JPH06302519A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To provide semiconductor manufacturing equipment capable of supplying a gas to a wafer surface uniformly. CONSTITUTION:The title semiconductor manufacturing equipment is characterized by having a guide board 19, with a hole in the center, on the side walls of the reaction chamber 1 at the same height as a board supporting table 4, and a susceptor ring 20 constituted so as to be joined to this guide board at their respective side surfaces and surrounding the peripheral part of the board supporting table 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus,
In particular, the present invention relates to a support structure for a susceptor ring arranged around a susceptor in a vapor phase growth apparatus for forming a uniform epitaxial growth film or an etching apparatus for performing uniform etching.

[0002]

2. Description of the Related Art With the miniaturization and high integration of semiconductor devices, the uniformity of the film thickness and the specific resistance distribution required for epitaxially grown films has become extremely high. In order to satisfy the condition of such uniformity, the film growth conditions must be uniform, and it becomes indispensable to supply the gas uniformly onto the substrate together with the uniformity of the substrate temperature. Therefore, in these vapor phase growth apparatuses, various attempts have heretofore been made to control the uniformity of the gas flow velocity distribution on the substrate.

For example, FIG. 7 shows an example of a conventional single-wafer type epitaxial growth apparatus. An open square pipe made of transparent quartz glass with flanges attached to both ends is used as the reaction container, and the reaction container is sandwiched between the metal gas inlet 3 and the gas outlet 6 via the rubber O-ring. The reaction chamber 1 is formed. Inside the reaction chamber 1, a gas inlet 3 is arranged, which is connected to the gas introduction pipe 2 and is located on the surface of the wafer 5 mounted on the susceptor 4 as the substrate support in the reaction chamber 1. Methods have been proposed for adjusting the gas flow to be uniform. The susceptor consists of a disk-shaped susceptor made of graphite with a size suitable for the wafer and a thickness of several mm. The susceptor is mounted on a rotating shaft 7 for supporting and rotating, and a donut-shaped susceptor ring 10 mounted on a quartz window 8 via a holder 9 forms a substantially same surface as the susceptor surface. It is arranged to prevent the gas flow from being disturbed. The quartz window on the lower surface is higher than the gas flow on the upstream side, that is, on the gas inlet side so that the introduced gas does not directly hit the side surface of the susceptor ring. Further, the susceptor rotating shaft 7 is led out of the reaction chamber where the driving device is provided due to the rotational drive.
This part is sealed by a magnetic seal or other method. When the epitaxial thin film is grown on the wafer 5, the susceptor 4 and the wafer 5 which are rotating through the upper and lower quartz windows 8 forming the reaction chamber and the quartz lamps arranged outside the quartz windows 8 are heated to a predetermined temperature, for example, 1050. Hold at ℃,
A reaction gas is introduced from the gas inlet 3.

However, in such a conventional device,
A holder having at least three supporting points is formed on the lower portion of the susceptor ring 10 and is directly placed on the lower quartz window. However, according to such a method for holding the susceptor ring, the holder is provided on the upper surface of the lower quartz window. High-precision processing is required for positioning the susceptor ring holder, and the strength of the quartz window is also reduced. There is also a problem that the portion of the quartz window that contacts the susceptor ring holder 9 is devitrified as the film formation progresses. The local devitrification of the glass not only hinders the uniform heating of the susceptor, but also may destroy the quartz glass reaction chamber itself. Further, the temperature of the portion of the quartz window in contact with the susceptor ring holder 9 is relatively easy to rise, and when a gas such as monosilane gas which decomposes at a relatively low temperature (400 ° C.) is used, this portion is used. Undesired thermal decomposition of monosilane gas occurs,
An amorphous film may be formed. Unlike quartz, this amorphous film is not transparent to infrared rays, and thus can easily rise in temperature. In this case, undesired thermal decomposition of monosilane gas is accelerated, and this portion is finally polycrystallized, and infrared rays as a heating source cannot reach the susceptor and the wafer. Therefore, the deterioration of the film quality is unavoidable, and it is often necessary to wash the reaction vessel. Further, when the susceptor ring holder is set, when polycrystalline silicon is deposited on this portion due to scratches on the inner surface of the quartz window,
Due to the difference in the coefficient of thermal expansion from quartz, the reaction chamber itself made of quartz glass will be destroyed.

Therefore, in terms of quality such as resistance distribution and film thickness distribution of the epitaxial thin film, it has been desired to solve this problem from the three directions of safety and economy.

[0006]

As described above, in the conventional epitaxial growth apparatus, since the susceptor ring is placed on the quartz window, devitrification occurs as the film formation progresses, or the susceptor ring becomes uniform. In addition to hindering heating, the reaction chamber itself made of quartz glass may be destroyed. However, the susceptor ring is indispensable in order to prevent the temperature of the peripheral portion of the susceptor from being fixed, and in each case, sufficient uniformity cannot be obtained, adjustment is extremely difficult, and the device becomes expensive. Note that this problem was not limited to the vapor phase growth apparatus such as the epitaxial growth apparatus, but was the same in the etching apparatus.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor manufacturing apparatus capable of supplying a uniform gas within a wafer surface.

[0008]

Therefore, in the first aspect of the present invention, a guide plate which is installed on the side wall of the reaction chamber at the height of the substrate support and has a hole formed in the center thereof,
And a susceptor ring that is configured to engage with the guide plates on their respective side surfaces and that surrounds the outer peripheral portion of the substrate support.

In the second aspect of the present invention, the side wall of the reaction chamber is
Installed so as to be the height of the substrate support, a guide plate formed with a hole in the center, and in the hole of the guide plate, fixed so as to cover the outer peripheral portion of the substrate support,
A susceptor ring that rotates together with the substrate support.

[0010]

According to the above construction, since the susceptor ring is not attached to the quartz window but to the side wall of the reaction chamber or the like, a stagnation layer of gas is formed and particles are maintained without being retained. The particles are carbonized under high temperature conditions during or before film formation, which consumes oxygen in the quartz and may devitrify the quartz window. However, according to the configuration of the present invention, since the particles are maintained without remaining, the quartz window is maintained in a clean state without devitrification, and the reactive gas passes over the guide plate. , Flowing on the surface of the susceptor ring and on the wafer surface of the substrate support while forming a uniform flow.

Further, according to the first structure, since the susceptor ring which engages with the side surface of the guide plate attached to the side wall of the reaction chamber is supported, the positioning can be performed with extremely high precision by a simple structure. Can be achieved. Further, it is necessary that the upper surfaces of the guide plate, the susceptor ring, and the substrate support are the same, and the boundaries are smoothly connected to each other so that turbulent flow does not occur. It is easy and can form a very good gas flow. Desirably, the upper surfaces of the susceptor ring and the guide plate are slightly lower than the lower surface of the gas introduction port by, for example, about 0.2 mm.

Further, according to the second structure, since the susceptor ring rotates together with the substrate support, the boundary between the substrate support and the susceptor ring can be made smoother.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

1 to 4 are views showing a vapor phase growth apparatus according to an embodiment of the present invention. 2 is a sectional view taken along the line AA 'in FIG. 1, FIG. 3 is a sectional view taken along the line BB' in FIG. 1, and FIG.

This apparatus is installed on the side wall of the reaction chamber 1 so as to have the height of the susceptor 4 as a substrate support, and a quartz guide plate 19 having a hole in the center thereof.
And ridges and valleys that are in agreement with each other so as to engage with the guide plates 19 on their respective side surfaces.
And a susceptor ring 20 surrounding the outer peripheral portion of the.

That is, this apparatus uses an open square pipe made of transparent quartz glass with flanges F attached to both ends, and this reaction container is provided with a metal gas inlet 3 and a gas outlet via a rubber O-ring. A reaction chamber 1 is formed by sandwiching the reaction chamber 6 with a susceptor 4 on which a silicon wafer 5 is placed, and a heating means H including a heater for heating the reaction chamber 1.
Then, the silicon wafer is heated. Here, the reactive gas may be used as a mixed gas with a carrier gas. Here, 6 is a gas outlet. The susceptor consists of a disk-shaped susceptor made of graphite with a size suitable for the wafer and a thickness of several mm. The susceptor is attached to the rotating shaft 7 for supporting and rotating, and a donut-shaped susceptor ring 10 mounted on the quartz window 8 via a guide plate 19 forms a substantially flush surface with the susceptor surface. It is arranged to prevent the gas flow from being disturbed. The quartz window on the lower surface is higher than the gas flow on the upstream side, that is, on the gas inlet side so that the introduced gas does not directly hit the side surface of the susceptor ring. Then, a purge gas (not shown) is introduced from below in order to prevent the introduced gas from flowing around to the back surface side of the susceptor, so that the front surface side and the back surface side of the susceptor are separated. Further, the susceptor rotating shaft 7 is led out of the reaction chamber in which the driving device is provided due to the rotational drive, but this portion is sealed by a magnetic seal or other method. When the epitaxial thin film is grown on the wafer 5, the susceptor 4 and the wafer 5 which are rotating through the upper and lower quartz windows 8 forming the reaction chamber and the quartz lamps arranged outside the quartz windows 8 are heated to a predetermined temperature, for example, 1050. The temperature is maintained at 0 ° C., and the reaction gas is introduced from the gas inlet 3.

The growth conditions are as follows.

Source gas: trichlorosilane Carrier gas: Hydrogen Dopant: Diborane Growth temperature: 1135 ° C. Growth pressure: Atmospheric pressure Growth time: 45 seconds / sheet Silicon substrate: p-type 8 inch wafers Processed number: Continuous 125 sheets In this device, The silicon wafer 5 is placed on the susceptor 4, and the reactive gas is injected from one gas supply pipe 2.
The reactive gas injected here passes through the guide plate 19, passes through the susceptor ring 10, and is supplied onto the susceptor 4. Since the wafer 5 is mounted on the susceptor 4 arranged from the side wall of the container through the guide plate and the susceptor ring, the temperature is stable.

Further, in this apparatus, the guide plate is supported by the convex portion that engages with the concave portion formed on the side wall of the reaction chamber 1. Further, the convex portion of the susceptor ring 20 is placed and supported in the concave portion formed on the inner circumference of the guide plate. For this reason, it is possible to assemble it extremely easily without any positional deviation, and it is possible to accurately install it at the reference level.

The epitaxial thin film thus formed has an average growth rate: 5.2 μm / min, film thickness distribution (between wafers): 3.92 μm (± 1.2%), specific resistance distribution (between wafers): 3 .22Ω · cm (± 2.4
%) Was obtained. A small amount of amorphous film was observed to be attached to the inner surface of the upper edge of the quartz window, but the inner surface of the lower quartz window remained clean. By using this device in this way, the susceptor ring and the guide plate are
While preventing the surrounding of reactive gas and preventing the temperature drop at the peripheral edge of the wafer, it plays its original role,
The quartz window 8 can be well maintained without devitrification.

The guide plate and the susceptor ring are installed so that a gap is formed between them. However, since the temperature of the susceptor and the like rises during the growth, the gap disappears and good growth can be achieved. Become.

Next, using the same apparatus, the epitaxial growth film was similarly formed under the following conditions.

The growth conditions were as follows.

Source gas: Monosilane Carrier gas: Hydrogen Dopant: Diborane Growth temperature: 1010 ° C. (lamp heating) Growth pressure: Atmospheric pressure Growth time: 240 seconds / sheet Silicon substrate: p-type 8 inch wafers Processed number: Continuous 50 sheets , In this example, in order to prevent the amorphous silicon generated by the thermal decomposition of monosilane from adhering to the inner wall of the quartz glass chamber located between the wafer and the lamp,
The gas was supplied in a laminar flow.

The epitaxial thin film thus formed has an average growth rate: 1.4 μm / min, film thickness distribution (between wafers): 5.6 μm (± 1.4%), specific resistance distribution (between wafers): 13 .2 Ω · cm (± 2.4
%) Was obtained. At this time, the deposition of amorphous on both the inner surface of the upper quartz window and the inner surface of the lower quartz window,
It was not observed at all and remained clean.

Next, an epitaxial growth film was similarly formed under the following conditions using the same apparatus.

The growth conditions were as follows.

Source gas: Monosilane Carrier gas: Hydrogen Dopant: Phosphine Growth temperature: 925 ° C. (lamp heating) Growth pressure: 50 Torr Growth time: 192 seconds / sheet Silicon substrate: p-type 8-inch wafer Processed number: Continuous 300 sheets Also in this example, in order to prevent adhesion of amorphous silicon generated by thermal decomposition of monosilane to the inner wall of the quartz glass chamber located between the wafer and the lamp,
The gas was supplied in a laminar flow.

The epitaxial thin film thus formed has an average growth rate: 0.56 μm / min, film thickness distribution (between wafers): 1.79 μm (± 1.2%), specific resistance distribution (between wafers): 1 0.5 Ω · cm (± 2.1
%) Was obtained. At this time, the deposition of amorphous on both the inner surface of the upper quartz window and the inner surface of the lower quartz window,
It was not observed at all and remained clean.

Further, although the low pressure CVD apparatus has been described in the above embodiment, it is needless to say that the present invention can be applied to an atmospheric pressure CVD apparatus, an etching apparatus and the like.

In the above-described embodiment, the guide plate 19 and the susceptor ring 20 are connected to each other by the engagement of the step-shaped unevenness. However, as shown in FIG. You may make it connect with the susceptor ring 20.

Next, a second embodiment of the present invention will be described.

In the apparatus of the first embodiment, the guide plate 19
The susceptor ring 20 is supported by the susceptor ring 20 as shown in FIG.
It is characterized in that it is engaged with the outer peripheral surface of the so as to rotate together with the susceptor 4, and the other parts are formed in the same manner as in the first embodiment. The guide plate 19 is installed on the side wall of the reaction chamber 1 at the height of the susceptor, and has a hole formed in the center thereof, as in the above-described embodiment.

According to this structure, in addition to the effect of the first embodiment, if the susceptor ring rotates together with the susceptor, the boundary between the susceptor and the susceptor ring can be made smoother.

[0035]

As described above, according to the present invention, devitrification of the quartz window is eliminated and uniform heating can be performed, and as a result, the quality of the epitaxial thin film such as the resistivity distribution and the film thickness distribution can be improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a vapor phase growth apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a sectional view taken along line BB ′ of FIG.

FIG. 4 is an explanatory view of a main part of the device.

FIG. 5 is a diagram showing another embodiment of the present invention.

FIG. 6 is an explanatory view of a main part of a second embodiment of the present invention.

FIG. 7 is a diagram showing a conventional vapor phase growth apparatus.

[Explanation of symbols]

 1 reaction chamber 2 gas inlet pipe 3 gas inlet 4 susceptor 5 wafer 6 gas outlet 7 shaft 8 quartz window 9 susceptor ring holder 10 susceptor ring 19 guide plate 20 susceptor ring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Hino 1200 Manda, Hiratsuka, Kanagawa Prefecture, Komatsu Seisakusho Laboratory (72) Inventor Naoto Hisanaga 1200, Manda, Hiratsuka, Kanagawa Seisakusho Laboratories, Inc. ( 72) Inventor Nozomi Ochi 1200 Manda, Hiratsuka, Kanagawa Prefecture Komatsu Ltd. Research Laboratory

Claims (2)

[Claims] 1. A reaction chamber, a substrate support placed in the reaction chamber for supporting a substrate to be processed, a gas supply means for supplying a reactive gas along the surface of the substrate to be processed, and the reaction chamber. A guide plate, which is installed on the side wall of the substrate so that it is at the height of the substrate support table and has a hole formed in the center thereof, and the guide plate is configured to engage with each other on their respective side surfaces. A semiconductor manufacturing apparatus comprising: a susceptor ring surrounding an outer peripheral portion of a table. 2. A reaction chamber, a substrate support placed in the reaction chamber for supporting a substrate to be processed, a gas supply means for supplying a reactive gas along the surface of the substrate to be processed, and the reaction chamber. A guide plate which is installed on the side wall of the substrate so that it is at the height of the substrate support, and has a hole formed in the central portion, and the hole of the guide plate covers the outer peripheral portion of the substrate support. A semiconductor manufacturing apparatus, comprising: a susceptor ring that is fixed and rotates together with the substrate support.