JPH03131442A - X-y stage - Google Patents

Abstract

PURPOSE:To functionally perform precise guiding extending over a long time and attain light weight construction by constituting the whole body out of a ceramic molded body, and forming a Y stage or a X-Y stage out of a hollow member into one body. CONSTITUTION:The under surface plate (Y stage) 10 of a X-Y stage is formed out of a molding sintered body in one body of Si3N4 in which ribs 2 are provided in the hollow space 1, and the under surface plate 10 of S-Y stage is obtained by forming a V-groove 3 through grinding work on this surface plate 10, hereafter, lapping the groove 3 so as to have surface roughness about under 0.8S. In this way, the whole body is formed out of ceramic of light weight compared with metals, further at least, the Y stage or the X-Y stage is constituted out of a a hollow member molded in one body, hereby, an ideal light weight X-Y stage which has sufficiently satisfactory property as to low thermal expansion coefficient, high wear resistance, high rigidity, and non-magnetism is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a means for transporting installed equipment along X-Y coordinates.
The present invention relates to an x-y stage that rotates and is used in particular for the movement of semiconductor manufacturing equipment such as projection exposure equipment and electron beam lithography equipment, or for high-speed, high-precision positioning of wire bonding equipment and the like.

[Conventional technology]

Conventionally, X-Y stages have been made of iron-based materials such as cast iron, or light alloys such as 8β, Ti, and Mg-based materials. However, these materials have a large inertial mass, which makes it difficult to achieve high speeds, a low elastic modulus, which makes them inferior in rigidity, and a high coefficient of thermal expansion, which makes it difficult to achieve high precision due to thermal deformation and thermal expansion. , poor wear resistance, and even
There are drawbacks such as an induced current generated during operation, which interferes with the electron beam and causes malfunction.

In order to overcome this drawback, it was proposed in Japanese Patent Application Laid-Open No. 59/1987 to partially use various fine ceramics as constituent materials.
-129633 publication, JP-A-60-9137 publication,
JP-A-60-37729, JP-A-61-5414
It is disclosed in Publication No. 3, Japanese Unexamined Patent Publication No. 62-84944, etc.

[Problem to be solved by the invention]

Necessary requirements for the X-Y stage include: making it as light as possible to minimize the inertial mass of movement and rotation in order to increase the precision of the machine's motion, and using a material with a high modulus of elasticity to create a structure that is difficult to deform. By using this method, we aim to achieve high rigidity in terms of both material and structure, have low thermal expansion when temperature changes, have excellent wear resistance and sliding properties, and in addition, from the viewpoint of processing using electron beams. It is required to be non-magnetic.

Although the use of ceramics is basically suitable for the above requirements, the degree of satisfaction is still insufficient.

In particular, regarding weight reduction, cast iron has a specific gravity of approximately 7.0, whereas 513NJ series and Sialon series have a specific gravity of 3.0 or more, ^l, 0. 3.8 or more for SiC systems, 3.0 for SiC systems
As mentioned above, it is 5.5 or more for ZrO2, and it cannot be said that a sufficient weight reduction has been achieved in the case where the metal material is simply partially replaced with ceramics.

As a countermeasure to this problem, it is conceivable to assemble the stage members into flat plates and integrate them in a hollow space by tightening bolts or the like, but this is not suitable for long-term, high-precision control because the high-speed operation causes minute misalignment of the joints.

The problem to be solved by the present invention is to make the most of the properties of ceramics in terms of heat resistance and wear resistance, to enable functional precision guidance over a long period of time, and to achieve weight reduction. It's about finding a way.

[Means to accomplish the task]

The X-Y stage of the present invention is entirely made of a ceramic molded body, and includes at least the Y stage or the X and Y stages.
The stage is constructed from an integrally molded hollow member.

[Effect]

The entire body is made of ceramics, which is lighter than metals,
Furthermore, since at least the Y stage or the X and Y stages are constructed from integrally molded hollow members, the X-
In addition to being lightweight, it is ideal for a Y stage, as well as having a low coefficient of thermal expansion.
High wear resistance and high rigidity.

A fully satisfactory result can be obtained in terms of non-magnetic properties.

As the above-mentioned integral molding method, it is possible to arbitrarily combine pressure casting, sludge casting, casting using a self-collapsing core, etc. during slip casting, and in particular, X-
In view of the high-speed, high-precision positioning function of the Y stage, it is necessary for the integral molded body to have ribs and the like formed in parallel to the direction of movement.

The ceramic material used is S 13 N 41
Sialon, Al1203-Ti C, Si C
, Zr0z (P S Z), etc. can be used, but from the viewpoint of strength per unit weight, Young's modulus, high toughness, and sliding properties, it is especially important to have good strength per unit weight. Considering that, Sialon, eight! ,
0°T+C, S+sN< or ceramics containing SiC as a main component are preferred.

The hollow surface plate member of the X-Y stage made of the same ceramics can be obtained by molding using any combination of molding methods such as pressure casting, sludge casting, casting using a self-collapsing core, etc., and sintering. Can be done.

In this molding, it is necessary to obtain a uniform molded body in order to obtain a sintered body of uniform density from the point of view of precise operation of the X-Y stage.

〔Example〕

Figure 1 shows the lower surface plate (Y
Stage) 10 is shown.

The identification board 10 is made of an integrally molded sintered body of 5lsN4 in which a rib 2 is provided in an inner space 1.

The identification board 10 contains 90% by weight of 813N4 powder with an average particle size of 0.8 μm, Y, and 0.8% by weight with an average particle size of 1 μm. 120. The powder is 5% by weight and has an average particle size of 0.5 μm. 5% by weight of the powder and 1% by weight of the TiN powder with an average particle size of 0.5 μm were put into a ball mill, and a ZrO□ ball was placed as a grinding pole, and the powder was ground and mixed with a water solvent. , using ammonium polycarboxylate as a peptizing dispersant and further adding a binder to produce 400 cp
A molded body was obtained by adjusting a slurry having a viscosity of 1.5 s and slip casting it into a predetermined plaster mold. After drying this in a wet dryer, it was sintered at 1700 ° C. for 2 hours in a nitrogen gas pressurized atmosphere.
A sintered body with a relative density of 95% or more was obtained. After forming V, 113 on this surface plate 10 by grinding, 0.
A lower surface plate for an XY stage was obtained by applying a lap having a surface roughness of 8S or less.

In addition, a hollow lower surface plate is made into a molded body with a solid layer of 3 buttons on the entire surface of the honeycomb structure by extrusion molding, and the convex part on the bottom side of the lower surface plate is joined at the stage of forming the molded body, and then integrated. As a result of sintering, a hollow member that satisfies the object of the present invention was obtained.

Table 1 shows the characteristics of the surface plate shown below along with comparative examples.

As a method of examining the sliding characteristics as a stage member, a wear resistance evaluation test was conducted under the conditions shown in FIG.

This method involves sandwiching three bearing steel rollers R between two ceramic plates C at equal intervals, applying stress P from the upper plate, and causing them to reciprocate at a predetermined speed and stroke, causing damage to the plates and rollers. It evaluates the degree of

The test conditions were as follows.

ceramic plate dimensions 30X200x 8t (related) surface roughness 0.05Rmax or less Test time: 30 hours/sample Test conditions P = 15kg V = 200 mm/sec Stroke 50 cities Roller: Bearing steel (SUJ) φ3×20! (mm) The results of the test are shown in Table 1.

Table 1 As shown in Table 1, compared to cast iron (PC25), ceramics have better wear resistance due to their high hardness, and Si3N has particularly high toughness.

Good results were obtained with and 1ro2. This is 5is
This is probably because N= and hot had high strength and high toughness, so there was less wear and tear due to grain dropout.

Table 2 shows other properties required for the stage material.

Additionally, as shown in the table, the lower surface plate for the x-Y stage can also be made thinner due to its higher Young's modulus and strength per unit weight compared to conventional metal (cast iron) plates. , a product with a small inertial mass, capable of high-speed movement, and excellent wear resistance was obtained.

However, from the mechanical properties per unit weight, Z
r O2 is considered unsuitable as a stage material, and 51
3N4. ^flxos -TiC and SiC are good, but Si and N< are particularly preferable.

Table 3 shows the relationship between the volume occupied by the hollow integration according to the present invention and the weight.

〔Effect of the invention〕

The present invention achieves weight reduction while fully satisfying other requirements necessary for an X-Y stage, which reduces inertial mass during operation, improves accuracy and improves workability of the X-Y stage. improved.

[Brief explanation of the drawing]

FIG. 1 shows a lower surface plate of an X-Y stage as an embodiment of the present invention. FIG. 2 is a diagram showing a method of testing sliding characteristics. Agent Fumi Otsuka Shou No. 9 Figure 0 Figure Procedure Amendment January 1991 Title of Invention

Claims (1)

[Scope of Claims] 1. An X-Y stage that is entirely made of a ceramic molded body and is made of a Y stage or a hollow member in which the X and Y stages are integrally molded. 2. In claim 1, the ceramic is Si_3N_4
, Sialon, an X-Y stage made of ceramics mainly composed of Al_2O_3-TiC or SiC.