JP2009105238A - Substrate holder, exposure apparatus, manufacturing method of device, and substrate conveying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate holder that generates no dust from a substrate and does not deteriorate the flatness of a top surface of the substrate. <P>SOLUTION: The substrate holder includes a substrate mount portion 10 which has one surface formed of an insulating material as a substrate holding surface and also has a plurality of pin-shaped projection portions 12 holding the substrate W on the substrate holding surface, a single-pole electrode 16 provided in the substrate mount portion or on the other surface, at least one air intake 24 provided on the substrate holding surface, at least one air outlet 30 provided on the substrate holding surface, and at least a portion 26 of an ionization portion ionizing a gas supplied from the air intake onto the substrate holding surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate holder for placing a substrate, an exposure apparatus including the substrate holder, a device manufacturing method using the exposure apparatus, and a substrate transport method for transporting a substrate to the substrate holder.

2. Description of the Related Art In recent years, an exposure apparatus for transferring a reticle (original plate) pattern onto a photosensitive substrate using extreme ultraviolet light having a wavelength of about 5 to 40 nm as exposure light, that is, EUV (Extreme Ultra violet) light has been put into practical use. ing. In an exposure apparatus for EUVL (extreme ultraviolet lithography), since EUV light is absorbed by air, it is necessary to maintain a high vacuum in the chamber that houses the apparatus. Therefore, when holding the substrate to which the reticle pattern is transferred on the substrate holder, an electrostatic chuck using Coulomb force is used because vacuum suction cannot be performed. An electrostatic chuck using Coulomb force is provided with a monopolar electrode inside a substrate mounting portion formed of an insulator, and the substrate is mounted on the substrate by Coulomb force generated by applying a voltage to the electrode. A single-pole electrostatic chuck that is attracted to a mounting portion is known (for example, see Patent Document 1).
JP 2006-86173 A

  In the above-described monopolar electrostatic chuck, it is necessary to generate a predetermined potential difference between the substrate placed on the substrate platform and the unipolar electrode provided inside the substrate platform. Therefore, a predetermined voltage is applied to the electrode, and the tip of the conductive needle is brought into contact with the back side of the substrate, and a voltage that causes a predetermined potential difference between the electrode and the substrate is applied to the substrate. . However, there is a possibility that dust is generated from the substrate by bringing the tip of the conductive needle into contact with the back side of the substrate. Further, by bringing the tip of the conductive needle into contact with the back side of the substrate, there is a risk that the portion with which the tip contacts will raise a part of the surface of the substrate and deteriorate the flatness of the substrate surface.

  An object of the present invention is to provide a substrate holder including a monopolar electrostatic chuck that does not generate dust from the substrate or deteriorate flatness of the substrate surface, an exposure apparatus including the substrate holder, and a device using the exposure apparatus. It is to provide a manufacturing method and a substrate transfer method for transferring a substrate to the substrate holder.

  In the following, the configuration of the present invention will be described with reference to one embodiment, but the present invention is not limited to the configuration of the present embodiment.

  The substrate holder of the present invention has a plurality of protruding first support portions (12) that support the substrate (W) in a predetermined region on one surface, and is a substrate mounting portion ( 10), a monopolar electrode (16) provided inside or on the other surface of the substrate platform, and at least one air inlet (24) provided in a predetermined region of the one surface, And at least one exhaust port (30) provided in a predetermined region of the one surface, and at least a part (26) of an ionization portion that ionizes gas supplied from the intake port.

  The exposure apparatus of the present invention includes the substrate holder (WH) of the present invention in a vacuum atmosphere chamber (100), and transfers the pattern of the original plate onto the substrate (W) placed on the substrate holder.

  Further, the device manufacturing method of the present invention includes an exposure step (S303) in which an original pattern is exposed on a substrate using the exposure apparatus of the present invention, and a development step in which the substrate exposed in the exposure step is developed (S303). S304).

  Further, the substrate transport method of the present invention is provided in a predetermined region on one surface, and surrounds the predetermined region, and includes a plurality of protruding first support portions that support the substrate, and the plurality of protruding first portions. A step (S10) of transporting the substrate onto a substrate platform having a support unit and a second support unit that supports the substrate, and a single unit provided on the inside or the other surface of the substrate platform. A step of applying a voltage to the electrode of the electrode (S11), and a step of supplying ionized gas from at least one intake port provided in the predetermined region (S12).

  According to the substrate holder of the present invention, the substrate can be reliably held without generating dust from the substrate and without deteriorating the flatness of the substrate surface.

  Further, according to the exposure apparatus of the present invention, since the substrate holder that does not generate dust from the substrate and does not deteriorate the flatness of the substrate surface is provided, good exposure can be performed.

  Further, according to the device manufacturing method of the present invention, exposure is performed using an exposure apparatus including a substrate holder that does not generate dust from the substrate and does not deteriorate the flatness of the substrate surface. Devices can be manufactured.

  Further, according to the substrate transport method of the present invention, the substrate is placed on the substrate platform provided with the second support portion in a state where the outer edge portion of the substrate is restrained in the direction intersecting the transport direction by the restraint portion of the transport device. Since the ionized gas is supplied by applying a voltage to the unipolar electrode provided on the substrate mounting portion after that, the supplied gas is surely prevented from leaking into the vacuum atmosphere chamber. be able to.

  Hereinafter, a wafer holder (substrate holder) according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a state where a wafer is placed on a wafer holder according to the embodiment, and FIG. 2 is a plan view showing a wafer holding surface of the wafer holder.

  The wafer holder (substrate holder) WH includes a wafer mounting portion (substrate mounting portion) 10 on a disc formed of SiC which is an insulating material. In order to support the wafer W, a plurality of protrusions (first support portions) 12 having the same height are formed on the wafer holding surface (one surface) of the wafer mounting portion 10. . The wafer holding surface is provided with a guard ring (second support portion) 14 having a cylindrical shape formed so that one end face is connected to the outer peripheral portion thereof. Here, the guard ring 14 has a height that matches the height of the plurality of pin-shaped protrusions 12 provided on the wafer holding surface, and supports the wafer W together with the plurality of protrusions 12. The plurality of convex portions 12 are provided in a central region in the wafer holding surface, and the guard ring 14 is provided so as to surround the outer side of the central region. A disk-shaped electrode (single electrode) 16 is arranged in the wafer mounting portion 10 so as to be parallel to the wafer holding surface, and is connected to the electrode 16 from a power source 18 via a switch 20. A predetermined DC voltage is applied.

An intake port 24 for supplying ionized N ₂ gas through an intake line 22 is provided on the wafer holding surface of the wafer mounting unit 10. Further, a discharge needle 26 that forms a part of an ionizer (ionization portion) for ionizing N ₂ gas is provided in the vicinity of the intake port 24 of the intake line 22. The wafer holding surface is provided with an exhaust port 30 for exhausting the ionized N ₂ gas supplied from the intake line 22 to the exhaust line 28. The intake port 24 and the exhaust port 30 can be provided at arbitrary positions in the wafer holding surface.

FIG. 3 is a diagram illustrating a state in which the wafer W is attracted to the wafer holder WH according to the embodiment. As shown in FIG. 3, when N ₂ gas ionized from the intake port 24 is supplied to the electrode 16 with a DC voltage applied from the power source 18, the charge having the opposite polarity to the charge induced in the electrode 16 is transferred to the wafer. The W is charged and the wafer W is attracted to the wafer mounting portion 10 by electrostatic attraction force. In this case, excess charges are exhausted from the exhaust port 30 together with the N ₂ gas.

  FIG. 4 is a view showing a schematic configuration of the exposure unit 40 of the EUV exposure apparatus including the wafer holder WH according to the present embodiment. The exposure unit 40 is housed in a vacuum atmosphere chamber 100, includes a plasma light source that emits EUV light, and includes an illumination optical system IL that includes a plurality of reflective optical members. The EUV light emitted from the illumination optical system IL is incident on a reflective reticle (original) R disposed at an object point position of the projection optical system PL described later. On the reflective reticle R, a pattern for transferring and exposing the wafer W is formed. The reflective reticle R is held by a reticle stage RST. The EUV light reflected by the pattern formed on the reflective reticle R enters the projection optical system PL. Projection optical system PL is composed of a plurality of reflective optical members, and wafer W is placed on wafer holder WH on wafer stage WST at a predetermined magnification and attracted by a pattern formed on reflective reticle R. Image on top. That is, the EUV light through the projection optical system PL forms an image of the pattern formed on the reflective reticle R on the wafer W, and exposes the pattern of the reflective reticle R on the exposure area of the wafer W.

As shown in FIG. 5, the EUV exposure apparatus according to the present embodiment carries the pattern formed on the reflective reticle R into the exposure unit 40 and the exposure unit 40 that expose the wafer W, which is a photosensitive substrate. A wafer transfer unit 42 that transfers the wafer W unloaded from the exposure unit 40 is provided. In addition, this EUV exposure apparatus transfers a wafer W between the exposure unit 40 and the load lock chamber 48 that receives the wafer W transferred by the atmosphere side robot 46 provided in the wafer transfer unit 42. The vacuum side robot 50 which performs is provided. Here, the wafer transfer unit 42, the atmosphere side robot 46, the load lock chamber 48, and the vacuum side robot 50 constitute a transfer device. The exposure unit 40 and the vacuum side robot 50 are accommodated in a vacuum atmosphere chamber. The load lock chamber 48 is configured to be evacuated and released to the atmosphere.

  FIG. 6A is a view showing a state where the wafer W is restrained by the end effector 50a provided at the tip of the loader arm of the vacuum side robot 50 and is transferred onto the wafer holder WH. FIG. These are enlarged views which show the shape of the front-end | tip part of the end effector 50a. As shown in this figure, the end effector 50a has a V-shaped recess into which the edge of the wafer W enters, and the front and back surfaces of the wafer W are formed on the upper and lower wall surfaces forming the V-shaped recess. The wafer W is transported in a state where the corners of the edge of the wafer are in contact with each other and restrain the movement of the wafer W in the vertical direction (the thickness direction of the wafer W). That is, the wafer W is transferred by the edge gripper type end effector 50a.

  Next, a method for carrying in (carrying) the wafer W to the exposure unit 40 according to the embodiment will be described with reference to a flowchart shown in FIG. First, the wafer W loaded into a predetermined position 44 of the wafer transfer device 42 is loaded into the load lock chamber 12 using the atmosphere side robot 46. After the wafer W is loaded into the load lock chamber 48, the load lock chamber 48 is evacuated to bring the wafer W into the exposure unit 40 in a vacuum atmosphere, and the load lock chamber 48 is evacuated. Next, the movement of the wafer W in the vertical direction is restricted by the end effector 50a at the tip of the loader arm of the vacuum side robot 50, and the wafer W is transferred onto the wafer holder WH of the exposure unit 40 (step S10). Accordingly, the upper end surface, which is the other end surface of the guard ring 14 of the wafer holder WH, and the tip of the pin-like convex portion 12 are in contact with the lower surface of the wafer W.

  Next, a predetermined voltage is applied to the electrode 16 using the DC power source 18 by turning on the switch 20 (step S11). At this time, since the wafer W is not charged, an adsorption force hardly develops between the wafer W and the wafer holder WH.

Next, N ₂ gas ionized from the intake port 24 is supplied to a space formed by the wafer holding surface, the guard ring 14, and the wafer W (hereinafter referred to as a closed space), and at the same time, the closed space is closed from the exhaust port 30. The N ₂ gas supplied to is exhausted (step S12). In this case, since the guard ring 14 is provided on the outer peripheral portion of the wafer holding surface, the N ₂ gas supplied to the wafer holding surface leaks into the vacuum chamber 100 in which the exposure unit 40 is accommodated. Instead, the wafer W can be charged with a charge having a polarity opposite to the charge induced in the electrode 16. Then, the electric charge charged on the wafer W and the electric charge induced on the electrode 16 attract each other, whereby the wafer W is adsorbed to the wafer mounting portion 10 by electrostatic attraction force.

Next, after the wafer W is attracted to the wafer platform 10 by electrostatic attraction, the supply of the ionized N ₂ gas to the closed space is stopped (step S13), and the gap between the wafer platform 10 and the wafer W is stopped. When the degree of vacuum rises to some extent (pressure on the upper surface of the wafer <electrostatic adsorption force), the gripping of the wafer W by the end effector 50a is released, and the loader arm is retracted (step S14).

  Next, a method for carrying out (carrying) the wafer W from the exposure unit 40 according to the embodiment will be described with reference to a flowchart shown in FIG. First, the wafer W is gripped by the end effector 50a at the tip of the loader arm of the vacuum side robot 50 (step S20), and the application of voltage from the DC power source 18 to the electrode 16 is stopped by turning off the switch 20 (step S20). S21). At this point, the wafer W is still charged and there is an electrostatic attraction force.

Then, the N ₂ gas ionizing the air inlet 24 is supplied to the closed space, for exhausting the N ₂ gas supplied to the closed space from the same time the exhaust port 30 (step S22). As a result, the charge induced on the electrode 16 charged with the wafer W is neutralized by the charge having the opposite polarity contained in the ionized N ₂ gas.

When the electrostatic attraction force becomes weak to some extent (electrostatic attraction force <the pressure on the surface of the wafer), the wafer W is lifted from the wafer holder WH while being held by the loader arm of the vacuum side robot 50 (step S23). The supply of N ₂ gas from the intake port 24 is stopped (step S24). Therefore, the wafer W can be detached from the wafer holder WH while maintaining a high degree of vacuum in the vacuum chamber. Note that the removal of the wafer W from the wafer holder WH in step S23 and the supply of N ₂ gas in step S24 may be stopped substantially simultaneously. Then, the wafer W is carried into the load lock chamber 12 by the loader arm of the vacuum robot 50. Thereafter, the load lock chamber 48 is opened to the atmosphere, and the wafer W is transferred to a predetermined position 44 of the wafer transfer device 42 using the atmosphere side robot 46.

  With the wafer holder according to the present embodiment, the wafer can be reliably held without generating dust from the wafer W and without deteriorating the flatness of the surface of the wafer W.

  In addition, the exposure apparatus according to the present embodiment includes the wafer holder WH that does not generate dust from the wafer W and does not deteriorate the flatness of the surface of the wafer W, so that good exposure is performed. be able to.

  Further, according to the wafer transfer method according to the present embodiment, the wafer W is provided with the plurality of convex portions 12 and the guard ring 14 while the outer edge portion of the wafer W is gripped by the end effector 50a of the loader arm of the vacuum side robot 50. The wafer is transferred onto the wafer mounting unit 10, and then ionized gas is supplied to the closed space. After the wafer W is adsorbed to the wafer mounting unit 10 by electrostatic adsorption, the load by the end effector 50 a of the loader arm is released. Since the loader arm is retracted, the gas supplied to the closed space can be reliably prevented from leaking into the vacuum atmosphere chamber.

  In the EUV exposure apparatus according to the above-described embodiment, a transfer pattern formed by a mask using a projection optical system is exposed (exposure process) on a photosensitive substrate (wafer), thereby obtaining an electronic device (semiconductor element, Imaging elements, liquid crystal display elements, thin film magnetic heads, etc.) can be manufactured. Hereinafter, a method of manufacturing a semiconductor device as an electronic device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the EUV exposure apparatus according to the above-described embodiment will be described with reference to the flowchart of FIG. To explain.

  First, in step S301 in FIG. 9, a metal film is deposited on one lot of wafers. In the next step S302, a photoresist is applied on the metal film on the wafer of one lot. Thereafter, in step S303, exposure and transfer are sequentially performed on each shot area on the wafer of one lot using the EUV exposure apparatus according to the above-described embodiment. Thereafter, in step S304, the photoresist on the one lot of wafers is developed, and in step S305, the resist pattern is used as an etching mask on the one lot of wafers to form the mask. A circuit pattern corresponding to the pattern is formed in each shot area on each wafer.

  Thereafter, a device pattern such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer. In steps S301 to S305, a metal is vapor-deposited on the wafer, a resist is applied on the metal film, and exposure, development, and etching processes are performed. Prior to these processes, on the wafer. It is needless to say that after forming a silicon oxide film, a resist may be applied on the silicon oxide film, and steps such as exposure, development, and etching may be performed.

  According to the device manufacturing method of this embodiment, exposure is performed using an exposure apparatus including a wafer holder without generating dust from the wafer and without deteriorating the flatness of the wafer surface. Semiconductor devices can be manufactured.

In the above-described embodiment, the wafer placement unit 10 is formed of SiC, but may be formed of Al ₂ O ₃ , AlN, or the like.

  Further, in the above-described embodiment, one intake port and one exhaust port are provided on the wafer holding surface of the wafer mounting unit 10, but a plurality of intake ports and a plurality of exhaust ports may be provided. Good.

  In the above-described embodiment, the wafer holder WH of the present invention is used as a wafer holder of an EUV exposure apparatus. However, a wafer holder of an electron beam exposure apparatus, a substrate of a substrate processing apparatus such as a sputtering apparatus, a plasma CVD apparatus, or a plasma etching apparatus. It may be used as a holder.

  Further, in the above-described embodiment, the monopolar electrode 16 is provided inside the wafer mounting unit 10. However, the monopolar electrode may be provided on the other surface (back surface) of the wafer mounting unit. Good.

  In the above-described embodiment, the end effector of the edge gripper method is provided at the tip of the loader arm of the vacuum side robot 50. However, if the movement of the wafer in the vertical direction can be restricted, the method is the edge gripper. It is not limited to the method.

It is sectional drawing which shows the state which mounted the wafer on the wafer holder which concerns on embodiment. It is a top view which shows the wafer holding surface of the wafer holder which concerns on embodiment. It is a figure for demonstrating the wafer adsorption state of the wafer holder which concerns on embodiment. It is a figure which shows the structure of the exposure part concerning Embodiment. It is a figure which shows the structure of the EUV exposure apparatus concerning embodiment. It is a figure which shows the shape of the end effector provided in the front-end | tip of the load arm which concerns on embodiment. It is a flowchart explaining the conveyance method of the reticle concerning embodiment. It is a flowchart explaining the conveyance method of the reticle concerning embodiment. It is a flowchart for demonstrating the manufacturing method of the device concerning embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 ... Wafer, 10 ... Wafer mounting part, 12 ... Protruding convex part, 14 ... Guard ring, 16 ... Electrode, 18 ... DC power supply, 20 ... Switch, 22 ... Intake line, 24 ... Intake port, 26 ... Discharge Needle, 28 ... exhaust line, 30 ... exhaust port, 40 ... exposure unit, 42 ... wafer transfer unit, 46 ... atmosphere side robot, 48 ... load lock chamber, 50 ... vacuum side robot, 50a ... end effector, 100 ... vacuum chamber , IL ... illumination optical system, R ... reflective reticle, RST ... reticle stage, PL ... projection optical system, W ... wafer, WH ... wafer holder, WST ... wafer stage

Claims (7)

A substrate mounting portion formed of an insulating material having a plurality of projecting first support portions for supporting the substrate in a predetermined region of one surface;
A monopolar electrode provided inside or on the other surface of the substrate mounting portion;
At least one air inlet provided in a predetermined region of the one surface;
At least one exhaust port provided in a predetermined region of the one surface;
A substrate holder comprising: at least a part of an ionization unit that ionizes gas supplied from the intake port.   The substrate holder according to claim 1, further comprising a second support portion that surrounds the predetermined region and supports the substrate together with the plurality of first support portions. A substrate holder according to claim 1 or 2 is provided in a vacuum atmosphere chamber,
An exposure apparatus that transfers an original pattern onto a substrate placed on the substrate holder. Further comprising a transfer device for transferring the substrate onto the substrate holder;
4. The exposure apparatus according to claim 3, wherein the transport device includes a grip portion that grips a part of an outer edge portion on the front surface side of the substrate and a part of an outer peripheral portion on the back surface side of the substrate. An exposure step of exposing a pattern of an original on a substrate using the exposure apparatus according to claim 3 or 4,
A development step of developing the substrate exposed by the exposure step;
A device manufacturing method including: A plurality of projecting first support portions that are provided in a predetermined region of one surface and support the substrate, and a second support that surrounds the predetermined region and supports the substrate together with the plurality of first support portions. A step of transporting the substrate onto a substrate mounting portion having a portion;
Applying a voltage to a unipolar electrode provided on the inside or the other surface of the substrate platform; and
Supplying a gas ionized from at least one air inlet provided in the predetermined area.   The substrate is transported in a state where a part of the outer edge part on the front surface side of the substrate and a part of the outer peripheral part on the back surface side of the substrate are gripped by a grip part included in the transport device, and the substrate is placed on the substrate mounting part The substrate transport method according to claim 6, further comprising a step of separating the substrate from the gripper and retracting the transport device after being placed on the substrate.

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