JPS6329945A - Package type wafer reerecting method - Google Patents

Abstract

PURPOSE:To avoid a biting phenomenon among a boat, a wafer and lifters by releasing clamping by a high-precision positioning means when the wafer is reerected in the boat and lifting or lowering a plurality of lifters, displacing the elevating timing of the lifters. CONSTITUTION:A plural pair of wafer holding means 8 with open-close-able stoppers 7 with mutually opposite pectinate grooves 6 for receiving wafers 3 pushed up by lifters 5 or delivering the wafers 3 to the lifters 5 are provided while a high-precision positioning means 9 for a boat 2 or a cassette 1 is furnished. The clamping of the boat by the high-precision positioning means 9 is released temporarily when the wafers are reerected in the boat 2, and the elevating timing of a plurality of the lifters 5 is displaced and each lifter 5 is lifted or lowered. Accordingly, a biting phenomenon among the boat 2, the wafers 3 and the lifters 5 can be avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a diffusion device in a semiconductor manufacturing process, a reduced pressure type CV
Among wafer advance machines used in wafer processes such as D equipment, the present invention relates to a batch type wafer advance machine that advances one set of wafers or a plurality of cassettes of wafers at the same time, and particularly relates to its advance method.

[Conventional technology]

The systems of wafer advance machines (automatic wafer transfer means between cassettes and boats) used in semiconductor wafer processes such as diffusion devices and low-pressure CVD systems are broadly classified into single-wafer systems and batch advance systems.

The single wafer type detects the multiple grooves on the boat and inserts wafers one by one into the multiple grooves, while the batch type detects the wafers for one force set (2 wafers).
This is a method that simultaneously transfers 5 wafers or multiple cassettes of wafers, and is currently the mainstream method.

[Problem that the invention seeks to solve]

Although the above-mentioned single-wafer type has a high possibility of avoiding operational errors caused by thermal deformation of the boat, etc., it takes a long time to rebuild the boat.
There is a problem that a large amount of dust is generated.

In addition, the all-in-one type has fewer mechanical movements, so it can shorten the turnaround time, generate less dust, and achieve sufficiently quiet operation.However, boats and other objects require high-precision machining, and are more susceptible to thermal deformation of boats due to long-term use. There was no countermeasure for this, and there were problems such as partial wafer toppling, minute damage to wafers and boats, and malfunctions due to jamming between boats, tools, and lifters.

The present invention improves the above-mentioned problems with the all-in-one type, reduces the required precision for new boats, and increases the tolerance for thermal deformation for boats in use. - It is an object of the present invention to provide a batch wafer reloading method that can avoid malfunctions due to jamming between wafers and lifters.

[Means for solving problems]

The method of the present invention solves the problem of the above-mentioned handle hole and achieves the above object by using a cassette 1 or a boat 2 as shown in the figure.
A comb-shaped 774 for pushing up the wafer 3 from the bottom of the
4 and a wafer 3 pushed up by the lifter 5 at the top of the cassette 1 or boat 2.
The boat 2 or the cassette 1 can be held with high accuracy. In a batch type wafer unloading machine having a positioning means 9, when wafers are unloaded on the boat 2, the boat clamp by the high precision positioning means 9 is temporarily released, and the lifting/lowering timing of the plurality of lifters 5 is staggered to adjust the position of each lifter. By raising and lowering the lifter 5, the phenomenon of jamming between the boat, wafer, and lifter is avoided.

〔Example〕

FIG. 1 is a simplified perspective view of a batch type wafer loading machine according to the present invention, FIGS. 2 and 3 are simplified cross-sectional views of the main parts during wafer loading in a cassette and wafer loading in a boat, respectively. The figure is a schematic cross-sectional view of the TV-IV line in Figure 3,
FIG. 5 is a detailed view of the boat groove shown in FIG. 4.

First, the one-time wafer advance machine according to the present invention will be explained.

In the figure, 1 is a cassette for placing a predetermined number (usually 25) of wafers 3 in multiple grooves 1a, and a plurality of cassettes are provided. 2
is a boat in which wafers 3 corresponding to a plurality of cassettes are placed on each rack 2a. The groove 2a of the boat 2 has a figure 7 shape as shown in Figure 5, and the depth (h) of the groove 2a (the depth of the vertical portion that actually supports the wafer) is about 1 to 2 inches.

5 is a lifter having a comb-shaped groove 4 for pushing up the wafer 3 from the lower part of the cassette 1 or boat 2; 8 is the upper part of the cassette 1 or boat 2 for receiving the wafer 3 pushed up by the lifter 5; This is a wafer holding means (also referred to as a clamper) with an openable and closable stopper 7 having comb-shaped grooves 6 facing each other for transferring wafers 3 and 3.

The lifter 5 and the wafer holding means 8 are grounded facing the upper and lower parts of the frame 10 so that the comb-shaped grooves 4 and 6 of both sets 2, the same number as the number of cassettes 1, are connected to each other.

The cassette 1 is positioned on a cassette moving table 11, and this table 11 is moved in the direction of the arrow in FIG.

In FIG. 2, it is possible to move in the front and back direction perpendicular to the plane of the paper.

The boat 2 is installed at the boat home station 14,
The station moving means 15 allows movement in the direction of the arrow in FIG. 1, in the left-right direction in FIG. 3, and in the direction perpendicular to the plane of the paper in FIG.

When loading wafers in the cassette 1, the table 11 is moved forward and the cassette 1 is moved between the lifter 5 and the wafer holding means 8.
cassette 1. Multi-groove 1a of lifter 5 and wafer holding means 8, 4.
Match the positions of 6.

Thereafter, the lifter 5 is moved upward by a lifter vertical movement means, for example, the lifter vertical feed screw 13, and one or more force cents worth of wafers 3 is delivered to the lifter 5, and then the wafer holding means 8 is opened and closed. Let this hold,
Alternatively, the wafers 3 for one set or multiple cassettes can be transferred from the wafer holding means 8 to the lifter 5 and then transferred to the cassette 1 by lowering the lifter 5.

Also, when transferring wafers on boat 2, station 1
4 to the left to guide the boat 2 between the lifter 5 and the wafer holding means 8, and move the boat 2. Good guide 2a of lifter 5 and wafer holding means 8, 4. 6, and high-precision positioning means 9 to place the boat 2 at the station 14.
Clamp.

Thereafter, in the same manner as in the case of the cassettes 1, one or more cassettes worth of wafers 3 can be transferred from the boat 2 to the wafer holding means 8, or vice versa.

Conventionally, in such a batch type wafer unloading machine, when wafers are unloaded on the boat 2, the boat 2 is clamped in a fixed position by a high-precision positioning means 9, and then a plurality of lifters 5
were raised and lowered individually or simultaneously.

In the present invention, after the boat 2 is clamped and positioned in a fixed position by the high-precision positioning means 9 when wafers are transferred to the boat 2, the clamp is temporarily released, and the timing of raising and lowering the plurality of lifters 5 is staggered. Each lifter 5 is raised and lowered.

In order to shift the timing of raising and lowering each lifter 5, for example, when transferring wafers 3 from the boat 2 to the wafer holding means 8, each lifter 5 is raised sequentially with a delay of a predetermined time, or conversely, when the boat 2 is transferred from the wafer holding means 8 to When receiving wafers 3, each lifter 5 may be lowered in sequence with a predetermined delay.

H is the height difference based on the time difference during the raising and lowering of each lifter 5, and is set to a value sufficiently larger than the depth 11 of the groove 2a of the boat 2, that is, H3-h, but h is 1 to 2 fins. Therefore, the value of H is not so large, and may be a very small value.

After the boat 2 is positioned in a fixed position with high precision in this way, the clamp is released, and each lifter 5 is raised and lowered sequentially with a time lag, so that the rising lifter 5 moves the boat 2 within /112a. When the wafers 3 come out upwards, or when the wafers 3 enter the grooves 2a of the boat 2 by the descending lifters 5, even if a part of the boat 2 is thermally deformed, it is difficult to properly guide each lifter 5 and the wafer holding means 8. Even if there is a groove 2a of the boat 2 that does not match the grooves 4 and 6, the boat 2 moves slightly on the station 14 when the wafer 3 enters or exits the groove 2a, and the groove 2a of the boat 2 and R4 of the lifter 5 match. Therefore, there is no fear that the groove 2a of the boat 2 and the groove 4 of the lifter 5 will come into contact with each other via the wafer 3.

In addition, by shifting the timing of raising and lowering each lifter 5, the number of sheets for multiple cents 2, for example, 100 sheets (for four cents),
Advance delivery of 150 wafers (6 cassettes) is also possible in 1 hour.
Since it will be performed sequentially in units of force set (25 sheets),
It is possible to increase the allowable value of dimensional error required between all the grooves along the entire length of the boat, and it is possible to provide an uprighting machine that is highly responsive to thermal deformation of the boat.

In this embodiment, a case has been described in which each lifter 5 is raised and lowered sequentially with a time difference, but the height position of each lifter 5 may be structurally shifted by 8 dimensions from the beginning.

〔Effect of the invention〕

That is, according to the present invention, after the boat 2 is clamped and positioned in a fixed position by the high-precision positioning means 9 when wafers are transferred to the boat 2, the clamp is released, and the timing of raising and lowering the plurality of lifters 5 is shifted. Since this is a method in which each lifter 5 is raised and lowered by
, of boat 2 that does not match 6? Even if there was n2a, that? When the wafers 3 enter and exit R2a, the boat 2 moves slightly on the station 14, and the groove 2a of the boat 2 and the groove 4 of the lifter 5 match, so it is possible to avoid the phenomenon of jamming between the boat, wafer, and lifter. can.

In addition, by shifting the timing of raising and lowering each lifter 5, the wafers for multiple cages can be moved sequentially in units of 1 force cent. It is possible to make the stand-up machine large and highly responsive to thermal deformation of the boat.

[Brief explanation of drawings]

FIG. 1 is a simplified perspective view of a one-time wafer stacking machine according to the present invention, and FIGS. 2 and 3 are simplified cross-sectional views of the main parts during wafer stacking in a cassette and wafer stacking in a boat, respectively. Figure 4 is a simplified sectional view taken along the line IV-IV in Figure 3;
FIG. 5 is a detailed view of the boat groove shown in FIG. 4. 1...Cassette, 1a...Groove, 2...
...Boat, 2a...Ditch, 3...
Wafer, 4... Comb-shaped groove, 5... Lifter, 6... Comb-shaped groove, 7... Stopper,
8...Wafer holding means, 9...High precision positioning means.

Claims (1)

[Claims] A lifter 5 having a comb-shaped groove 4 for pushing up the wafer 3 from the lower part of the cassette 1 or the boat 2;
It is equipped with a plurality of sets of wafer holding means 8 with openable and closable stoppers 7 having comb-shaped grooves 6 facing each other for transferring wafers 3 to and from the wafer 3, and also has means 9 for highly accurate positioning of the boat 2 or the cassette 1. In the batch type wafer unloading machine, when wafers are unloaded on the boat 2, the boat clamp by the high-precision positioning means 9 is temporarily released, and the lifting timings of the plurality of lifters 5 are staggered to raise and lower each lifter 5. A batch wafer reloading method characterized by avoiding jamming between the boat, wafers, and lifter.