JPS60109219A - Gas phase reactor - Google Patents

Abstract

PURPOSE:To contrive the facilitation of maintenance and the reduction of cost by enabling the treatment of plurality of large-diameter wafers without enlarging the diameter of a tube reactor by forming the reactor with dividing it into plural pieces in a longitudinal direction. CONSTITUTION:A substrate 4 provided with a rotary mechanism 5 is lifted by a soft mechanism and a wafer holding jig 2 is also lifted unitarily with said substrate 4 till the upper half of the jig is exposed. With keeping this state, large- diameter wafers W of only half number of the total charged number are loaded on the upper half surface of the wafer holding jig 2. Next, an upper pipe 11 is lifted by the soft mechanism together with a heat source 17 and another half of wafers W are loaded on the exposed lower half surface of the wafer holding jig 2. Consequently, loading of all wafers is completed and after that, the wafer holding jig 2 united with the substrare 4 and the upper pipe 11 are lowered to unite the upper pipe and the lower pipe. For taking out the wafers after gas- phase reaction, the operation of wafer loading is performed inversely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas phase reaction technique suitable for use in forming thin films on the surfaces of semiconductor wafers and other members.

[Background technology]

CVD (Chemical CVD) is essential to the manufacturing process of semiconductor devices.
In so-called gas phase reaction techniques such as alVapore Deposition, epitaxy, and sputtering, conventionally,
A batch method is used to process a large number of semiconductor wafers at once (Japanese Unexamined Patent Publication No. 142387/1987).
.

In this patch method, the diameter of the wafer is 76 mm.
As the diameter has increased from (1) to 100K and 125fi, the equipment has been increased in size and the number of wafers processed has been kept from decreasing too much to prevent a decrease in throughput (number of wafers processed per hour). However, in recent years, the increasing size of the quartz glass reaction tube, SiC-coated graphite susceptor, etc. that constitute the main parts of the device has gradually approached its limits.

It has become difficult to cope with the decrease in throughput simply by increasing the size of the device.

In particular, when the diameter of the wafer is increased to 175 mm or more, a decrease in the number of wafer charges within 1 x is unavoidable even if the diameter of the reaction tube is slightly increased. Furthermore, if the reaction tube and the susceptor are made larger in size, maintenance such as disassembly, cleaning, and reassembly of the tube becomes difficult, and the cost of the apparatus increases. On the other hand, it is possible to increase the number of charges by increasing the length of the quartz tube, but simply increasing the length of the quartz tube may cause maintenance and cost problems as described above, and the susceptor Problems also arise in that it becomes difficult to attach and detach wafers to and from the reactor, and it becomes difficult to ensure uniformity of the reaction gas within the reaction tube.

On the other hand, as another method for dealing with the increase in the diameter of wafers, a single wafer type apparatus that processes wafers one by one may be considered.

However, in the case of a single-wafer type, the throughput naturally decreases, and to prevent this, it is necessary to install multiple devices and operate them in parallel.

As the area occupied by the apparatus increases, area efficiency (the number of sheets processed per square meter) decreases, and the cost of the apparatus increases.

[Purpose of the invention]

The purpose of the present invention is to provide a gas phase reaction technology that enables processing of a large number of large diameter wafers without increasing the diameter of the reaction tube, and that facilitates maintenance and reduces costs. be.

Another object of the present invention is to provide a gas phase reaction technique that facilitates maintenance, wafer attachment and detachment, and uniformity of internal reaction gas.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, the reaction tube containing the wafer holding jig is divided into parts in the length direction so that each part can be moved independently in the length direction, and gas nozzles are installed between each part of the reaction tube as necessary. This arrangement improves wafer processing efficiency without increasing the diameter of one reaction tube, making maintenance difficult or increasing costs, and makes it easy to attach and detach wafers in a busy and uniform gas condition. This achieves a good gas phase reaction.

〔Example〕

Figure 1 shows an embodiment in which the present invention is applied to a vertical gas phase reactor, a so-called barrel-type reactor, in which a circular reaction tube 1' made of quartz glass is installed extending vertically, and a wafer is held at its center. A jig 2 is installed inside. This wafer holding jig 2 is SI
It is made of C-coated graphite and is formed by combining, for example, six strip-shaped (rectangular) plates to form a hexagonal column shape, so that it is possible to hold, for example, four large diameter wafers W on the top and bottom K on each surface of the hexagonal column. . The wafer holding jig 2 is suspended and supported on the substrate 4 by a sleeve 3 provided at the upper center position. The sleeve 3 is rotatably supported by a base plate 4, and a rotating mechanism 5 is provided at the upper end thereof. The rotation mechanism 5 is
An inner ring magnet 6 consisting of a plurality of magnets equally arranged in the positioning direction on the upper end of the sleeve 3, an outer ring magnet 8 consisting of a plurality of magnets attached to an annular gear 7 arranged nine concentrically on the outside thereof; It is equipped with a motor 9 that rotates a pinion that meshes with the annular gear 7. By driving the motor 9, the outer ring magnet 8 is rotated together with the annular gear 7, and the inner ring magnet 6, that is, the sleeve 3, and the wafer holding jig are further rotated by magnetic force. The tool 2 can be rotated. Note that a protection tube 10 having a temperature measurement sensor installed therein is suspended vertically at the center of the wafer holding jig 2.

On the other hand, one quartz tube 1 is composed of an upper tube 11 and a lower tube 12, which are divided into two parts lc in the length direction (vertical direction). The clay pipe 11 was formed into a cylindrical shape, and the lower pipe 12 was formed into a cylindrical shape with a narrowed lower end, and both pipes 11 and 12 were arranged in series in the length direction via a space ring 13''k, and were arranged at the upper edge of the upper pipe 11. It is connected to the lower surface of the substrate 4 by a space ring 14.The space rings 13, 14 each have a seal ring on both end surfaces to keep the space between the two tubes 11, 12 or the upper tube 11 and the substrate 4 airtight. The upper space ring 14 is provided with a main reaction gas nozzle 15, and the lower space ring 13 is provided with a main reaction gas nozzle 15.
A replenishment gas nozzle 16 is provided. Furthermore, the upper pipe 1
1. Heat sources 17 and 18 consisting of infrared lamps are integrally provided around the upper tube 12, respectively, so that the inside of the quartz tube 1 is heated by radiation. The lower end of the upper tube 12 is used as an exhaust port, and the substrate 4 and the upper tube 11 are configured to be able to move up and down independently by means of a software mechanism (not shown).

The operation for epitaxial growth of a silicon wafer using the gas phase reaction apparatus having the above configuration will be explained.

First, as shown in FIG. 2, the substrate 4 provided with the rotation mechanism 5 is
is moved upward by a software mechanism (not shown), and together with this, the wafer holding jig 2 is moved upward until about half of its upper portion is exposed. In this state, the wafer holding jig 2
Large-diameter wafers W are loaded onto the upper half surface of the wafer W by half of the total number of charges.

Next, the upper tube 11 and the heat source 17 are moved upward as shown in FIG. 3 by a software mechanism (not shown), and the remaining half of the wafers W are loaded onto the exposed lower half surface of the wafer holding jig 2. All wafers have been loaded completely during this busy period.
Thereafter, the upper tube 11 and the wafer holding jig 2 integrated with the substrate 4 are moved down to set the state shown in FIG.

Thereafter, the wafer holding jig 2 is rotated, and N gas is supplied into the reaction tube 1 from the main reaction gas nozzle 15 and, depending on the required pressure, the supplementary gas nozzle 16, and from a persilo (not shown) provided in the rotation mechanism 5. Purge the air and then purge the Nt gas with H and gas to completely make the air in the reaction tube 1 H.
Replace with 7.

At this time, the inside of the reaction tube 1 is evacuated using a vacuum pump (not shown) to replace the gas, and the inside of the tube is kept at a low pressure of Hz (50 to 80 rorr).
It may be kept in this state.

Next, the wafer W is heated to 900 to 1
150CK radiation heating, reactant gas (SiH4tSiHt
C4, SiC, 6, etc.) and doping gas (PHI I
B, H, etc.) and '&H, flowed into the reaction tube 1 together with the gas,
St is epitaxially grown on the wafer W.

At this time, H, gas, reaction gas, and doping gas are usually introduced into the reaction tube 1 through the main reaction gas nozzle 15. However, the wafer W loaded at the bottom of the wafer holding jig 2
In order to control the film quality and resistivity uniformity of the above epitaxial film, H, gas, co-active reaction gas, and doping gas can be introduced together or singly from the supplementary gas nozzle 16 as needed.

To take out the wafer after the gas phase reaction is completed, the operation for loading the wafer may be performed in reverse. That is, after heating is stopped, it is cooled in H1 gas to a predetermined temperature.

In the case of a low-pressure reaction, the pressure is returned to normal pressure, and ① is replaced with N gas pressure. Then, the wafer holding jig 2 and the upper tube 11 are moved upward to unload the lower half of the wafers W in the state shown in FIG. It is sufficient to unload half of the wafers W. Note that in this state, the next wafer can be loaded immediately.

Therefore, as can be seen from the above configuration and operation explanation, one reaction tube 1 is divided into an upper tube 11 and an upper tube 12, so even if the reaction tube 1 is made long, it will be half the length. It often disassembles after handling.

Maintenance such as cleaning and assembly can be made easier.

Further, when loading and unloading the wafer W, it is only necessary to move the wafer holding jig 2 upward by half the length of the reaction tube 1, making loading and unloading easy. Further, since a supplementary gas nozzle 16' is provided in the middle of the reaction tube 1, the gas inside the reaction tube can be made uniform, and an epitaxial layer with a uniform thickness can be formed.

FIG. 4 shows a modification of the present invention, and the same parts as those in FIG. 1 are given the same reference numerals and their explanation will be omitted. In this example, the reaction tube l
The wafer holding jig 2A has an upper and a lower two-stage configuration corresponding to the division, and the upper stage 19 and the lower lR2O are connected by a connecting sleeve 21. These upper stage 19 and lower stage 20 can be separated at the connection sleeve 21 portion, and if they are separated during maintenance, handling becomes easier. In this apparatus as well, the same gas phase reaction as in the above-mentioned example can be carried out.

〔effect〕

(1) The reaction tube is divided into sections in the length direction so that each part can move independently, so when the length of the reaction tube is increased to increase the number of charges for large-diameter wafers. Also, one reaction tube can be divided into various parts, cleaned, and reassembled, making maintenance easier.

(2) By dividing the reaction tube, all wafers can be loaded even if the amount of movement of the wafer holding jig is reduced.

It can be unloaded, making loading and unloading operations extremely easy.

(3) Since the length of the reaction tube is increased to increase the number of wafers charged, there is no need to form one reaction tube with a large diameter, making it possible to batch process a large number of large diameter wafers, increasing throughput. can achieve improvements in

(4) Install a supplementary gas nozzle in the middle of the divided reaction tubes.

Since the reaction gas and doping gas can be introduced together or individually, and the wafer holding jig can be rotated during the reaction, the uniformity of the film thickness and resistivity of the vapor-phase grown layer can be improved. can.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the number of divisions of the reaction tube may be set to three or more, and the wafer holding jig may also be arranged in multiple stages accordingly. Furthermore, the number of supplementary gas nozzles may be increased accordingly. Further, in this embodiment, the wafer holding jig is provided to hold the wafer vertically, but it may be configured to hold the wafer horizontally.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to a barrel-type gas phase reactor, which is the background field of application, but the invention is not limited thereto. It can also be applied to structural devices.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an apparatus according to an embodiment of the present invention. 2 and 3 are fracture pressure surface views for explaining the operation, and FIG. 4 is a sectional view of a modified example. 1... Reaction tube, 2... Wafer holding jig, 4...
substrate. 5... Rotation mechanism, 11... Upper tube, 12... Upper tube,
13゜14...x Hose y yy, 15... Main reaction gas nozzle, 16... Replenishment gas nozzle, 17.18.
...Heating source, 19...Upper stage, 20...Lower stage, W...
・Wafer. Figure 1 Figure 2 Figure 3'

Claims (1)

[Scope of Claims] 1. An apparatus that includes a wafer holding jig inside a reaction tube, holds a wafer in the wafer holding jig, and performs a gas phase reaction by maintaining a predetermined gas atmosphere inside the reaction tube. ,
A gas phase reactor characterized in that the reaction tube is divided into a plurality of pieces in the length direction thereof. 2. The gas phase reaction apparatus according to claim 1, wherein the wafer holding jig and the divided reaction tubes are configured to be able to move independently in the length direction. 3. The gas phase reactor according to claim 1 or 2, wherein a supplementary gas nozzle is provided between the divided reaction tubes. 4. The gas phase reaction apparatus according to any one of claims 1 to 3, wherein the wafer holding jig is divided into multiple stages in the length direction.