JP2003152049A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating a wafer having merits of a wafer transfer method of one-by-one and merits of a batch transfer method. SOLUTION: The semiconductor manufacturing apparatus transfers the wafer between a cassette for housing the wafer and a boat for supporting the wafer at the time of processing and processes the wafer supported in the boat in a reaction chamber. The apparatus comprises a required number of plates for transferring the wafer in a vertical direction above a rotatable and vertically movable rotary base in such a manner that the plate is retractably provided on the base. In the apparatus, the required number of the supporting plates transfer the wafers between the cassette and the boat by a wafer transfer unit having the plurality of the plates for transferring a plurality of the wafers at once together with the plate 38 for transferring the sheets and the plates 39, 40, 41 and 42 for transferring the sheets one by one at once the wafers by the required number of the supporting plates, and the pitch between the plats is changed in the vertical direction of other plate and with the plates for transferring the sheets at the time of transferring the wafer as a reference of the other plate.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus such as a vertical CVD diffusion apparatus. 2. Description of the Related Art One of the processes for manufacturing semiconductor devices is CV.
There is D processing. In this method, a required number of silicon wafers are heated in a CVD apparatus and subjected to chemical vapor deposition (CVD). To homogenize the CVD process, both ends of a row are sandwiched between product wafers. , A plurality of dummy wafers are arranged, and one monitor wafer for inspection is arranged at a required interval in the middle of a product wafer. This is outlined in FIG. In a diffusion furnace, a wafer 1 is supported by a boat 2, and the wafer 1 is supported by the diffusion furnace.
When the CVD process is performed, first, the wafers 1 are inserted into the boat 2 so as to have a required arrangement, and the boat 2 into which the wafers 1 are inserted is loaded into a diffusion furnace. Generally, the temperature inside the diffusion furnace is not uniform over the whole area,
Therefore, the boat 2 is provided with a sufficient number of wafer storage spaces (for example, 1.5 times the number of processed wafers) for the number of wafers to be processed. The wafer storage position of the boat 2 is selected so as to correspond to a location having a uniform temperature distribution or according to the number of wafers. At the upper end and the lower end of the wafer array of the boat 2, dummy wafer groups 3 and 4 each including an appropriate number of dummy wafers 1b are accommodated, and a monitor wafer 1c is provided.
The product wafer group 5 composed of a predetermined number of product wafers 1a is housed with the monitor wafer 1c interposed therebetween.
The product wafer group 5 is stored in order. The monitor wafer 1c is inserted between the lowermost product wafer group 5 and the dummy wafer group 4. The wafer transfer device performs a series of operations for transferring the wafers loaded in the cassette to the boat and loading the processed wafers in an empty cassette. A conventional wafer transfer device will be described with reference to FIG. FIG. 4 shows a wafer transfer apparatus of a single wafer type (a system for transferring one wafer at a time). A cassette 7 loaded with the wafer 1 is the same around a handling unit 6. A required number of units are arranged on the circumference, and a transfer elevator 8 and a loading / unloading elevator 9 are provided adjacent to the handling unit 6, and the boat cradle 10 of the transfer elevator 8 The vertical diffusion furnace 12 is provided above the boat cradle 11 of the load / unload elevator 9. A transfer unit 13 for transferring the boat 2 is provided between the transfer elevator 8 and the load / unload elevator 9. The handling unit 6 includes a rotating arm 14 that rotates about the center of the circumference and moves up and down, and a wafer suction chuck 15 that advances and retreats in a radial direction along the rotating arm 14. The picked-up wafers 1 are sucked and taken out one by one, and are sequentially transferred to the boat 2 placed on the transfer elevator 8 from the upper side. The transfer elevator 8 descends step by step following the transfer of the wafer 1. The boat 2 on which the transfer of the wafer 1 has been completed is transferred from the transfer elevator 8 to the load / unload elevator 9 by the transfer unit 13, and the load / unload elevator 9 is mounted on the boat. 2
Is charged into the diffusion furnace 12. When the CVD process is completed, the boat 2 is taken out of the diffusion furnace 12 and the transfer unit 1
The transfer elevator 3 transfers to the transfer elevator 8, and the handling unit 6 loads the cassette 7 in the reverse order to the above. Although the above-mentioned conventional transfer apparatus is of a single-wafer type, there is also a collective type as shown in FIG. In this method, the wafer suction chuck 15 has 25 sets of suction plates 16, and collectively chucks all 25 wafers 1 loaded in the cassette 7 and transfers them to the boat 2. is there. [0011] However, the above-mentioned conventional single-wafer type transfer apparatus and the batch type transfer apparatus have the following disadvantages. The arrangement of the wafers to be inserted into the boat 2 and the number of upper and lower dummy wafers or the number of monitor wafers and the number of monitor wafers are determined. It depends on the processing conditions or the processing specifications of the customer. In the former single-wafer method, since wafers are transferred one by one, any arrangement of wafers can be handled. However, the number of operations is remarkably large, so that the transfer time is long and the efficiency is low. In addition, the fact that the number of operations is large increases the probability of dust generation stochastically, which adversely affects product quality. On the other hand, the latter batch method has an advantage that the transfer time is short and extremely efficient, but since the processing is performed in batches of 25 wafers, the arrangement of the wafers at the time of wafer transfer cannot be adjusted. Can not. Therefore, dummy wafers, monitor wafers, and product wafers are mixed so that a predetermined arrangement is made when the wafers are loaded into the cassette. The operation of loading wafers into a cassette is manual, and the operation of loading different types of wafers in a predetermined arrangement is extremely complicated, inefficient, and unavoidable. Was. The present invention has been made in view of the above circumstances, and has as its object to provide a semiconductor manufacturing apparatus capable of fully exhibiting the advantages of the single-wafer transfer method and the advantages of the batch transfer method. According to the present invention, wafers are transferred between a cassette for storing wafers and a boat for supporting wafers during processing, and the wafers supported by the boats are moved in a reaction chamber. In the processing apparatus, a wafer transfer plate having a recess in which a wafer can be placed is formed above a turntable that can be rotated and moved up and down, and a horizontal tip surface position of each plate is aligned in a vertical direction. The required number of plates are provided in such a state that the plate can be moved forward and backward on the turntable, and the required number of plates are used for transferring a wafer one by one at a time. Plate and
It consists of a plurality of plates for transferring a plurality of wafers at a time together with the single-wafer transfer plate, and when transferring the wafers one by one at a time, the single-wafer transfer plate includes the plurality of plates. Disclosed is a semiconductor manufacturing apparatus characterized by popping out from a position aligned with a plate. Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a wafer transfer device according to the present embodiment, in particular, a wafer gripper 18, which is a rotary table, for example, FIGS.
The rotary arm 14 is provided so as to be able to advance and retreat in the radial direction. Hereinafter, the grip 18 will be described. The vertical substrate 20 is fixed to the base plate 19, and the upper substrate 21 is fixed to the base plate 19 via a support not shown. A guide block 22 is fixed to the upper substrate 21, and a pair of right and left sliders 2 is attached to the guide block 22.
3, 24, 25, 26 are slidably mounted. The sliders 23, 24, 25, 26 are screwed into screw rods 27, 28 rotatably provided on the upper substrate 21, respectively, and driven gears 29, 30 are fitted to upper ends of the screw rods 27, 28, respectively. . A pitch changing motor 31 is mounted between the driven gears 29 and 30, and a driving gear 32 fitted on an output shaft of the pitch changing motor 31 is engaged with the driven gears 29 and 30. The sliders 23, 24, 25, 26 have inverted L-shaped plate holders 34, 35, 36,
37, and the plate holders 34, 35, 36, 3
7, the wafer support plates 39, 40, 41, 4
Install 2. Each wafer support plate 38, 39, 4
On the upper surface of 0, 41, 42, a concave portion 4 on which a wafer can be placed
3 are formed. Further, the plate holders 34, 3
5, 36, 37 are the wafer support plates 39, 4
0, 41, and 42 are supported at appropriate intervals in the vertical direction.
Sliders 23, 2 to which 35, 36, 37 are fixed
The screwing relationship between the screw rods 27, 28 and the screw rods 27, 28 is determined by the screw pitch at which the slider 23 to which the plate holder 34 supporting the second lower support plate 39 is fixed is screwed. On the other hand, the screw pitch of the portion where the slider 24 to which the plate holder 35 supporting the third-stage support plate 40 from the bottom is fixed is screwed is doubled, and the screw pitch of the fourth-stage slider 25 is similarly set. Is 3
The screw pitch of the fifth-stage slider 26 is quadruple, and when the pitch changing motor 31 is driven, the slider 2 is moved through the screw rods 27 and 28.
3, 24, 25, 26, each wafer support plate 3
The pitch can be expanded or reduced while maintaining the relationship that the pitches among 8, 39, 40, 41 and 42 are equal. The first-stage support plate (single-leaf support plate) 38 is fixed to a plate holder 33 attached to an advance / retreat mechanism 44 so that it can be moved forward and backward without any vertical displacement. Hereinafter, the reciprocating mechanism 44 will be described. The vertical swing link 45,
The pivotal link 46 is pivotally connected to the parallel swinging links 45 and 46, respectively, at the intermediate portions of the floating parallel links 47 and 48, respectively. The upper ends of the floating parallel links 47 and 48 are pivotally connected to the first-stage plate holder 33, and the lower ends of the floating parallel links 47 and 48 are pivotally connected to the slider 49. The slider 49 is provided with a guide 50.
Is provided slidably on the vertical substrate 20 via the. The rotation radii of the parallel swing links 45 and 46 and the rotation radii of the floating parallel links 47 and 48 at the pivot point of the plate holder 33 are made equal to each other, and the two parallel links 45, 46 and 47 are formed. , 48 to offset the vertical displacement. The lowermost single wafer support plate 38 is mounted on the plate holder 33. A pivot 51 fixed to one of the parallel swing links 46 projects through the vertical board 20, and a pulley 52 is fixed to the protruding end. An advancing / retracting motor 54 is fixed to the anti-parallel oscillating link side of the vertical board 20 via a motor support bracket 53, and a driving pulley 55 is fitted to an output shaft of the advancing / retracting motor 54, and the driving pulley 55 and the pulley 52 and a timing belt 56. The forward / backward rotation of the forward / backward motor 54 allows the single wafer support plate 38 to advance and retreat, and the amount of advance of the single wafer support plate 38 depends on the upper wafer support plate. 39,40,4
It is assumed that they completely protrude from 1,42. In the drawings, 57 and 58 are sensors for detecting the stroke ends of the floating parallel links 47 and 48, and 59 and 60 are detecting pieces for operating the sensors 47 and 48. The operation will be described below. All the wafer support plates 38, 39,
When the wafers are supported and transferred at one time in the steps 40, 41 and 42, the wafer supporting plates 38, 39, 40 and 4
2 are the positions indicated by the solid lines in FIG. Next, when performing fraction processing for transferring five or less wafers 1, the reciprocating motor 54 is driven to drive the parallel swing link 45, 45 via the driving pulley 55, the timing belt 56, and the pulley 52. 46 is swung clockwise in FIG. By the swing of the parallel swing links 45 and 46, the floating parallel links 47 and 48 rotate counterclockwise while descending downward, and send out the plate holder 33. When the sensor 57 detects the stroke ends of the floating parallel links 47 and 48, the forward / backward motor 54 is stopped. Thus, only the lowermost wafer supporting plate 38 can be transferred (indicated by a two-dot chain line in FIG. 2), and the wafers can be transferred one by one. When the fraction processing has been completed and five wafers 1 are to be transferred at the same time again, the advance / retreat motor 54 is driven to rotate in the reverse direction, and the lowermost single wafer support plate 38 is retracted to the position indicated by the solid line in FIG. Return to Next, the pitch between the wafers when the wafers are stored differs depending on the size of the wafers. In this case, the pitch of the wafer support plates 38, 39, 40, 41, and 42 is adjusted. The pitch changing motor 31 is driven to rotate the screw rods 27 and 28 via a driving gear 32 and driven gears 29 and 30. The screw rod 2
By the rotation of 7, 28, the sliders 23, 24, 25, 26 to which the plate holders are fixed move. The screw pitches of the sliders 23, 24, 25, and 26 are screwed at the same magnification as described above, so that the upper wafer support plate 38 with respect to the lowermost wafer support plate 38 is used as a reference. The plates 39, 40, 41, and 42 move while maintaining an equal interval, and the pitch is adjusted. In the above embodiment, considering that the number of wafers stored in the wafer cassette is 25,
Although the number of support plates is set to “5” which is a divisor of “25”, the number of support plates may be set to 25. Further, it is a matter of course that various changes can be made without departing from the gist of the present invention, such as a case where the wafer support plate is formed by a vacuum suction method. As described above, according to the present invention, the transfer of a plurality of wafers at once and the transfer of one wafer at a time can be appropriately selected and performed, so that the wafer can be efficiently transferred and the wafer can be efficiently transferred. Can correspond to any array of
Also, an excellent effect that it can easily cope with a change in the wafer storage pitch is exhibited.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a wafer transfer device embodying the present invention as viewed from a distance. FIG. 2 is a perspective view of the front wafer transfer apparatus as seen from a distance. FIG. 3 is an explanatory view showing an arrangement of wafers in a boat. FIG. 4 is an explanatory view showing a conventional wafer transfer device. FIG. 5 is an explanatory view showing a conventional wafer transfer device. [Description of Signs] 1 Wafer 18 Wafer gripper 27 Screw rod 28 Screw rod 31 Pitch changing motor 38 Single wafer support plate 39 Wafer support plate 40 Wafer support plate 41 Wafer support plate 42 Wafer support plate 44 Advance / retreat mechanism 54 Advance / retreat motor

Claims (1)

Claims: 1. A wafer is transferred between a cassette for accommodating a wafer and a boat supporting the wafer during processing,
In an apparatus for processing wafers supported by the boat in a reaction chamber, a wafer transfer plate having a concave portion on which a wafer can be placed is formed above a rotatable rotatable table in a vertical direction. A required number of horizontal end face positions of each plate are provided, the plates are provided so as to be able to advance and retreat on the turntable, and the required number of plates are used for transferring a wafer one by one at a time. And a plurality of plates for transferring a plurality of wafers at a time together with the single-wafer transfer plate. When transferring wafers one by one at a time, A semiconductor manufacturing apparatus, wherein a transfer plate protrudes from a position aligned with the plurality of plates.