JP3871112B2 - Substrate processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately measure film thickness after a film forming processing without installing separately a film thickness measuring room and a film thickness measuring unit or without installing separately a film thickness measuring process. SOLUTION: Substrate processing parts 7 and 9 performing a substrate processing, and a substrate transport part 12 transporting a substrate between the substrate processing parts and substrate storage parts 3 and 20, are arranged. A film thickness measuring device 16 for measuring film thickness formed on the surface of the substrate is disposed in the operation range of the substrate transport part. The film thickness measuring device has a measuring head 16b which can be moved between a measuring position and a saving position giving no interference to substrate transport.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing apparatus for manufacturing a semiconductor device by forming various insulating films and electrode films on a substrate such as a silicon wafer, or performing an etching process, particularly a substrate processing capable of measuring a film thickness after the film forming process. It relates to the device.
[0002]
[Prior art]
When manufacturing semiconductor devices, it is necessary to know the film thickness and film thickness distribution after film formation in order to control the film formation state and to improve the quality and yield of semiconductor devices. is there.
[0003]
As a substrate processing apparatus, there is a batch type substrate processing apparatus that processes a required number of sheets at once, a single wafer type substrate processing apparatus that processes one or two pieces individually, and in a batch type substrate processing apparatus, A plurality of monitor wafers are interposed between product wafers, and the film thickness is measured on the monitor wafers after film formation.
[0004]
The film thickness quality and film thickness uniformity of the batch processed wafer are judged from the result of the film thickness measurement of the monitor wafer, and are reflected in the setting of conditions for the next substrate processing.
[0005]
Conventionally, a film thickness measuring chamber provided with a film thickness measuring device is provided, and a monitor wafer is taken out from the substrate processing apparatus after the film forming process, and the film thickness is measured in the film thickness measuring chamber.
[0006]
Alternatively, a film thickness measurement unit equipped with a film thickness sensor is provided in the vicinity of the substrate processing apparatus, the monitor wafer is taken out of the substrate processing apparatus after the film formation process, and the film thickness measurement unit measures the film thickness.
[0007]
[Problems to be solved by the invention]
The film thickness measurement performed in the conventional film thickness measurement chamber of the above-described conventional chamber has a problem that the management of the film thickness abnormality cannot be performed immediately after the substrate processing.
[0008]
Further, when the film thickness measuring unit is provided in the vicinity of the substrate processing apparatus, the manufacturing cost of the substrate processing apparatus is increased, and a space for housing the film thickness measuring unit is required in the clean room, and the clean room is enlarged. Further, if the film thickness measurement is incorporated into one of the film thickness processing steps, a process of taking out the monitor wafer and measuring the film thickness is required, which causes a problem that the entire processing process becomes complicated and throughput is lowered.
[0009]
In view of such circumstances, the present invention enables film thickness measurement to be performed immediately after a film forming process without separately providing a film thickness measuring chamber and a film thickness measuring unit or without providing a film thickness measuring step. It is.
[0010]
[Means for Solving the Problems]
The present invention includes a substrate processing unit that performs substrate processing, and a substrate transport unit that transports a substrate between the substrate processing unit and the substrate storage unit, and the substrate surface is within the operating range of the substrate transport unit. Substrate processing having a film thickness measurement device for measuring the film thickness formed, and having a measurement head that is movable between the measurement position and a retreat position that does not interfere with substrate conveyance of the substrate conveyance unit It concerns the device.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
First, the substrate processing apparatus will be described with reference to FIGS.
[0013]
A cassette stage 2 is provided on the front surface of the housing 1, a cassette shelf 3 is provided behind the cassette stage 2 inside the housing 1, and a spare cassette shelf 4 is provided above the cassette stage 2. Yes. A cassette elevator 5 is provided between the spare cassette shelf 4, the cassette stage 2 and the cassette shelf 3, and a cassette transport robot 6 is provided in the cassette elevator 5.
[0014]
A reaction furnace 7 composed of a reaction tube 23, a heater 24, and the like is provided above the rear portion of the housing 1, and a boat elevator 8 is provided below the reaction furnace 7. The boat elevator 8 causes the boat 9 to The reactor 7 is charged and removed. A wafer elevator 11 is provided between the boat elevator 8 and the cassette shelf 3, and the wafer transport robot 12 is moved up and down by the wafer elevator 11.
[0015]
The wafer transfer robot 12 includes a turntable 17 that is moved up and down by the wafer elevator 11 and a plate holder 18 that can be moved back and forth on the turntable 17, and a required number (for example, five) of substrates by the plate holder 18. A transfer plate 13 is held. The wafer transfer robot 12 can transfer the required number of wafers (up to 5 in the figure) at a time by raising and lowering the wafer elevator 11, rotating the turntable 17, and moving the plate holder 18 forward and backward.
[0016]
Thus, the substrate processing apparatus mainly includes a cassette transfer unit including the cassette stage 2, a wafer storage unit including the cassette shelf 3, the spare cassette shelf 4 and the cassette 20, and a wafer transfer including the wafer transfer robot 12. And a wafer processing unit including the reaction furnace 7 and the boat elevator 8.
[0017]
As shown in FIGS. 3 to 7, the lowermost substrate transfer plate 13 a is supported by a separation plate holder 19, and the separation plate holder 19 can move forward and backward together with the plate holder 18. It is possible to advance and retreat independently. Thus, wafers can be transferred one by one by the independent movement of the separation plate holder 19. The separation plate holder 19 may be configured to support the uppermost substrate transfer plate 13.
[0018]
The required position of the cassette shelf 3 is an empty shelf 14, and a film thickness measuring device 16 is provided on the lower surface of the upper shelf plate 15 of the empty shelf 14.
[0019]
The film thickness measuring device 16 has a measuring unit main body 16a and a measuring head 16b, and the measuring unit main body 16a has a driving machine (not shown) such as a cylinder, and the driving machine moves the measuring head 16b to the wafer. Advancing and retreating toward the transfer robot 12 is possible.
[0020]
The film thickness measuring device 16 irradiates the wafer surface with measurement light as a measurement medium, reflects the measurement light on the wafer surface, and receives the reflected light. The reflection of the measurement light depends on the state of the film thickness formed on the wafer surface, and the film thickness can be measured by measuring the change of the reflected light state, for example, the polarization state.
[0021]
The result detected by the film thickness measuring device 16 is sent to a control unit (not shown), and the control unit determines whether there is an abnormality in the film thickness.
[0022]
In the figure, reference numeral 25 denotes a furnace port lid for closing the furnace port of the reaction furnace 7 when the boat 9 is lowered.
[0023]
Next, an outline of substrate processing will be described.
[0024]
The cassette 20 is transported to the cassette stage 2 by an external transport device (not shown), and the cassette 20 is further moved in cooperation with the raising / lowering of the cassette elevator 5, the advance / retreat, rotation, and traversal of the cassette transport robot 6. It is transported from the stage 2 to the cassette shelf 3 and further to the spare cassette shelf 4.
[0025]
The cassette shelf 3 has a wafer transfer position in which a cassette 20 to be transferred by the wafer transfer robot 12 is stored. The cassette 20 used for transferring a wafer is transferred by the cassette elevator 5 and the cassette transfer robot 6. It is moved to the wafer transfer position.
[0026]
The wafer 21 is transferred from the cassette 20 of the cassette shelf 3 to the boat 9 in the lowered state by the cooperation of the advance / retreat of the wafer transfer robot 12, rotation, and raising / lowering of the wafer elevator 11.
[0027]
When a predetermined number of wafers 21 are transferred to the boat 9, the boat elevator 8 loads the boat 9 into the reaction furnace 7, the wafer 21 is heated in the reaction furnace 7, and a film forming material gas is used. Is supplied to the surface of the wafer 21 by the thermally decomposed gas.
[0028]
When the processing on the wafer 21 is completed, the boat 9 is pulled down from the reaction furnace 7 by being lowered by the boat elevator 8, and further the cassette 20 of the cassette shelf 3 from the boat 9 by the wafer transfer robot 12. Then, the processed wafer 21 is transferred.
[0029]
As described above, monitor wafers are loaded in the boat 9 for each required number of product wafers. When the monitor wafer is transferred by the wafer transfer robot 12, the transfer operation of the wafer transfer robot 12 is controlled so as to be held by the lowermost substrate transfer plate 13a of the substrate transfer plate 13. Is done.
[0030]
When the wafer transfer robot 12 transfers a processed wafer and includes a monitor wafer, the film thickness of the monitor wafer is measured by the film thickness measuring device 16 before being transferred to the cassette 20.
[0031]
When the film thickness measurement of the monitor wafer is completed, transfer to the cassette 20 is performed.
[0032]
The measurement of the film thickness of the monitor wafer will be described with reference to FIGS.
[0033]
FIG. 3 shows the position immediately before or after the film thickness measurement, and also shows the home position of the film thickness measuring device 16.
[0034]
When the wafer transfer robot 12 holds the processed wafer 21 including the monitor wafer 21a from the boat 9, as shown in FIG. 3 and FIG. Moving.
[0035]
At the home position of the film thickness measuring device 16, the measuring head 16 b is retracted and is approximately stored in the cassette shelf 3. That is, at the retracted position of the measuring head 16b, the wafer transfer operation by the wafer transfer robot 12 is not hindered.
[0036]
When the measurement is started, the measurement head 16b moves forward to the measurement position. Next, only the substrate transfer plate 13 a holding the monitor wafer 21 a moves forward by the advancement of the separation plate holder 19.
[0037]
It is assumed that the amount of movement is small and the peripheral edge of the monitor wafer 21a reaches the measurement point of the measurement head 16b. The film thickness is measured at the peripheral measurement point A (see FIGS. 4 and 9).
[0038]
The separation plate holder 19 further advances, and the substrate transfer plate 13a is moved so that the measurement point B becomes the center of the monitor wafer 21a. The film thickness is measured at the measurement point B (see FIGS. 5 and 10).
[0039]
Further, the separation plate holder 19 moves the substrate transfer plate 13a forward so that the measurement point becomes the measurement point C on the periphery of the monitor wafer 21a opposite to the measurement point A. The film thickness is measured at the measurement point C (see FIGS. 6 and 11). The amount of movement of the separation plate holder 19 reaching the measurement point C is the maximum amount of movement of the separation plate holder 19 in the film thickness measurement. As shown in FIGS. This is a part of the operation amount at the time of transfer, and is within the range of operation that the wafer transfer robot 12 has for transferring the wafer.
[0040]
The separation plate holder 19 is moved backward by a predetermined amount and the turntable 17 is rotated 45 ° counterclockwise in FIG. The measurement point D is the periphery of the monitor wafer 21a rotated 90 ° clockwise from the measurement point A. The film thickness is measured at the measurement point D (see FIGS. 7 and 12).
[0041]
The turntable 17 is rotated 90 ° clockwise. The measurement point E is the periphery of the monitor wafer 21a rotated 90 ° counterclockwise from the measurement point A. That is, it is on the opposite side of the measurement point D. The film thickness is measured at the measurement point E (see FIGS. 7 and 13).
[0042]
The turntable 17 rotates 45 ° clockwise, the separation plate holder 19 moves backward, the measurement head 16b moves backward to the home position, and the film thickness measurement is completed.
[0043]
In addition, although the measurement point of the said film thickness measurement demonstrated five typical points, the film | membrane of the arbitrary positions of the whole surface of the said monitor wafer 21a by the cooperation of rotation of the said turntable 17 and the advance / retreat of the said separation plate holder 19 was carried out. Thickness measurement is possible. Needless to say, the film thickness is not contacted, and the film thickness can be measured not on the monitor wafer 21a but on the product wafer.
[0044]
The film thickness measurement is performed on a required monitor wafer, and the result of the film thickness measurement is input to the control unit of the substrate processing apparatus to determine whether the film thickness is normal or abnormal.
[0045]
When an abnormality is determined, the determination result is displayed on a predetermined display unit and reflected in the next batch process. That is, the film forming conditions are adjusted so as to correct the film thickness, or when there is a possibility of product failure, a warning is issued and the processing is stopped.
[0046]
As described above, in the film thickness measurement of the present invention, the film thickness measurement device 16 is provided using the space inside the substrate processing apparatus, and is further provided within the operable range of the wafer transfer robot 12. Therefore, it may be on the wafer transfer operation path of the wafer transfer robot 12 or may be a position deviated from the wafer transfer operation path.
[0047]
In particular, when the film thickness measuring device 16 is provided in the empty space in the cassette shelf 3 described above, it is not necessary to change the shape and structure of the cassette shelf 3, the casing 1, and the like. In addition, since the measurement point is selected and changed using the transfer operation of the wafer transfer robot 12, there is no need to change the structure of the wafer transfer robot 12, and a special mechanism for measuring the film thickness is provided. There is no need to provide it.
[0048]
In the above embodiment, the film thickness measuring device 16 is provided on the empty shelf 14 of the cassette shelf 3, but it may be provided at a position that does not hinder the transfer operation of the wafer transfer robot 12, for example, at the end of the cassette shelf 3. . Furthermore, it is not limited to the cassette shelf 3 and may be provided within the operation range of the wafer transfer robot 12. Further, if the measuring head 16b is moved forward and backward and the measuring head 16b is moved to move the measurement point in the front-rear direction, the wafer transfer robot 12 only needs to rotate the turntable 17 during measurement. .
[0049]
Further, the present invention is not limited to a batch type substrate processing apparatus, and it is needless to say that even a single wafer type substrate processing apparatus can be implemented as long as the substrate processing apparatus includes a substrate transfer robot.
[0050]
【The invention's effect】
As described above, according to the present invention, a substrate processing unit that performs substrate processing and a substrate transfer unit that transfers a substrate between the substrate processing unit and the substrate storage unit are provided. A film thickness measuring device for measuring the film thickness formed on the substrate surface is provided within the range, and the film thickness measuring device is movable between a measurement position and a retreat position that does not interfere with the substrate conveyance of the substrate conveyance unit. Since it has a measuring head, it is possible to measure the film thickness immediately after the film forming process without providing a film thickness measuring chamber and a film thickness measuring unit or without providing a film thickness measuring process. Can be reflected in the next process, and it has the excellent effect of improving yield and product quality.
[Brief description of the drawings]
FIG. 1 is a schematic overall perspective view of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic side view of the substrate processing apparatus according to the previous embodiment.
FIG. 3 is an explanatory diagram viewed from the side showing the operation of film thickness measurement in the previous embodiment.
FIG. 4 is an explanatory view seen from the side showing the operation of film thickness measurement in the previous embodiment.
FIG. 5 is an explanatory view seen from the side showing the operation of film thickness measurement in the previous embodiment.
FIG. 6 is an explanatory view seen from the side showing the operation of film thickness measurement in the previous embodiment.
FIG. 7 is an explanatory view seen from a side surface showing an operation of film thickness measurement in the same embodiment.
FIG. 8 is an explanatory view seen from a plane showing the operation of film thickness measurement in the previous embodiment.
FIG. 9 is an explanatory view seen from a plane showing the operation of film thickness measurement in the previous embodiment.
FIG. 10 is an explanatory view seen from a plane showing the operation of film thickness measurement in the previous embodiment.
FIG. 11 is an explanatory view seen from a plane showing the operation of film thickness measurement in the previous embodiment.
FIG. 12 is an explanatory diagram viewed from a plane showing the operation of film thickness measurement in the previous embodiment.
FIG. 13 is an explanatory view seen from a plane showing the operation of film thickness measurement in the previous embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 2 Cassette stage 3 Cassette shelf 5 Cassette elevator 6 Cassette transfer robot 7 Reactor 8 Boat elevator 9 Boat 12 Wafer transfer robot 16 Film thickness measuring device 16b Measuring head 20 Cassette

Claims (1)

A substrate processing unit that performs substrate processing, and a substrate transfer unit that transfers a substrate between the substrate processing unit and the substrate storage unit, and the film is formed on the substrate surface within the operation range of the substrate transfer unit A substrate having a film thickness measuring device for measuring a film thickness, the film thickness measuring device having a measuring head movable between a measurement position and a retracted position that does not interfere with substrate conveyance of the substrate conveyance unit Processing equipment.

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