JPH069515Y2 - Wafer storage boat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention places a large number of thin plate-shaped wafers used for various semiconductor elements in a row in a front-rear direction at appropriate intervals such that their respective wide surfaces are lateral. The present invention relates to the structure of a container that can be transported (hereinafter referred to as a storage boat).

[Conventional technology]

A thin disk-shaped wafer made of Si or the like is used to manufacture various semiconductor elements such as elements such as power transistors and integrated circuits such as MOSIC and LSI, and a large number of chips to be the bases of the elements are formed on one side of the wafer. Performs so-called batch processing that can be built at once.

In this case, the number of chips obtained from a single wafer is large, and the economy is improved. For example, in a manufacturing process of an npn, Si mesa transistor, plasma delamination is performed to remove a film of a portion of an SiO 2 film previously formed on one surface of an n-type Si wafer to be an emitter, or an emitter and a base are removed. The part is covered with wax and then etched to perform plasma etching to remove unnecessary parts.

In such a process of plasma stripping or plasma etching, so-called batch processing is performed to process a large number of wafers at a time, and therefore, in the prior art, it is shown in FIGS. 5 and 6 and JP-A-56-120124. As described above, the U-shaped or V-shaped groove 4 having an open cross-section and an upward cross-section is cut out at appropriate intervals in the front-rear direction on the upper surface of the longitudinal storage boat, and the wafer 10 is formed in each groove 4. The lower edge of the is placed and stored in an upright state at appropriate intervals.

[Problems to be solved by the device]

As described above, the edge portion 5 of each wafer 10 is inserted into each groove 4 having a U-shaped cross section (FIG. 5) or V-shape (FIG. 6). Is set substantially vertically, the electron or ion beam 6 emitted toward the surface 10a of the wafer 10 in the plasma separation or plasma etching has a strong straight-line property, while the front side surface 4a of the groove 4 and the surface of the wafer 10 are Since the space between them is narrow, the front side surface 4a of the groove 4 blocks the beam 6.
The front surface of the edge portion 5 of the wafer 10 located in the groove 4 is not irradiated with the beam 6 and a so-called shadow is formed, so that peeling or etching of the oxide film at that portion is incomplete or impossible, and the chip portion at those portions is removed. There is a problem in that it becomes defective, the number of chips as non-defective products in one wafer decreases, and the economical efficiency deteriorates.

Further, as described in JP-A-56-120124, in order to mount the wafer 10 in the groove 4 in the storage boat or to remove it vice versa, the width of the groove 4 is made slightly larger than the thickness of the wafer 10. There must be. Moreover, when only the lower edge of the wafer 10 is inserted into the groove formed on the upper surface of the storage boat and the storage boat is placed on the horizontal substrate (table), the width of the groove 4 is wider (larger) than the thickness of the wafer 10. Therefore, the standing state of each wafer becomes different due to the wafer 10 tilting forward and backward, and the irradiation of the beam 6 such as plasma etching on the wafer 10 also becomes different. In order to forcibly incline each wafer by injecting gas from the front side of the wafer placed on the inclined surface of the storage boat or standing on the storage boat placed on the horizontal substrate. Is disclosed.

However, when a wafer is loaded and carried by this storage boat of the prior art, only the lower edge of the wafer is engaged with the groove, so that the wafer is shaken in the direction of the wide surface thereof. Since the wafers are easily dropped from the storage boat, the wafers are damaged during transportation, resulting in poor yield.

Further, it is very difficult to carry the wafer while maintaining the rearward tilted state, and there is a problem that the working efficiency is extremely lowered.

The present invention is intended to solve the above problems.

[Means for Solving the Problems]

In order to achieve this object, the present invention relates to a storage boat capable of transporting thin plate-shaped wafers arranged in a row at appropriate intervals in the front-rear direction such that the wide surface of the wafer faces forward. The front and rear ends of the lower end support frame that supports the lower end edge of the wafer in the support groove and the front and rear ends of the left and right support frames that support the left and right side edges of the wafer in the support groove are placed on a horizontal substrate. A front frame and a rear frame that are vertically mounted are connected to each other, and the cross-sectional shape of each of the support grooves has a steep slope where the wide back side of each wafer is supported and a gentle slope where the wide front side does not adhere to each other. And the three support frames are horizontally arranged, and the positions of the steeply inclined surfaces in the support grooves of the left and right support frames are set in the support grooves of the lower end support frame. Slide it so that it is located on the backside of the wafer with respect to the position of the steep slope. Or location, or the left and right side support frame and a lower supporting frame, the higher in the front frame side, is obtained by a structure which is arranged in inclined to be lower at the rear frame side.

[Function and effect of device]

The storage boat of the present invention has a front frame and a rear frame that are vertically mounted on a horizontal substrate, and is arranged in a row so that the wide surface of the wafer faces the front frame and is arranged in a row. Since the front and rear ends of the lower end support frame that supports the lower end edge of the plate-shaped wafer and the front and rear ends of the left and right support frames that support the left and right side edges of each wafer are connected, Can support three points.

Therefore, the wafer placed on the storage boat can be safely and reliably transported, and the wafer can fall off during transportation of the storage boat as compared with the conventional technique that supports only the lower edge of the wafer. Can be extremely reduced.

The cross-sectional shape of the support groove formed on each of the left and right support frames and the lower end support frame has a steep slope in the rear facing the wide back surface of the wafer and a gentle slope in the front facing the wide front surface of the wafer. If the V-shape is biased so that the surface becomes a surface, on the gently inclined surface side where the angle in each support groove is gentle, only the edge portion of the wafer at the supported portion abuts and the wide surface side of the wafer becomes The beam irradiated toward the wafer surface without being in close contact can also be irradiated on the wide surface side of the wafer located in the support groove, and the peripheral portion of the wafer can be peeled off or etched.

On the other hand, since the back surface side of the wafer is supported by the steeply inclined surface of each support groove, the wafers arranged in a row do not move backward.

Moreover, the three support frames are arranged horizontally,
The position of the steeply sloping surface in the support groove of the left and right side support frames supporting the left and right side edges of each wafer is closer to the wafer back side than the position of the steeply sloping surface in the support groove of the lower end support frame supporting the lower edge of the wafer. Or shift it so that it is located at
Alternatively, since the left and right support frames and the lower end support frame are provided such that their longitudinal axes are higher on the front side of the wafer array and lower on the rear side, each support is provided in any of these states. At the groove portion, the upper side can be leaned against the lower end of the wafer so as to be shifted to the back side of the wide surface, and there is no fear that the thin plate-shaped wafer will fall forward.

As described above, according to the present invention, it is possible to uniformly irradiate the beam to the peripheral portion of the wide surface of each wafer placed in the storage boat, and increase the number of non-defective chips that can be obtained from one wafer. This has the effect of significantly reducing costs and improving economic efficiency.

Further, the storage boat connects the front and rear frames with the lower end support frame and the left and right side support frames, and supports not only the lower end edge of the wafer laid vertically with the wide surface but also the left and right side edges, In addition to the so-called three-point support, each wafer can be leaned to the back side as described above, and even if it is a thin wafer, these may slip backward in the boat or fall forward. This has the effect that it is possible to prevent this, and to carry a large number of wafers safely and reliably, and also to perform stable batch processing of wafers.

〔Example〕

Next, an embodiment of the present invention will be described.
Reference numeral 10 denotes a thin disk-shaped wafer made of Si or the like, and reference numeral 11
Shows a storage boat in which a large number of these wafers 10 are arranged side by side in a row so that their wide surfaces are lateral.

The storage boat 11 has a front frame 13 and a rear frame 13 'each provided with grips 12, 12 on the outer surface, a pair of left and right side support frames 14, 14' connecting the front and rear frames 13, 13 ', and both sides thereof. The lower half of the wafer 10 is composed of a lower end support frame 15 located in the lower part between the support frames 14 and 14 ', and the lower half of the wafer 10 is formed by the inner surfaces of the left and right side support frames 14 and 14' facing each other and the upper surface of the lower end support frame 15. It is provided so as to surround the wafer and to support the three edges of the wafer 10.

The three support frames 14, 14 ′, 15 having a circular cross section and formed longitudinally in the front-rear direction are located at high positions on the front frame 13 side.
The rear frame 13 'is inclined so as to be at a low position on the side of the rear frame 13', and arranged in parallel with each other.

On the inner side surfaces of the left and right side support frames 14 and 14 'facing each other and on the upper surface of the lower end support frame 15, support grooves 16, 17 and 18 respectively long in the direction perpendicular to the longitudinal axis of each support frame are provided. A large number are provided at regular intervals (P) along the longitudinal axis of. As shown in FIG. 3 and FIG. 4, the cross-sectional shape of each of the support grooves 16, 17, and 18 is substantially right angle to the support frame surfaces 19, 19, and 20 at the downward tilted position of each support frame. Has steep steep slopes 21, 21, 22 and, on the opposite side thereof, gentle gentle slopes 23, 23, 24 having an acute angle (θ1), (θ2) with respect to the surfaces 19, 19, 20 as appropriate. Is formed in a biased V-shape.

According to this structure, as shown in FIG. 1, a large number of wafers 10 are attached to the support grooves 16, 17, 1 at the three positions 10a, 10b, 10c of the lower edge of each wafer 10.
It can be stored in the storage boat 11 by being arranged in a row in front and rear at fixed intervals (P) while being locked at eight locations.

At this time, the support grooves 16 of the left and right support frames 14, 14 ',
Since the 17 position is formed slightly on the back surface side of the wafer 10 (closer to the rear frame 13 'of the storage boat) than the vertically upper position of the support groove 18 position of the lower end support frame 15 (see FIG. 3).
The respective wafers 10 are arranged in a so-called rearward tilted manner in which the upper end side is closer to the rear side than the lower end side, and each wafer 10 has its back edge side edge portions 10a, 10b, and 10c each supporting groove 1.
Since the steeply inclined surfaces 21, 21, 22 in 6, 17, 18 can be leaned against each other, the wafers 10 can stand in a state of being tilted backward, and there is no possibility that the respective wafers 10 fall forward.

If the storage boat 11 is arranged so that the surface side of the wafer 10 inside the storage boat 11 faces the irradiation side of the beam 25 of ions or the like in the plasma stripping apparatus or the plasma etching apparatus,
Gently sloping surface 23 in each of the supporting grooves 16, 17, 18
A large triangular space is formed between the surfaces 23 and 24 and the surface side of the wafer 10, and the beam 25 is formed on each of the gently inclined surfaces 23 and 2.
It is possible to reach the front surface side edge of the wafer 10 in each of the supporting grooves 16, 17, and 18 without being disturbed by 3, 24, and the peeling or etching process of that portion can be completed.

Then, the heights of the left and right support frames 14, 14 'and the lower end support frame 15 are changed in the front-rear direction so that the longitudinal axes thereof are at a high position at the front frame 13 and at a low position at the rear frame 13'. The wafer 10 placed on these
Is inclined rearward so that it can lean against the steeply inclined surfaces 21, 21, 22 of the support grooves 16, 17, 18, but as another embodiment for realizing this rearward inclination, The left and right side support frames 14, 14 'and the lower end support frame 15 are arranged substantially horizontally, and the left and right side support frames 14, 1
The positions of the steeply sloping surfaces 21 and 21 of the support grooves 16 and 17 in 4 ′ are the steeply sloping surfaces 2 of the support grooves 18 in the lower end support frame 15.
It can also be achieved by biasing the vertical direction from the vertically upper position with respect to 2 by an appropriate amount.

Further, the cross-sectional shape of each of the support frames 14, 14 ', 15 can be any shape such as a quadrangle or a hexagon.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is a side view of a storage boat, FIG. 2 is a front view, and FIG. 3 is a second view.
FIG. 4 is an enlarged sectional view taken along line III-III in FIG. 4, and FIG. 4 is IV-IV in FIG.
FIG. 5 is an enlarged cross-sectional view of a main portion of a support groove, and FIG. 6 is an enlarged cross-sectional view of a main portion of another support groove. 10 ... Wafer, 11 ... Storage boat, 13 ... Front frame,
13 '... rear frame, 14, 14' ... left and right support frames, 1
5 ... Bottom support frame, 16, 17, 18 ... Support groove, 2
1,2,22 ... steep slopes, 23, 23, 24 ... gently slopes.

Claims (1)

[Scope of utility model registration request] 1. A storage boat capable of transporting thin plate-shaped wafers arranged in a row at an appropriate interval in the front-rear direction so that a wide surface of the wafer faces forward, and a lower edge portion of each wafer. The front and rear ends of the lower end support frame for supporting the wafer in the support groove and the front and rear ends of the left and right support frames for supporting the left and right side edges of the wafer in the support groove are vertically mounted on a horizontal substrate. The front and rear frames are connected to each other, and the cross-sectional shape of each of the supporting grooves is substantially X, which is composed of a steeply inclined surface on which the wide back surface side of each wafer stands and a gently inclined surface on which the wide front surface side does not adhere. On the other hand, the three support frames are arranged horizontally, and the positions of the steep slopes in the respective support grooves of the left and right support frames are set to the positions of the steep slopes in the respective support grooves of the lower end support frame. It is arranged so that it is located on the back side of the wafer, or it is placed on both the left and right sides. A support frame and a lower supporting frame, the higher in the front frame side, the wafer storage boat, characterized in that disposed in inclined to be lower at the rear frame side.