JP4027372B2 - Vertical wafer holder - Google Patents

Description

The present invention relates to a vertical wafer holder for holding a wafer in a semiconductor manufacturing process.

When a wafer is processed in a conductor manufacturing process, particularly in a vertical furnace, the wafer is supported in multiple stages in a horizontal posture by a vertical wafer holder.

A conventional vertical wafer holder will be described with reference to FIG. 5 in relation to a vertical furnace.

In the figure, 1 is a cylindrical heater whose upper end is closed, 2 is an external reaction tube provided concentrically with the heater 1 and its upper end is closed, and 3 is provided concentrically within the external reaction tube 2 and has an upper portion. A cylindrical space 8 having a closed lower end is formed between the outer reaction tube 2 and the inner reaction tube 3. An exhaust pipe 9 communicates with the lower end of the space 8, and a reaction gas introduction pipe 10 communicates with the lower end of the internal reaction pipe 3.

A vertical wafer holder is inserted into the internal reaction tube 3, and the vertical wafer holder is mainly composed of a boat 4 and a boat cap 6.

The boat 4 is erected via a boat cap 6 on a lift flange 5 of a boat elevator (not shown). The elevating flange 5 is provided with a furnace port lid 7, and the furnace port lid 7 hermetically closes the lower end of the external reaction tube 2.

The boat 4 has a plurality of support pillars 11, and holds wafers 12 in grooves formed in the support pillars 11. The boat cap 6 forms a cylindrical space, and a columnar heat insulating plate holder 13 is provided inside the boat cap 6, and a required number of heat insulating plates 14 are held horizontally by the heat insulating plate holder 13. . The boat cap 6 communicates with the inside of the internal reaction tube 3 through a hole provided in the lower part. The boat cap 6 insulates the furnace opening.

A boat 4 in which wafers 12 are loaded in a furnace heated to a predetermined temperature by the heater 1.
Is charged into the furnace, the inside of the furnace is evacuated, the reaction gas is introduced from the reaction gas introduction pipe 10, a CVD (Chemical Vapor Deposition) process is performed on the wafer surface, and the exhaust gas is exhausted from the exhaust pipe 9. Is done.

When the treatment was completed, the introduction of the reaction gas was stopped, the inert gas was introduced and the gas was purged, and then the boat 4 was pulled out.

As described above, the inside and outside of the boat cap 6 communicate with each other through the lower hole so that the boat cap 6 is not damaged due to the difference between the inside and outside pressures when evacuated. Accordingly, the inside of the boat cap 6 is filled with the reaction gas during wafer processing, and is purged with an inert gas after wafer processing. Although this gas purge is performed through the lower hole, it is inevitable that the gas flow is poor, and sufficient gas purge is not performed. For this reason, when the boat 4 is pulled out after purging the inside of the reaction tube, the atmosphere flows into the boat cap 6, and the reaction gas staying in the boat cap 6 reacts with the atmosphere to produce a reaction product. The product remains in the boat cap 6 as a particle source. Thus, when wafers are processed over several batches, there is a problem that particles remaining in the boat cap 6 diffuse into the reaction chamber and adhere to the wafer being processed.

In view of such circumstances, the present invention suppresses the generation of particles in the boat cap and prevents wafer contamination by the particles.

The present invention is characterized in that a vertical wafer holder that holds a wafer and is loaded into a vertical furnace has an open structure throughout, and a heat insulating plate is loaded in a lower required range.

According to the present invention, since the entire vertical wafer holder has an open structure, the gas purge after the wafer processing is completely performed, and there is no residual reaction gas that causes particles.

Further, according to the present invention, since the heat insulating plate that is located below the substrate to be processed and that blocks the heat is held open, the reaction gas does not stay even during the gas purge, so It is possible to suppress the generation of particles due to this, and since it is supported openly, the structure becomes simple, the number of parts is reduced, and the production cost of the apparatus can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a vertical furnace provided with a vertical wafer holder according to the present invention. In the vertical furnace, the same components as those shown in FIG.

A vertical wafer holder 20 according to the present embodiment will be described with reference to FIGS.

The vertical wafer holder 20 is an integrated structure of the boat 4 and the boat cap 6 shown in the conventional example, and includes four shelf columns 16 along the periphery of the donut-shaped boat lower flange 15.
However, it is erected on a substantially semicircle so that the wafer can enter and exit. On the side facing the center of the shelf column 16, grooves 17 into which the periphery of the wafer is inserted are engraved over the substantially entire length of the shelf column 16 at a required pitch. A boat upper flange 18 is fixed to the upper end of the shelf column 16, and the shelf column 1
Support the upper end of 6.

The height of the vertical wafer holder 20 configured as described above is the same as the combined height of the boat cap 6 and the boat 4 when the boat 4 is erected on the conventional boat cap 6.

A heat insulating plate 14 is loaded in a lower portion of the vertical wafer holder 20, that is, a portion corresponding to the conventional boat cap 6. Heat insulation is performed by the required number of heat insulating plates 14. Further, a wafer 12 is loaded in a portion corresponding to the conventional boat 4 in the vertical wafer holder 20. Insulation plate 14
With the wafer 12 loaded, the vertical wafer holder 20 is loaded into the internal reaction tube 3 to process the wafer.

Thus, the portion where the heat insulating plate 14 is loaded is completely open, so that the reaction gas does not stay when the gas purge is performed after the treatment.

Next, FIG. 4 shows another embodiment, in which the vertical wafer holder is composed of a boat and a boat mounting table, the boat is the same as the conventional one, and the boat cap has an open structure. 21 is substituted.

The base support 23 is erected on the base flange 22 as required, and the base support 23 is provided with heat insulating plate holding grooves 24 at a required pitch. A boat seat 25 is fixed to the upper end of the pedestal 23, and the boat 4 is placed on the boat seat 25. If the base column 23 has sufficient strength, the column 11
The cross-sectional area may be increased to increase the strength, or the number may be changed as appropriate.

The base support 23 is loaded with a required number of heat insulating plates 14. Heat insulation is performed by the boat mounting table 21 loaded with the heat insulating plate 14.

Since the boat mounting table 21 also has no member surrounding the heat insulating plate 14 and has a completely open structure, the reaction gas does not stay when the gas purge is performed after the wafer processing, and therefore, the atmosphere when the boat is pulled out. Generation of particles caused by contact with the reaction gas is prevented.

In another embodiment shown in FIG. 4, the boat 4 and the boat mounting table 21 can be handled separately,
Further, since the shape is reduced, maintenance work is facilitated.

It is sectional drawing of the vertical furnace which comprises the vertical wafer holder which concerns on this invention. It is an elevation sectional view showing one example of the present invention. It is an AA arrow line view of FIG. It is sectional drawing of the vertical furnace which comprises the other vertical wafer holder which concerns on this invention. It is sectional drawing of the vertical furnace which comprises the conventional vertical wafer holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heater 2 External reaction tube 3 Internal reaction tube 4 Boat 12 Wafer 14 Heat insulation board 20 Vertical wafer holder 21 Boat mounting base

Claims (2)

In a semiconductor manufacturing apparatus in which a wafer is held in a vertical furnace by a boat and the inside of the vertical furnace is heated and processed by a heater, the boat and a heat insulating plate holding part for holding a predetermined number of heat insulating plates below the boat, Has a monolithic structure, and the predetermined number of heat insulating plates can be loaded into grooves provided in a plurality of support columns of the heat insulating plate holding portion so that the peripheral edge portion thereof is held. Manufacturing equipment. Heat insulating plate holder below the baud preparative and the boat has become an integral structure, and the insulating plate in a groove provided in a plurality of supports of the heat insulating board holding section, so that its peripheral edge is held A predetermined number of the heat insulating plates are loaded in a groove that holds the peripheral edge of the heat insulating plate, the wafer is loaded into the boat, the boat is loaded into a vertical furnace, and the inside of the vertical furnace is heated. A method for manufacturing a semiconductor, comprising: heating a wafer by a reaction gas and processing a wafer by introducing a reaction gas; then stopping the introduction of the reaction gas and drawing the boat out of the vertical furnace.

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