JP2876250B2 - Vertical heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a vertical heat treatment apparatus.

(Prior Art) In recent years, as a heat treatment apparatus used in a heat diffusion step or a film formation step in a semiconductor device manufacturing process, a vertical heat treatment apparatus capable of achieving dust-free and space-saving has been used. It has become.

That is, in such a vertical heat treatment apparatus, a heat treatment furnace including a cylindrical reaction tube and a soaking tube provided around the reaction tube, a heater, a heat insulating material, and the like is provided substantially vertically in the housing. Have been. A vertical movement mechanism (boat elevator) for loading and unloading a wafer boat on which semiconductor wafers to be processed are loaded into and from the heat treatment furnace is provided below the heat treatment furnace in the housing. I have. Therefore, the installation space can be reduced and space can be saved as compared with a horizontal heat treatment apparatus in which the heat treatment furnace is provided substantially horizontally, and the wafer boat can be loaded and unloaded into the heat treatment furnace without contact with the reaction tube. It can be loaded and dust-free.

An opening for loading and unloading an object to be processed (semiconductor wafer) is provided on the front surface of the housing in which the heat treatment furnace and the boat elevator are housed. Further, for example, a fan for blowing air and a filter for removing dust and the like are provided on the lower side of the rear portion of the housing, and a cleaning gas flow flowing in the front-rear direction is formed on the boat elevator arrangement portion from the rear side to the front, and the semiconductor wafer is There is also a vertical heat treatment apparatus configured to prevent dust from adhering.

(Problems to be Solved by the Invention) However, in recent years, semiconductor wafers have tended to be large in diameter, while circuit patterns of semiconductor devices have tended to be miniaturized.

For this reason, in the vertical heat treatment apparatus, it is necessary to further improve the yield by reliably preventing dust from adhering to the object to be processed, and to save space and improve maintainability while supporting a large-diameter wafer. Etc. are required.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional situation, and it is possible to reliably prevent dust from adhering to an object to be processed, to improve a yield, and to save space and improve maintainability. It is an object of the present invention to provide a vertical heat treatment apparatus that can perform the heat treatment.

[Structure of the Invention] (Means for Solving the Problems) That is, a vertical heat treatment apparatus according to the present invention includes a housing having an opening for loading / unloading an object to be processed on a front surface, and a substantially rear upper portion inside the housing. A vertically disposed heat treatment furnace, a vertical movement mechanism provided below the heat treatment furnace in the housing, and configured to load and unload an object to be processed into the heat treatment furnace, and the vertical movement in the housing. A mechanism for forming a cleaning gas flow flowing in a lateral direction from one side surface of the housing to the opposite side surface, at a portion of the mechanism.

Further, in the vertical heat treatment apparatus according to claim 2, the mechanism for forming the cleaning gas flow includes a blowing fan and a dust removal filter attached to a maintenance door provided on a side surface of the housing. It is characterized by having.

Further, the vertical heat treatment apparatus according to claim 3, a housing having an opening for loading and unloading a cassette containing the object to be processed, a heat treatment furnace provided substantially vertically in an upper part of the housing, A vertical movement mechanism provided at a lower portion of the heat treatment furnace in the housing and for loading and unloading an object to be processed provided on a boat into the heat treatment furnace; and a side of the heat treatment furnace in the housing. A carrier stage configured to accommodate a plurality of the cassettes; a carrier transfer configured to convey the cassettes in the housing; and a transfer configured to transfer the workpiece between the cassettes and the boat. And characterized in that:

Further, in the vertical heat treatment apparatus of claim 4, the carrier stage has a fan for blowing air and a filter for removing dust, and has a mechanism for applying a cleaning gas flow to a cassette housed in the carrier stage. It is characterized by.

Further, the vertical heat treatment apparatus according to claim 5, while purifying air taken in from an upper portion of the housing, goes from the rear to the front of the carrier stage, and thereafter, the vicinity of the arrangement portion of the carrier transfer and the vicinity of the opening. And a mechanism for forming a cleaning gas flow that flows laterally through an arrangement portion of the vertical movement mechanism from one side surface of the housing to an opposite side surface. It is characterized by the following.

(Operation) In the vertical heat treatment apparatus of the present invention having the above-described configuration, for example, the mechanism such as the blower fan and the dust removal filter attached to the maintenance door provided on the side surface of the casing causes the vertical movement in the casing. A cleaning gas flow that flows in the lateral direction (left-right direction) is formed at the mechanism (boat elevator).

Therefore, for example, even if a wafer transfer mechanism or the like is provided in front of the boat elevator (on the side of the housing opening), it is possible to reliably prevent dust from adhering to the semiconductor wafer to be processed and improve the yield. . Further, by attaching the blower fan and the dust removal filter to the maintenance door, space saving and improvement in maintainability can be achieved.

Further, in the vertical heat treatment apparatus of the third aspect, a carrier stage configured to accommodate a plurality of cassettes is provided on a side of the heat treatment furnace in the housing. Then, the cassette is transported by carrier transfer, and the processing is performed by transferring an object (for example, a semiconductor wafer) between the cassette and the boat by the transfer.

That is, in the conventional vertical heat treatment apparatus, the side of the heat treatment furnace in the housing is a space that becomes an empty space, but by providing the carrier stage here, space can be saved. In particular, in the case of an apparatus compatible with a large diameter such as an 8-inch wafer, the size of the carrier stage and the like becomes large, so that the effect of space saving becomes remarkable.

Further, by providing the carrier stage at the upper part in the housing, the object to be processed is placed in a clean environment with relatively high cleanliness in the housing (the lower part in the housing is lower in cleanliness than the upper part), It is possible to prevent dust from adhering to the object. Further, the carrier stage is provided with a mechanism including a fan for blowing air and a filter for removing dust, and a mechanism for applying a cleaning gas flow to a cassette accommodated in the carrier stage, thereby reliably preventing dust from adhering. it can.

Furthermore, while purifying the air taken in from the upper part of the housing, it goes from the rear of the carrier stage to the front, and then descends through the arrangement position of the carrier transfer and the vicinity of the opening to once reach the bottom part, and thereafter. By forming a cleaning gas flow that flows laterally through the position of the vertical movement mechanism from one side of the housing toward the opposite side,
Each part can be reliably maintained in a clean environment.

(Embodiment) An embodiment in which the present invention is applied to a vertical heat treatment apparatus capable of handling an 8-inch diameter semiconductor wafer will be described below with reference to the drawings.

As shown in FIG. 2, the casing 1 is formed in a substantially rectangular shape from, for example, an iron plate or the like, and has a width (W) of, for example, 100 c.
The depth (D) is, for example, about 200 cm, and the height (H) is, for example, about 280 cm.

A reaction tube formed in a cylindrical shape and a heat equalizing tube provided so as to surround the reaction tube,
A heat treatment furnace 2 made of a heater, a heat insulating material and the like is provided substantially vertically. Also, a wafer boat 3 on which a semiconductor wafer (not shown) as an object to be processed is loaded and unloaded into the heat treatment furnace 2 under the heat treatment furnace 2 in the housing 1. A moving mechanism (boat elevator) 4 is provided.

On the other hand, an opening 5 having a door (not shown) is provided on the front surface of the housing 1, and a wafer cassette containing a semiconductor wafer (not shown) to be processed in the housing 1 from the opening 5. 6 can be loaded and unloaded.

That is, in the case of the present embodiment, a carrier IO configured to be able to mount two wafer cassettes 6 at a time in a substantially horizontal state (a state in which semiconductor wafers are vertical) is provided in the opening 5.
A port 7 is provided, and a carrier transfer 8 for carrying the wafer cassette 6 is provided behind the carrier IO port 7. The carrier IO port 7 has a wafer alignment mechanism (not shown) for aligning semiconductor wafers in the wafer cassette 6 in a predetermined direction using an orientation flat, and performs horizontal-vertical conversion by rotating the wafer cassette 6. A horizontal-vertical conversion mechanism (not shown) is provided. After the semiconductor wafers in the wafer cassette 6 are aligned in a predetermined direction by the wafer alignment mechanism, the wafer cassette 6 is vertically moved by the horizontal-vertical conversion mechanism ( The wafer cassette 6 is transported by a carrier transfer 8 after that.

Behind the carrier transfer 8, a carrier stage 9 is provided at the upper part, and a transfer stage 10 is provided at the lower part.
A wafer transfer 11 for transferring a semiconductor wafer is provided behind the transfer stage 10. The carrier stage 9 is configured to be able to store a plurality of, for example, eight wafer cassettes 6 in a shelf shape, and temporarily stores the wafer cassettes 6 carried into the housing 1. On the other hand, transfer stage 10
Is configured such that, for example, two wafer cassettes 6 can be accommodated in a correctly positioned state, and between the wafer cassette 6 accommodated in the transfer stage 10 and the wafer boat 3 provided on the boat elevator 4. The transfer of the semiconductor wafer is performed by the wafer transfer 11.

Further, as shown in FIG. 1, two maintenance doors 12 are provided on the side of the boat elevator 4 and the wafer transfer 11 of the housing 1 (on the left side when viewed from the front of the housing 1). As shown in FIG. 3, the maintenance door 12 has a built-in fan 13 and a filter 14 for removing dust, which clean the air taken in from the lower side and clean the inner side almost from the front. It is configured to deliver air. Also, these maintenance doors
An exhaust portion 15 is provided on the opposite side of the housing 1 (on the right side when viewed from the front of the housing 1) so as to face the housing 12. It is configured to discharge (partially recirculate under the floor) to the rear of the housing 1.

Then, as shown by arrows in FIG. 1, the air taken into the housing 1 from the ceiling opening 16 of the housing 1 is moved from the upper part to the lower part to the carrier stage 9, the carrier transfer 8, and the carrier IO port 7. And then once taken into the lower part of the floor, and then passed through the boat elevator 4, the wafer transfer 11, and the transfer stage 10,
The cleaning gas flow is formed from the maintenance door 12 to the exhaust unit 15 (from left to right when viewed from the front of the housing 1).

The carrier stage 9, the carrier transfer 8, and the carrier IO port 7 are provided with a fan for blowing air, a filter for removing dust, and the like (not shown). It is configured to prevent dust from adhering.

Next, the operation of the vertical heat treatment apparatus of the present embodiment having the above configuration will be described.

In advance, the heat treatment furnace 2 is set to a predetermined temperature in accordance with the processing to be performed, and the blower fan 13 provided on the maintenance door 12 and the blower fan provided on each section are driven, so that the inside of the housing 1 is First, a cleaning gas flow as shown by an arrow in FIG. 1 is formed. Then, two wafer cassettes 6 each accommodating a plurality of (for example, 25) semiconductor wafers having a diameter of, for example, 8 inches (20 cm) are placed at predetermined positions of the carrier IO port 7 by, for example, a transfer robot.

Then, the vertical heat treatment apparatus aligns the semiconductor wafers in the wafer cassette 6 in a predetermined direction by a wafer alignment mechanism (not shown), and thereafter places the wafer cassette 6 vertically rearward by a horizontal-vertical conversion mechanism (not shown). Semiconductor wafer is horizontal). Then, the wafer cassette 6 is transferred by the carrier transfer 8, and
Housed in carrier stage 9. By repeating such an operation, a desired number of wafer cassettes 6 are accommodated in the carrier stage 9.

Thereafter, the wafer cassette 6 of the carrier stage 9 is sequentially moved to the transfer stage 10, and the semiconductor wafer in the wafer cassette 6 is transferred to the wafer boat 3 provided on the boat elevator 4 by the wafer transfer 11.

When the transfer of the desired number of semiconductor wafers (for example, 100 or more) is completed, the boat elevator 4 is raised, the wafer boat 3 is loaded into the heat treatment furnace 2, and the desired number of semiconductor wafers are loaded for a predetermined time, at a predetermined temperature and in a predetermined atmosphere. When the heat treatment is completed and the processing is completed, the processed semiconductor wafer is unloaded in a procedure opposite to the above procedure.

As described above, in the vertical heat treatment apparatus of the present embodiment, during the above-described series of processing, each part where the semiconductor wafer as the processing target is located, that is, the carrier stage 9, the carrier transfer 8, the carrier IO port 7, the boat elevator 4,
A cleaning gas flow is formed at the portions of the wafer transfer 11 and the transfer stage 10.

In particular, in the lower part of the housing 1, a maintenance door is provided.
By means of a blower fan 13 and a dust removal filter 14 provided on the boat 12, the boat elevator 4, the wafer transfer 11 and the transfer stage 10 in the housing 1
A cleaning gas flow that flows in the lateral direction (from left to right when viewed from the front of the housing 1) is formed. Therefore, unlike, for example, a case where a cleaning gas flow is formed in these portions in the front-rear direction, a high-purity gas flow immediately after passing through the dust removal filter 14 is applied to the semiconductor wafer provided in each portion. Can be. As a result, it is possible to reliably prevent dust from adhering to the semiconductor wafer and improve the yield.

That is, for example, when a cleaning gas flow is formed in these portions in the front-rear direction, for example, the gas that has passed through the boat elevator 4 passes through the wafer transfer 11 and then passes through the transfer stage 10, The semiconductor wafer provided on the downstream side (in this case, the wafer transfer 11) is exposed to a gas stream having a low degree of cleanliness including dust, which may cause dust to adhere to the semiconductor wafer.

In addition, since the blower fan 13 and the dust removal filter 14 are provided in the maintenance door 12, there is no need to separately provide an installation space for these devices, and space can be saved.

The filter 14 for dust removal is attached to the maintenance door 12.
It is also conceivable to provide only the air blower 13 and the blower fan 13 at the lower part of the housing 1. However, if this configuration is adopted, the occurrence of leakage at the connection portion of the gas flow path between the blower fan 13 and the maintenance door 12 may be considered. Therefore, it is preferable to integrally provide the blower fan 13 and the dust removal filter 14 in the maintenance door 12 as in the present embodiment.
Further, in the present embodiment, two maintenance doors 12 are provided. However, this reduces the size of one maintenance door 12 and reduces the free space on the side of the housing 1 required for opening and closing the door. This is to reduce it. That is, for example, if one large maintenance door is provided, a large space is required on the side of the housing 1 to open and close the door, and a large dead space is generated.

Further, these maintenance doors 12 allow the boat elevator 4 in the housing 1 to be opened from the side of the housing 1, for example.
Since the wafer transfer 11, the transfer stage 10, and the like can be accessed, the maintenance performance can be improved. In particular, in the vertical heat treatment apparatus of this embodiment, 8
Since the boat elevator 4 and the wafer transfer 11 are arranged side by side in the front-back direction in the housing 1 to accommodate an inch semiconductor wafer, the depth of the housing 1 becomes longer,
For example, if a maintenance door or the like is provided behind the housing 1, the maintenance of the wafer transfer 11 and the like will be significantly deteriorated. However, since the wafer transfer 11 and the like can be accessed from the side by the maintenance door 12, it is possible to ensure the maintainability for these.

[Effects of the Invention] As described above, according to the vertical heat treatment apparatus of the present invention, it is possible to reliably prevent dust from adhering to an object to be processed, to improve the yield, to save space, and to perform maintenance. Performance can be improved.

[Brief description of the drawings]

1 and 2 are diagrams showing the configuration of a vertical heat treatment apparatus according to one embodiment of the present invention, and FIG. 3 is a diagram showing the main configuration of the vertical heat treatment apparatus according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Heat treatment furnace, 3 ... Wafer boat, 4
…… Vertical movement mechanism (boat elevator), 5… Opening,
6 Wafer cassette 7 Carrier IO port 8
... Carrier transfer, 9 ... Carrier stage, 10
…… Transfer stage, 11 …… Wafer transfer, 12 …… Maintenance door, 13 …… Blower fan,
14 ... Dust removal filter, 15 ... Exhaust part, 16 ... Ceiling opening.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/02 H01L 21/22-21/24 H01L 21/31 H01L 21/322-21/326

Claims (5)

(57) [Claims] 1. A housing having an opening for loading / unloading an object to be processed on a front surface thereof, a heat treatment furnace provided substantially vertically on a rear upper portion in the housing, and a heat treatment furnace in the housing below the heat treatment furnace. A vertical movement mechanism for loading and unloading the processing object into the heat treatment furnace; and And a mechanism for forming a cleaning gas flow flowing in a direction. 2. A mechanism for forming a flow of the cleaning gas, comprising: a fan for blowing air and a filter for removing dust attached to a maintenance door provided on a side surface of the housing. 2. The vertical heat treatment apparatus according to 1. 3. A housing having an opening for loading and unloading a cassette containing an object to be processed, a heat treatment furnace provided substantially vertically in an upper part of the housing, and the heat treatment furnace in the housing. A vertical movement mechanism for loading and unloading an object to be processed provided in a boat into the heat treatment furnace, provided in a lower portion of the boat, A carrier stage configured to accommodate a cassette; a carrier transfer configured to transport the cassette in the housing; and a transfer configured to transfer the workpiece between the cassette and the boat. Vertical heat treatment apparatus. 4. The carrier stage has a fan for blowing air and a filter for removing dust, and a mechanism for applying a cleaning gas flow to a cassette housed in the carrier stage. The vertical heat treatment apparatus described in the above. 5. The method according to claim 5, further comprising purifying air taken in from an upper portion of the housing, from a rear side of the carrier stage to a front side, and then descends once through an arrangement portion of the carrier transfer and a vicinity of the opening. A mechanism for forming a cleaning gas flow which reaches a bottom portion, and thereafter forms a cleaning gas flow flowing from one side surface of the housing to an opposite side surface in a lateral direction at a position where the vertical movement mechanism is disposed. 4. The vertical heat treatment apparatus according to 3.