JP2005340719A - Stage mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stage mechanism that does not adversely affect the position controllability of a stage itself, has high temperature controllability of a sample, and can keep the vicinity of the sample nonmagnetic.
SOLUTION: The temperature controllability is improved while avoiding piping for guiding the temperature adjusting fluid to the stage 46 by using the temperature adjusting thermoelectric elements 51, 52, and the thermoelectric elements 51, 52 are arranged away from the sample 40 and the sample is arranged. The vicinity of 40 is kept non-magnetic, and the heat transport means 53 and 54 are interposed therebetween.
[Selection] Figure 3

Description

  The present invention relates to a stage mechanism that can move while holding a sample. In particular, the present invention is used in a manufacturing process of a charged particle beam apparatus, a semiconductor integrated circuit, or the like, and deflects an electron beam generated by an electron beam source. The present invention relates to a stage mechanism for holding a wafer and a mask in an electron beam exposure apparatus that scans a mask having a mask pattern corresponding to the exposure pattern to expose the exposure pattern onto the wafer.

  In recent years, with the need for higher integration of semiconductor integrated circuits, further miniaturization of circuit patterns has been demanded. At present, the limits of miniaturization are mainly limited to exposure apparatuses, and new exposure apparatuses such as an electron beam direct writing apparatus and an X-ray exposure apparatus have been developed.

  Recently, an electron beam proximity exposure apparatus that can be used for ultrafine processing at a mass production level has been disclosed as a new type of exposure apparatus (for example, Patent Document 1 and Patent Document 2 corresponding to Japanese Patent Application). .

FIG. 1 is a diagram showing a basic configuration of an electron beam proximity exposure apparatus disclosed in Patent Document 1. As shown in FIG. The electron beam proximity exposure apparatus will be described with reference to this figure. As shown in the figure, the electron beam proximity exposure apparatus 1 includes an electron optical column (column) 10 and a sample chamber (chamber) 8 whose interior is kept in a high vacuum state.
In the column 10, an electron gun 12 having an electron beam source 14 that generates an electron beam 15, a shaping aperture 18, and an irradiation lens 16 that makes the electron beam 15 a parallel beam, a pair of main deflectors 21 and 22. And scanning means 13 for scanning the electron beam parallel to the optical axis.
On the other hand, in the chamber 8, a mask holder 34 for holding a mask 30 having an opening corresponding to a pattern to be exposed, a mask stage 36 capable of moving the mask holder 34 at least in the XY direction, an electrostatic chuck 44, and XY Stage 46 is provided. A sample (semiconductor wafer) 40 has a resist layer 42 formed on the surface thereof and is held on an electrostatic chuck 44.

  The mask 30 has a thin film portion in which an opening is formed at the center portion of the thick outer edge portion, and the sample 40 is disposed so that the surface is close to the mask 30. In this state, when the electron beam 15 is irradiated perpendicularly to the mask, the electron beam 15 that has passed through the opening of the mask is irradiated onto the resist layer 42 on the surface of the sample 40.

  The main deflectors 21 and 22 included in the scanning unit 13 control the deflection of the electron beam 15 so as to scan the entire surface of the thin film portion 32 of the mask 30 while keeping the optical axis thereof parallel to the optical axis 19 of the electron gun 12. To do. Thus, the electron beam 15 scans the entire surface of the thin film portion, whereby the mask pattern of the mask 30 is transferred to the resist layer 42 on the sample 40 at the same magnification.

  The XY stage 46 moves the sample 40 to be placed in the horizontal orthogonal two-axis direction (XY direction), and moves the sample 40 by a predetermined amount each time when the mask pattern is transferred at the same magnification. A plurality of mask patterns can be transferred to the sample 40. The XY stage 46 can also rotate the sample 40 with the vertical direction (Z direction) as a rotation axis.

The sub deflectors 51 and 52 included in the scanning unit 13 control (tilt correction) the incident angle of the electron beam to the mask pattern so as to correct the mask distortion. Assuming that the incident angle of the electron beam 15 to the mask 30 is α and the gap between the exposure mask 30 and the sample 40 is G, the shift amount δ of the transfer position of the mask pattern due to the incident angle α is expressed by the following equation:
δ = G ・ tanα
The mask pattern is transferred to a position shifted from the normal position by a shift amount δ. Therefore, even if the exposure mask 30 has a mask distortion, the mask distortion can be corrected by controlling the tilt of the electron beam in accordance with the mask distortion at the electron beam scanning position.

  Now, in order to keep the transfer magnification of the mask 30 and the sample 40 constant (for example, the same magnification in the electron beam proximity exposure apparatus), it is necessary to suppress size variation due to thermal expansion and contraction of the mask 30 and the sample 40. However, since the mask 30 and the sample 40 are constantly irradiated with the electron beam 15, the temperature tends to gradually increase. For this reason, in an electron beam exposure apparatus such as the electron beam proximity exposure apparatus, the mask 30 and the sample 40. It is necessary to provide temperature control means for adjusting the temperature of the temperature.

  As a means for adjusting the temperature of such a sample (wafer), there is conventionally known a structure in which a water guide pipe for circulating cooling water is provided on a stage that supports a wafer as in Patent Document 3 below. Patent Document 4 below discloses a structure in which a radiant heat plate is provided for cooling a chuck that supports a wafer.

US Pat. No. 5,831,272 (Overall) Japanese Patent No. 2951947 (Overall) JP 11-233598 A (Overall) JP 2003-229347 A (Overall)

  However, if a conduit structure as shown in Patent Document 3 is provided in the mask holder 34 or the XY stage 46, the controllability of the stage is deteriorated due to the piping. In particular, when the movement range is wide like the XY stage 46, it is difficult to supply cooling water to the stage.

  In order to avoid such piping, a method of arranging a thermoelectric element such as a Peltier element in the vicinity of the sample 40 is also conceivable. However, in a charged particle beam apparatus such as the above-mentioned electron beam proximity exposure apparatus, the vicinity of the sample is required to be nonmagnetic in order to prevent the charged current from affecting the trajectory of the charged particle beam. It is also difficult to arrange an element having a large current near the sample 40.

  Further, as shown in Patent Document 4, in the structure in which the temperature of the chuck 44 is adjusted by a radiation plate provided in non-contact with the chuck 44, the temperature controllability is low as compared with the case where the temperature adjusting element is brought into contact with the chuck 44. .

  In view of the above problems, the present invention provides a stage mechanism that does not adversely affect the position controllability of the stage itself, has high temperature controllability of the sample, and can keep the vicinity of the sample nonmagnetic. Objective.

  In order to achieve the above object, in the present invention, a thermoelectric element for temperature adjustment is used in order to improve temperature controllability while avoiding a pipe for guiding a temperature adjustment fluid, and in order to keep the vicinity of the sample nonmagnetic, this thermoelectric element is used. They were placed away from the sample, and a heat transport means was interposed between them.

  That is, the stage mechanism according to the present invention includes a movable table, a sample holder provided in the movable table, a heating thermoelectric element and a cooling thermoelectric element provided in the movable table apart from the sample holder. A heating heat transporting means for transporting heat between the heating thermoelectric element and the sample holding part, and a cooling heat transporting means for transporting heat between the cooling thermoelectric element and the sample holding part.

In order to keep the vicinity of the sample more non-magnetic, it is preferable that the heat transport means is made of a non-magnetic material. In order to improve temperature controllability, the stage mechanism provides a temperature sensor provided in the sample holder and / or heat transport means and a driving signal for the heating thermoelectric element and / or the cooling thermoelectric element based on the temperature detected by the temperature sensor. A thermoelectric element control unit that outputs and maintains the sample held in the sample holding unit at a predetermined temperature.
At this time, the thermoelectric element control unit may drive the heating thermoelectric element based on the temperature detected by the temperature sensor while driving the cooling thermoelectric element with a constant signal. Since the temperature of the sample can be adjusted relatively quickly when it is heated, the temperature controllability can be further enhanced by such control. Of course, the thermoelectric element control unit may drive the thermoelectric element for cooling based on the temperature detected by the temperature sensor while driving the thermoelectric element for heating with a constant signal.

  The heating thermoelectric element and the cooling thermoelectric element are each constituted by a heat exchange element, and the heating heat transporting means transports heat between the heat generating element of the heat exchange element as the heating thermoelectric element and the sample holding part. The cooling heat transport means transports heat between the heat receiving part of the heat exchange element as the cooling thermoelectric element and the sample holding part, and receives the heat receiving part of the heat exchange element as the heating thermoelectric element and the cooling thermoelectric element. It is preferable to exchange heat with the heat generating part of the heat exchange element as an element via a movable base.

With the stage mechanism according to the present invention, it is possible to improve the controllability of the stage position by avoiding the pipe for guiding the temperature adjusting fluid, to improve the temperature controllability, and to keep the vicinity of the sample nonmagnetic.
Furthermore, the vicinity of the sample can be further kept nonmagnetic by configuring the heat transporting means with a nonmagnetic material.
The temperature controllability can be further improved by adjusting the temperature with the heating thermoelectric element while cooling the sample with the cooling thermoelectric element driven by a constant control signal at all times.

  The heat receiving part of the heat exchange element as the thermoelectric element for heating and the heat generating part of the heat exchange element as the thermoelectric element for cooling exchange heat through the movable base, thereby reducing the heat generation amount of the entire system and generating heat. Can be minimized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a schematic configuration diagram of a stage mechanism according to the embodiment of the present invention. In the following description, the case where the stage mechanism 2 is applied to the electron beam proximity exposure apparatus 1 shown in FIG. 1 will be described as an example, but the stage mechanism according to the present invention includes an electron beam exposure apparatus, an electron microscope, and an electron beam inspection. It can be suitably used for various charged particle beam devices such as devices.
Since the electron beam proximity exposure apparatus itself has already been described, the description thereof will be omitted, and the same functional parts as those in FIG. 1 are denoted by the same reference numerals.

The stage mechanism 2 includes an XY stage 46 including a coarse movement stage 48 and a fine movement stage 47 that can move an electrostatic chuck 44 as a sample holder in at least two X and Y axial directions.
On fine movement stage 47, a plurality of heating Peltier elements 51, which are heat exchange elements as heating thermoelectric elements, and a plurality of cooling Peltier elements 52, which are heat exchange elements as cooling thermoelectric elements, are provided. The heating Peltier element 51 and the cooling Peltier element 52 are arranged so that the magnetic field generated by the energizing current does not affect the trajectory of the electron beam applied to the sample 40 on the electrostatic chuck 44. It is provided away from.

  The heat generated in the heat generating portion of each heating Peltier element 51 is conveyed to the electrostatic chuck 44 by a plurality of heating heat transporting means 53 provided for each heating Peltier element 51, and on the contrary, the electrostatic chuck The heat on 44 is conveyed to the cooling part (heat receiving part) of the cooling Peltier element 52 by a plurality of cooling heat transporting means 54 provided for each cooling Peltier element 52. The heat transport means 53 for heating and the heat transport means 54 for cooling may be realized by a heat transport means such as a heat pipe or a heat lane (registered trademark). On the other hand, the cooling part of the heating Peltier element 51 and the heat generating part of the cooling Peltier element 52 are provided in contact with the block of the fine movement stage 47 having a large heat capacity, and perform heat exchange via the block of the fine movement stage 47. Further, it is preferable that the heating heat transporting means 53 and the cooling heat transporting means 54 are made of a nonmagnetic material so as not to affect the electron beam trajectory with which the sample 40 is irradiated.

  The heating heat transporting means 53 and the cooling heat transporting means 54 are laid out along the surface of the sample 40 in a temperature control unit 55 provided below the electrostatic chuck 44. In FIG. 2, the heat transport means 53 for heating and the heat transport means 54 for cooling are laid out vertically, but for example, as illustrated in FIG. 3, each heat heat transport for heating extending in the radial direction of the temperature control portion 55. The positions of the means 53a to 53h and the cooling heat transporting means 54a to 54h, the heating Peltier elements 51a to 51h, and the cooling Peltier elements 52a to 52h are shifted on the stage 46 plane in the circumferential direction of the temperature control section 55. Alternatively, they may be arranged alternately on the same plane. The temperature adjustment unit 55 is provided on the fine movement stage 47 via the heat insulating support member 49, and the heat flux between the block of the fine movement stage 47 and the temperature adjustment plate 55 is blocked.

  Between the temperature control unit 55 and the electrostatic chuck 44, a heat equalizing plate 45 is provided which is made of a material having a low thermal resistance and / or a structure having a low thermal resistance. The heat equalizing plate 45 makes the non-uniform heat on the temperature control unit 55 uniform and transmits it to the electrostatic chuck 44 and the sample 40 through this. In addition to or instead of this, the electrostatic chuck 44 may be made of a material having a low thermal resistance and / or a structure having a low thermal resistance.

  As shown in the figure, temperature sensors 61a and 61b are provided for the electrostatic chuck 44, a temperature sensor 61c is provided for the soaking plate 45, and a temperature sensor 61d is provided for each cooling heat transport means 53 in the vicinity of each heat for cooling. A temperature sensor 61e is provided in the vicinity of the transport means 54, and a temperature sensor 61f is provided in the vicinity of the lower surface of the fine movement stage 47. The stage mechanism 2 performs heating based on the temperature of each part detected by the temperature sensors 61a to 61e. The thermoelectric element control part 70 which controls and outputs the electric current to the Peltier element 51 for cooling and the Peltier element 52 for cooling is provided.

  The control of the heating Peltier element 51 and the cooling Peltier element 52 by the thermoelectric element control unit 70 drives the cooling Peltier element 52 with a constant output current, while 61a, 61b and / or 61 provided in the electrostatic chuck 44 Alternatively, it may be performed by variably controlling the output current to the heating Peltier element 51 so that the temperature detected by the temperature sensor 61c provided on the soaking plate 45 becomes a preset temperature. In general, temperature adjustment can be performed relatively quickly in the case of heating rather than in the case of cooling, and thus such control contributes to the improvement of temperature controllability.

  If the temperature sensors 61a to 61e detect non-uniform temperature distribution along the sample surface in the electrostatic chuck 44, the heat equalizing plate 45, and the temperature control unit 55, the thermoelectric element control unit 70 3, the heating Peltier elements 51 a to 51 h for heating the heating ends of the heating heat transporting means 53 a to 53 h, which are arranged at different positions on the plane of the stage 46, and the cooling heat transporting means 54 a. The cooling Peltier elements 52a to 52h that cool the cooling ends of ~ 54h may be individually controlled to perform zone control so as to eliminate the uneven temperature distribution.

  Further, the thermoelectric element control unit 70 may adjust the exhaust heat amount of the entire stage mechanism 2 by changing the control signal applied to the cooling Peltier element 52 in accordance with the temperature detected by the temperature sensor 61f disposed on the fine movement stage 47. . Furthermore, when the temperature detected by the temperature sensor 61f exceeds a predetermined allowable temperature, an alarm signal that warns of overheating may be generated to notify the operator.

In the above description, the case where the stage mechanism 2 is applied to the XY stage 46 that moves while supporting the wafer of the electron beam proximity exposure apparatus 1 has been described. However, the same temperature adjustment function is applied to the mask holder 34 or the mask holder that holds the mask. 34 may be applied to a mask stage 36 that moves.
That is, the mask stage mechanism of the electron beam proximity exposure apparatus 1 includes a mask stage 36 that is a movable stage, a mask holder 34 that is a sample holder provided on the mask stage 36, and a mask holder 34 that is separated from the mask holder 34. A heating Peltier element that is a heating thermoelectric element provided on the stage 36, a cooling Peltier element that is a cooling thermoelectric element, and a heating heat transport means that transports heat between the heating Peltier element and the mask holder 34. A certain heat pipe (or heat lane (registered trademark)), and a cooling heat pipe (or heat lane (registered trademark)) that is a heat transport means for cooling that transports heat between the cooling peltier element and the mask holder 34; , May be provided.

In order to keep the vicinity of the mask more non-magnetic, it is preferable that the heat transport means is made of a non-magnetic material. In addition, in order to improve temperature controllability, a driving signal for the heating Peltier element and / or the cooling Peltier element is output based on the temperature sensor provided in the mask holder 34 and / or the heat transport means and the temperature detected by the temperature sensor. And a thermoelectric element controller that maintains the mask 30 held by the mask holder 34 at a predetermined temperature.
The thermoelectric element controller may drive the Peltier element for heating based on the temperature detected by the temperature sensor while driving the Peltier element for cooling with a constant signal. The cooling Peltier element may be driven based on the temperature detected by the temperature sensor while being driven by the signal.

  The heat transport means for heating performs heat transport between the heat generating part of the heating Peltier element and the mask holder 34, and the heat transport means for cooling transports heat between the heat receiving part of the Peltier element for cooling and the mask holder 34. It is preferable that the heat receiving part of the heating Peltier element and the heat generating part of the cooling Peltier element exchange heat via the mask stage 36.

  INDUSTRIAL APPLICABILITY The present invention is widely applicable to an apparatus that includes a stage mechanism that holds a sample and that needs to adjust the temperature of the sample to be held, and in particular, a charged particle beam apparatus, an electron beam exposure apparatus, an electron microscope, and an electron beam. It can be suitably used for various electron beam devices such as inspection devices.

It is a schematic block diagram of an electron beam proximity exposure apparatus. It is a schematic block diagram of the stage mechanism based on the Example of this invention. It is a layout view of heat transport means.

Explanation of symbols

40 ... Sample 44 ... Chuck 45 ... Soaking plate 49 ... Heat insulation support member 53 ... Heating heat pipe 54 ... Cooling heat pipe 55 ... Temperature control sections 61a to 61e ... Temperature sensor

Claims (6)

A movable base,
A sample holder provided on the movable table,
A heating thermoelectric element and a cooling thermoelectric element provided on the movable base part apart from the sample holding part,
A heating heat transporting means for transporting heat between the heating thermoelectric element and the sample holder;
A cooling heat transport means for transporting heat between the cooling thermoelectric element and the sample holder;
A stage mechanism comprising:   The stage mechanism according to claim 1, wherein the heat transport means is made of a nonmagnetic material. Furthermore, a temperature sensor provided in the sample holder and / or the heat transport means,
A thermoelectric element control unit that outputs a driving signal of the heating thermoelectric element and / or the cooling thermoelectric element based on a temperature detected by the temperature sensor and maintains the sample held in the sample holding part at a predetermined temperature;
The stage mechanism according to claim 1, comprising:   The stage mechanism according to claim 3, wherein the thermoelectric element control unit drives the heating thermoelectric element based on a temperature detected by the temperature sensor while driving the cooling thermoelectric element with a constant signal.   The stage mechanism according to claim 3, wherein the thermoelectric element control unit drives the cooling thermoelectric element based on a temperature detected by the temperature sensor while driving the heating thermoelectric element with a constant signal. The heating thermoelectric element and the cooling thermoelectric element are each constituted by a heat exchange element,
The heating heat transporting means performs heat transport between the heat generating element of the heat exchange element as the heating thermoelectric element and the sample holding part,
The cooling heat transporting means performs heat transport between a heat receiving part of the heat exchange element as the thermoelectric element for cooling and the sample holding part,
The heat receiving part of the heat exchange element as the thermoelectric element for heating and the heat generating part of the heat exchange element as the thermoelectric element for cooling perform heat exchange via the movable base. Stage mechanism.

Images