JPS6022499B2 - Wafer processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer processing apparatus for cleaning the main surface of a semiconductor thin plate (wafer) used in the manufacture of semiconductor devices.

In the manufacture of semiconductor devices, there is a wafer processing step in which impurity atoms are partially diffused into the wafer and an insulating film, wiring film, etc. are partially formed on the surface of the wafer. Since this wafer processing step requires partial processing, the main surface of the wafer is partially masked with a photoresist film before processing. In other words, after coating the entire main surface of the wafer with photoresist,
The mask is formed by partially exposing the photoresist and removing the exposed or non-exposed areas by development. By the way, since positive photoresists have a lower molecular structure than negative photoresists, they have poor adhesion with wafers and have the disadvantage of being easily peeled off from the wafer.

Such peeling of the photoresist results in inaccurate masking, which prevents proper processing and reduces yield. In order to prevent the photoresist from peeling off, before applying the photoresist A commonly used method is to clean the main surface of the wafer by washing it with pure water.

After cleaning, the wafer is heated and dried to remove moisture from the main surface. However, it has been found that even with such drying, moisture (hydroxyl groups) remains on the main surface of the wafer, reducing the adhesion of the photoresist. Therefore, the subordinate
A technique has been developed to clean the wafer by spraying a processing gas (for example, hexamethyl G silazane gas) on the main surface of the wafer after drying to decompose and evaporate water (hydroxyl groups). Incidentally, this process gas spraying is performed using a device as shown in FIG.

That is, a cartridge 2 containing a wafer is placed in a hot air circulation furnace 1, and a conduit 3 is inserted into the hot air circulation furnace 1.
Nitrogen gas containing muxamethyl G silazane is introduced through the reactor. One end of the conduit 3 is connected to the upper part of the supply gas chamber 4 . In addition, a hexamethyl G silazane solution (processing liquid) 5 is placed in the Tosonsha gas chamber 4, one end of a supply pipe 6 is inserted into this processing liquid 5, and nitrogen is supplied from one end of the supply pipe 6. Gas is blown out. As a result, the nitrogen gas rising in the form of bubbles in the processing liquid 5 contains hexamethyl G silazane, and the nitrogen gas containing this processing gas enters the hot air circulation furnace 1 through the conduit 3. . However, such a device has the following drawbacks. {11 Although it is a circulation furnace, it is extremely difficult to uniformly disperse the processing gas throughout the room, and there is a drawback that uniform processing cannot be performed.

'2) After processing is completed, the door of the hot air circulation furnace is opened, the cartridge is removed, a new cartridge is inserted, and processing is started again. Because this is a batch process, the atmosphere inside the furnace (temperature, processing gas, etc.) is changed each time the cartridge is replaced. concentration, distribution) are destroyed.

Therefore, processing time becomes longer and workability becomes lower. If cleaning, drying and purifying the glue wafer is viewed as a series of operations, it takes a lot of time and effort to transfer the wafer.

Therefore, an object of the present invention is to improve the processing efficiency such as the cleanliness of wafers, to make the cleanliness uniform, and to reduce the number of man-hours by employing automation.

The present invention will be explained in detail below with reference to Examples. FIG. 2 and FIG. 3 are a front view and a plan view showing the outline of a basket shelf of a wafer cleaning apparatus according to an embodiment of the present invention.

As can be seen from these figures, this wafer cleaning apparatus has a loading mechanism 7, a transfer mechanism 8, a cleaning mechanism 9, a drying mechanism 10, a cleaning mechanism 11, and an unloader mechanism 12 arranged in order from left to right. . Next, each of the above mechanisms will be explained.

The loading mechanism 7 includes a table 15 that holds cartridges 14 that accommodate wafers 13 in a stacked manner, and a pusher that is disposed behind the table 15 and pushes out the wafers 18 of the cartridges 14 stacked on the table 15 and sends them forward. Consists of 16. Further, the table 15 is moved up and down using a male screw provided on a support 17 that supports the table 15. Therefore, table 15 is 1
The wafers 13 in the cartridge 14 are pushed out one by one by the pusher 16 each time the wafers 13 are lowered by pitches, and transferred to the transfer mechanism 8. The transfer simulator 8 consists of a flat moving plate 19 having a long bifurcated finger portion 18, and the wafer 13 fed from the loading mechanism 7 is placed at the base of the finger portion of the moving plate 19, i.e. U-shaped groove 20
(This is called the loader side direct part 21.)

). Further, a spinner-side layer portion 22 for layering the wafer 13 is provided at the tip of the finger portion 18, and the pitch therebetween is constant a. Also, as shown by the arrow group in FIG.
and then move forward one pitch again. Thereafter, after descending by b, it retreats by 2 pitches 2a and enters a state in which it receives the wafer 13 from the loading mechanism 7 (wafer receiving state). When the movable plate 19 is in the wafer receiving state, the cleaning mechanism 9 includes a spinner (rotating disk) 24 rotated by a motor 23 located on the forward side a distance a from the spinner side calendar section 22, and a spinner (rotating disk) 24 located above the spinner 24. It consists of a radially extending cylindrical brush 25 that is positioned and rotates while descending during cleaning, and a cleaning liquid supply pipe 26 that supplies pure water.

Although not shown, a suction hole for vacuum suction is provided on the wafer holding surface of the spinner 24, so that the wafer 13 sent onto the spinner 24 is held by vacuum suction. Further, the diameter of the spinner 24 is formed smaller than the interval between the two fingers 27 and 28 of the finger portion 18 of the transfer mechanism 8, and when the moving plate 19 is raised and lowered, the fingers 27 and 28 are
8 does not hit the spinner 24. The drying mechanism 10 includes a drying oven 30 including a heater 29 consisting of an infrared lamp extending along the center;
0 and a belt conveyor 31 extending through the lower part of the belt.

Further, the spinner side end of the belt conveyor 31 is connected to the spinner 2
The wafer 13 is located at a position approximately a distance away from the position 4, and receives the wafer 13 carried on the spinner side counterfeit portion 22 of the moving plate 19 in a stacked manner. Therefore, in order to prevent interference between the belt conveyor 31 and the movable plate 19, the width of the belt conveyor 31 is set so that the fingers 27 and 2, like the spinner, do not interfere with each other.
It is narrower than the 8-space. The purification mechanism 11 is located at the end of the belt conveyor 31 and includes a layer table 32 for cleaning the wafers 13 carried by the belt conveyor 31, and an injection pipe 33 for injecting processing gas for purification onto the loading table 32. , a guide 34 arranged in an umbrella shape at the tip of the injection pipe 33 to regulate the flow of the processing gas, and a processing gas flowing out from the green surrounding the guide 34 (for example, hexathymel G silazane: this gas smells and should not be recovered for sanitary reasons). That's not good.

) and a collection cylinder 37 having an exhaust hole 36. In addition, the layer table 32
has two rows of inclined ejection holes 38 that eject gas (nitrogen, etc.) from its upper surface along the wafer transfer direction, and uses the flowing gas to direct the wafers 13 sent from the belt conveyor 31 to the unloader mechanism 12 side. It is designed to be transferred to The loading table 32 is also provided with two stoppers 39 and 40, which are normally located below the upper surface of the loading table 32, but the wafer 13 is fed onto the loading table 32. The wafer 13 rises and presses the advancing end of the wafer 13 with its tip, stopping its advancement. Further, the drying oven 30 and the purification mechanism 11 are covered with a cover 41, and the inside of this cover 41 is hollow, and the cooling water 42 is covered with a cover 41.
It is designed to be cooled by flowing water. In addition, the cover 41
An exhaust hole 43 is provided in the purification mechanism 11 to exhaust hot air and gas inside the purification mechanism 11. The unloader mechanism 12 includes a table 45 that holds cartridges 44 that accommodate the wafers 13 in a stacked manner.
5 is supported by a column 46 having a female thread on its outer circumferential surface.

The table 45 is moved up and down using this male screw. As a result, the table 45 moves down one pitch at a time, and sequentially stores the cleaned wafers 13 from the lower stage of the cartridge 44 toward the upper stage. Next, wafer cleaning work will be explained.

The wafer 13 in the cartridge 14 in the loading mechanism 7 is pushed onto the loader side layer part 21 of the moving mechanism 8 by the pusher 16.

Then, the moving plate 19 of the moving mechanism 8 moves forward by 1 pitch a,
The finger section 18 is positioned directly below the spinner 24, and then raised by a distance b, and receives the wafer 13 cleaned with pure water by the brush 25 placed on the spinner 24 on the spinner-side copying section 22 of the finger section 18. lift.
At this time, the brush 25 that performs the cleaning operation and the cleaning liquid supply pipe 26 that supplies pure water both rise to avoid colliding with the movable plate 19. Next, the wafer 13 before and after cleaning
The movable plate 19', which has each of The wafer 13 on the section 21 is placed on the spinner 24, and the spinner 24 moves backward two pitches 2a to return to the initial position in preparation for receiving the next wafer 13 sent from the loading mechanism 7.

On the other hand, in the cleaning mechanism 9, the brush 25 and the cleaning liquid supply pipe 26 are lowered, and pure water is spouted onto the wafer 13 from the cleaning liquid supply pipe 26, and the brush 25 is rotated to scrub the upper surface of the wafer 13 for cleaning. do.

At this time, the wafer 13 on the spinner 24 is held by the spinner 24 by vacuum suction and rotated by the rotation of the motor 24, thereby achieving effective cleaning. After being cleaned for a certain period of time, both the brush 25 and the cleaning liquid supply pipe 26 rise, and then,
The spinner 24 stops rotating. On the other hand, the wet wafer 13 placed on the belt conveyor 31 is carried into the drying oven 30 by the belt conveyor 31, and is dried while being moved by the heater 29.

The wafer 13 sent from the end of the belt conveyor 31 onto the counterfeit table 32 of the purification mechanism 11 is moved on the stacking table 32 by the gas flowing out from the jet hole 38, and is temporarily placed on the counterfeit table 32. It is stopped at the stereotactic layer by protruding stoppers 39, 40. In addition, in this state, a processing gas (for example, hexamethyl G silazane) is sprayed toward the wafer 13 from the injection pipe 33 located directly above the wafer 13 to decompose moisture (hydroxyl groups) adhering to the surface of the wafer 13. Evaporate. The evaporated dirty processing gas is guided to the hood 35 and exhausted to the outside from the exhaust hole 36. On the other hand, when receiving time processing gas, the calendar table 3
The stoppers 39 and 40 protruding from above 2 are lowered, and the wafer 13 is moved by the gas (nitrogen, etc.) ejected from the ejection hole 38 to move the cartridge 44 of the analog loader mechanism 12.
Go inside. According to the apparatus of the embodiment, the following effects can be obtained.

(1- Since the series of wafer cleaning, drying, and purification operations are automated, the processing conditions are almost constant, quality is stable, and workability (productivity) is improved.

(2) Since wafers are processed one by one and each process is performed over the entire processing surface, the degree of wafer purification is higher than in the past.

'3} The drying mechanism and purification mechanism have a structure in which a thin wafer passes through the processing atmosphere, and the entrances and exits are thin, so the processing atmosphere does not change significantly due to the entry and exit of the wafer. This eliminates the need for a large amount of time to adjust the processing atmosphere after loading and unloading wafers, as in secondary batch processing, and reduces the number of man-hours.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be applied to processing apparatuses that perform various types of processing on processing objects such as wafers.

As described above, according to the wafer processing apparatus of the present invention, it is possible to improve the processing level such as the cleanliness of the wafer, stabilize the quality, and reduce the manufacturing cost by reducing the number of man-hours. can.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of a subordinate wafer cleaning device, Fig. 2 is a partially sectional front view schematically showing a wafer cleaning device which is an embodiment of the present invention, and Fig. 3 is the same. FIG. 1...Hot air circulation furnace, 2...Cartridge, 3
... Conduit, 4 ... Supply gas chamber, 5 ...
...Processing liquid, 6... Supply V supply pipe, 7...
Loading mechanism, 8... Transfer sword mechanism, 9...
...Washing mechanism, 10...Drying mechanism, 1 1...
・・Total amount, 12・・・・Unloader mechanism, 1
3...Wafer, 14...Cartridge, 15...
...Table, 16...Busha, 17...
...Strut, 18...Finger part, 19...Moving plate, 20...U-shaped groove, 21...Loader side battle layer part,
22...Spinner side bed layer part, 23...Motor, 24...Spinner, 25...Brush, 26...Cleaning liquid supply pipe, 27 , 28...finger, 29...heater, 30...drying oven, 31...
... Belt conveyor, 32 ... Layering table, 33 ... Injection pipe, 34 ... Guide,
36...Hood, 36...Exhaust hole, 3
7...Recovery tube, 38...Blowout hole, 39
, 40...Stopper, 41...Cover, 42...Cooling water, 43...Exhaust hole,
44...cartridge, 45...table, 46...
...Strut. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1: a loading mechanism that sequentially delivers a plurality of wafers accommodated in a cartridge one by one; an unloading mechanism that sequentially accommodates a plurality of wafers delivered by the loading mechanism into a cartridge one by one; and the loading mechanism and the unloading mechanism. A wafer surface washing processing unit that washes the wafer surface with water, a wafer drying unit that heats and dries the wafer, and a processing gas injection unit that injects a processing gas that evaporates water on the wafer surface, which are installed between the wafer surface and the wafer surface. The wafer surface washing processing section includes a processing mechanism having a processing section, and a wafer transfer mechanism that is provided between the loading mechanism and the unloading mechanism and transfers the wafer from the processing section of the processing mechanism to the processing section. The wafer drying section has a rotary table on which the wafers are placed one by one, and a brush that scrubs the surface of the wafers placed on this table. The processing gas injection unit has a table on which wafers are placed one by one, a hood that covers the table, and a processing gas injection pipe that injects processing gas from inside the hood to the wafers on the table. A wafer processing device before photoresist coating, which is characterized by: