JPH0610043B2 - Semiconductor substrate carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a semiconductor substrate transfer apparatus.

(Prior Art) In the manufacture of semiconductors such as ICs and LSIs, as a semiconductor substrate transfer device, for example, a transfer device that floats and transfers the semiconductor substrate using ultrasonic waves in consideration of prevention of dust generation and the like is available. Is being considered.

Then, regarding the conveyance using ultrasonic waves, for example, JP-A-58-148682, JP-A-59-43724, JP-A-59-82222,
JP-A-60-144224, JP-A-60-188213, JP-A-61-7126
, JP-A-61-55012 and the like.

(Problems to be Solved by the Invention) However, the above-described disclosure has the following problems.

1) The ultrasonic “standing wave” type has a single transport direction and it is difficult to change the direction.

2) The transport mechanism is complicated.

3) The control of ultrasonic intensity is complicated.

The present invention has been made in response to the above conventional circumstances,
An object of the present invention is to provide a semiconductor substrate transfer device having a simple mechanism and easy to handle.

[Structure of Invention]

(Means for Solving the Problems) The present invention relates to a first AC power supply, and a dimension in the strain direction is set to a length of ½ wavelength of the AC voltage of the first AC power supply and a thickness of the first AC power supply. Piezoelectric body (2) that generates a strain that expands laterally when a voltage is applied in the vertical direction and piezoelectric body (3) that generates a strain that contracts laterally
And the piezoelectric body (2) and the piezoelectric body (3), the first piezoelectric body portion being formed by alternately sticking and in the strain direction and to which an alternating voltage is applied in the thickness direction by the first AC power source. ) Are alternately stuck in the strain direction, and the first piezoelectric body portion is displaced in the strain direction by a length corresponding to a quarter wavelength of the AC voltage of the first AC power source. A second piezoelectric body portion attached to one surface side of the piezoelectric body portion, and an alternating current having a phase difference of 90 degrees from the alternating voltage of the first alternating current power supply in the thickness direction of the second piezoelectric body portion. A second AC power supply for applying a voltage; and an elastic body attached to the other surface side of the first piezoelectric body portion. A semiconductor substrate is placed on the elastic body, and the first piezoelectric body portion and Second
The elastic body is excited by the traveling wave generated by the piezoelectric body section to convey the semiconductor substrate on the elastic body.

(Operation) According to the transporting device of the present invention, since the transported object is floated and transported by utilizing the rotational motion generated on the elastic body surface, clean transportation without generation of dust or the like can be performed.

(Embodiment) An embodiment of the conveying apparatus of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a thin plate-like elastic body (1) made of synthetic resin such as Delrin (trade name) has a substantially flat plate-like shape on the lower surface, and when the voltage is applied to the upper and lower surfaces, it "extends" in the lateral direction. A plurality of piezoelectric elements that generate strain, such as piezoelectric ceramics (2) and piezoelectric materials that generate "shrink" strain, such as piezoelectric ceramics (3), are alternately arranged adjacent to each other in the same direction as the strain. First piezoelectric part (4)
However, it is attached by an adhesive or other means.

The width of the piezoelectric ceramics (2) (3) in the strain direction is half the wavelength λ of the first AC power source (5) applied to the piezoelectric ceramics (2) (3). Has been selected.

Next, on the lower surface of the first piezoelectric body portion (4) , a plurality of layers, for example, a second piezoelectric body portion (6) having the same configuration and arrangement is formed.
However, the first piezoelectric body portion (4) is pasted with an adhesive or other means in a state where it is displaced by a distance corresponding to 1/4 of the wavelength λ and is displaced rightward, for example. It is attached. And
The upper surface (7) and the lower surface (8) of the first piezoelectric body portion (4 ), the second piezoelectric body portion
The upper surface (9) and the lower surface (10) of (6) are, for example, all elastic bodies (2) (3) when a voltage is applied to the left end of the first and second piezoelectric body portions (4) and (6 ). Are connected by a conductor so that the above voltage is applied to.

Next, on the upper surface (7) and the lower surface (8) of the first piezoelectric body portion (4) at the left end of the first and second piezoelectric body portions (4) and (6) , the first AC power source is provided.
(5) is connected, the upper surface (9) the lower surface of the second piezoelectric body (6) (1
A second AC power source (11) is connected to (0) and is configured so that a voltage can be applied to the first piezoelectric body portion (4) and the second piezoelectric body portion (6) , respectively.

Then, the first AC power source (5) and the second AC power source (11)
The first piezoelectric body part (4) and the second piezoelectric body part, respectively.
An AC voltage is applied to (6) to generate "stretch" and "shrink" distortions. The elastic body (1) is excited by the movement of this strain, and the semiconductor substrate (12) placed on the elastic body (1) is configured to be transported by the movement generated in the elastic body (1), for example, the rotational movement. ing.

Next, the operation will be described.

First, the strains of "stretching" and "contracting" of the piezoelectric ceramic will be described. As shown in FIG. 2 (a), for example, a piezoelectric ceramic (21) that "shrinks" from left to right
In the piezoelectric body part ( 23 ) alternately arranged with the "stretching" piezoelectric ceramics (22), the "shrinking" piezoelectric ceramics (21), ..., From the left end, positive voltage is applied to the upper surface (24) and negative voltage is applied to the lower surface (25) ( It is known that when 26) is applied, strain is generated in each of the above-mentioned piezoelectric ceramics in the direction indicated by the arrow in FIG.

When an elastic body (not shown) is attached to, for example, the upper surface (24) of the piezoelectric body portion ( 23 ), the elastic body (not shown) is “shrinked” by the above-mentioned strain.
Part 1) becomes a mountain, and also "stretches" voltage ceramics
Deflection (27) that becomes a valley occurs at the portion (22).

Next, as shown in FIG. 2 (b), the upper surface of the piezoelectric body portion ( 23 )
When a negative voltage is applied to (24) and a positive voltage (28) is applied to the lower surface (25), a deflection (29) in the opposite direction to that in FIG. 2 (a) is generated.

Therefore, when an AC voltage is applied as the voltage (26) (28), the flexures (27) and (29) are alternately generated, and the flexures (27) and (29) are generated in the elastic body (not shown). It is known that a standing wave that repeatedly moves up and down in the same place is generated.

Therefore, in FIG. 1, from the first AC power source (5) to the third
The first ultrasonic wave represented by ASinωt as shown in Fig. (A)
Fig. 3 shows the AC voltage (31) from the second AC power supply (11)
Represented by -ACosωt as shown in (b), the above AC voltage (31)
The second AC voltage (32), which is 90 degrees out of phase with time,
The voltage is applied to the first piezoelectric body part (4) and the second piezoelectric body part (6) , respectively.

At this time, the first piezoelectric body part(Four)And the second piezoelectric body part(6)
Are the first AC voltage (31) and the second AC voltage, respectively.
Corresponding to (32), standing wave vibration is generated.
Phase shift, and the first and second AC voltage (31), (32) exceeding
1/4 wavelength of sound wave, that is, mechanically shifted by 90 degrees
Since it is placed, it is a wave that combines the above standing waves
The vibration of the sexual body (1) progresses to the right with the passage of time.
Become a wave.

Then, the elastic body (1) is excited by the traveling wave of the ultrasonic waves, and the elastic body (1) moves so that the wave proceeds to the right as shown in FIG. Focusing on a point a (41) on the surface of the moving elastic body (1), this point a (41) rotates so as to draw a counterclockwise circular trajectory that is opposite to the right direction in which the traveling wave advances. Known to be exercising (42). Then, this rotational movement (42) acts to push the air on the surface of the elastic body (1) almost to the left.

Therefore, when the semiconductor substrate (12) is placed on the elastic body (1) in which the traveling wave is excited, the rotational movement (42) causes the semiconductor substrate (12) to move in a direction opposite to that of the traveling wave. Is floated in the direction of and transported.

To change the transport direction, for example, the first and second piezoelectric body parts
The traveling wave may be directed to the left by a method such as applying a voltage from the right ends of (4) and (6) .

Further, the transport speed can be varied by changing the amplitude A of the applied AC voltage (31) (32) or the angular velocity ω. For example, if the amplitude A is increased and the angular velocity ω is increased, the transport speed becomes faster. Become.

In addition, since no mechanical mechanism is used, the structure is simple, and since the semiconductor substrate (12) is levitated and conveyed, the generation of dust due to sliding and friction is extremely small.

Although the elastic body (1) formed of Delrin (trade name) has been described in the above embodiment, the present invention is not limited to the above embodiment, and the elastic body (1) has elasticity, such as vibration. It goes without saying that any elastic body that does not easily generate dust can be used.

Further, what is transported is not limited to the semiconductor substrate (12), and any sheet can be transported.

The piezoelectric body may be LiTaO ₃ , LiNbO ₃ , ZnO, or any other material that has a piezoelectric effect.

Furthermore, the piezoelectric body is not limited to the piezoelectric ceramics of the above-mentioned embodiment, but “stretches” when a voltage is applied.
Other materials may be used as long as they generate a mechanical strain of "shrinking", and the same effect as in the above embodiment can be obtained.

〔The invention's effect〕

As described above, according to the transfer device of the present invention, clean transfer can be performed without generation of dust or the like. In particular, it is suitable for transporting semiconductor wafers in an ultra clean room.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of the transporting device of the present invention, FIGS. 2 (a) and 2 (b) are principle explanatory diagrams of the main part of FIG. 1, and FIGS. 3 (a) and 3 (b). FIG. 4 is a diagram showing an example of applied voltage in FIG. 1, and FIG. 4 is a diagram explaining the transport principle of the main part of FIG. DESCRIPTION OF SYMBOLS 1 ... Elastic body, 2, 3 ... Piezoelectric ceramics 4 ... 1st piezoelectric body part, 5 ... 1st AC power supply, 6 ... 2nd piezoelectric body part, 11 ... 2nd AC power supply, 12 …… Semiconductor substrate, 31 …… First alternating voltage, 32 …… Second alternating voltage, 42 …… Rotary motion.

Claims (1)

[Claims] 1. A first AC power supply, wherein a dimension in a strain direction is set to a length of 1/2 wavelength of an AC voltage of the first AC power supply and a voltage is applied in a thickness direction. Piezoelectric body (2) that generates laterally extending strain and piezoelectric body (3) that generates laterally contracting strain
And the piezoelectric body (2) and the piezoelectric body (3), the first piezoelectric body portion being formed by alternately sticking and in the strain direction and to which an alternating voltage is applied in the thickness direction by the first AC power source. ) Are alternately stuck in the strain direction, and the first piezoelectric body portion is displaced in the strain direction by a length corresponding to a quarter wavelength of the AC voltage of the first AC power source. A second piezoelectric body portion attached to one surface side of the piezoelectric body portion, and an alternating current having a phase difference of 90 degrees from the alternating voltage of the first alternating current power supply in the thickness direction of the second piezoelectric body portion. A second AC power supply for applying a voltage; and an elastic body attached to the other surface side of the first piezoelectric body portion. A semiconductor substrate is placed on the elastic body, and the first piezoelectric body portion and Second
2. A semiconductor substrate transfer apparatus, wherein an elastic body is excited by a traveling wave generated by the piezoelectric body section to transfer a semiconductor substrate on the elastic body.