JPH06151547A - Traveling device, wafer having the traveling device, and manufacture of the wafer - Google Patents

Abstract

PURPOSE:To provide a wafer transfer means in which the occurrence of particles from the rear surface of a wafer can be suppressed when it is transferred, or a wafer in which the occurrence of particles from the rear of the wafer can be suppressed when it is transferred. CONSTITUTION:A traveling device 10 is made up of a roller 12, a frame 14, and a shaft bearing 16 that is provided on the frame 14 and also supports the roller 12. These are made of a material which can be etched. The rear surface of a wafer is joined to such a traveling device or a traveling device made up of a turbofan composed of a material which can be etched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling device to which a micromachine technology is applied, a wafer equipped with such a traveling device, and a method for producing such a wafer.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have been highly integrated and have improved in performance, requirements for cleanliness in semiconductor device manufacturing processes and semiconductor device manufacturing processes or wafer contamination prevention from the manufacturing devices have become more and more severe. There is. For example,
When manufacturing a semiconductor device of the 0.35 μm rule,
Even if particles of about 1 μm adhere to the surface of the wafer, they cause defects in the semiconductor device. Therefore, it is necessary to strictly control particle adhesion on the wafer surface, and the number of particles adhered to the wafer surface is required to be 10 or less.

On the other hand, particles adhering to the back surface of the wafer have recently received attention. During wafer transfer and batch processing, the backside of the wafer and the frontside of other wafers frequently come close to each other, and particles adhering to the backside of the wafer scatter and adhere to the frontside of other wafers. Because it will be one. For example, when a wafer is transferred between semiconductor device manufacturing processes, the wafer is placed in a wafer carrier. When the wafer is heat-treated in a diffusion furnace or the like, the wafer is placed on the boat. In these cases, the distance between the wafers is about 5 mm to 10 mm,
The distance is sufficient for the particles adhering to the back surface of the wafer to scatter and adhere to the surface of the adjacent wafer. Therefore, the number of particles attached to the back surface of the wafer is also required to be 10 or less.

[0004]

The main cause of the particles adhering to the back surface of the wafer is the contact between the wafer and the manufacturing apparatus or transfer apparatus in each process. When the wafer is transferred in the manufacturing apparatus, the transfer apparatus of the manufacturing apparatus and the back surface of the wafer come into contact with each other, and thus thousands of particles to tens of thousands of particles may be attached to the back surface of the wafer.

As one means for solving this problem,
A belt conveyance method as shown in FIG. 19 can be mentioned. In this belt transfer means, a set of O-ring belts moves like a belt conveyor, and a wafer is placed on this set of belts and transferred. In this transfer method, particles may be generated by rubbing the back surface of the wafer and the belt when the transfer is started or stopped. Further, at the time of wafer positioning, the wafer is pressed by positioning pins (not shown). At this time, the belt runs idle, the belt rubs the back surface of the wafer, and particles are generated. The number of generated particles is about 10,000.

As shown in FIG. 20, there is also a roller transfer system in which rollers are arranged instead of a belt, a wafer is placed on the rollers, and the rollers are rotated to transfer the wafer.
Since the roller and the back surface of the wafer are in point contact with each other, it is possible to reduce the generation of particles as compared with the belt transfer method. However, when the transfer is started or stopped, the roller rubs the back surface of the wafer and particles are generated. The number of generated particles is about several thousand to 10,000.

As shown in FIG. 21, there is also a walking beam system in which a wafer is placed on two beams and the beams are moved to convey the wafer. Although less than the roller transfer method, particles may be generated due to the back surface of the wafer rubbing against the beam. The number of generated particles is several thousand or less.

Further, as shown in FIG. 22, there is also a method of holding a wafer by a robot and transferring the wafer. After the wafer is positioned, the robot arm holds the wafer and conveys the wafer, so that the back surface of the wafer is less likely to be rubbed. Currently, this transfer method is mainly used, but even in this method, about 500 particles are generated from the back surface of the wafer.

In the various methods described above, generation of particles from the back surface of the wafer is being suppressed,
Still, the number of particles adhering to the back surface of the wafer is 10
A transport method for less than individual pieces has not been found.

Therefore, a first object of the present invention is to provide a wafer transfer means capable of suppressing the generation of particles from the back surface of the wafer when the wafer is transferred.

A second object of the present invention is to provide a wafer capable of suppressing the generation of particles from the back surface of the wafer during transportation.

A third object of the present invention is to provide a method of manufacturing a wafer that can suppress the generation of particles from the back surface of the wafer during transportation.

Further, a fourth object of the present invention is to provide a method for easily bonding a micromachine made of a silicon material to an article such as a wafer made of the silicon material.

[0014]

In order to achieve the above first object, the traveling apparatus of the present invention comprises a roller, a frame, and a bearing portion formed on the frame and supporting the roller. It is characterized by being formed of an etchable material. As materials that can be etched, single crystal silicon, polycrystalline silicon, single crystal or polycrystalline silicon doped with impurities, SiN,
TiN, aluminum, tungsten, etc. can be mentioned. In a preferred aspect of this traveling device, an electrostatic motor can be formed from the roller and the frame by forming the rotor portion on the roller and the stator portion on the frame.

The wafer according to the first aspect of the present invention is characterized in that, in order to achieve the above-mentioned second object, the above traveling device is bonded to the back surface of the wafer.

In order to achieve the above-mentioned second object, the wafer according to the second aspect of the present invention is such that a traveling device including a turbofan made of an etchable material is bonded to the back surface of the wafer. Is characterized by. The turbo fan includes a casing, a bushing protruding from the inner wall of the casing, and a fan loosely fitted in the bushing. As the material that can be etched, single crystal silicon, polycrystalline silicon, single crystal or polycrystalline silicon doped with impurities, SiN, TiN, aluminum,
Tungsten etc. can be mentioned. It is desirable that the turbofan function as an electrostatic motor by providing a stator part in a casing of the turbofan and using the fan as a rotor.

The method of manufacturing a wafer according to the present invention is the same as the above third method.
In order to achieve the above object, a traveling device is manufactured on the back surface of the wafer by a micromachine technique, and then the front surface of the wafer is polished. The traveling device may be, for example, a turbo fan.

In order to achieve the above-mentioned fourth object, the joining method of the present invention for joining a micromachine made of a silicon-based material to an article made of a silicon-based material is a mirror-finished portion of the micromachine. To form a mirror-finished portion on the article. The mirror finishing portion of the micromachine and the mirror finishing portion of the article are joined together. Prior to bonding, it is desirable to impart hydrophilicity to the micromachined mirror finish and the article mirror finish. Alternatively, it may be desirable to heat or apply electrostatic pressure to the micromachine and article during bonding. An oxide film may be formed on the mirror-finished portion of the micromachine and / or the mirror-finished portion of the article.

[0019]

Since all the constituent materials of the traveling apparatus of the present invention are composed of etchable materials, the traveling apparatus can be manufactured by the micromachine technology. Since the traveling device or the wafer provided with the traveling device is manufactured in a clean room, it is very clean. Since the wafer can be self-propelled by the traveling device, for example, a transfer device is unnecessary in the manufacturing process of the semiconductor device.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

(Example-1) Example-1 relates to the traveling apparatus of the present invention. FIG. 1A is a perspective view of the traveling device 10 according to the first embodiment (however, the traveling device is shown upside down). In addition, line I (B) -I in FIG.
A sectional view taken along the line (B) is shown in FIG.
1C is a cross-sectional view taken along line I (C) -I (C) of FIG.
Shown in.

The traveling device 10 comprises a roller 12, a frame 14, and a bearing portion 16 formed on the frame 14 and pivotally supporting the roller 12. Roller 12,
The frame 14 and the bearing portion 16 are made of an etchable material. As an etchable material,
In Example-1, polycrystalline silicon was used. Roller 12
Has a cylindrical shape, and is provided with a shaft 18 protruding on its axis. In Example-1, the shaft 18 and the roller 12
And are made in one. The shaft 18 and the ring-shaped bearing portion 16 engage with each other, and the roller 12 is axially supported by the bearing portion 16. The bearing portion 16 and the frame 14 are integrally formed. The frame 14 has a box-like shape with one surface open, and has side walls 14A, 14B, 14C, 14
D, and the top surface 14E. The bearing portion 16 is formed on the side walls 14A and 14C. A part of the roller 12 projects from the frame 14.

The traveling device 10 of the present invention can be manufactured by applying so-called micromachine technology. This manufacturing process will be described below with reference to FIGS. Incidentally, FIG.
5A to 5C, the top surface 14E of the frame is located below the paper surface, and is not shown. Also, FIGS.
Corresponds to a cross-sectional view taken along line I (B) -I (B) of FIG.

First, a sacrificial layer 32 made of SiO ₂ is deposited on a silicon substrate 30, a polycrystalline silicon layer is deposited on the sacrificial layer 32, and then the polycrystalline silicon layer is etched to form, for example, a frame. 14 side wall 14A
Are formed (see FIG. 2A).

Next, a resist mask is formed on the entire surface,
After forming an opening in such a resist mask by photolithography technology, a polycrystalline silicon layer is deposited,
Then, the unnecessary polycrystalline silicon layer is removed by etching, and the resist mask is further removed to form the bearing portion 16, and the side walls 14B, 14D and a part of the top surface 14E ((B) of FIG. 2). reference). Bearing part 16
Is formed on the sidewall 14A.

Next, a sacrificial layer 34 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 34 is etched to form the shaft 1.
8, openings are formed in the sacrificial layer 34 corresponding to the side walls 14B and 14D and the top surface 14E (see FIG. 2C). Thereafter, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is removed by etching to form the shaft 18, and the side walls 14B and 14D and a part of the top surface 14E ((D in FIG. 2). )reference).

Thereafter, a sacrificial layer 36 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 36 is etched to form openings in the sacrificial layer 36 corresponding to the roller 12, the side walls 14B and 14D, and the top surface 14E. (See FIG. 2E). Then deposit a layer of polycrystalline silicon, then
The unnecessary polycrystalline silicon layer is removed by etching, and the roller 12, the side walls 14B, 14D and the top surface 14 are removed.
A part of E is formed (see FIG. 3A).

If necessary, the sacrificial layer 38 made of SiO ₂ is deposited, the side walls 14B and 14D are formed by etching the sacrificial layer 38, and the openings corresponding to the top surface 14E are formed, and the polycrystalline silicon layer is deposited. Alternatively, the unnecessary polycrystalline silicon layer may be repeatedly removed by etching, and the roller 12, the sidewalls 14B and 14D, and the top surface 14E may be laminated to form the layer.

Further, a sacrificial layer 38 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 38 is etched to form the shaft 1
8, openings are provided in the sacrificial layer 38 corresponding to the side walls 14B and 14D and the top surface 14E (see FIG. 3B). Then, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is etched away to form the shaft 18, and the side walls 14B, 14D and a part of the top surface 14E ((C in FIG. 3). )reference).

Next, a sacrificial layer 40 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 40 is etched to form openings in the sacrificial layer 40 corresponding to the bearing portion 16, the side walls 14B and 14D, and the top surface 14E. It is provided (see FIG. 4A). Then deposit a layer of polycrystalline silicon, then
The unnecessary polycrystalline silicon layer is removed by etching to form the bearing portion 16, the side walls 14B and 14D, and the top surface 14E (see FIG. 4B).

Then, a sacrificial layer 42 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 42 is etched to form an opening in the sacrificial layer 42 corresponding to the side wall 14C (FIG. 4).
(See (C)). Then, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is removed by etching to form the sidewall 14C (see FIG. 5).

Finally, all the sacrificial layers are removed by etching to complete the traveling device 10 of Example-1.

(Example-2) Example-2 is a modification of Example-1. As shown in (A) and (B) of FIG. 6, in the traveling device 10 of Example-2, the roller 12 is
It is composed of a ring portion 12A and a shaft portion 12C passing through a through hole 12B formed on the axis of the ring portion 12A. The ring portion 12A freely rotates with respect to the shaft portion 12C. The other constituent elements of Example-2 are the same as those of Example-1. Incidentally, (A) and (B) of FIG. 6 are (A) of FIG.
2 is a cross-sectional view taken along lines I (B) -I (B) and I (C) -I (C) of FIG.

(Embodiment 3) Embodiment 3 is also a modification of Embodiment 1. As shown in FIG. 7, in the traveling device 10 of Example-3, the bearing portion 16 is a cylindrical recess formed in the frame 14. The shaft 18 of the roller 12 is supported in the bearing portion 16. The other components of Example-3 are the same as those of Example-1. Incidentally, FIG. 7 (A)
1A and 1B are cross-sectional views taken along lines I (B) -I (B) and I (C) -I (C) of FIG.

(Embodiment 4) Embodiment 4 is also a modification of Embodiment 1. As shown in FIG. 8, in the traveling device 10 of Example-4, the plurality of rotor portions 22 are formed on the two side walls 20 of the cylindrical roller 12. Further, the shape of the space formed by the side walls 14A, 14B, 14C, 14D of the frame 14 and the inner wall of the top surface 14E is
It has a substantially cylindrical shape. Then, the side wall 14 of the frame 14
A plurality of stator portions 24 are formed on B and the side wall 14D. The stator portion 24 can be formed by doping polycrystalline silicon with a high concentration of impurities.
8A is a line I (B) -I of FIG.
FIG. 9 is a cross-sectional view taken along line (B) of FIG. 8 (B) and (C).
Is a line VIII (B) -VIII (B) in FIG.
FIG. 8 is a cross-sectional view taken along line VIII (C) -VIII (C).

The rotor portion 22 formed on the roller 12
The stator portion 24 formed on the side wall 14B and the side wall 14D of the frame 14 constitutes a so-called edge drive type electrostatic motor. When a voltage is applied to the pair of stator portions 24 facing the axis of the roller 12, the rotor portion 22 is attracted to the stator portion 24 by an electrostatic force. When a voltage is sequentially applied to the adjacent stator portions 24 with time, the rotor portion 22 rotates due to electrostatic attraction, and as a result, the roller 12 also rotates.

(Example-5) Example-5 is a modification of Example-4. As shown in FIG. 9, in the traveling device 10 of Example-5, a plurality of rotor portions 22 are formed on the side wall 20 of the cylindrical roller 12. A plurality of stator portions 24 are formed on the side wall 14A and the side wall 14C of the frame 14. The rotor portion 22 formed on the roller 12 and the stator portions 24 formed on the side walls 14A and 14C of the frame form a so-called overhang type electrostatic motor. When a voltage is applied to the pair of stator portions 24 facing the axis of the roller 12, the rotor portion 22 is attracted to the stator portion 24 by an electrostatic force. When a voltage is sequentially applied to the adjacent stator portions 24 with time, the rotor portion 22 rotates due to electrostatic attraction, and as a result, the roller 12 also rotates. 9A is a cross-sectional view taken along line I (B) -I (B) of FIG. 1A, and FIGS. 9B and 9C are views of FIG. Line IX (B) -IX (B) and line IX (C)-of (A)
It is sectional drawing which followed IX (C).

(Embodiment-6) In Embodiment-6, Embodiment 1-
It relates to the first aspect of the wafer of the present invention to which the traveling device 10 of the present invention described in the fifth embodiment is joined. As shown in FIG. 10, the traveling device 10 is bonded to the back surface 52 of the wafer. In order to bond the traveling device 10, the back surface 52 of the wafer and the top surface 14E of the traveling device 10 are mirror-finished, and then hydrophilicity is given to these surfaces. The back surface 52 of the wafer and the traveling device 10 can be joined by overlapping the surface 14E.

Alternatively, after mirror-finishing the back surface 52 of the wafer and the top surface 14E of the traveling apparatus 10, an oxide film is formed on these surfaces. Then, after superposing these surfaces, a pulsed voltage (± 100 to ± 500) is applied between the wafer 50 and the traveling device 10 under a reduced pressure of about 10 ⁻¹ Pa.
V) is added. By such electrostatic pressure, the back surface 52 of the wafer and the traveling device 10 can be bonded.

Alternatively, after the back surface 52 of the wafer and the top surface 14E of the traveling apparatus 10 are mirror-finished, these surfaces are overlapped and the temperature is raised to about 1000 ° C. and left for several hours. Back surface 52 and top surface 1 of traveling device 10
4E can be joined.

When the traveling device described in Embodiments 1 to 3 is bonded to the wafer 50, the wafer 50 is moved using, for example, air discharge by a turbo fan to which a micromachine technology described later is applied as a driving force. be able to. In addition, when the traveling device described in Embodiment 4 and Embodiment 5 is bonded to the wafer 50, the wafer 50 can be moved by the rotation of the roller itself in the traveling device. In this case, the control of the stator portion 24 and further the movement of the wafer can be controlled by, for example, a semiconductor device (not shown) mounted, bonded or formed on the back surface 52 of the wafer. Further, for example, by supplying electric power to the transport rail to bring the flexible rail, which is attached to the travel device and electrically connected to the travel device (or semiconductor device), into contact with the transport rail, the travel device Can be powered.

Example-7 Example-7 relates to a wafer having a turbofan bonded to the back surface. 11A and 11B are cross-sectional views of this turbofan 60. Figure 1
11 (A) is the line XI (A) -XI in FIG. 11 (B).
FIG. 12 is a cross-sectional view taken along the line (A) of FIG. 11, and FIG.
FIG. 3 is a cross-sectional view taken along line XI (B) -XI (B) of FIG.

The turbo fan 60 comprises a casing 64, a bushing 66 protruding from the top surface of the casing 64, and a fan 62 loosely fitted around the bushing 66. The casing 64 is provided with an air introduction section 68 and an air discharge section 70. Further, a stator portion 72 is provided in a portion of the casing 64 that faces the fan 62 in the horizontal direction. The horizontal direction here means a direction perpendicular to the rotation axis of the fan 62. In FIG. 11, 64A, 6
4B, 64C and 64D are side walls of the casing,
E is the bottom surface of the casing, and 64F is the top surface of the casing.

This turbofan can be manufactured by applying so-called micromachine technology. This manufacturing process will be described below with reference to FIGS.

First, a sacrificial layer 32 made of SiO ₂ is deposited on the silicon substrate 30, a polycrystalline silicon layer is deposited on the sacrificial layer 32, and then the polycrystalline silicon layer is etched to, for example, a casing. Forming a bottom surface 64E (see FIG. 12A).

Next, a sacrificial layer 34 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 34 is etched to form openings in the sacrificial layer 34 corresponding to the side walls 64A, 64B, 64C, 64D of the casing ( (See FIG. 12B). Then deposit a layer of polycrystalline silicon, then
The unnecessary polycrystalline silicon layer is removed by etching to form a part of the side walls 64A, 64B, 64C, 64D (see FIG. 12C). In addition, in FIG. 12C, a part of the formed side walls 64A, 64C, 64D is not shown.

After that, a sacrificial layer 36 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 36 is etched to form side walls 64A, 64B, 64C, 64D and an air introducing portion 68.
An opening is provided in the sacrificial layer 36 corresponding to the upper surface 68A of the (see FIG. 12D). In FIG. 12D, the sacrifice layer 36 corresponding to the sidewalls 64A, 64C, 64D is formed.
The openings provided in the are not shown.

After that, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is removed by etching to form a part of the sidewalls 64A, 64B, 64C, 64D and an upper surface 68A of the air introducing portion 68. (See FIG. 13A). In addition, in FIG. 13 (A), a part of the formed side walls 64A, 64C, 64D is not shown.

Further, a sacrificial layer 38 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 38 is etched to form a part of the bushing 66 and side walls 64A, 64B, 64C, 64.
An opening is provided in the sacrifice layer 38 corresponding to D (see FIG. 13B). Then deposit a layer of polycrystalline silicon,
Then, the unnecessary polycrystalline silicon layer is removed by etching, and a part of the bushing 66 and the sidewalls 64A, 64B, 6 are removed.
A part of 4C and 64D is formed (see FIG. 13C). In addition, in FIG. 13C, a part of the formed sidewalls 64A and 64C is not shown.

Next, a sacrificial layer 40 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 40 is etched to form a part of the bushing 66 and the sidewalls 64A, 64B, 64C, 6.
An opening is provided in the sacrificial layer 40 corresponding to 4D (see FIG. 13D). Then deposit a layer of polycrystalline silicon,
Then, the unnecessary polycrystalline silicon layer is removed by etching, and part of the bushing 66 and the sidewalls 64A, 64B, 6 are removed.
A part of 4C and 64D is formed (see FIG. 14A). In addition, in FIG. 14A, a part of the formed side walls 64A and 64C is not shown.

After that, a sacrificial layer 42 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 42 is etched to form a part of the bushing 66 and the side walls 64A, 64B, 64C, 6a.
An opening is provided in the sacrificial layer 40 corresponding to 4D and the fan 62 (see FIG. 14B). Next, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is removed by etching, and a part of the bushing 66 and the sidewall 6 are removed.
Part of 4A, 64B, 64C, 64D and fan 6
Form 2. In addition, in FIG. 14C, a part of the formed side walls 64A, 64B, 64C is not shown.

Next, a predetermined region is doped with a high concentration of impurities to form the stator portion 72 (see FIG. 14C).

Next, a sacrifice layer 44 made of SiO ₂ is deposited on the entire surface, and the sacrifice layer 44 is etched to form openings in the sacrifice layer 44 corresponding to the bushing 66 and the side walls 64A, 64B, 64C and 64D. (See FIG. 15A). Then deposit a layer of polycrystalline silicon, and then
The unnecessary polycrystalline silicon layer is removed by etching to form the bushing 66 and the side walls 64A, 64B, 64C and 64 (see FIG. 15B). The formed side walls 64A and 64C are not shown in FIG.

Next, a sacrificial layer 46 made of SiO ₂ is deposited on the entire surface, and the sacrificial layer 46 is etched to form an opening in the sacrificial layer 46 corresponding to the top surface 64F of the casing 64 ((C in FIG. 15). )reference). Next, a polycrystalline silicon layer is deposited, and then the unnecessary polycrystalline silicon layer is removed by etching to form the top surface 64F of the casing (see FIG. 16). In addition, in FIG. 16, the formed side walls 64A and 64C are not shown.

Finally, the turbofan is completed by etching away all sacrificial layers.

FIG. 17 shows a wafer 50 according to the second aspect of the present invention in which a turbofan 60 is bonded to the back surface. To bond the turbo fan 60 to the back surface 52 of the wafer, the back surface 52 of the wafer and the top surface 6 of the turbo fan 60 are joined together.
After mirror finishing 4F, hydrophilicity is given to these surfaces, and the back surface 52 of the wafer and the top surface 64F of the turbo fan 60 are provided.
By stacking and, the back surface 52 of the wafer and the turbo fan 60 can be joined.

Alternatively, the back surface 52 of the wafer and the top surface 64F of the turbofan 60 are mirror-finished, and then an oxide film is formed on these surfaces. Then, after superposing these surfaces, under a reduced pressure of about 10 ⁻¹ Pa, a pulse-shaped voltage (± 100 to ± 100) between the wafer 50 and the turbofan 60.
± 500V) is added. By such electrostatic pressure, the back surface 52 of the wafer and the turbo fan 60 can be bonded.

Alternatively, after the back surface 52 of the wafer and the top surface 64F of the turbo fan 60 are mirror-finished, these surfaces are overlapped and the temperature is raised to about 1000 ° C. and left for several hours. Back 52 and turbo fan 60
Can be joined to the top surface 64F.

Further, the turbo fan 60 is formed directly on the back surface 52 of the wafer. Also in this case, the back surface 52 of the wafer
It is included in the category that the turbofan is joined to. In order to directly form the turbofan 60 on the back surface 52 of the wafer, the steps of manufacturing the turbofan 60 described above may be reversed and the formation of the sacrificial layer 32 may be omitted. That is, first, the top surface 64F of the turbo fan 60 may be directly formed on the back surface 52 of the wafer, and finally the bottom surface 64E of the turbo fan 60 may be formed. After that, the wafer surface is polished by a usual method. In this way, a wafer having the traveling device on the back surface of the wafer can be manufactured.

In the seventh embodiment, the fan 62 of the turbo fan 60 and the stator portion 72 constitute a so-called edge drive type electrostatic motor. When a voltage is applied to the pair of stator portions 72 facing the axis of the fan 62, the fan 62 is attracted to the stator portion 72 by an electrostatic force.
When voltage is sequentially applied to the adjacent stator portions 72 with time, the fan 62 rotates due to electrostatic attraction. The rotation of the fan 62 causes air to be ejected from the air discharge portion 70 of the turbo fan 60, which allows the wafer to float and move. The control of the stator portion 72 and the movement of the wafer can be controlled by, for example, a semiconductor device (not shown) attached to, bonded to or formed on the back surface 52 of the wafer. Further, for example, by supplying electric power to the carrier rail and bringing the flexible rail, which is attached to the turbofan and electrically connected to the turbofan (or the semiconductor device), into contact with the carrier rail, the turbofan Can be powered.

(Embodiment-8) In the turbofan described in Embodiment-7, particles are contained in the air discharged from the air discharge portion 70, and there is a risk of contamination by the particles. In order to prevent this, in Example-8, the filter 80 is provided in the air discharge unit 70.
To provide. In this filter 80, a polycrystalline silicon layer 82 is formed on the side wall 64B of the casing 64, and a plurality of holes are opened in the polycrystalline silicon layer 82 by photolithography and etching. After forming a sacrificial layer made of SiO ₂ thereon, a polycrystalline silicon layer 84 is formed on the surface of the sacrificial layer, and then a plurality of holes are opened in the polycrystalline silicon layer 84 by photolithography and etching. Then, the sacrificial layer is removed by etching to form the filter 80.

The present invention has been described above based on the embodiments, but the present invention is not limited to these embodiments. The shape of the roller, frame, or bearing of the traveling device of the present invention can be changed as appropriate. In order to reduce friction, the shaft and bearing of the roller, or the fan and bushing can be made of SiN or the like. PSG can be used instead of SiO ₂ as the sacrificial layer. Further, when SiN is used as the etchable material, for example, polycrystalline silicon can be used as the sacrificial layer.

The method for manufacturing the traveling device is an example, and can be changed as appropriate. In addition, for example, when manufacturing the traveling device, X
Line lithography technology can also be applied. In order to form the etch stop layer in the polycrystalline silicon layer, it is possible to dope the polycrystalline silicon layer with a high concentration of boron or form a pn junction in the polycrystalline silicon layer.

In Example-4 and Example-5, the roller portion 22 was provided on the roller 12, but the roller 12 described in Example-1 to Example-3, that is, the roller without the rotor portion was used. It can also be used in Example-4 and Example-5. The shapes and the numbers of the rotor parts, the fans, and the stator parts in the traveling device or the turbofan described in the example-4, the example-5, or the example-7 are examples, and the shapes and the numbers may be appropriate. .

[0065]

Since all the constituent materials of the traveling apparatus of the present invention are composed of materials that can be etched, the traveling apparatus or a wafer equipped with the traveling apparatus can be manufactured in a clean room by the micromachine technology. Very clean. Since the wafer can be self-propelled by the traveling device, the transfer device is not necessary in the manufacturing process of the semiconductor device, for example. Therefore, it is possible to prevent the generation of particles due to the contact between the wafer and the transfer device in the conventional technique, and it is also possible to prevent the contamination of the wafer surface due to the particles attached to the back surface of the wafer. as a result,
It is possible to improve the manufacturing yield of semiconductor devices. According to the bonding method of the present invention, an article made of a silicon-based material such as a wafer and a micromachine can be bonded easily and reliably.

[Brief description of drawings]

FIG. 1 is a diagram showing a traveling device of the present invention described in Example-1.

FIG. 2 is a schematic cross-sectional view of a traveling device for explaining a manufacturing process of the traveling device of the present invention.

FIG. 3 is a schematic cross-sectional view of the traveling device for explaining the manufacturing process of the traveling device of the present invention, following FIG.

FIG. 4 is a schematic cross-sectional view of the traveling device for explaining the manufacturing process of the traveling device of the present invention, following FIG.

FIG. 5 is a schematic cross-sectional view of the traveling device for explaining the manufacturing process of the traveling device of the present invention, following FIG.

FIG. 6 is a diagram illustrating a traveling device of the present invention described in Example-2.

FIG. 7 is a diagram showing a traveling device of the present invention described in Example-3.

FIG. 8 is a diagram illustrating a traveling device of the present invention described in Example-4.

FIG. 9 is a diagram illustrating a traveling device of the present invention described in Example-5.

FIG. 10 is a diagram showing a wafer according to the first aspect of the present invention.

FIG. 11 is a diagram showing a turbofan bonded to a wafer according to the second aspect of the present invention.

FIG. 12 is a schematic cross-sectional view of a turbo fan for showing a manufacturing process of the turbo fan.

FIG. 13 is a schematic cross-sectional view of the turbofan, which is subsequent to FIG. 12 and shows a manufacturing process of the turbofan.

FIG. 14 is a schematic cross-sectional view of the turbo fan, which is subsequent to FIG. 13 and shows a manufacturing process of the turbo fan.

FIG. 15 is a schematic cross-sectional view of the turbofan, which is subsequent to FIG. 14 and shows a manufacturing process of the turbofan.

FIG. 16 is a schematic cross-sectional view of the turbo fan, which is subsequent to FIG. 15 and shows a manufacturing process of the turbo fan.

FIG. 17 is a diagram showing a wafer according to a second aspect of the present invention.

FIG. 18 is an enlarged cross-sectional view of the turbo fan and the filter described in Example-8.

FIG. 19 is a diagram for explaining a conventional belt transfer method for transferring a wafer.

FIG. 20 is a diagram for explaining a conventional roller transfer system for transferring a wafer.

FIG. 21 is a diagram for explaining a conventional walking beam system for carrying a wafer.

FIG. 22 is a diagram for explaining a conventional robot transfer system for transferring a wafer.

[Explanation of symbols]

10 Traveling device 12 Roller 14 Frame 14A, 14B, 14C, 14D Side wall of frame 14E Frame top surface 16 Bearing part 18 Shaft 30 Silicon substrate 32, 34, 36, 38, 40, 42, 44, 46 Sacrificial layer 12A Ring part 12B Through hole 12C Shaft part 20 Roller side wall 22 Rotor 24 Stator part 50 Wafer 52 Wafer backside 60 Turbo fan 62 Fan 64 Casing 64A, 64B, 64C, 64D Casing side wall 64E Casing bottom surface 64F Casing top surface 66 Bushing 68 Air introduction part 68A Air introduction part upper surface 70 Air discharge part 72 Stator part 80 Filter

Claims (5)

[Claims] 1. A traveling device comprising a roller, a frame, and a bearing portion formed on the frame and supporting the roller, the roller being formed of an etchable material. 2. A wafer, wherein the traveling device according to claim 1 is bonded to a back surface. 3. A traveling device comprising a casing, a bushing projecting from the inner wall of the casing, and a fan loosely fitted in the bushing, and a turbofan formed of an etchable material, the traveling device being joined to the rear surface. Wafer characterized by 4. A method for manufacturing a wafer, which comprises manufacturing a traveling device on the back surface of the wafer by a micromachine technique and then polishing the front surface of the wafer. 5. A joining method for joining a micromachine made of a silicon-based material to an article made of a silicon-based material, wherein a mirror-finished portion is formed on the micromachine, and the article has a mirror-finished portion. To form
A joining method comprising joining a mirror-finished portion of a micromachine and a mirror-finished portion of an article.