JPS62172737A - Wafer handling device - Google Patents

Abstract

PURPOSE:To realize a clean process by a method wherein an electrode section is divided into some electrodes, an insulating film is provided, and a power source applying voltages to the electrodes are grounded at its middle point, and a voltage applied to an electrode is opposite in polarity to the voltage applied to the other electrodes. CONSTITUTION:A wafer attracting static chuck electrode section 10 is constituted of electrodes 11 and 12 that are semicircular conductors of metal or the like provided, respectively, with semicircular recesses 11a and 12a on their rear, inner surfaces. The electrodes 11 and 12 are coated thin with insulating films 13 and 14 and separated from each other at an interval D. The electrodes 11 and 12 are concave on their inner surfaces, with their rims of a width W roughly forming semicircles of a radius R remaining flat. The portions with the width D serve as attracting sections 15 and 16, coated with insulating films 15a and 16a. A power source for the static attracting chuck is grounded at its middle point, and the electrodes 11 and 12 are supplied with V/2 voltages opposite in polarity to the ground respectively. A wafer 8 is attracted to the attracting sections 15 and 16 along its circumference. This enables a wafer to be held and removed by electrical control only, realizing a clean process.

Description

Detailed Description of the Invention [Technical Field to which the Invention Pertains] The present invention relates to semiconductor wafers, conductive wafers, etc. (hereinafter simply referred to as wafers) used in semiconductor device manufacturing equipment such as LSI (Large Scale Integrated Circuits). ) In particular, the present invention relates to a wafer handling device in a transport mechanism that adsorbs and transports only silicon, gallium arsenide, or other wafers between a reaction chamber and an antechamber in a short period of time.

[Conventional technology] The progress and development of LSI technology is extremely rapid, and there are already 1
LSIs are being manufactured using fine patterns of micrometers or less. In order to manufacture such submicron-level LSIs, a high-performance manufacturing process with better controllability is naturally required that is less affected by uncertain factors.

Examples of this include lower process temperatures and higher selectivity processes. Mainly, process temperature reduction is ゛1''-
This is necessary in order to suppress the re-diffusion of impurities within the conductor and to realize +E precise impurity distribution.

In particular, lowering the process temperature is necessary to suppress grain growth in various thin film CI's (conductors, metals, insulators) used in LSIs, and also to suppress the growth of grains in the substrate crystal and its -1-
It is also effective in suppressing thin films and interfacial reactions between thin films. On the other hand, high selectivity due to differences in materials is essential for etching or thin film formation for forming fine patterns.

Additionally, the most important requirement for achieving low process temperatures and high selectivity is that unnecessary gas components other than the gas components necessary for the reaction are almost completely removed from the atmosphere of the reaction chamber in which the process proceeds. be. That is, the ultra-clean process is essential for realizing the low-temperature process and the high-selectivity process that are essential for manufacturing ultra-fine LSIs.

To explain the importance of clean process with a few examples: ■Silicon epitaxial growth SI Hq+Si +2H2・・・・・・・・・(1)
SI H2C12+H2→81 +2HC1+H...
(2) For example, silane (S) is used for epitaxial growth of silicon.
iH2) (formula (1)) and dichlorosilane (SI
H2C12) by a hydrogen reduction reaction (formula (2)).

However, oxygen (02) and moisture (H2O) are present in the reaction atmosphere.
In the presence of , the silicon substrate surface is continuously oxidized,
A thin 5to2 film is formed on the surface. High temperature is required to remove this 5102 film by evaporation or etching.

A very clean reaction atmosphere ensures a clean silicon surface at all times. On a clean surface, the surface migration of adsorbed SI atoms occurs violently, and the surface adsorbed atoms tend to settle into IE standard lattice sites, making it possible to form a high-quality epitaxial growth layer at low temperatures.
It will be rJ. That is, in a clean reaction atmosphere, it is possible to lower the process temperature.

■Tungsten selective growth 2WF6+3Si→2W+3Si Fq・・・・・・・・・
(3) Selective growth of medium crystal tungsten (W) onto silicon (Si) or poly 5l-1- using source gas WF6 proceeds by a Si substrate reduction reaction.

In order for the reaction represented by formula (3) to proceed, 5I-W
No oxide film or the like must exist at the interface, and of course W itself must not contain any oxide film or the like.

Both St and W are substances that are extremely easily oxidized.

Therefore, if O2 or H2O is included in the reaction atmosphere, the substrate reduction reaction as shown in equation (3) will not occur. At the interface between Sl and metal without interposing an intermediate layer such as an oxide film, the 5i-3i bond breaks at an extremely low temperature due to the shielding effect of the metal, and the St raw material R reaches the surface of the metal thin film along the grain boundaries of the polycrystalline metal. The substrate is diffused, and the substrate reduction reaction as shown in equation (3) continues to occur.

Naturally, surfaces other than 81, e.g. SI 0
2. As long as a substrate reduction reaction is used on Sl, 7N4, W
does not accumulate. That is, if the reaction atmosphere is clean, W is selectively deposited only on 81-1- at a low temperature.

As mentioned in 1-1 above, a clean reaction atmosphere enables the process to be carried out at lower temperatures and with higher selectivity.

In order to keep the reaction atmosphere clean, the gas supply system 9 from the raw material gas cylinder (or liquefied gas capacity "ISt", hereinafter collectively referred to as gas cylinder) to the reaction chamber 9 and the gas exhaust system must all be clean. .

The main conditions are listed as follows: ■The raw material gas must be as pure as possible.

■Gas supply system 9 Concerning the reaction chamber and exhaust system, (a) External leakage should be extremely small and there should be no air pollution.

(b) The amount of gas released from the piping system and reaction chamber tube wall is as low as 1 minute. In other words, the materials that make up the piping system and reaction chamber themselves do not contain gas components. At the same time, the tube wall surface must be sufficiently flat, without any process-altered layers, and with a sufficiently low amount of adsorbed gas. Furthermore, it must be equipped with equipment that ensures that the inside of the reaction chamber and the gas supply piping system are not exposed to the atmosphere.

(C) There should be no dead zone where gas accumulates.

(d) Generation of particles should be as low as possible. Even if a movable mechanism is provided, there should be as few sliding parts as possible inside the gas supply system or reaction system.

Some of the above conditions can be achieved through management or operation, but the generation of particles in the movable system of the device is a problem with the structure of the mechanical system itself in the waeno 1 conveying device. is important.

In this case, what is particularly important is a transport mechanism for carrying the wafer into the reaction chamber, which requires a mechanism for supporting or holding the wafer.

[Problem to be solved] Conventional wafer holding mechanisms include mechanisms that suction and hold the wafer using vacuum chucks and grips, as well as mechanical mechanisms such as wafer holders and gripping arms that hold the wafer at its edges, etc. holding through.

As a result, there are more mechanical moving parts, and
In particular, in the case of vacuum suction, the air flow has an adverse effect on the generation of tickling because the suction mechanism is made negative and positive.

As a result, the amount of particles generated inevitably increases, and it is difficult to limit this to a predetermined level or less.

Therefore, at present, it is difficult to reduce the temperature of the process and realize a highly selective process as described above.

[Object of the Invention] The present invention solves the problems of the prior art, and is capable of holding the sea urchin/X without generating almost any particles in a mechanism that conveys the Ueno 1. In particular, we provide a wafer handling device suitable for lowering the process temperature in the manufacturing process of klt and conductors. We have proposed a suction chuck in which each electrode is provided with a suction part with an insulating film coated on the surface, which releases the suctioned wafer when the voltage applied to the electrostatic chuck falls below a predetermined value. The present applicant has already filed an application for the invention of a wafer handling device having such a suction chuck.

However, after further consideration, the inventors found that
With this kind of electrostatic chuck, there is an unresolved problem that due to electrostatic adsorption, when the inside of the chamber is not in a sufficiently lean state, dust and the like may adhere to the adsorbed wafer side. I discovered that.

Therefore, the object of the present invention is to further solve the problems of the prior art described above, and to provide a wafer handling device in which it is difficult for particles or dust to adhere to the suction wafer. .

[Steps to Solve the Problems] However, the configuration of the wafer handling device of the present invention to achieve such an objective includes an electrostatic chuck with a plurality of electrodes that attract and hold the wafer, and The electrostatic chuck is equipped with a power supply that applies a voltage between the plurality of electrodes, and each of the plurality of electrodes has a voltage applied to the electrostatic chuck that is lower than or equal to a predetermined value.
A suction part having an insulating film coated on the surface is provided to release the suctioned wafer when This involves applying a polar voltage.

[Operation] By dividing the electrode into a plurality of parts and providing an insulating film in this way, the wafer can be held and removed by electrical control, so there are fewer moving parts in 1-11. The generation of verticles can be restricted to a smaller state, and a wafer handling device that is extremely clean and operates at high speed can be realized, which is suitable for lowering the process temperature and realizing a highly selective process.

Moreover, the power source that applies voltage to these electrodes is configured to have its midpoint grounded and apply voltages of different polarities to one and the other of the multiple electrodes, so the potential of the wafer being attracted is almost the same as the ground potential. This makes it difficult for the wafer side to absorb generated particles, dust, etc.

[Embodiment 1] An embodiment of the wafer handling apparatus of the present invention will be described below with reference to the drawings.

FIG. 1(a) is a diagram of an electrostatic chuck that sucks a wafer, which is the main part of the wafer handling device of the present invention.
A cross-sectional schematic diagram along the I-I line in FIG. 1(b) is,
FIG. Furthermore, Fig. 2(a) is similar to Fig. 1(a).
) is a cross-sectional view of a state in which a wafer is attracted to the electrostatic chuck electrode portion, and FIG. 2(b) is an equivalent circuit diagram thereof. In addition,
Identical parts in these figures and subsequent figures are designated by the same reference numerals.

As shown in FIGS. 1(a) and 1(b), the electrode portion 10 of the electrostatic chuck for wafer suction has a semicircular plate shape with circular recesses 11a and 12a provided inside the back surface, respectively. The first part is made of a conductor such as metal. It is formed by the second electrode 11.12.

By the way, when automatically transporting a wafer, it is overwhelmingly necessary to pick up and transport the wafer from the front side. Therefore, the electrode section 10 is attached to a wafer handling device as an electrostatic suction chuck with its suction surface facing downward.

Here, these first. The second electrode 11.12 is the insulating film 1
3.14, and are arranged at predetermined intervals. This gap 1] may be left as a void, or an insulator may be inserted therein depending on the structure. The selection may be determined based on the overall structure of the electrostatic chuck.

1st. As shown in FIG. 1(a), the second electrodes 11 and 12 are recessed inside with a width W remaining on the circular outer periphery to approximately 1 of the radius R, and this width W The part 15 is the suction part 15 for the conductor wafer. It has become IEl. Adsorption part 15
．． The insulating films 13 and 14 are formed on the surfaces of each of the insulating films 13 and 18.
An insulating film 15a+lea is provided as a coated layer as a - part, and these insulating films 15a, le
The film thickness a is determined based on the suction force of the wafer, etc. The thickness of the insulating films 13 and 14 other than this part is
This electrode part is determined in consideration of having sufficient withstand voltage when it comes into contact with other metal parts.

As shown in FIG. 1(a), if the capacitance between the two divided suction parts and the wafer is equal, when the voltage V is applied, the wafer itself will drop to V/2. Become electrically charged.

This electrification causes electrostatic adsorption of small particles to become a problem.

Therefore, as shown in FIGS. 2(a) and 2(b), the power source may be grounded at the center point, and voltages of both positive and negative polarities may be applied.

As a result, the wafer is kept mostly at ground potential, and no electrostatic attraction of dust occurs.

In FIGS. 2(a) and 2(b), reference numeral 18 is a voltage source (its voltage value V) for this electrostatic adsorption chuck, the middle point of which is grounded, and the first . The second electrodes 11 and 12 are
In each case, a voltage of V/2 of opposite polarity to the ground is applied.

As a result, the potential of the attracted wafer 17 becomes the ground potential, and even if there are particles or dust floating around, it is unlikely that they will be electrostatically attracted.

In addition, in the case of an electrostatic chuck consisting of a plurality of electrode parts of three or more, these are divided into two blocks, and voltages of opposite polarity are applied in parallel to the electrodes of each block.

Next, the operation of the electrostatic chuck electrode section 10 to attract a wafer will be explained. As shown in FIG. It is absorbed by IES. When the wafer 17 is automatically transported, the electrostatic chuck picks up the wafer 17 from its front side and holds it. Then, it is transported from, for example, a front chamber to a reaction chamber as a transport source to a reaction chamber as a transport destination. In this respect, the situation is different from that of a vacuum chuck, which normally only sucks and fixes the wafer from the back side.

Incidentally, normally, in an area of about 1111 from the outside in the peripheral part of the disc-shaped wafer 17, ICs (integrated circuits),
Devices such as LSI (large scale integrated circuit) are not provided. Therefore, attracting the peripheral portion of the wafer 17 by the electrostatic chuck electrode section 10 does not involve any deterioration in the performance of ICs and LSIs. FIG. 2(a) shows a case where the outer diameter of the electrostatic chuck is almost equal to the outer diameter of the wafer 17.

In order to allow the wafer 17 to fall under its own weight, the suction part width W is normally set to a value of about 0.1 to 31-31, and particularly preferably in the range of about 0.211111 to [I. Good. Note that the narrower the width W, the less 2η staining and damage to the wafer 17. Of course, the contact pressure when bringing the electrostatic chuck electrode lO into contact with the wafer 17 is 1
Of course, the pressure must be set at a pressure value that will prevent defects such as dislocations from entering the wafer 17 with due consideration.

The diameter (2R) of the electrostatic chuck electrode section 10 is the same as that of the wafer 17.
The diameter of the electrostatic chuck electrode 10 may be slightly larger or smaller than the diameter of the wafer 17.
The diameter of the wafer 17 is the same as the electrode 11 of the electrostatic chuck electrode section 10.
．． Almost equal to the diameter (2R) formed by 12,
It is better to make it slightly larger.

There are various types of wafers used in the semiconductor manufacturing process. For example, in terms of materials, Sl, Ge
, GaAs, InP, etc. are used. The resistivity value ρ of the wafer is also 10”Ω41cm depending on the material.
It varies within a range of about 10-3Ω·ell. Also,
In some cases, an insulating film such as oxidation film with a thickness of about 1 μm or more is provided on the wafer surface, and in some cases, a resist film is further attached on top of the insulating film.

The dielectric relaxation time τd of the wafer is given by τd:ρε (4). ρ is resistivity and ε is dielectric constant.

Here, ρ= t x i osΩ・cm” l
Assuming 10-3Ω・C■, the dielectric relaxation time rd given by equation (4) is lXl0-"5ee-IXIO-'
The value is about 5 seconds. In other words, if the material (wafer) has a resistivity within this range, it can be treated as a conductor in terms of direct current.

Therefore, if the state in which the wafer 17 is attracted to the electrodes 11.12 of the electrostatic chuck electrode part 1O as shown in FIG. A capacitor 19 formed by .16 and a voltage source 18 of voltage (V/2+V/2) whose midpoint is grounded
connected in series.

The value of capacitor C is given by: However, δ and S are the thickness of the insulating film of the suction part and the area of the suction part. ε1 is the dielectric constant of the insulating film.

The value of the capacitor C varies to some extent depending on the thickness of the oxide film on the wafer, the thickness of the resist, the resistivity of the wafer, etc.

The area is calculated from the radius (R) in Figure 1 (b), Habo, S Aya π
RW ・・・・・・・・・・・・(6) gives ′j. However, this is the case of R>>W, R>>1). Of course, the relationship between R and one is not necessarily limited to the above relationship. The force F acting on the capacitor electrode is given by t4. Here, ■ is the power supply voltage. In FIG. 2(b), the voltage applied to one capacitor is V/2. Therefore, the force f'(N
ewton) is as follows. On the other hand, the quality fitM and weight f of the wafer are M=
ρ0πR2t ・・・・・・・・・(9) f=
MG=ρo yr R2t G=iIO) However, ρO
: specific gravity, R=wafer radius, 1=wafer thickness, G=gravitational acceleration (9.8 m/5ec2). As an example, the quality mm and the height f of the Sl wafer are shown in the table of FIG.

The specific gravity ρ0 of si is 2.328g/c+m3=2.32
8X103kg/m3.

The voltage V required to absorb the weight of the wafer given by equation (10) is obtained from equations (8) and (10). εχ
is the dielectric constant of the insulating film. When the wafer is not completely adhered to the insulating film and there is a gap χ, the voltage V required to pick up the wafer is as follows.

For example, R=501. W=5m■, D=IOIII
+.

If δ=10μm, εχ=2.5, M=2°38g
The voltage V required to vacuum a wafer of (f=2.31xlO-2N) is 24v, calculated from equation (II).
becomes. Of course, it is not actually possible to create a state in which the electrostatic chuck is in complete contact with the electrostatic chuck, so a voltage of several hundred volts, which is larger than the value in 1-, is required.

Polyimide resin is used for the insulating film of the electrode part, and the electrode 11.1
According to an example of an electrostatic chuck for 4" wafers using aluminum (AI) as the conductor of 2 (R = 50 m
m, D= 1 0+sm, δ” 1 0
u m, eχ=2.5), adsorption 1115a-1e
If the width W of a is 5+W+W, the wafer 17 has a voltage of 500V.
It can be easily picked up and transported. However, since the wafer surface is normally flat on the order of several tens of eights, once the wafer 17 is attracted to the electrostatic chuck electrode section 10, even if the voltage is returned to 0, the wafer 17 remains attracted.
7. I can't move away from the electrostatic chuck because of my own sense of humor.

The problem with automatic wafer transport using the electrostatic chuck electrode section 10 lies in the detachment of the wafer 17 rather than the adsorption of the wafer 17. Although it depends on the outer diameter of the wafer 17, 1) In the above-mentioned electrostatic chuck for 4" wafers, the suction part width W is 5 mm or more.
2, even if the wafer 17 can be attracted, the wafer 17 cannot be detached due to its own weight (detachment due to falling) only by electrical operation. However, it is not preferable to provide a special detachment mechanism because it has the potential to increase the generation of particles. It is preferable that the wafer be adsorbed and the wafer removed by its own weight using all electrical operations.

The width W of the suction portions 15 a and I E3 a in each electrode 11° 12 of the electrostatic chuck electrode portion 10 described above is set to 0.
When set to about 2@m~is-, wafer adsorption is
This can be done by applying a voltage of 500 to 700V, and the applied voltage is 200V.
When the voltage is lowered to about 300 V or less, the wafer detaches from the electrostatic chuck due to its own weight. In other words, when attempting to hold a wafer by electrostatic attraction in order to transport it,
The suction part width W is adjusted so that the weight of the wafer can fall depending on the weight of the wafer.
It is essential to keep it narrow to 1 minute. or,
It is also possible to set the suction part width W to about 1 to 211111 mm, provide notches at important points in the circumferential direction, and make the effective suction part area smaller than a predetermined value.

Therefore, the width of the suction part is basically related to its total suction area.

In this way, by suctioning the surface within about 1 m of the wafer periphery, the wafer can be sucked up, held under the electrostatic chuck, and transported. Therefore, the wafer surface, especially the IC and LSI device parts, is hardly damaged or contaminated, and an ideal wafer handling apparatus can be provided.

Next, a specific example of another structure of the electrostatic chuck electrode section is shown in FIG. 3(a).

In this electrostatic chuck, suction parts 15 and 16 are provided at the inclined tip in order to reduce the weight of the electrode Pii and to more accurately align the wafer and the electrostatic chuck electrode. Similarly, the electrostatic chuck electrode section 30 shown in FIG. 3(b) has a suction section 31a in each electrode,
The width of 31b is from low to about 2II11, especially
In the case of 4# wafer, the third
As shown in the enlarged view of the suction part 31a shown in FIG.
(This is not shown), and the recess 32 inside each electrode is approximately circular in shape.

FIG. 4(a) shows still another specific example, in which the suction portion 33 of each electrode of the electrostatic chuck electrode portion 33 is shown.
a and 33b have a corrugated cross section, and each convex portion has a diameter of 0.2
The sizes are from ■ to [■], and FIG. 4(b) shows an example in which the shape of the suction part has one relatively sharp waveform.

Further, FIG. 4(C) shows an electrode part structure for adsorbing not the surface of the wafer 17 but the edge portion of the outer periphery of the wafer 17. The suction portion 34a of each electrode of the electrostatic chuck electrode portion 34 has a structure that causes the least amount of contamination on the wafer surface.

34b has a gentle slope.

In any case, it is an electrostatic chuck that can electrically adsorb a wafer and detach it electrically in relation to its own weight, and has at least two or more parts around the wafer that do not affect the device. Of course, any structure may be used as long as the wafer is attracted by a suction section provided with a thin insulating film by applying a DC voltage to the divided electrodes.

So far, we have described a mechanism for applying a voltage to the wafer to attract it, and a mechanism for releasing the wafer from the electrostatic chuck by its own weight by returning the voltage to a predetermined voltage or lower or OV.

Therefore, the surface side (upper surface side) of the wafer is adsorbed and transported.
If it is sufficient to simply place the wafer facing upward on a holder or susceptor, the applied voltage may be returned to a predetermined voltage or lower or Ov at a necessary location. For example, the wafer is attracted to an electrostatic chuck, transported to a predetermined location such as a reaction chamber, and the electrostatic chuck is lightly contacted with a substrate (hereinafter collectively referred to as a susceptor) on which the wafer is placed in the reaction chamber, or By moving the wafer directly to 1- and returning the applied voltage to Ov, the wafer is separated from the electrostatic chuck and placed in a predetermined place such as a susceptor.

On the other hand, in plasma processes such as reactive ion etching (RIE) equipment, a susceptor structure in which the electrode is covered with an insulator is often used to suppress contamination from the susceptor (electrode) on which the wafer is placed. . Moreover, it is often necessary to control the wafer temperature by closely contacting the wafer with the susceptor.

Furthermore, it is also required that the wafer be installed vertically or in the F direction. In such a case,
Since an electrostatic chuck attracts a wafer using electrostatic force, the electrostatic chuck can be rotated and moved in any direction such as vertically or downward while the wafer is attracted.

FIG. 5 shows an example of vertical support in such a case, in which the susceptor 2 is installed vertically and is divided into two parts.
1 is an explanatory diagram of a case where a wafer 17 is transferred and set on the receiver 1. Note that 21a is an insulating portion that divides the susceptor into two.

First, the wafer 17 attracted to the electrostatic chuck electrode section 35
The susceptor 21 is covered with an insulator 22 and divided into two parts.
come into contact with. In this state, a voltage Vs is applied to the susceptor 21, and the voltage V applied to both electrodes 11 and 12 of the electrostatic chuck 35 is set to OV.

Next, referring to the material and dimensions of the electrostatic chuck electrode part, in Figures 1 (a) and (b), the thickness h of the electrode 11°12
It is desirable that the electrostatic chuck electrode portion 10 be as thin as possible if mechanical precision permits, so that the electrostatic chuck electrode portion 10 does not become too large or too heavy. For example, although it depends on the material, 3+++m
It is selected from about 2C11.

Since the electrode material does not pass current, any conductor is sufficient. Any conductive material may be used as long as it can be easily electrically contacted with a wire or the like for applying voltage. For example, metals such as aluminum and stainless steel, and semiconductors such as silicon to which impurities are added to a certain high concentration are used, and the material may be determined based on the environmental atmosphere of the device to be used.

Further, as the insulating film applied to the suction part, etc., an insulating material that does not contaminate the silicon wafer, does not emit much gas in a vacuum, etc., and has a certain degree of heat resistance may be selected. For example, an imide resin such as polyimide, a fluorine resin such as Teflon, etc. are selected. The thickness of the insulating film on the suction part is
It is sufficient if the thickness is sufficient to withstand pressure. As is clear from equation (11), as the insulation thickness δ increases, the voltage V required to attract the wafer increases in proportion to δ.

Insulation at a voltage of about 1000 to 2000 V is extremely easy if the system does not carry much current.

For example, if the thickness of the insulating film is set to about 10 to 50 μm,
500 for both polyimide resin and fluorine resin
Wafer suction can be sufficiently performed at a voltage of ~100 OV.

As described above, in the embodiments, various types of wafer handling devices have been explained using examples of wafer handling devices that are devices that transport wafers around a reaction chamber. It goes without saying that the present invention can also be applied to a transport mechanism, and its shape is not limited to those mentioned in the embodiments.

For example, if the shape of the wafer is other than a cylinder, it may be matched to that shape. Although only the case where one wafer is handled has been described, when a plurality of wafers are handled at the same time, electrostatic chucks corresponding to the number of wafers may be installed in parallel.

Further, although the explanation has been given mainly on the handling of semiconductor wafers, it is needless to say that the handling is not necessarily limited to semiconductor wafers. This device can be applied to any conductive wafer.

In the example, in addition to the wafer falling under its own weight, there is also an example where the wafer is attracted to another electrostatic chuck. Of course, various shapes can be selected depending on the condition and shape.

[Effects of the Invention] The wafer handling device of the present invention includes an electrostatic chuck having a plurality of electrodes that attracts and holds a wafer, and a power source that applies a voltage between the plurality of electrodes, and a plurality of The electrode is provided with a suction part whose surface is coated with an insulating film, which releases the sucked wafer when the voltage applied to the electrostatic chuck reaches a predetermined value or higher.
Since the center point is grounded and voltages of different polarities are applied to one and the other of the plurality of electrodes, the wafer can be held and removed by electrical control.

As a result, wafers can be transported freely, and the transport mechanism is simple, so external leakage and gas released from the inside of the device are overwhelmingly low. It is possible to limit the generation of particles to a lower level, and to realize a wafer handling device that operates extremely cleanly and at high speed, which is suitable for lowering the process temperature and realizing a highly selective process.

Moreover, the power source that applies voltage to these electrodes is configured to have its midpoint grounded and apply voltages of different polarities to one and the other of the multiple electrodes, so the potential of the wafer being attracted is almost the same as the ground potential. This makes it difficult for the wafer side to absorb generated particles, dust, etc.

[Brief explanation of drawings]

FIG. 1(a) is a diagram of an electrostatic chuck that sucks a wafer, which is the main part of the wafer handling device of the present invention.
A cross-sectional schematic diagram along the I-I line in FIG. 1(b) is,
The back view, FIG. 2(a), is a cross-sectional view of the state where the wafer is attracted to the electrostatic chuck electrode part of FIG. 1(a), and FIG. 2(b) is its equivalent circuit diagram, FIG. Figures 3 (a) and (b) are
An explanatory diagram showing an example of the electrode shape of an electrostatic chuck, FIG. 3(C) is an enlarged view of the suction part of FIG. 3(b), and FIGS. ) are explanatory diagrams showing examples of other electrode-shaped rods of an electrostatic chuck, and FIG. 5 is an explanatory diagram showing an example of vertical wafer suction and holding when wafers are received and transferred to a stacked susceptor. The explanatory diagram, Figure 6, is SI
He is a person who explains the relationship between the mass and weight of a wafer. 10.30.33,34.35...Electrostatic chuck, 1
1... First electrode, 12... Second electrode, 11a,
12a... hollow part, 15t 16+ 31am 31b* 33aw 3
3b. 34a, 34b--Adsorption part, 15a, 16a--Insulating film, 17--Wafer, 18--Power supply, 21--
Susceptor. Patent applicant Tokyo Electron Ltd. Figure 1 11a I Za Figure 2 (Q) Figure 4 (Q) (b)

Claims (6)

[Claims] (1) An electrostatic chuck having a plurality of electrodes that attracts and holds a wafer, and a power source that applies a voltage between the plurality of electrodes, each of the plurality of electrodes having a voltage applied to the electrostatic chuck. A suction part having an insulating film coated on the surface is provided, which releases the suctioned wafer when the wafer becomes less than a predetermined value. A wafer handling device characterized in that voltages of different polarities are applied to one side and the other side. (2) The suction unit is designed to remove the suctioned wafer by its own weight or by adsorbing it to another electrostatic chuck when the voltage applied to the electrostatic chuck becomes less than a predetermined value. A wafer handling apparatus according to claim 1, characterized in that: (3) The suction part is for suctioning the peripheral part of the wafer, and is formed as a protrusion with a predetermined width in order to detach the wafer when the voltage applied to the electrostatic chuck becomes less than a predetermined value. A wafer handling device according to claim 2, characterized in that: (4) the protruding portion is formed in a substantially semicircular shape corresponding to the peripheral portion of the wafer in order to adsorb the peripheral portion of the wafer;
A wafer handling device according to claim 3, characterized in that its width is in the range of 0.1 mm to 2 mm. (5) The suction part is for suctioning the peripheral part of the wafer, and is formed as an uneven part with a predetermined width in order to detach the wafer when the voltage applied to the electrostatic chuck becomes less than a predetermined value. A wafer handling device according to claim 2, characterized in that: (6) the suction part is formed in a substantially semicircular shape corresponding to the peripheral part in order to suction the peripheral part of the wafer;
6. The wafer handling device according to claim 5, wherein the convex portion of the uneven portion has a width in a range of 0.1 mm to 1 mm, and has a plurality of convex portions.