JPS6253945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor wafer processing interval conversion apparatus used for automating the manufacturing process of semiconductor devices.

In the manufacturing process of semiconductor devices, thermal diffusion treatment,
There are treatment processes that use so-called horizontal heating furnaces, such as CVD (chemical vapor deposition) treatment or annealing treatment.
In these processing steps, it is desired to automate the series of steps in which the semiconductor wafers are taken out of the cassette, arranged at regular intervals and transferred to a heating furnace, and then returned to the original cassette after the processing is completed. The procedure for this type of work when using conventional equipment is (i) taking out the semiconductor wafers from the cassette with tweezers, (ii) using tweezers to line up the wafers on a boat with a predetermined pitch, and (iii) placing the wafers on the boat. (iv) Hold the boat cradle in your hand and move the boat into the furnace core tube. (v) Pull the boat insertion rod onto the boat to operate the boat loader and place the boat in the center of the furnace core tube. (vi) Inserting the boat will lower the temperature inside the furnace core tube, wait for it to recover, then inject gas and perform processing such as diffusion or CVD.
(vii) After the processing is completed, the above operations (v) to (i) are performed in reverse order, and the processed wafers are stored in the same original cassette. Of these work steps, only the steps from (v) boat loader work to (vi) in-furnace main processing are automated; all other work is done manually.

In view of the above-mentioned points, the present invention has been devised to automatically process semiconductor wafers stored in a storage container (cassette) in order to automate the processing process using a horizontal heating furnace in the manufacture of semiconductor devices. The object of the present invention is to provide a semiconductor wafer processing interval converting device that can convert the processing interval to a required processing interval according to the requirements and transfer the processing interval to a processing boat.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows an entire semiconductor manufacturing apparatus equipped with a semiconductor wafer processing interval converting apparatus according to the present invention. This semiconductor manufacturing equipment takes out the wafers from a container (cassette) containing a plurality of objects to be processed, that is, semiconductor wafers, supports them in an array at regular intervals, inserts them into a designated heating furnace, and performs a predetermined process (diffusion). , CVD, annealing, etc.) and storing the processed wafers back into their original cassettes. , a control operation unit 1 that automatically controls all of the above-mentioned work processes by a microcomputer, and a plurality of storage containers (12 in this example) that store a plurality of semiconductor wafers 3 and are each assigned a code number. 2 [2A, 2B...2L], a processing section 4 equipped with, for example, three heating furnaces 4A, 4B, 4C arranged vertically, and a transfer section for transferring wafers 3 between the cassette 2 and the processing section 4. It comprises a device 5. Each cassette 2 has a box shape with one opposing side surface open, and each cassette 2 has, for example, 25 semiconductor wafers 3 for one lot stacked at a predetermined pitch (for example, 4.76 mm pitch) in the height direction. It is stored in a shape. The plurality of cassettes 2 are arranged in two rows as shown in FIG. 2, and are transported intermittently and cyclically one cassette at a time along the directions of arrows a, b, c, and d. The code number assigned to each cassette 2 is recognized and selected by the photosensor D when it reaches position _S0 . For this purpose, for example, four holes 10 are provided next to each cassette 2 so that the microcomputer can check them, and correspondingly reflective light emitting diodes D ₁ , D ₂ , D ₃ , D _{4 are} provided.
The photosensor D consists of a photo sensor D that distinguishes between reflected areas and non-reflected areas, generates a 4-bit hexadecimal signal, and digitizes the code number of the cassette.
The reflective parts are left with the same metal surface, and the non-reflective parts are covered with black rubber that does not reflect the infrared light from the light emitting diode. A mechanism 6 for cyclically transporting the cassettes 2 is provided with claws 7 disposed below the two rows of cassettes 2 and located between each cassette 2.
a pair of feed claw members 8A, 8B integrally having;
A pair of arms 9 provided corresponding to both ends of the row
It is composed of A and 9B. In this case, the feed claw member 8A is raised by the cylinder CY ₂ and each claw 7
is inserted between the cassettes and moved by one cassette in the direction of the arrow a by the rear cylinder CY ₁ , so that the cassettes 2A to 2F in one row are pushed by each claw 7 and transferred by one cassette, and the cassettes are 2A is brought to position _S0 . Next, the cylinder CY ₈ moves the arm 9A in the direction of arrow b to transfer the cassette 2A at position _S0 to the other row, and the cylinder CY ₉ moves the arm 9B in the direction of the arrow d to transfer the cassette 2A to the other row.
G is transferred to one column side. Subsequently, the feed claw member 8B is raised by the cylinder CY ₃ and moved in the direction of the arrow c by the cylinder CY ₄ , thereby moving the cassettes 2A, 2L...2H of the other row in the same manner as above.
is transferred by one cassette, and in this way each cassette 2 is transferred in a circular manner.

On the other hand, as shown in FIG. 3, the transfer device 5 includes a pitch conversion small case 12 for transferring the wafers 3 in the cassette 2 specified by the photosensor D to the cassette 2 at the same pitch as the cassette 2, and a small case 12 for pitch conversion. A large case 14 for pitch conversion is provided in which the wafers 3 are transferred one by one using an air bearing 13 and are arranged sequentially at a predetermined pitch. The small case 12 is located in a position close to and facing the cassette 2 brought to the position _S0 , and can be vertically moved one pitch at a time via a vertical moving means 15 including a pulse motor _M1 across an air bearing 13. will be distributed. In addition, in order to transfer the wafers 3 between the cassette 2 and the small case 12 specified at the position _S0 , a cylinder _CY7 is installed above the cassette 2 and the small case 12 as shown in FIG. a support 17 that moves up and down, and arms 16A and 16 held by this support 17 and driven in opposite directions by cylinders CY ₅ and CY ₆ , respectively.
A transfer mechanism 30 consisting of B is provided. In this transfer mechanism 30, for example, when transferring the wafer 3 from the cassette 2 to the small case 12, the support 17 is lowered by the cylinder CY ₇ , and then the cylinder CY ₅ is operated and the arm 16A moves in the direction of arrow H. inside the cassette 2 by the arm 16A.
Twenty-five wafers 3 are transferred into the small case 12 at one time. When transferring the wafer 3 from the small case 12 to the cassette 2, the cylinder CY ₆ moves the arm 16B in the direction of arrow Y.

The pitch conversion large case 14 is attached to the other end of the air bearing 13 so as to face the small case 12, and the vertical movement means 3 including the pulse motor M ₂ is connected to the other end of the air bearing 13 and straddles the same.
2 so that it can be moved up and down in the vertical direction one pitch at a time, and when it reaches the top, the motor
Constructed to fall horizontally by M ₃ . In this case, the large case 14 accommodates wafers 3 at a pitch of 4.0 mm, for example. When the pitch is 4.0 mm, 100 wafers 3 (4 cassettes) can be accommodated, and when the pitch is 8.0 mm, 50 wafers 3 (2 cassettes) can be accommodated. When the wafers 3 (for one cassette) have a pitch of 12.0 mm, 25 wafers 3 (for one cassette) can be accommodated. To transfer the wafers 3 from the small case 12 to the large case 14, the small case 12 containing the wafers 3 is lowered one pitch at a time, and the stacked wafers 3 are sequentially moved from the bottom along the air bearing 13 to the large case 14 side. The large case 14 is moved up one pitch at a time in synchronization with the lowering of the small case 12, and the wafers 3 are sequentially received from above. To transfer the wafer 3 from the large case 14 to the small case 12, move the small case 12 from the bottom to the top.
This is done by raising the large case 12 one pitch at a time and lowering the large case 12 from above one pitch at a time. When the wafers 3 have been transferred to the large case 14, the facets 31 (a portion of the wafer cut horizontally for alignment) of each wafer 3 are not aligned. Therefore, the means 1 for aligning the facets 31 of each wafer 3 together
8 is provided at the bottom of the large case 14. This means 18 is composed of, for example, a rod-shaped rotating body 33 which is in common rolling contact with the circumferential side of all the accommodated wafers 3 and rotated by a motor _M4 , and each wafer 3 is rotated by this rod-shaped rotating body 33. When the wafers 3 are rotated, the facets 31 of the wafers 3 hit the bar-shaped rotating body 33, and the rotation of the wafers 3 is stopped, thereby aligning the facets 31 of the wafers 3. Further, a wafer lift 19 for lifting all the wafers 3 housed in the large case 14 above the large case 14 is arranged at the lower part of the large case 14 . CY ₁₀ is a cylinder for moving the wafer lift 19 up and down.

Further, in the transfer device 5, as shown in FIG. 4, the wafers 3 housed in the large case 14 are collectively held and transferred onto the boat 20 of the designated heating furnace 4 [4A, 4B or 4C]. 2
1 is installed. The chuck 21 is arranged to be movable in the vertical direction via a vertical moving means (for example, a feed screw mechanism, etc.) 34 including a pulse motor _M6 , and horizontally via a horizontal moving means 35 including a motor _M5 . movably arranged. CY ₁₁ is a cylinder for opening and closing chuck 21. In addition, in the processing section 4 equipped with three heating furnaces 4A, 4B, 4C, heating furnaces 4A, 4B, 4
A boat 20 is provided corresponding to C, and this boat 20 has respective boat loader arms 36A, 36
B, 36C are connected and boat loaders 37A, 37
B and 37C are used to enter and exit the furnace. still,
A cradle 38 for receiving the boat 20 is provided near the outside entrance of each heating furnace 4A, 4B, 4C, and when the boat 20 is inserted into the furnace, the corresponding cylinder CY ₁₂ , CY ₁₃ , CY ₁₄ is inserted. It is moved sideways and placed in a standby state.

Next, the operation of this configuration will be explained.

For example, 25 semiconductor wafers for one lot 3
When a plurality of cassettes 2, in this example 12 cassettes 2, containing .
The cassette transfer mechanism 6 sequentially transfers one cassette at a time intermittently and cyclically. When the first cassette 2A is transferred to position _S0 , the code number of cassette 2A is confirmed by photosensor D, and if this cassette 2A is the designated one, a code number is sent to cylinder _CY7 as shown in FIG. Therefore, the support body 17 is lowered, and the arm 16A is attached to the cassette 2A.
facing the open side of the cylinder, then the cylinder
By moving the arm 16A in the direction of arrow H by CY ₅ so as to pass through the cassette 2A, all 25 wafers 3 in the cassette 2A are transferred into the small case 12 for pitch conversion. Next, the air bearing 13 is activated, and the lowermost wafer 3 facing the air bearing 13 is transferred on the air bearing 13, and the pitch conversion large case 1
Thereafter, the small case 12 is lowered one pitch at a time, and the wafers 3 are housed one by one from below at a pitch of 4 mm, for example, in the large case 14, which is raised one pitch at a time through an air bearing 13. (The pitch to be stored in the large case 14 can be freely selected such as 4 mm pitch, 8 mm pitch, 12 mm pitch, etc. by specifying the pitch that will rise intermittently to the large case 14 in advance.) Wafers for one cassette 3, the second, third, and fourth cassettes 2B, 2C, and 2 are placed in the same manner.
The wafers 3 of D enter from the next stage of the large case 14, and as shown in FIG.
A total of 100 wafers 3 D are housed in the large case 14. When all the wafers 3 in the designated cassette 2 are stored in the large case 14, the next large case 1
4 is driven by the motor _M3 , and falls horizontally as shown by the chain line in FIG. Next, the rod-like rotating body 33 is rotated by the motor _M4 , and after the facets 31 of each wafer 3 are aligned, the wafer lift 19 is raised by the cylinder _CY10 , and all the wafers 3 in the large case 14 are lifted. It will be done. Next, the position shown in Figure 4
The wafer chuck 21, which was waiting at _S34 , descends to the position _S31 by the vertical transfer means 34, uses the cylinder _CY11 to pick up all the wafers 3 on the lift 19, and then transfers them to a designated heating furnace, for example, the first heating furnace. The wafer 3 is raised to a position corresponding to the height of the furnace 4A, and then horizontally moved in the direction of arrow E via the horizontal transfer means 34, and the wafer 3 is transferred to the boat 2 of the designated heating furnace 4A.
0. At this time, the boat 20 is
It is held on 8. After placing the wafer 3 on the boat 20, the wafer chuck 21 moves in the direction of arrow H.
It is moved horizontally in the direction S34, and then returned to the normal position _S34 in the vertical direction and is put on standby. After the wafers 3 are placed on the boat 20, the boat 20 is inserted into the heating furnace 4A via the boat loader arm 36A and the boat loader 37A. In this way, four designated cassettes of semiconductor wafers 3 are inserted into designated heating furnaces 4B and 4C, respectively. Then, necessary treatments (diffusion, CVD, annealing, etc.) are performed in a heating furnace.

After being processed, the boat 20 carrying the wafers 3 is taken out from each of the heating furnaces 4A, 4B, and 4C, and the wafers are then loaded into the original cassette 2 in the completely reverse order of insertion. 3 is stored. That is, first, the wafer chuck 21 operates to grab the wafer 3 processed in the heating furnace 4C and place it on the wafer lift 19 inside the large case 14 for pitch conversion. Lift 19 is a cylinder
Descending by CY ₁₀ , wafer 3 is in large case 14
contained within. The wafer chuck 21 is returned to its original position _S34 . The large case 14 is erected by the motor _M3 so as to face the air bearing 13, and then the wafers 3 in the large case 14 are stored one by one into the small case 12 by the operation of the air bearing 13. At this time, the large case 14 descends one pitch at a time, and the small case correspondingly rises one pitch at a time. On the other hand, on the cassette 2 side, the cassette 2 is transferred by the cassette transfer mechanism 6, the code number of each cassette 2 is confirmed by the photosensor D, and the designated cassette, in this case cassette 2L, is selected and placed in position. Make S ₀ standby. 1
Cassette portion (i.e. the amount stored in cassette 2L)
When the 25 wafers 3 are stored in the small case 12, the cylinder CY ₇ is actuated to lower the support 17, and then the cylinder CY ₆ moves the arm 16B in the direction of the arrow Y to move it into the small case 12. All wafers 3 are stored in the designated original cassette 2L.
In the same way, the next 25 wafers 3 in the large case
The wafers 3 are stored in cassette 2K, and the corresponding wafers 3 are sequentially stored in cassettes 2J and 2I. After the wafers 3 in the heating furnace 4C have been stored, the same operation as described above is repeated, and the wafers 3 in the second heating furnace 4B and the wafers 3 in the first heating furnace 4A are returned to their corresponding original locations. It is stored in cassette 2.

As described above, according to the present invention, semiconductor wafers can be processed at different processing intervals according to various processes, and uniform processing can be performed. Furthermore, if this device is installed, all processing steps such as diffusion, CVD, and annealing using the horizontal heating furnace can be performed during the manufacture of semiconductor devices, in other words, semiconductor wafers are taken out of the cassette and heated while being arranged at regular intervals. A series of work steps such as transporting the cassette to the furnace and returning it to the original designated cassette after processing is completed can be performed automatically. Therefore, this makes it possible to operate unattended all night, improving the operating rate of the equipment, and
It has the advantage of reducing the number of workers.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the entire semiconductor wafer processing interval conversion device of the present invention when it is used in semiconductor manufacturing equipment, FIG. 2 is a schematic layout diagram showing the cassette portion thereof, and FIG. FIG. 4 is a schematic layout diagram of the main parts of the transfer device, FIG. 4 is a schematic layout diagram of other main parts, and FIG. 5 is a diagram for explaining the operation. 1 is a control operation unit, 2 is a cassette, 3 is a wafer, 4 is a processing unit, 5 is a transfer device, D is a photosensor, 12 is a small case for pitch conversion, 13 is an air bearing, 14 is a large case for pitch conversion, 21
is a wafer hack.

Claims (1)

[Scope of Claims] 1. A storage container that stores a plurality of semiconductor wafers at regular intervals; an interval conversion container that determines the processing interval of the semiconductor wafers; means for arranging semiconductor wafers to be stacked vertically at predetermined intervals and moving both vertically relative to each other; transport means arranged vertically at intervals; means for laying down the interval changing container in which the semiconductor wafers are arranged vertically; pushing means for protruding the semiconductor wafers upward from the interval changing container; A semiconductor wafer processing interval conversion apparatus comprising a chuck for collectively supporting the protruding semiconductor wafers while maintaining processing intervals and transferring them to a processing boat.