JPH04133314A - Vertical-type heat treatment apparatus - Google Patents

Abstract

PURPOSE:To suppress drop of the treatment efficiency due to the transfer operation of an object to be treated and to suppress the defect of the object due to an increase in the waiting time by a method wherein a function of pretreating the object is additionaly provided to a stocker for storing a container for treatment use, which has been provided so as to keep the object on standby and all devices from the stocker of a container, for conveyance use, in which the object has been housed to a vertical- type heat treatment furnace are incorporated inside a series of devices. CONSTITUTION:A wafer boat 4 conveyed to a vertical-type heat treatment furnace 30 by using a boat conveyance mechanism 40 is loaded inside a reaction container 31 by using a boat elevator 38; a semiconductor wafer 2 is treated. On the other hand, the wafer boat 4 conveyed to a boat stocker 50 is placed on a turntable 52; it is covered with a reaction table 54 which has been lowered; a desired pretreatment is executed during the waiting period of a heat treatment process by using a gas, for pretreatment use, which has been supplied from a treatment gas introduction pipe 56. The boat stocker 50, a carrier stocker in which a wafer carrier 3 conveyed from a previous process is housed, a transfer mechanism of the semiconductor wafer 2 and individual mechanisms 40, 60 which transfer and convey the wafer boat 4 are installed inside one apparatus.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a vertical heat treatment apparatus.

(Conventional technology) In recent years, heat treatment equipment used in the thermal diffusion process and film formation process in the semiconductor device manufacturing process has been developed to save space, save energy, increase the diameter of semiconductor wafers to be processed, and increase automation. Vertical heat treatment equipment has been developed for reasons such as ease of handling.

In such vertical heat treatment equipment, a large number of semiconductor wafers are stored on shelves at predetermined intervals in a vertical heat treatment furnace in which a heater, heat insulating material, etc. are arranged around a cylindrical reaction vessel made of quartz or the like. A wafer boat made of quartz or the like is loaded from below by an elevating mechanism and subjected to a predetermined heat treatment. Further, since semiconductor wafers are normally transported in a transport container called a wafer carrier made of resin, it is necessary to transfer the semiconductor wafers between the wafer boat and the wafer carrier. Therefore, vertical heat treatment apparatuses equipped with a wafer transfer mechanism between a wafer boat and a wafer carrier are commonly used.

On the other hand, by arranging multiple vertical heat treatment furnaces in parallel and sharing one wafer transfer mechanism with multiple vertical heat treatment furnaces,
It has also been proposed to suppress a decrease in processing efficiency due to the time taken to transfer semiconductor wafers between a wafer boat and a wafer carrier, and to improve the efficiency of the heat treatment process.

(Problem to be solved by the invention) By the way, in the conventional vertical heat treatment apparatus as described above,
Although we aim to improve processing efficiency by using multiple vertical heat treatment furnaces, depending on the processing content, the time required to transfer semiconductor wafers between the wafer boat and wafer carrier may be a factor in reducing processing efficiency. There is a strong desire to further improve processing efficiency. Also,
There is a demand for a vertical heat treatment apparatus that improves processing efficiency not only for transferring semiconductor wafers but also for transporting wafer carriers and wafer boats.

On the other hand, with the increasing integration of semiconductor devices, wiring networks are becoming increasingly finer, and as a result, even a few dozen natural oxide films can cause wiring defects, and the natural oxide film Since it is a non-uniform film, it is more likely to cause defects, so by suppressing the formation of a natural oxide film and making it possible to remove the natural oxide film before heat treatment. , it is desired to improve the processing quality.

The present invention has been made to address these problems, and aims to provide a vertical heat treatment apparatus that improves the efficiency of the heat treatment process and further improves the quality of the treatment.

[Structure of the Invention] (Means for Solving the Problems) That is, the vertical heat treatment apparatus of the present invention includes a transport container stocker that stores a transport container containing a workpiece, and a transport container stocker that stores a transport container in which a workpiece is stored, and a A transfer mechanism that transfers the object to be processed to and from the container; A processing container stocker on standby; a plurality of vertical heat treatment furnaces for accommodating processing containers loaded with the objects to be processed and subjecting the objects to predetermined heat treatment; The method is characterized by comprising a transport mechanism for transporting the processing container between mold heat treatment furnaces.

(Function) The vertical heat treatment apparatus of the present invention is equipped with a processing container stocker for keeping the objects to be processed on standby. It is possible to suppress a decrease in processing efficiency due to transfer of the processed material. In addition, since the processing container stocker has a pre-processing function for the objects to be processed, it is possible to suppress the occurrence of defects in the objects to be processed due to an increase in the waiting period, and further improve the processing quality. becomes possible.

In addition, since everything from the stocker for transport containers containing the workpieces to the vertical heat treatment furnace is integrated into a series of equipment, each process, including the transfer of the workpieces and transportation of each container during heat treatment, is integrated into a series of devices. It becomes possible to implement this efficiently.

(Example) Hereinafter, an example of the vertical heat treatment apparatus of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the vertical heat treatment apparatus 1 in this embodiment includes a carrier stocker 10 that can store a large number of wafer carriers 3, such as a transport container in which semiconductor wafers 2 are accommodated as objects to be processed. , a transfer mechanism 2 for transferring the semiconductor wafers 2 housed in the wafer carrier 3 to a processing container, for example, a wafer boat 4 made of quartz or the like.
0 and a wafer boat 4 on which the semiconductor wafer 2 is mounted.
A plurality of vertical heat treatment furnaces 30 arranged in parallel to accommodate wafers and perform predetermined heat treatment are provided in front of the vertical heat treatment furnaces 30 along the arrangement direction of the vertical heat treatment furnaces 30, and transport the wafer boat 4 in a vertical state. A boat transport mechanism 40 and an unprocessed semiconductor wafer 2 provided along the boat transport mechanism 40.
Boat stocker 5 which is a standby position and performs pre-treatment
0, and a boat transfer mechanism 60 that transfers the wafer boat 4 between the wafer transfer mechanism 20 and the boat transfer mechanism 40 while performing horizontal-vertical conversion.

In the carrier stocker 10, carrier arrangement shelves 11 are installed in multiple stages, and each carrier arrangement shelf 11 is configured to store a plurality of carriers 3. In addition, a carrier strike lever 10 and a wafer transfer mechanism 20 are also provided.
The Ueno\carrier 3 is transported between the two by a carrier transport mechanism 70. In order to transfer the wear/carriers 3 from the multi-stage carrier arrangement shelves 11 to the carrier transport mechanism 70, the carrier stocker 10 has a carrier holding and transport mechanism 12 that is movable in the X-Z direction.

Further, the wafer transfer mechanism 20 is configured to transfer a plurality of semiconductor wafers 2.
It has a holding part 21 that holds the boat all at once, and the boat mounting table 2 is moved by the boat transfer mechanism 60.
The above-mentioned /
The semiconductor wafer \2 is transferred by the handling section 21.

The boat transfer mechanism 60 includes a boat handling section 61 that holds the upper and lower ends of the Ueno boat 4, and a transfer section 62 of the boat handling section 61, and the semiconductor wafer 2 is loaded by the wafer transfer mechanism 20. The boat 4 is transferred onto the boat mounting section 41 of the boat transport mechanism 40 while holding the boat 4 in the horizontal state and converting it into a vertical state.

Further, the boat transport mechanism 40 transfers the boat mounting section 41 on which the wafer boat 4 is vertically mounted to the boat stocker 50 or the vertical heat treatment furnace 30 based on the processing program.
It has a transport rail 42 and a drive mechanism (not shown) for transporting to either of the two.

As shown in FIG. 3, each vertical heat treatment furnace 30 is constructed of a heat treatment furnace main body made of a reaction vessel 31 made of, for example, quartz, a heater 32 arranged to surround the reaction vessel, and a heat insulating material (not shown). 33, and this heat treatment furnace main body 33 is fixed to a base plate 34 so as to be arranged substantially vertically.

A wafer boat 4 in which semiconductor wafers 2 are stacked and stored at a predetermined pitch is mounted on a boat transfer arm 3 above a heat insulating tube 36 installed on a rotatable turntable 35.
7 from the boat transport mechanism 40, and loaded into the reaction vessel 31 by an elevating mechanism such as the boat elevator 38. Further, the open portion of the reaction container 31 is sealed by a disk-shaped cap portion 39 that is raised and lowered by a boat elevator 38 together with the turntable 35 and the like.

In addition, the port stocker 50 has a configuration in which two buildings are arranged in parallel, and by keeping the wafer boat 4 containing unprocessed semiconductor wafers 2 on standby, it is possible to suppress a decline in processing efficiency due to wafer transfer time and to , semiconductor wafer 2
This is an attempt to improve the processing quality by applying pre-processing to the data.

Each port stocker 50 is equipped with a turntable 52 that is rotatable by a rotation drive mechanism 51, and the wafer boat 4 is transferred from the boat transfer mechanism 40 onto the turntable 52 by a boat transfer arm 53. Ru. Further, above the turntable 52, a reaction tube 54 in the shape of a cylindrical container made of quartz or the like is arranged at a position where it will not interfere with the transfer of the wafer boat 4. This reaction tube 54 is moved by a lifting mechanism 55. It can be raised and lowered so as to cover the periphery of the wafer boat 4 placed on the turntable 52.

Further, a processing gas introduction pipe 56 is connected to the reaction tube 54, and a desired pretreatment gas such as nitrogen gas or etching gas is supplied from the processing gas introduction pipe 56 to the reaction pipe 54.
A semiconductor wafer 2 that is supplied into the interior of the
applied to

For example, if nitrogen gas is used as a pretreatment gas, it is possible to form a natural oxide film on the semiconductor wafer 2 or
It is possible to prevent dust from adhering to the surface. Furthermore, if an etching gas is used, the natural oxide film formed in the previous process can be removed immediately before the heat treatment.

In the vertical heat treatment apparatus 1 in this embodiment, four vertical heat treatment furnaces 30 are arranged in parallel, and the structure is such that different heat treatments, such as Si epitaxial growth and a thermal diffusion process, can be performed simultaneously. ing. Therefore, in order to prevent cross-contamination due to different heat treatments, the parts that the wafer boat 4 comes into contact with, namely the boat mounting part 41 of the boat transport mechanism 40, the boat holding part 61 (not shown) of the boat transport mechanism 60, Two sets of boat mounting tables 22 (not shown) and the like of the mounting mechanism 20 are provided, and each can be changed according to the processing content of the wafer boat 4 to be handled.

In the vertical heat treatment apparatus 1 having such a configuration, first, the wafer carrier 2 transferred from the carrier placement shelf 11 of the carrier stocker 10 to the carrier table 71 of the carrier transport mechanism 70 is transported to the wafer transfer mechanism 20 side.

On the other hand, the wafer boat 4 is transferred onto the boat mounting table 22 by the boat transfer mechanism 60, and the semiconductor wafers 2 accommodated in the wafer carrier 2 are transferred to the wafer boat 4.

When the transfer of the semiconductor wafers 2 is completed, the wafer boat 4 carrying the semiconductor wafers 2 is transferred to the boat transfer mechanism 60 while being converted horizontally to vertically by the boat transfer mechanism 60.

Next, the wafer boat 4 is transported to either each boat stocker 50 or each vertical heat treatment furnace 30 by the boat transport mechanism 60 based on the processing program.

For example, the wafer boat 4 transported to the vertical heat treatment furnace 30 is placed on a heat insulating cylinder 36, loaded into the reaction vessel 31 preheated to, for example, about 800° C. by the boat elevator 38, and the cap portion 39 seals the reaction container 31. After this, reaction vessel 3
While maintaining the inside of the chamber at a predetermined degree of vacuum, for example, about 10 Torr, a processing gas such as 5tH2C12, HCI, H
2 is supplied from a gas introduction pipe (not shown), and processing of the semiconductor wafer 2, such as Si epitaxial growth, is performed.

Also, the wafer boat 4 transported to the port stocker 50
is placed on a turntable 52 and covered by a descending reaction tube 54, and is heated by a pretreatment gas such as nitrogen gas or etching gas supplied from a processing gas introduction pipe 56 during the standby period of the heat treatment process. is subjected to the desired pretreatment.

The transfer of the semiconductor wafers 2 and the transportation of the wafer boat 4 to the vertical heat treatment furnace 30 or the port stocker 50 are performed sequentially, and the wafer boat 4 waiting in the port stocker 50 is also transferred to the vertical heat treatment furnace 30 according to the processing program.
transported to.

On the other hand, the semiconductor wafer 2 that has been processed in the vertical heat treatment furnace 30 is transferred together with the wafer boat 4 to the boat mounting table 22 of the wafer transfer mechanism 20 by the boat transfer mechanism 40 and the boat transfer mechanism 60, and then The wafer is transferred to the wafer carrier 3.

Wafer carrier 3 containing processed semiconductor wafers 2
is returned to the carrier stocker 10 and transported to the next process.

In the vertical heat treatment apparatus having the above configuration, the semiconductor wafer 2
The semiconductor wafer boat 4 has a plurality of port stockers 50 as standby positions for the wafer boat 4 loaded with the semiconductor wafers 2.
Regardless of the processing content, it is possible to suppress a decrease in processing efficiency due to the transfer of the semiconductor wafer 2. In addition to having the port stocker 50, the carrier stocker 10 stores the wafer carrier 3 transported from the previous process, the semiconductor wafer 2 transfer mechanism 20, and each mechanism 40 that transfers and transports the wafer boat 4. .60 is installed in the equipment, each process related to a series of heat treatments can be carried out continuously and flexibly according to the processing content, which also helps improve processing efficiency. It becomes possible.

These make it possible to reduce manufacturing costs associated with heat treatment of the semiconductor wafer 2.

In addition, a reaction tube 54 that can be raised and lowered freely in the port stocker 50 is provided.
This makes it possible to perform, for example, inert gas treatment or etching treatment on the semiconductor wafer 2 as a pretreatment for heat treatment, so that it is possible to prevent the formation of a natural oxide film during the waiting period. Moreover, it is also possible to remove a natural oxide film. In addition, since it is kept on standby within the reaction tube, it is also possible to suppress the occurrence of defects due to adhesion of dust and the like.

By employing the boat stocker 50 described above, it becomes possible to perform preprocessing while the semiconductor wafers 2 are placed on the wafer boat 4 and are on standby, thereby suppressing the occurrence of defects caused by the waiting period. Furthermore, it becomes possible to improve the efficiency of the heat treatment process while improving the treatment quality.

[Effects of the Invention] As explained above, according to the vertical heat treatment apparatus of the present invention, it is possible to improve the efficiency of the heat treatment process, suppress the occurrence of defects, and further improve the processing quality. It becomes possible to achieve this goal.

[Brief explanation of drawings]

1 is a perspective view for explaining the configuration of a vertical heat treatment apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of the vertical heat treatment apparatus shown in FIG. 1, and FIG. 3 is a vertical view of the vertical heat treatment apparatus shown in FIG. FIG. 2 is a front view showing a main part of the mold heat treatment apparatus in partial cross section. 1... Vertical heat treatment equipment, 2... Semiconductor wafer 3... Wafer carrier, 4...
Wafer boat, 10...Carrier stocker, 1
1...Carrier placement shelf, 20...Wafer transfer mechanism, 21...Wafer handling section,
22...Boat mounting stand, 301. ... Vertical heat treatment furnace, 31 ... Reaction vessel, 32 ...
・Heating heater, 33...Heat treatment furnace body, 37.
...Boat transfer arm, 38...Boat elevator, 39...Cap section, 40...
... Boat transport mechanism, 41 ... Boat mounting section, 42 ... Transport rail, 50 ... Port stocker, 52 ... Turntable, 53・
... Boat transfer arm, 54 ... Reaction tube, 55 ... Lifting mechanism, 56 ... Processing gas introduction piping, 60 ... Boat Transfer mechanism, 61.
... Boat holding section, 70 ... Carrier conveyance mechanism. Applicant Tokyo Electron Sagami Co., Ltd. Agent Patent Attorney Sasa Suyama - (1 other person)

Claims (1)

[Scope of Claims] A transport container stocker that stores a transport container in which an object to be processed is stored; a transfer mechanism that transfers the object to be processed between the transport container and the processing container; , a processing container stocker that pre-processes the unprocessed workpieces loaded in the processing container and temporarily waits the workpieces; A plurality of vertical heat treatment furnaces that accommodate containers and perform predetermined heat treatment on the objects to be processed, and a transport mechanism that transports the processing containers between the processing container stocker and the vertical heat treatment furnace. A vertical heat treatment equipment that is characterized by: