the inner wall of the furnace core tube 17 with the substrate holding jig 10; Even if it touches the substrate holding jig 10, the entire load of the substrate holding jig 10 is supported by the substrate holding jig up/down mechanism, that is, the stainless steel wire 15, so the substrate holding jig 10 strongly rubs against the inner wall of the furnace core tube 17. There is no occurrence of quartz powder.

2a and 2b show a substrate holder 1 made of general transparent quartz used in the high-temperature reaction processing apparatus shown in the above embodiment, and a semiconductor substrate 3 to be processed is inserted into the substrate insertion groove 2 and mounted.

Further, the substrate holding jig 10 used in the same embodiment is the third one.
As shown in the figure, the hanger 4 is welded and the exhaust port 5 is
is provided with a furnace core tube cover 6 made of a transparent quartz plate on the upper part (in the figure, it is shown in a horizontally lying state), and is made of transparent quartz welded vertically to the furnace core tube cover 6. The other ends of the three pillars 7 have annular frames 8a and 8b made of transparent quartz, and a core made of transparent quartz is welded and fixed to the annular frame 8b at the lower center of the annular frame 8b via a quartz rod. It has a structure in which an outlet pipe 9 is provided.

Note that 11 in the figure indicates a pocket portion on which the substrate holder 11 is mounted.

FIG. 4 shows a state in which a substrate to be processed is mounted on the substrate holding jig 10.

That is, the substrate holder 11 on which a plurality of the semiconductor substrates 3 to be processed are mounted is placed on the pocket portion 11 formed surrounded by the three pillars 7, and the furnace core tube cover of the substrate holding jig 10 is placed. The substrate holding jig 10 is inserted through the substrate holding rod insertion hole 12 formed in the substrate holding jig 6.
A substrate presser rod 14 made of transparent quartz is inserted into the substrate presser rod insertion groove 13 formed in the annular frame 8, and the substrate holding jig 10 is vertically attached to the substrate holding jig vertical mechanism via the hanger 4. This prevents the semiconductor substrate 3 to be processed from falling when it hangs down.

As shown in the above embodiment, in the high-temperature reaction processing apparatus of the present invention, a gas introduction pipe 19 is connected to the lower end via the tapered part 20, and the furnace core tube 17 of the vertical heating furnace 16 is open at the upper end. , the furnace core tube 17
A substrate holding jig vertical mechanism 15 provided on the tube axis of the furnace core tube in the upper part of the opening allows a substrate having an outer diameter smaller than the inner diameter of the furnace core tube 17 suspended perpendicularly to the vertical mechanism 15. A holding jig 10 (on which the substrate to be processed is mounted horizontally) is inserted downwardly along the central axis of the furnace core tube 17, and the substrate holding jig 10 is inserted downwardly along the central axis of the furnace core tube 17.
A core tube lid 6 having a centering tube 9 in contact with the tapered part 20 at the lower end of the core tube and an exhaust port 5 fixed to the upper end of the substrate holding jig 10. As a result, high-temperature reaction processing is performed on substrates to be processed that are supported in the center of the furnace core tube 17 and mounted on the tower.

Therefore, it is possible to take the substrate holding jig 10 in and out of the furnace core tube 17 and to support it within the furnace core tube 17 without touching the inner wall of the furnace core tube 17. Even if the substrate holding jig slightly tilts and touches the inner wall of the furnace core tube 17 when taking it in and out of the furnace, the entire load of the substrate holding jig 10 is supported by the substrate holding jig up/down mechanism 15. Since the inner wall of the furnace core tube 17 is not strongly rubbed by the substrate holding jig 10, the inner wall of the furnace core tube 17 and the substrate holding jig 10 are rarely scraped and fine powder is hardly generated. Therefore, a decrease in the yield of high-temperature reaction treatment due to burning of the fine powder is prevented.

In the above embodiment, the high-temperature reaction apparatus according to the present invention was constructed using a furnace core tube and jig made of transparent quartz, but the present invention uses a furnace core tube and jig made of high-purity carbon, silicon carbide, etc. Of course, it can also be effectively applied when configuring.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to prevent the generation of fine powder from the material of the furnace core tube and the jig due to friction between the furnace core tube and the substrate holding jig in a high-temperature reaction processing apparatus. Contamination of the substrate to be processed due to adhesion is prevented, and the yield of high-temperature reaction processing is improved.

Additionally, due to the above effects, the frequency of cleaning the furnace core tube to remove fine powder can be significantly reduced compared to conventional methods.
Effects such as a reduction in cleaning man-hours, a longer life of the furnace core tube, and an improvement in the operating rate of the heating furnace are produced.

[Brief explanation of the drawing]

1A and 1B are schematic side sectional views of an embodiment of the present invention according to each step, FIG. FIG. 4 is a perspective view of the substrate holding jig used in the same embodiment, and FIG. 4 is a side view of the substrate holding jig when the substrate holder is mounted in the same embodiment. In the figure, 1 is a substrate holder, 2 is a substrate insertion groove, 3 is a semiconductor substrate to be processed, 4 is a hanger, 5 is an exhaust port, 6 is a furnace core tube, 7 is a column, 8a and 8b are annular frames, and 9 is a Centering tube, 10 is a substrate holding jig, 11 is a pocket portion, 12 is a substrate presser rod insertion hole, 13 is a substrate presser rod insertion groove, 14 is a substrate presser rod, 15
1 is a stainless steel wire, 16 is a vertical heating furnace, 17 is a furnace core tube, 18 is a reaction gas, 19 is a gas introduction tube, 2
0 is a tapered part, 21 is a clean bench, 22
indicates an exhaust duct, and 23 indicates a pulley.

Claims (1)

[Scope of Claims] 1. A vertical heating furnace 16 having a furnace core tube 17 with an open top and a gas introduction tube 19 connected to the lower end via a tapered portion 20; a substrate holding jig 10 that has an outer diameter that allows it to hang down into the furnace core tube 17 without touching it, supports the substrate to be processed almost horizontally, and is equipped with a centering tube 9 at its lower end; and an exhaust port 5 is fixed to the upper end of the substrate holding jig 10, and the substrate holding jig 10 is held approximately perpendicular to the center of the furnace core tube 17 while being placed over the opening of the furnace core tube 17. The furnace core tube lid 6 to be supported and the substrate holding jig 10 are suspended almost perpendicularly onto the tube axis of the furnace core tube 17 via the furnace core tube lid 6, and the substrate holding jig 10 is attached to the furnace core tube lid 6. It has a substrate holding jig vertical mechanism 15 that moves the substrate holding jig in and out of the furnace core tube 17 along the central axis of the core tube 17, and the substrate holding jig 10 is moved in and out of the furnace core tube 17 by the substrate holding jig vertical mechanism 15. Inside the furnace core tube 17, the furnace core tube lid 6 is installed.
is inserted to a position where it touches the open end of the furnace core tube 17, and the centering tube 9 contacts the tapered part 20 of the furnace core tube 17, and the furnace core tube lid 6 is placed over the opening of the furnace core tube 17. A high-temperature reaction processing apparatus characterized in that high-temperature reaction processing of a substrate to be processed is performed with the substrate holding jig 10 supported substantially perpendicularly to the center of the furnace core tube 17.