JP2011210967A - Substrate holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate holder which can suppress the adhesion of a resist to a pressing member when holding a substrate where the resist is formed.SOLUTION: The substrate holder includes: a stage 14 to which the substrate 100 including the resist 101 is mounted; a pressing member 16 which includes a claw 15 having a tip surface 15a in contact with a peripheral portion of the substrate 100 placed on the stage 14 to press the substrate 100 toward the stage 14; and a plurality of protruding portions 21 on the tip surface 15a of the claw 15.

Description

The present invention relates to a substrate holder for holding a substrate on which a resist is formed, for example, in a substrate processing apparatus such as an ion milling apparatus.

In the manufacture of semiconductors, a substrate processing apparatus, such as an ion milling apparatus, is used for processing the surface of a substrate by using a physical action due to collision of ions, or processing a wiring or an element provided on the substrate. ing. In an ion milling apparatus, a substrate such as a semiconductor wafer (silicon wafer) is placed on a stage, and the substrate surface is processed by irradiating the substrate on the stage with an ion beam generated by an ion source while rotating the stage. Do. That is, ions generated by the ion source (for example, Ar ions) are accelerated by a high voltage and collide with the surface of the target substrate. Thereby, the surface of the substrate is scraped off. At that time, by forming a resist in a predetermined pattern on the substrate, only a portion of the substrate where the resist is not formed is shaved and a substrate having a desired surface shape can be formed.

By the way, such a substrate processing apparatus such as an ion milling apparatus includes a substrate holder for holding a substrate to be processed. As the substrate holder, for example, the peripheral portion of the substrate placed on the substrate stand (stage) is pressed onto the substrate stand by a ring chuck (pressing member) to clamp the substrate placed on the substrate stand. There is something like that (see, for example, Patent Document 1).

JP 2003-297905 A

Such a substrate holder can favorably hold the substrate placed on the stage. However, when clamping a substrate on which a resist is formed by the pressing member, if the high temperature and high pressure are directly applied to the resist via the pressing member, the resist may adhere (transfer) to the pressing member. The resist adhering to the pressing member may adhere (re-transfer) to the substrate as a foreign substance when the substrate to be processed next is clamped. And there exists a problem that it will become difficult to peel the resist to which the foreign material adhered. Further, if foreign matter exists between the pressing member and the substrate, the substrate is strongly pressed locally through the foreign matter when the substrate is pressed by the pressing member, which may cause damage to the substrate.

Depending on the configuration of the substrate processing apparatus, the substrate holder may hold the substrate downward. In such a case, since it is necessary to press the substrate on the stage with a relatively strong force by the pressing member, the problem of resist adhesion to the pressing member as described above is particularly likely to occur.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate holder that can suppress adhesion of a resist to a pressing member when a substrate on which a resist is formed is held. And

The present invention for solving the above problems comprises a stage on which a substrate is placed, and a claw portion whose tip surface abuts on a peripheral portion of the substrate placed on the stage, and the substrate faces the stage. The substrate holder is characterized in that a plurality of protrusions are provided on a tip surface of the claw portion.
In the present invention, since the protrusion is provided on the claw portion of the pressing member, the region where high temperature and high pressure are directly applied to the resist is reduced. As a result, adhesion of the resist to the pressing member is suppressed.

Here, the height of the protrusion is preferably 10 to 100 μm. Moreover, it is preferable that the space | interval of the said projection part is 50 micrometers or more. Thereby, even if a foreign substance adheres to the tip surface of the claw part, the foreign substance enters between the protrusions. Therefore, when the substrate is pressed by the pressing member, the substrate is not strongly pressed locally through the foreign matter.

Moreover, it is preferable that the said protrusion part is arrange | positioned radially with respect to the center part of the said press member. If the substrate expands due to heating when processing the substrate, it is conceivable that the resist provided on the substrate is scraped off by the protrusions. However, since the protrusions are provided in a radial pattern, the amount of resist scraped off can be minimized. Therefore, the amount of resist adhering to the pressing member can be minimized.

Moreover, it is preferable that the cross-sectional shape of the said protrusion part is circular. Thereby, the rigidity of the protrusion is sufficiently ensured. Therefore, the substrate on the stage can be pressed and held with a relatively strong force by the protrusion.

It is a schematic block diagram of the ion milling apparatus which concerns on one Embodiment of this invention. It is the top view and sectional view of a substrate holder concerning one embodiment of the present invention. It is sectional drawing which shows the press member which concerns on one Embodiment of this invention. It is sectional drawing which shows the use condition of the substrate holder which concerns on one Embodiment of this invention. It is sectional drawing which shows the modification of the press member which concerns on one Embodiment of this invention. It is a top view which shows the modification of the press member which concerns on one Embodiment of this invention. It is a top view which shows the modification of the press member which concerns on one Embodiment of this invention.

Hereinafter, the present invention will be described in detail based on embodiments. 1 is a schematic configuration diagram of an ion milling apparatus including a substrate holder according to an embodiment of the present invention, FIG. 2 is a plan view and a cross-sectional view of the substrate holder according to the present embodiment, and FIG. It is sectional drawing of the press member which comprises a substrate holder.

As shown in FIG. 1, an ion source chamber 3 is connected to a vacuum processing chamber 2 constituting an ion milling apparatus 1. The ion source chamber 3 is connected to an introduction tube 4 into which an inert gas such as argon (Ar) is introduced. For example, a filament 5 that emits thermoelectrons is provided on the surface opposite to the vacuum processing chamber 2. A power source 6 is connected to the filament 5. The ion source chamber 3 is provided with an acceleration electrode 7 and a deceleration electrode 8 on the boundary side with the vacuum processing chamber 2.

On the other hand, a plurality of substrate holders 9 are fixed in the vacuum processing chamber 2 and a rotation stage 11 is rotatably supported by a support shaft 10. The substrate holder 9 will be described later in detail. A plurality of wafers (substrates) 100 as substrates are placed and held. For example, in the present embodiment, four substrate holders 9 are fixed on the rotation stage 11 at a predetermined interval on the same circumference around the support shaft 10. In the present embodiment, the rotary stage 11 is arranged in a state inclined at a predetermined angle with respect to the irradiation direction of the ion beam extracted from the ion source chamber 3 when the wafer 100 is processed. . A shutter 12 is disposed between the rotary stage 11 and the deceleration electrode 8 provided in the ion source chamber 3 so that the ion beam drawn from the ion source chamber 3 can be blocked as necessary. ing.

The vacuum processing chamber 2 or the ion source chamber 3 is connected to an exhaust system (rotary pump and turbo-molecular pump or claion pump) 13. The exhaust system 13 allows the vacuum processing chamber 2 and the ion source chamber 3 to be connected to each other. The inside is held at a predetermined pressure under reduced pressure. In the present embodiment, the exhaust system 13 is connected to the vacuum processing chamber 2.

In such an ion milling apparatus 1, first, the vacuum processing chamber 2 is operated by the exhaust system 13.
In addition, the inside of the ion source chamber 3 is depressurized to a predetermined pressure, and an inert gas, for example, argon gas is introduced into the ion source chamber 3 through the introduction pipe 4 while maintaining this pressure. When power is supplied from the power source 6 to the filament 5 in a state where the ion source chamber 3 is filled with argon gas, the argon gas in the ion source chamber 3 is ionized. By applying a voltage to the accelerating electrode 7 and the decelerating electrode 8 by a power source (not shown), the ionized argon gas (argon ions) is accelerated and extracted as an ion beam into the vacuum processing chamber 2. And the shutter 1 arrange | positioned in the vacuum processing chamber 2
By opening 2, each wafer 100 held by the substrate holder 9 is irradiated with an ion beam. When irradiating each wafer 100 with an ion beam in this manner, the rotary stage 11 to which the substrate holder 9 is fixed is continuously rotated at a predetermined speed, whereby the substrate is placed on the rotary stage 11. The plurality of wafers 100 held by the holder 9 are processed uniformly.

Here, the configuration of the substrate holder 9 according to the present embodiment will be described. As shown in FIG. 2, the substrate holder 9 according to this embodiment is a wafer stage 1 on which a wafer 100 is placed.
4 and a pressing member 16 having a claw portion 15 provided in contact with the peripheral portion of the wafer 100 placed on the wafer stage 14 so as to be sandwiched between the wafer 100 and the wafer stage 14.

The wafer stage 14 has a substantially circular outer shape, and a groove portion 17 is formed in the vicinity of the periphery of the wafer stage 14 along the outer shape of the wafer stage 14. An O-ring 18 is fitted in the groove portion 17. Yes. The wafer 100 is placed on the wafer stage 14 via the O-ring 18. The O-ring 18 plays a role as a non-slip of the wafer 100 placed on the wafer stage 14, a role as a so-called shock absorber, and the like.

The pressing member 16 is for pressing the peripheral portion of the wafer 100 on the wafer stage 14 toward the wafer stage 14, and is formed in a ring shape corresponding to the peripheral portion of the wafer 100 in this embodiment. Yes. Further, the vicinity of the end portion on the inner peripheral side of the pressing member 16 is a claw portion 15 that protrudes toward the wafer stage 14 from the end portion on the outer peripheral side. The claw portion 15
In this embodiment, it has a shape in which the thickness gradually decreases toward the tip side. The pressing member 16 is disposed such that the tip surface (contact surface) 15 a of the claw portion 15 can contact the surface of the wafer 100 placed on the wafer stage 14.

A pair of guide members 19 are fixed in the vicinity of the outer peripheral end of the pressing member 16, and the guide members 19 are inserted into guide holes 20 formed in the wafer stage 14. That is, the pressing member 16 is configured to be linearly movable along the guide hole 20 by the guide member 19 and the guide hole 20.

In such a substrate holder 9, the wafer 100 is placed at a predetermined position on the wafer stage 14.
The wafer 100 is pressed by the tip surface (contact surface) 15a of the claw portion 15 of the pressing member 16 by moving the pressing member 16 to the wafer stage 14 side in a state where the substrate is placed. That is, the wafer 100 is sandwiched between the claw portion 15 and the wafer stage 14. Thereby, the wafer 100 is satisfactorily held on the wafer stage 14.

In the present invention, as shown in FIG. 3, the tip surface 15a of the claw portion 15 of the pressing member 16 constituting such a substrate holder 9 has, for example, a plurality of conical protrusions whose diameters are narrower toward the tip side. The part 21 is provided over the entire surface at a predetermined interval. In other words, the tip surface 15 of the claw portion 15
A recess is provided in a, leaving the protrusion 21. That is, the front end surface 15a of the claw portion 15 is an uneven surface.

By providing such a protruding portion 21, as shown in FIG.
Even when the resist 101 is formed on the surface of the wafer 10,
It is possible to suppress the occurrence of problems such as adhesion (transfer) of the resist 101 to the tip surface 15a of the claw portion 15 and peeling of the resist 101 while maintaining 0 well. First, the wafer 100 can be satisfactorily held by pressing a predetermined range of the wafer 100 with the tip surface 15a of the claw portion 15. Further, since the plurality of protrusions 21 are provided on the distal end surface 15a of the claw portion 15, the contact area of the distal end surface 15a with the resist 101 is relatively small, and the resist 101 adheres (transfers) to the distal end surface 15a. ) Is suppressed.

Therefore, when the new wafer 100 is held on the wafer stage 14, the resist adhering to the pressing member 16 does not adhere to the new wafer 100 as a foreign substance, and the resist 101 formed on each wafer 100 is peeled off. Becomes easy. Further, the wafer 100 is not strongly pressed locally by the pressing member 16 through the foreign matter, and damage to the wafer 100 can be suppressed.

The height of the protrusion 21 is not particularly limited, but is preferably about 10 to 100 μm. Moreover, it is preferable that the space | interval of each projection part 21 is 50 micrometers or more. Thereby, even if a foreign substance adheres to the front end surface 15a of the claw part 15, the foreign substance does not enter between the protrusions 21, and the wafer 100 is not strongly pressed locally.

Moreover, in this embodiment, although the projection part 21 was formed in cone shape, the shape of the projection part 21 is not specifically limited, For example, a column shape may be sufficient as shown in FIG. Regardless of the shape of the protrusion 21, the cross-sectional shape of the protrusion 21 is preferably circular. Thereby, the rigidity of the protrusion 21 can be sufficiently ensured to such an extent that the wafer 100 can be satisfactorily held. Of course, the cross-sectional shape of the protrusion 21 is not particularly limited.

In addition, in the present embodiment, the protruding portions 21 are provided at predetermined intervals over the entire front end surface 15a of the claw portion 15, but the arrangement of the protruding portions 21 is not particularly limited. For example,
As shown in FIG. 6, the protrusions 21 may be arranged in a staggered manner. Regardless of the arrangement, the provision of the protrusions 21 can suppress adhesion of the resist to the pressing member 16.

Alternatively, the protrusions 21 may be arranged radially with respect to the center of the pressing member 16 (center of the wafer 100), as shown in FIG. 7A, for example. Further, when the protrusions 21 are formed radially, the protrusions 21 may be formed in a continuous beam shape from the inner end to the outer end of the claw portion 15 as shown in FIG. . If the wafer 100 expands due to heating during processing of the wafer 100, the resist 101 may be scraped off by the protrusions 21, but the amount of the protrusions 21 is minimized by providing the protrusions 21 in a radial pattern. This is because the adhesion amount of the resist 101 to the pressing member 16 is also minimized.

Further, the protrusions 21 do not necessarily have to be regularly provided on the tip surface 15 a of the claw part 15. For example, the protrusions 21 may be provided randomly or the tip surface 15 of the claw part 15.
It may be formed by roughening the surface of a.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, in the above-described embodiment, an ion milling apparatus that processes a plurality of wafers (substrates) at the same time has been exemplified. Of course, the present invention is also applied to a so-called sheet-type apparatus that processes one substrate at a time. Can be adopted. For example, in the above-described embodiment,
Although the present invention has been described by exemplifying an ion milling apparatus, the substrate holder according to the present invention can also be used in other substrate processing apparatuses for processing a substrate on which a resist is formed.

1 ion milling device, 2 vacuum processing chamber, 3 ion source chamber,
4 Introduction tube, 5 Filament, 6 Power supply, 7 Acceleration electrode, 8 Deceleration electrode, 9
Substrate holder, 10 Support shaft, 11 Rotating stage, 12 Shutter, 13
Exhaust system, 14 wafer stage, 15 claw part, 15a tip surface, 16 pressing member, 17 groove part, 18 O-ring, 19 guide member, 20 guide hole, 2
1 protrusion, 100 wafer, 101 resist

Claims (5)

A stage on which the substrate is placed, and a pressing member that includes a claw portion that abuts on the peripheral surface of the substrate placed on the stage and presses the substrate toward the stage. ,
A substrate holder, wherein a plurality of protrusions are provided on a tip surface of the claw portion. The substrate holder according to claim 1, wherein a height of the protruding portion is 10 to 100 μm. The substrate holder according to claim 1, wherein an interval between the protrusions is 50 μm or more. The substrate holder according to any one of claims 1 to 3, wherein the protrusions are arranged radially with respect to a central portion of the pressing member. The substrate holder according to any one of claims 1 to 4, wherein a cross-sectional shape of the protrusion is circular.

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