JP2591202Y2 - Vertical CVD equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature oxide film (LTO film) such as a low-temperature oxide film (LTO film)
The present invention relates to a vertical CVD apparatus that generates a VD film and the like. Conventionally, when a CVD film such as a polysilicon film or a nitride film is formed on the surface of a wafer,
This is carried out by loading the wafer 2 on a quartz wafer boat 5 and using an LTO film (forming temperature 3) using SiH ₄ and O _2.
00 to 400 ° C.), PSG film (LTO film doped with phosphorus), high-temperature oxide film using SiH ₄ and N ₂ O (HTO film, generation temperature 700 to 850 ° C.), phosphorus-doped polysilicon film, etc. In the production, a quartz wafer holder held by a boat is used.
As shown in the figure, the wafer 2 is placed on the wafer holder 16.
Are placed in close contact with each other to form a film. [0003] However, in the wafer holder 16 of the conventional vertical CVD apparatus, since the back surface of the wafer 2 is in close contact with the wafer holder 16, the wafer 2 is There is a problem that it is difficult to carry out automatic conveyance when attaching or detaching to or from the holder 16. Further, since the wafer 2 can freely move on the wafer holder 16, there is a problem that the wafer may drop off when the wafer holder 16 moves. [0004] The present invention has been made in view of such a problem, and a vertical CV capable of automatically carrying a wafer.
It is intended to provide a D device. In order to achieve the above object, a vertical CVD apparatus according to the present invention accommodates a wafer holder for holding a wafer during wafer processing and an unprocessed or processed wafer. A cassette, a wafer transfer arm for transferring a wafer from the cassette to the wafer holder or from the wafer holder to the cassette, and a processing chamber for processing the wafer held by the wafer holder, the wafer holder has a flat surface A wafer holder body having a plurality of pawls provided on a flat surface of the wafer holder body along the held wafer, on which the wafer is mounted and which can contact the peripheral surface of the mounted wafer; The plurality of claws allow the held wafer to float from the flat surface of the wafer holder body. A gap is formed between the wafer and the flat surface of the wafer holder main body so that the wafer transfer arm can be inserted thereinto, and the wafer transfer arm moves in and out of the gap to place the wafer on the claw of the wafer holder. Or removing the wafer from the claws of the wafer holder. A wafer transfer arm for transferring an unprocessed wafer is lowered from above the wafer holder to bring the wafer into contact with the claws, and then further lowered to allow the wafer and the flat surface of the wafer holder main body to move down. By escaping from the gap therebetween, the wafer can be placed on the claws without the wafer transfer arm coming into contact with the wafer holder. Also,
For the processed wafer held on the wafer holder, the wafer transfer arm is inserted into the gap between the wafer and the flat surface of the wafer holder main body, and ascends,
The wafer can be taken out of the wafer holder and transferred without the wafer transfer arm contacting the wafer holder. FIG. 1 is a perspective view showing one embodiment of a wafer holder used in a vertical CVD apparatus according to the present invention. In this embodiment, a plurality (four in this example) of pawls 7 are provided along the wafer 2 held on the wafer holder main body 6a flush with the wafer holder 6. Each pawl 7
Is formed with a stepped portion 7a above the wafer holder main body 6a and on which the wafer 2 is placed. The step portion 7a has a substantially flat flat surface 7b in contact with the back surface of the wafer 2, and a movement limiting surface 7c orthogonal to the flat surface 7b and capable of contacting the peripheral surface of the wafer 2. The step portion 7a composed of 7b and the movement limiting surface 7c faces the center of the wafer 2 to be placed. The wafer 2 is lifted from the surface of the wafer holder main body 6a by, for example, about 4 mm by the stepped portion 7a, so that the wafer transfer of the wafer reloading machine 3 between the wafer 2 and the wafer holder main body 6a is performed when the wafer 2 is attached to or detached from the wafer holder 6. The vacuum suction part 4a of the arm 4 can be inserted and the back surface of the wafer 2 can be sucked and moved. Further, since the plurality of movement limiting surfaces 7c are arranged at intervals around the peripheral surface of the wafer 2, the movement of the wafer 2 on the wafer holder 6 in the lateral direction is limited by these movement limiting surfaces 7c. I have. FIG. 2 is a perspective view showing a vertical CVD apparatus. The wafer holder 6 is a vertical quartz wafer boat 5
The wafer 2 is held at an angle of about 1.1 degrees, and at least one or more pawls 7 support the wafer 2 from below, thereby preventing the wafer 2 from falling off and rotating or moving the wafer boat 5 up and down. When this is done, the wafer 2 can be prevented from moving. The cassette 1 containing the unprocessed wafers 2 is mounted on a cassette elevator 8 and has a vacuum suction unit 4a (FIG. 3) of a wafer transfer arm 4 having a telescopic unit of a wafer refilling machine 3 and a vertical mechanism. 2), the wafer 2 is sucked out of the cassette 1 and taken out. Next, the wafer transfer arm 4 of the wafer changer 3 rotates the taken-out wafer 2 by 90 degrees and transfers it to the wafer holder 6 held on the boat 5. When the wafer 2 comes above the wafer holder 6, the wafer transfer arm 4 descends to bring the wafer 2 into close contact with the step 7 a of the pawl 7 of the wafer holder 6. At the same time, the suction by the vacuum suction unit 4a is released, and the wafer 2 is placed on the step 7a.
The wafer transfer arm 4 is further lowered and then contracted, escapes from the gap between the wafer 2 and the wafer holder main body 6a, and prepares for transfer of the next wafer 2. Since the thickness of the wafer transfer arm 4 is about 2 mm, if the gap between the wafer 2 and the wafer holder body 6a is about 4 mm as described above, the mounting or detachment of the wafer 2 to or from the wafer holder 6 can be performed. At this time, the wafer transfer arm 4 can sufficiently move up and down in the gap. When the boat 5 is moved up and down by the elevating mechanism 10 and a predetermined number of wafers 2 are transferred to the boat 5, the boat 5 on which the film-formed wafers are mounted and the unprocessed wafers are mounted by the boat transfer mechanism 9. The boat 5 on which the unprocessed wafers are placed is moved to the lifting mechanism 11.
The reaction gas is supplied from the gas inlet 13 into the reaction tube 12 (processing chamber) from below, and a CVD film is formed on the wafer surface in the reaction tube 12. When the film forming process is completed, the wafer 2 is transferred to the cassette 1 in the reverse procedure. The automatic transfer of the wafer 2 can be performed according to the above procedure.
Since the pawl 7 is provided on the wafer holder main body 6a, when the wafer holder 6 is used to form an LTO film under the conditions shown in Table 1 below, N
As shown in o.2, the film thickness at the peripheral portion of the wafer becomes thick, and the uniformity of the film thickness at the 5 mm peripheral portion exceeds ± 10%, and the uniformity of the entire film thickness becomes ± 4 to 8%. Table 2 below
As shown in No. 1, although the overall film thickness uniformity when using the conventional wafer holder 16 is lower than ± 2 to 3%, the wafer 2 is automatically transferred. Therefore, manufacturing costs can be reduced. [Table 1] [Table 2] As described above, the vertical CV according to the present invention is provided.
According to the D apparatus, on the flat surface of the wafer holder main body, a plurality of claws are provided along the held wafer. Since a gap is formed between the wafer transfer arms so that the wafer transfer arms can be inserted, the wafer can be placed on the nails without the wafer transfer arms coming into contact with the wafer holder. It is possible to take out and transport the wafer placed on the claw without the wafer transport arm coming into the gap and contacting the wafer holder, so that the automatic transport of the wafer is possible, and the wafer processing is efficiently performed. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (a) and 1 (b) are perspective views showing an embodiment of a wafer holder used in the present invention, respectively, and its IV.
FIG. 4 is a sectional view taken along line IV. FIG. 2 is a perspective view showing the vertical CVD apparatus of the present invention. FIG. 3 is a perspective view of a wafer transfer arm used in FIG. 2; FIG. 4 is a side view showing a conventional wafer holder. [Description of Signs] 1 cassette 2 wafer 4 wafer transfer arm 6 wafer holder 6a wafer holder main body 7 pawl 7a step 12 reaction tube (processing chamber)

Claims (1)

(57) [Rules for requesting registration of utility model] A wafer holder for holding wafers during wafer processing, a cassette for storing unprocessed wafers or processed wafers, a wafer transfer arm for transferring wafers from the cassette to the wafer holder or from the wafer holder to the cassette, and a wafer holder A processing chamber for processing the processed wafer, wherein the wafer holder is provided on a flat surface of the wafer holder main body along a wafer holder main body having a flat surface and a held wafer, and the wafer is mounted thereon. And a plurality of claws that can be brought into contact with the peripheral surface of the placed wafer, wherein the plurality of claws allow the held wafer to float from the flat surface of the wafer holder body, and the wafer and the wafer holder Form a gap between the flat surface of the main body and the wafer transfer arm. A vertical CVD apparatus, wherein the wafer transfer arm moves in and out of the gap to place a wafer on a nail of a wafer holder or remove a wafer from a nail of a wafer holder. 2. The vertical CVD apparatus according to claim 1, wherein each of the claws is provided with a step portion on which a wafer is mounted and which can be brought into contact with a peripheral surface of the mounted wafer. .