JP2001291670A - Semiconductor manufacturing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the evenness of a film thickness over a plurality of substrates in a semiconductor manufacturing device, in which a plurality of substrates are stacked and held vertically and are processed. SOLUTION: In the semiconductor manufacturing device, a plurality of wafers 4 and dummy wafers 5 disposed above and below the wafers 4 are stacked and held in the downward direction in a boat 3 disposed in a reaction tube 1, and a plurality of heat insulating plates 6 are stacked and held in the downward direction below the wafers. In such a semiconductor manufacturing apparatus, the dummy wafers 5 and the heat insulating plates 6 are disposed successively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor manufacturing apparatus provided with a heater for heating a substrate outside a reaction tube.

[0002]

2. Description of the Related Art A conventional semiconductor manufacturing apparatus includes a reaction tube for processing a substrate, a heater for heating a substrate provided outside the reaction tube and surrounding the reaction tube, and a processing tube disposed inside the reaction tube for processing. It is provided with a boat or the like that holds a number of substrates to be stacked in the vertical direction and holds them.

FIG. 3 is a sectional view of a boat in a conventional semiconductor manufacturing apparatus. For the overall configuration of the semiconductor manufacturing apparatus, see FIG. 2 (described later).

Reference numeral 4 denotes a product substrate, for example, a semiconductor wafer, 5 denotes a dummy wafer, 6 denotes a heat insulating plate, 3 denotes a boat for vertically stacking and holding the wafer 4, dummy wafer 5, and heat insulating plate 6, 11 denotes a wafer area, 12 is a dummy wafer area,
13 is a product wafer region, 14 is a heat insulating plate region, 10 is a space between the wafer region 11 and the heat insulating plate region 14 (dummy wafer 5).
And the heat insulating plate 6).

[0005] The boat 3 vertically holds a large number of wafers including a predetermined number of dummy wafers 5 arranged above and below a plurality of wafers 4 as products, and holds a plurality of heat insulating plates 6 below the wafers. They are stacked vertically and held. For example, 150 product wafers 4, five dummy wafers 5 above the product wafer 4, ten dummy wafers 5 below the product wafer 4, and six heat insulating plates 6 are held.
The heat insulating plate 6 is used for obtaining a heat insulating effect in the furnace port below the reaction tube and for adjusting the temperature of the furnace port.

[0006]

In the conventional semiconductor manufacturing apparatus as described above, a space 10 having a length of, for example, about 40 mm is provided between the wafer region 11 and the heat insulating plate region 14.
was there. This space 10 exists below the dummy wafer 5 arranged at the bottom of the wafer region 11 for the convenience of the apparatus that the wafer transfer machine cannot move.

In a conventional semiconductor manufacturing apparatus, this space 10
, Gas phase reaction is likely to occur in this space 10 part, and the reaction gas flow changes abruptly in this space 10 part, and unstable gas flow occurs. There is a problem that the film thickness uniformity of the wafer 4 in the region below the wafer region 13 is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor manufacturing apparatus for stacking and holding a plurality of substrates in a vertical direction and processing the same so that the film thickness uniformity over the entire plurality of substrates can be improved. .

[0009]

In order to solve the above-mentioned problems, a semiconductor manufacturing apparatus of the present invention holds a plurality of substrates (including a dummy substrate) stacked vertically,
In a semiconductor manufacturing apparatus in which a plurality of heat insulating plates are vertically stacked and held, the substrate and the heat insulating plates are continuously arranged.

[0010] The continuous arrangement of the substrate and the heat insulating plate means eliminating a space between the substrate and the heat insulating plate, which generates an unnecessary gas phase reaction or an unstable gas flow.

For example, the interval between the lowermost substrate and the uppermost heat insulating plate is made substantially equal to the pitch of the substrates.

Further, for example, the pitch of the heat insulating plate in a portion adjacent to the substrate is made substantially the same as the pitch of the substrate.

Further, for example, the pitch of the heat insulating plate is made different depending on the portion.

According to the present invention, in a semiconductor manufacturing apparatus in which a plurality of substrates are vertically stacked and held and processed, a substrate and a heat insulating plate below the substrate are continuously arranged to prevent unnecessary gas phase reactions and unstable operations. Eliminating the space for generating a flow of the gas can improve the uniformity of the film thickness over the plurality of substrates.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, those having the same functions are denoted by the same reference numerals, and the repeated description thereof will be omitted.

FIG. 2 is a sectional view showing the overall configuration of the semiconductor manufacturing apparatus according to the embodiment of the present invention.

1 is a reaction tube for processing a wafer, 1a is an outer reaction tube, 1b is an inner reaction tube, 16 is a furnace port below the reaction tube 1, and 2 is an outside of the reaction tube 1 surrounding the reaction tube 1. The provided heater for heating the wafer, 15 is a heat insulating layer of the heater, 4 is a large number of semiconductor wafers to be processed as products, 5 is a dummy wafer placed in an area where reaction conditions are unstable, and 6 is a furnace port of the reaction tube 1. A heat insulating plate for obtaining the heat insulating effect in the section 16 and adjusting the temperature of the furnace port 16 is disposed inside the reaction tube 1, and the wafer 4, the dummy wafer 5, and the heat insulating plate 6 are vertically stacked and held. Boat 7 is provided on boat 3,
Holding projections for holding the wafer 4, the dummy wafer 5, and the heat insulating plate 6, 11 are a wafer region, 12 is a dummy wafer region, 13 is a product wafer region, 14 is a heat insulating plate region, 8 is a reactive gas introducing unit, and 9 is an exhaust unit. It is.

FIG. 1 is an enlarged detailed sectional view of the boat 3 in the semiconductor manufacturing apparatus of FIG. In addition, the dimension of the space | interval of the wafer 4, the dummy wafer 5, and the heat insulation board 6 in FIG.
Unlike actual dimensions, they are exaggerated.

S represents the lowermost dummy wafer 5 and the uppermost section.
Spacing with hot plate 6, P₁Is the first pitch, P₂Is the second pick
Switch, P₁<P₂It is. P1 is the first pitch
Chi-P ₁, P2 has a pitch of the second pitch P₂so
An area.

In the semiconductor manufacturing apparatus of this embodiment, a plurality of wafers 4 and dummy wafers 5 are vertically stacked and held, and a plurality of heat insulating plates 6 are vertically stacked and held below the wafers 4 and dummy wafers 5. The wafer 4 and the dummy wafer 5 in the region 11 and the heat insulating plate 6 are continuously arranged. That is, the dummy wafer 5 or the heat insulating plate 6 is arranged at the space 10 in the conventional apparatus shown in FIG.
As described above, since the wafer transfer device cannot move to the space 10, the dummy wafer 5
Alternatively, the heat insulating plate 6 is manually charged. Alternatively, the wafer transfer device or the like may be improved so that the wafer transfer device can access this portion so that it can be loaded by the wafer transfer device. For example, in the present embodiment, six heat insulating plates 6 are arranged in the same manner as in the related art, and five dummy wafers 5 are arranged in the conventional space 10 (FIG. 3). 6 may be arranged). Also,
Above that, ten dummy wafers 5 are arranged in the same manner as in the prior art, 150 product wafers 4 are arranged above, and five dummy wafers 5 are arranged above.

[0021] In this embodiment, the spacing S between the dummy wafer 5 at the bottom with heat insulating plate 6 at the top, the wafer 4, are made substantially the same as the pitch P ₁ of the dummy wafer 5. The pitch of the upper heat insulating plate 6 adjacent to the dummy wafer 5 is substantially the same as the pitch of the wafer 4 and the dummy wafer 5 (pitch P ₁ ). In addition, the pitch of the heat insulating plate 6 differs depending on the portion, and the upper heat insulating plate 6 adjacent to the dummy wafer 5.
Is P ₁ , the lower pitch is P ₂ , and P ₁ <P ₂ . For example _{P 1} is 5.2 mm, _{P 2} is 12 mm. In FIG. 2, the pitches of the heat insulating plates 6 are all substantially the same, but the details are as shown in FIG.

In the present embodiment, the dummy wafer 5 and the heat insulating plate 6 are continuously arranged, and a space (a conventional space 10 in FIG. 3) for generating an unnecessary gas phase reaction and an unstable gas flow is formed. By eliminating unnecessary gas phase reactions,
Further, since the gas flow can be stabilized, the film thickness uniformity of the wafer 4 in the region below the product wafer 4 can be improved, and the film thickness uniformity over a plurality of substrates can be improved.

The shape, diameter and thickness of the heat insulating plate 6 are substantially the same as those of the wafer 4 and the dummy wafer 5. For example, when the diameter is 8 inches (200 mm), the thickness is about 2 mm. In addition, 12 inches in diameter (3
00 mm), the thickness is about 2 mm to 4 mm.
The material of the heat insulating plate 6 is, for example, quartz or SiC.

Using the semiconductor manufacturing apparatus of the present embodiment as shown in FIGS. 1 and 2, a surface of a wafer 4 made of silicon having a diameter of 8 inches and a thickness of about 2 mm is heated to a temperature of 620.
° C, pressure 15Pa, used reaction gas SiH ₄ , gas flow rate 2
When a polycrystalline silicon film having a film thickness of 2500 ° was formed under the condition of 00 sccm, the film thickness uniformity of the wafer 4 in the region below the product wafer region 13 could be improved by ± 0.5%.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various changes can be made without departing from the gist of the present invention. It is.

[0026]

As described above, according to the present invention,
In a semiconductor manufacturing apparatus that stacks, holds, and processes a plurality of substrates in a vertical direction, it is possible to improve the film thickness uniformity over the plurality of substrates.

[Brief description of the drawings]

FIG. 1 is a sectional view of a boat in a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an overall configuration of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view of a boat in a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction tube, 1a ... Outer reaction tube, 1b ... Inner reaction tube, 2
... Heater, 3 ... Boat, 4 ... Wafer, 5 ... Dummy wafer, 6 ... Heat insulation plate, 7 ... Retention gas introduction means, 9 ... Exhaust means, 11 ... Wafer area, 12 ... Dummy wafer area, 13 ... Product Wafer area, 14 ... heat insulating plate area,
15: Heat insulation layer of heater, 16: Furnace opening.

Claims (1)

[Claims] 1. A plurality of substrates are vertically stacked and held,
In a semiconductor manufacturing apparatus which holds a plurality of heat insulating plates vertically stacked below the semiconductor manufacturing apparatus, the substrate and the heat insulating plates are continuously arranged.