JPS60258013A - Sample conveying apparatus - Google Patents

Abstract

PURPOSE:To convey a sample in a vacuum with high reliability in a small-sized conveying apparatus for a manufacturing process by providing a vibrator in a conveying path to form a progressive wave on a conveying surface, and conveying the sample in the opposite direction to the progressive wave. CONSTITUTION:When alternating voltage is applied to piezo-electric elements 7, the piezo-electric elements are expanded and contracted according to the degree of voltage so that a creep wave 8 according to the phase of applied voltage is formed on the surface of a conveying path 1. Thus, a sample 4 on the conveying path 1 is conveyed in the opposite direction to the advancing direction. In this arrangement, if the phase of applied alternating voltage is suitably selected, the conveying direction can be freely selected to be normal or reverse. Furthermore, the sample can be conveyed in a vacuum without a rubber or the like reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sample transport device used in various manufacturing processes, and particularly to a sample transport device using traveling waves (peristaltic waves).

(Technical Background of the Invention and Problems Thereof) Conventionally, in various manufacturing processes, particularly in semiconductor manufacturing, various transport devices have been used to transport samples such as semiconductor wafers and mask substrates.

Various types of conveyance methods are employed in such conveyance devices, and typical ones are shown in the following (1) to (2).

■ A method in which a rubber belt is wrapped around a roller and the roller is rotated to transport the sample on the belt.

■ Method of transporting the sample using an electric membrane (J.

A, paiVanas, J, K, Hassan,
A New AlrF+1III Technique
for Low ContactHandllnoo
f 5ilicon Wafers, April 19
80゜5solid 5tate Technology
, 148).

■ A method in which the sample is transported a predetermined distance using a single arm or drive rod.

However, this type of system has the following problems. That is, since the method (2) uses rubber, its use in a vacuum is restricted. Additionally, the rubber may wear out or break due to long-term use. Furthermore, the rubber may come off the roller during use, resulting in poor reliability. Although the method (2) has the advantage of having fewer moving parts and high reliability, it cannot be used in a vacuum. In addition, with method (■), the conveyance distance becomes longer, and the length of the arm and drive rod also becomes longer.
The disadvantage is that the device becomes larger.

[Purpose of the invention]

An object of the present invention is to provide a small and highly reliable sample transport device that can be used not only in the atmosphere but also in a vacuum.

[Summary of the invention]

The gist of the present invention is to form a peristaltic motion (traveling wave) on the surface (transporting surface) of the sample transport path, and to transport the sample by this traveling wave.

That is, the present invention provides a sample transport device that transports a sample placed on a transport surface of a transport path along the transport path, in which the transport path is made of an elastic material, and a portion or the entirety of the transport path is made of an elastic material. A vibrator for forming a traveling wave is attached to the transport surface of the transport path, and the sample is transported in a direction opposite to the traveling direction of the traveling wave.

〔Effect of the invention〕

According to the present invention, since the sample is driven by a peristaltic wave, that is, a traveling wave, on the contact surface, the transport path may be formed of an elastically deformable material, for example, a metal such as Fe, Cu, or AI.・Can be used regardless of whether it is in a vacuum. In addition, as a drive mechanism, motors, gears, rollers, arms, etc. are conventionally used. □Yes. □It's so big. 1, □
) - can be prevented from deteriorating in reliability due to wear, assembly errors, and changes over time. Furthermore, since these parts are not used, the structure is simplified, and only a conveyance path and a small imager for forming peristaltic waves are required, allowing the device to be miniaturized. Unlike conventional vibrating conveyors, the sample only moves on top of the traveling waves, so the sample does not wear out due to vibration, and the conveying surface does not wear out. In addition, by setting the frequency of the traveling wave to the ultrasonic range,
A completely noiseless drive system can be achieved. moreover,
Straight forward movement, rotation, and inversion formation have the advantage that these combinations can be freely performed, and their usefulness is enormous.

[Embodiments of the invention]

FIG. 1 is a perspective view showing a schematic configuration of a sample transport device according to a first embodiment of the present invention. In the figure, reference numeral 1.2 is a linear conveyance path, and 3 is a rotary conveyance path on a ring, and these conveyance paths 1, 2, and 3 are Fe.

It is made of an elastic material such as Cu or AI. and,
A sample 4 such as a semiconductor wafer is placed on the transport path 1.2.3, and the sample 4 runs on the transport path surface (transport surface) 5-.

A plurality of vibrators are arranged on the lower surface of the transport path L 2.3 along the transport direction.

For example, as shown in FIG. 2, piezoelectric elements 7 made of lead titanate-based piezoelectric material 5 sandwiched between electrodes 6a and 6b are attached to the lower surface of the conveyance path 1 at regular intervals along the conveyance direction. .

These piezoelectric elements 7 are moved in the longitudinal direction (
(in the same direction as the transport direction), each electrode 6a
, 6b, a voltage is applied with a phase shift of 120 degrees from that of the adjacent piezoelectric element 7.

In such a configuration, when an alternating current voltage is applied to each piezoelectric element 7, each piezoelectric element 7 expands and contracts depending on the magnitude of the voltage. Now, when a three-phase □ AC voltage is applied to the piezoelectric element 7 (71, to 76) as shown in FIG. 71° 74 expansion/contraction m is zero, piezoelectric element 7
The applied voltage of 2.75 is (V sinω';ω' =
When the voltage applied to the piezoelectric elements 7B and 7s is (V sin ω'';ω'' = ω+270°), the elements 72 and 75 are expanded. As a result, the conveyance path 1
A peristaltic wave (traveling wave) 8 is formed on the surface of. here,
The expansion/contraction form of the piezoelectric element 7 changes depending on the phase of the applied voltage. That is, if the phase is delayed by 120 degrees, the piezoelectric element 7s
, 74 are contracted and the piezoelectric element 73.7s is expanded, and in this case, a traveling wave as shown in FIG. 3(b) is formed. Furthermore, when the phase is delayed by 270 degrees, the piezoelectric element 7
1.74 will expand and the piezoelectric elements 72.76 will contract, and in this case a traveling wave as shown in FIG. 3(C) is formed. In other words, due to the expansion and contraction of the piezoelectric element 7, the conveyance path 1
A traveling wave 8 is generated on the surface (conveying surface) of the paper, and this traveling wave 8 travels to the right in the paper.

As the traveling wave 8 advances, the sample 4 on the transport path 1 is transported in a direction opposite to the traveling direction.

Thus, according to the present apparatus, a traveling wave can be formed on the transport surface on the transport path 1, and the sample 4 placed on the transport surface can be transported along the transport direction of the transport path 1. Furthermore, by reversing the phase of the alternating current voltage applied to the piezoelectric element 7, it is also possible to reverse the transport direction. Therefore, the sample 4 can be freely transported on the straight transport path 1.2 and the rotary transport path 3. In this case, there is no need to use rubber or the like, and it can be used not only in the atmosphere but also in a vacuum without any inconvenience.

Further, there is an advantage that a protruding ring can be formed with an extremely simple structure consisting of the conveying paths 1, 2.3 made of an elastic material and the piezoelectric element 7. In addition, the transport speed of the sample 4 is determined by the vibration amplitude of the piezoelectric element 7,
That is, it can be freely varied by changing the magnitude of the applied voltage. Furthermore, select the frequency of the applied voltage,
If the frequency of the traveling wave formed on the conveyance surface is in the ultrasonic range, noise generation can be prevented.

Note that in the above example, multiple piezoelectric elements are attached to the lower surface of the conveyance path at regular intervals, but it is also possible to attach one piece of piezoelectric material to the lower surface of the conveyance path and only connect the electrodes along the conveyance direction. It may also be divided into two parts.

・17 It is also possible to form a traveling wave by reversing the polarization directions of adjacent piezoelectric elements and applying voltages with a phase difference of 90 degrees to adjacent piezoelectric elements. Furthermore, the arrangement of the piezoelectric element is not limited to the entire conveyance path, but may be placed in a part of the conveyance path. Further, in the case of the straight conveyance paths 1 and 2, since reflection at the end faces cancels out the traveling waves, a process is required to reduce the reflected waves. This can be achieved by attaching an attenuator to the end face of the conveyance path.

Alternatively, the end surface may be roughened to create random reflections, or the tip may be sharpened to achieve both at the same time.

FIG. 4 is a plan view showing a schematic configuration of a second embodiment of the present invention. In this embodiment, a semiconductor wafer is transported and rotated. Four straight transport paths 11.12.13.
14 intersect in a criss-cross pattern, and a rotary conveyance path 15 made of a disc body is arranged at the intersection. In addition, the straight conveyance path 11. ~.

A triangular conveyance path 16 is provided between the rotary conveyance path 14 and the rotary conveyance path 15.
．． 17, 18, and 19 are arranged, respectively. Here, the straight conveyance path 11. .

−〇− Conveyance path 16. . . . , 19 is the conveyance path 11. This is an auxiliary device that prevents the sample 4 from stopping due to discontinuation of the traveling wave between the transport path 15 and the transport path 15, and its transport direction is vertical and horizontal in the paper. As shown in FIGS. 5(a) and 5(b), a plurality of piezoelectric elements 21 are attached to the lower surface of the rotary conveyance path 15 along the circumferential direction, and a plurality of piezoelectric elements 21 are attached in a cross shape passing through the center point. A piezoelectric element 22 is attached. Here, the piezoelectric element 21 is for forming a traveling wave along the circumferential direction, and the piezoelectric element 22 is for forming a traveling wave in the vertical direction and the horizontal direction on the page. Note that FIG. 5(a) is a plan view, and FIG. 5(b)
Is this the arrow in figure (a)? 11A-A cross section is shown.

In such a configuration, the sample 4 placed on the straight conveyance path 11 is first conveyed to the right in the paper in the same manner as in the previous embodiment, and then transferred onto the rotary conveyance path 15 by the conveyance paths 16 and 17. . The sample 4 transported onto the rotary transport path 15
The sample 4 is further conveyed to the right by the traveling wave generated by the piezoelectric element 22 of No. 5, and as a result, the sample 4 is set at the center of the conveyance path 15. Thereafter, the sample 4 is rotated by a traveling wave generated by the piezoelectric element 21 of the rotary conveyance path 15. This rotation sets the orientation flat surface of the sample 4 in a desired direction. This set of orientation flat surfaces is extremely important for reading wafer marks. Next, the sample 4 is transported, for example, downward in the plane of the paper by the piezoelectric element 22 of the rotary transport path 15, and further transferred onto the linear transport path 12 by the action of the transport paths 17 and 18. Then, the conveyance path 12
As a result, the sample 4 is conveyed downward in the plane of the paper.

Therefore, according to this embodiment, the trial cost of $44 is the same as in the previous embodiment.
can be transported, and the sample 4 can also be rotated. Therefore, it is effective for orientation of semiconductor wafers, setting of flat surfaces, etc.

FIG. 6 is for explaining the third embodiment, and shows a schematic configuration diagram of an electron beam exposure apparatus to which the present invention is applied. In the figure, 31 is a sample chamber, and 32 is an electron optical column. A sample stage 32 is accommodated in the sample chamber 31, and a first transport mechanism 41 is provided on the sample stage 33. Sample chamber 31
A preliminary chamber 35 is connected to the auxiliary chamber 35 via a gate valve 34.

A moving table 36 is housed in the preliminary chamber 35, and a second transport mechanism 41 is provided on the moving table 36.

Further, in the figure, numeral 37 indicates a gate valve that isolates the preliminary chamber 35 from the atmosphere, numeral 38 indicates a moving table, and a third transport mechanism 43 is provided on the moving table 38.

Here, the transport mechanism 41. formed on the sample stage 33 and the moving stage 36.38. ~． Reference numeral 43 is similar to the conveyance path and piezoelectric element described in the previous embodiment.

In such a configuration, a wafer transferred from a wafer carrier (not shown) first travels on the atmosphere side transport mechanism 43. Next, enter the preliminary room 35. h a r: e /
7″-ht<Ay737trZkai■”361C, l.

Then, the conveying mechanism 42 is moved by the thickness of the gate valve 37, and the conveying mechanisms 42 and 43 are brought into contact with each other. The wafer enters the preliminary chamber 35 by the transport mechanism 42, and the gate valve 37 is closed. After the preliminary chamber 35 is evacuated, the gate valve 34 is opened, and the transfer mechanism 42 is moved by the moving table 36 to bring it into contact with the transfer mechanism 41. Next, the wafer is transported to the center of the sample stage 33 by the transport mechanism 41, and the gate valve 34 is
Close. At this position, the wafer will be subjected to electron beam exposure.

Thus, according to this embodiment, the wafer can be transferred by the electron beam exposure apparatus. In this case, the structure is simple and the overall structure can be made smaller than the conventional structure using a transfer arm or a drive ring.

Note that the present invention is not limited to the embodiments described above. For example, the member forming the conveyance path is made of Fe, Cu.
, AI, and any elastic member having a desired degree of elasticity may be used. Moreover, conditions such as the shape, arrangement position, and number of the piezoelectric elements can be changed as appropriate according to specifications.

Furthermore, the direction of expansion and contraction of the piezoelectric element is not necessarily limited to the length direction 13- (conveyance direction), and even if the piezoelectric element expands and contracts in the thickness direction (direction perpendicular to the conveyance direction), the traveling wave can be formed. It is possible. Further, instead of the piezoelectric element, any vibrator that applies distortion to the conveyance path and forms a traveling wave on the conveyance surface can be used. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a schematic configuration of a sample transport device according to a first embodiment of the present invention, FIG. 2 is a sectional view showing an enlarged configuration of main parts of the device, and FIG. FIG. 4 is a schematic diagram for explaining the operation, FIG. 4 is a plan view showing the schematic configuration of the second embodiment of the present invention, FIG. FIG. 3 is a schematic configuration diagram showing an electron beam exposure apparatus for explaining a third embodiment of the present invention. 1.2.11. ~． 14...straight conveyance path, 3゜15
Rotating conveyance path, 4...sample, 5...piezoelectric material, 6a. 14-6b...electrode, 7.71. ~． 7s, 21.22・
... Piezoelectric element, 8... Traveling wave (peristaltic wave), 31...
・Sample chamber, 32... Electron optical lens barrel, 33... Sample stage, 34° 37... Gate valve, 35... Preliminary chamber,
36.38...Moving table, 41,42.43...Transportation mechanism. Applicant's agent Patent attorney Takehiko Suzue 15-

Claims (5)

[Claims] (1) Equipped with a conveyance path made of an elastic material on which the sample is placed, and a vibrator attached to a part or the entirety of this conveyance path to form a traveling wave on the conveyance surface of the conveyance path. A sample transport device, characterized in that the sample is transported by the traveling wave in a direction opposite to the traveling direction of the traveling wave. (2) The sample transport device according to claim 1, wherein the transport path is of a straight type, a hairpin type, a rotation type, or a combination thereof. (3) The sample transport device according to claim 1, wherein a piezoelectric element is used as the vibrator. (4) The sample transport device according to claim 1, wherein the frequency of the traveling wave is set in an ultrasonic range. (5) The sample transport device according to claim 1, wherein the transport speed of the sample is controlled by changing the vibration amplitude of the vibrator.