TW552613B - The drive of wafer stepper - Google Patents

Abstract

A piezoelectric-driven 2-D stage (X-Y axis) utilizing the frictional stick-slip effect and inertia force can be designed and fabricated to achieve ultra high resolution and long travel range. Based upon the principle of elastic deformation, a high resolution piezoelectric-driven micropositioner (Z-axis) is designed and fabricated. Moreover, a CD pick-up head and analog linear controller are integrated with Z-axis micropositioner to be a autofocus system. This design is based upon the requirement of the optical lithography development by using 193 nm Excimer Laser. During this special lithography process, Z-axis micropositioner is needed for the laser beam focusing. A 2-D X-Y stepper is also needed for the movement of the wafer under laser exposure. The wafer stepper is based on the step-repeat and step-scan processes.

Description

552613 V. Creation description (1) Industrial application field The creative design is a long-stroke high-precision positioning work platform with 12 degrees of freedom (XY axis) movement; and a laser light reading head is used as a low-cost optical probe. Z-axis piezoelectric stage and analog linear controller, optical autofocus system. Jingbei㈣3 The continuous improvement of the precision process, whether it is the semiconductor industry, precision machinery industry, biological cell field, photovoltaic system process, STM, SPM, etc. 々 々 Resurface engineering SPM specialization, are all toward miniaturization and precision, so For micron-scale blows and umbrellas, a-magic universal moves forward, and the demand for systems in the industry f X p π ^ is increasing, and many precision positioning instruments have been used in the industry. At present, the same mechanism is used to form the wafer stepper. 11ίIn the industry, there are already many precision positioning instruments or equipment, and the instrument: because of its accuracy, the total displacement is recited ~ but This type of large stroke is only about 200 ~ 300, but take Fengmu II: report small, the most processing as an example, the table of eight o'clock wafer :: wafer type instrument in the conductor industry cry: θ said round processing Technology has gradually become the main stream, because I-inch, beneficially speaking, there is more than precision, but the head office of the second, so this nibble characteristics to meet the needs of the future semiconductor industry and precision industry is not

Page 5 552613 V. Creative Instructions (2) In order to match the development goals of 193 nm Excimer Laser's optics | worm lithography, a high precision single-degree-of-freedom (Z-axis) piezoelectric platform must be performed. Design and manufacture of step platform with two degrees of freedom (X_Y axis). The single-degree-of-freedom actuator is used for focusing applications of excimer lasers, and the main function of the optical autofocus system is to keep the working plane of the Z-axis piezoelectric platform within the focusing range of the excimer laser. The two-degree-of-freedom stepping platform is used as a step-repeat-projection and step-scan-projection method for etching wafers.

Page 6 552613

Constructs an optical autofocus system. The purpose of this creation is to reveal a long-stroke high-precision positioning work platform with two degrees of freedom (X-Y axis) movement. 552613 V. Creation instructions (4) Schematic part: first picture second picture third picture fourth picture fifth picture sixth picture seventh picture eighth picture ninth picture tenth picture eleventh twelfth tenth Three-chip stepper structure diagram Actuating mechanism structure diagram Friction mechanism structure diagram Friction drive platform motion diagram | a) Repeated movement ⑻ one-way C c) Relation diagram of input voltage signal and output displacement in fixed period w (a) Sawtooth Waveform input (b) Schematic diagram of pulsed waveform input optical auto-focusing system ^ Optical reading #head signal processing diagram @ t-focus error signal of S curve chart wafer stepper operation block diagram Axis friction drive platform displacement experiment chart (pulse waveform input) Fig. XY friction platform displacement experiment chart (sawtooth waveform input) = · Z axis piezoelectric platform displacement experiment chart (staircase waveform input) θ · Autofocus system volume test piece outline experiment chart

I Drawing number description Actuating mechanism WOl · mass block 1002. Piezoelectric actuator

Page 8552552 V. Creative Instructions (5) 2. 3. 1 0 0 3 · Flat leaf spring ι〇〇4 · Fixed base of penetrating slot 9 Motion platform 3 1 · Friction interface 4 · Guiding device 41 · Interchange Roller slider 5 · Measuring system 5 1 · Linear optical encoder 6 · Friction mechanism 6 3 · Clamping block 61 · Prestressing screw 6 2 · Stainless steel gasket 6 5 · Friction base 64 · Fiber optic sleeve (〇1 as s ρ i ber Ferru 1 e) X-axis friction drive platform Y-axis friction drive platform 83 · Ruler insect-proof power amplifier 82 · Analog / digital card (AD / DA) • Focus error signal processing circuit 8 5 · Analog Linear controller 9. Z-axis piezo stage 91. Piezo actuator 92 ^ ^ ^ u ^ ^ 93. Penetration slot 94. Displacement work 9 level 2. Taiwan plate type blade spring 1 〇. Test piece Type fixture 9 6. Capacitive displacement sensor 1 1 * Laser light reading head lu. Laser diode 112. Beamsplitter lens

$ 9 pages 552613 V. Creative Instructions (6)

I 11 3 · Parallel lens 1 1 4. Astigmatic lens, 1 1 5. Quadruple light detector 11 6 · Objective lens 12 · Optical suspension platform

This creation uses the existing multi-layer piezoelectric ceramics as a displacement actuator, and designs and manufactures a long-stroke high-precision positioning work platform with one or two degrees of freedom (X-Y axis) movement in conjunction with friction hysteresis and inertial forces. In addition, based on the principle of elastic deformation of materials, a single-degree-of-freedom (z-axis) high displacement resolution piezoelectric platform is designed and manufactured, and a laser light reading head is used as a low-cost optical probe in conjunction with the z-axis piezoelectric type The platform and the analog linear controller constitute an optical autofocus system. The wafer stepper of Μ Υ = is divided into three sub-systems ... All of them are discussed, which are X, Z axis friction drive platform, Z axis piezoelectric platform and system. -A kind of wafer stepper includes: sub-eye movement to focus the bottom χ: electricity; =; (Π, 7,8), the independent movement set on the axis of the wafer stepper moves the actuator 'to drive the platform to work X axis and γ // χ ^ ^ «Rub over the drive platform, so χ, = can be completed, because ^ is placed on the X-Χ axis grinding

Page 10 Independent motion in one axis direction 552613 5. Creation instructions (7) The optical autofocus system is set above the Z-axis platform, where the light source and light sensor can project the light source onto the chip, and detect the light on the chip. Reflected light is used to process the beam focusing signal; / Z-axis stage is fixed on the χ — γ-axis friction drive stage, and the optical auto-focusing system is fixed on another base higher than the wafer. ， The light beam is reflected on the surface of the wafer. “The light reflected from the wafer is projected on the optical auto-focusing system. The light sensor in the auto-focusing system passes the focus error signal processing circuit (84) and the analog linear controller (85) for signal and closed-loop feedback control. The Z-axis platform is used to adjust the Z-axis and move the wafer on the Z-axis platform to drive the movement in the z-axis direction so that the beam is focused on the wafer. An overview of the subsystems of this creation. The investigating committee members can have a better understanding of the structure, efficacy and advantages of this case. The wafer stepper of this creation is divided into three sub-stages and two secondary movements; γί Friction-driven platform, ζ-axis piezo-electric flat ”, and the detailed description is shown below:% Moving platform please refer to Figure 1. The structure of Y k # The shaft can be rubbed and rubbed, and the motion / stage ⑺ and γ-axis friction drive ⑴, friction mechanism 6, guidance: two or five parts' are the actuator device (4), the measurement system (5) and the control system

Page 11 552613 V. Creation Instructions (8) System. Please refer to FIG. 2, the actuating mechanism (1) includes a mass (1001), a piezoelectric actuator (1002), a flat leaf spring (丨 〇〇3), and a penetrating slot (104) ) And so on. Please refer to FIG. 3, the friction mechanism (6) includes a pre-2 application screw (61), a stainless steel washer (62), a clamping block (63), a fiber optic sleeve (Glass Fiber Ferrule, 64) and a friction base ( 65). The guide device (say 4) is a high-linearity, low-friction coefficient cross roller slide (4ij. The measurement system (5) uses a ultra-high-resolution linear optical encoder (51) and its electronic type The controller is divided, and the laser interferometer and precision capacitive micrometer are used as the measurement verification of the linear optical encoder (51) in the experiment. The system includes a personal computer, analog / digital card (AD / DA, 82) Wash the drive ^ 2 actuator (1 002) power amplifier ⑻), etc., and use the 0 language to write the input voltage waveform, and pass the linear optical encoder (5) back to the seat to find the value of the flat H body to control X The displacement resolution and positioning accuracy of the shaft friction drive platform ⑺ and γ-axis friction drive thousands (8). One end of the actuator is connected to the motion platform, the other end of the actuator is connected, one end of the flat leaf spring is connected to the motion platform, the other end is connected to the mass block, and the motion platform is connected to the cross section. The device is installed between the moving platform and the fixed base; the two friction mechanisms are connected, and the friction mechanism is connected to the fixed base; spring = port: there is a differential discontinuity point in the drive source (ie, broken motion: fast motion, f gauge block and motion The platforms are subject to the same inertia. This inertia force is greater than the maximum static friction of the friction interface. 2 and solid order pan & «V Βθ π; ^ Movement level 厶 552613 5. Creation instructions (9) Fork roller is slow There is no single-step to continuous displacement stroke when moving to the friction platform provided by the over-friction mechanism, and the application of resolution can be detected at any time. When the seat guide becomes an original length, the maximum static frictional force of the movement is at a fixed step. Displacement. If this function is used, friction is limited and its displacement stroke is measured with a long line. The linear displacement of the linear stepping movement, when the inertia of the driving platform is acting, the movement is flat at this time. The platform uses the 'movement and movement program' on the base to continuously drive. The principle of linear motion and high accuracy designed by the driving principle is to achieve its goal. As an optical source, the actuator is not forced to exceed the friction mechanism program. , It can reach Taiwan's motion optical encoder long-stroke orientation etching of the wafer ^ axis friction drive platform and Y axis friction drive platform electrically actuated cry = electric actuator (1002) as a source of power, Fast pressing and rising: the lowest piezoelectric ceramic, which has a small volume and responds to the advantages of UOOU two anvils: easy to make, etc. Although the effect of the hysteresis of the piezoelectric actuator on the line is not significant, the displacement is not After the presentation, but after feedback control, I electric actuator (η) can be made with high accuracy, coupled with high resolution and high thrust, so P is used. Piezoelectric actuator (1 0 0 2) With external voltage waveform

Different waveforms can be used to achieve different forms of motion. The moving platform will generate a continuous ck-siip Effect) 'It can make the stepping movement of the operation platform and install an ultra-high solution on the platform. 2 Encoder (5) ☆ It is a displacement sensor, which uses the computer-based control method to perform feedback positioning control of the χ-γ axis.

Page 13 552613 V. Creation Instructions (10) The coexistence of degree and long-stroke positioning ability is the biggest feature of this creation.

The piezoelectric actuator (1002) can expand and contract with the periodic voltage signal, which can be used as the power source of the motion platform (3). With the difference of the external lightning pressure waveform, the piezoelectric actuator can be changed. The movement state of the actuator and the friction between the stainless steel washer (62) and the fiber sleeve in the friction mechanism (6) can cause the χ and γ axes to frictionally drive the 台, 7. 8) In the case of voltages with different waveforms, amplitudes, and frequencies, there will be non-displacement. If the driving voltage is a periodic waveform input, & Motion 3 can continuously make a small amount of step displacement. For the X and Y axis friction drive platforms (7, 8), it is only necessary to discuss the principle of single axis 1 motion, and the schematic diagram of its step motion is shown in Figure 4. Please refer to Figure 4 (a) and match the components of Figure 1. The piezoelectric actuator (i0f connects the mass (1001) and the motion platform (3). The motion platform uses a stainless steel gasket (62). The contact friction with the optical fiber sleeve (64) is stationary on the fixed base (2). If the input voltage causes the piezoelectric actuator (1002) to move rapidly, the mass (1001) and the motion platform ( 3) Both bear the same inertial force. When the inertial force is greater than the maximum static friction between the stainless steel gasket (62) and the fiber sleeve (64), there is a gap between the moving platform 3 and the fixed base (2). The relative position f occurs, as shown in Figure 4 (b); if the input voltage causes the piezoelectric actuator (1 002) to slowly move to its original length, the inertial force on the moving platform (3) will not exceed The maximum static friction between the stainless steel gasket (62) and the optical fiber sleeve (64), so the motion platform (3) will be stationary on the fixed base (2).

552613 V. Creation Instructions (11) As shown in Figure 4 (C), the single-step stepping Wang Xu of this one (7, 8) can achieve the work of continuous displacement of the X, Y axis friction drive / = this A motion program is continuously performed, that is, the motion stroke is not limited. The platform designed by the principle of friction drive, which is the most representative sawtooth waveform for X, Z axis friction drive, is shown in Figure 5 (a). When the wheel-in waveform (1002) has a fast displacement rate, the force will be greater than the friction hysteresis phenomenon. The X and Y-axis friction drive platforms (7, the moving platform (3), and the fixed base (2) (1 〇〇1) The situation of the inertial force rubbing occurred, and the action description of the platform (7, 8) also occurred. This paper probes into the input voltage signal. Its principle is shown in the figure. The slope of the tangent line is larger, that is, the piezoelectric actuator motion platform ( 3) The critical force caused by inertia. Because the inertia force has a decisive effect on the movement of 8), if the friction between the transport can't resist the mass, the moving platform (3) will have a single step of sliding friction Of displacement.

The tangent slope of the life wave is small. When the piezoelectric actuator (1002) has a low m, the inertial force of the mass ⑽υ 4 = the critical force of the hysteresis phenomenon. Therefore, the motion platform 静止 will be stationary at On the solid two two (2) ±. This completes one cycle of step motion. If the voltage waveform of the input cycle is continuously input, continuous step motion can be achieved. Cut the input waveform and t 'also use other driving voltage waveforms to drive the electric actuation to 1 002)', and the displacement performance of the platform will be greatly different, such as pulse waveform (Impulse WaVeform), transcendence function waveform (Trans _

Page 15 552613 V. Creative Instructions (12) f cendental Waveform) or Cycloidal Waveform. The operation mode of the pulse waveform is shown in Figure 5 (b). It can be clearly seen from the figure that if there is a differential discontinuity point (ie, a broken point) in the input waveform, and the slopes on both sides of this point are greatly different, the sharp part of the waveform is the main part of the driving platform movement. '. When the input voltage passes through the sharp point of the driving waveform (such as a pulse waveform), the momentum of the mass (1000) changes too much, so the motion platform (3) receives a large inertial force. The stainless steel gasket ( 62) The contact surface with the fiber optic sleeve (64) cannot provide sufficient friction to fix the motion platform (3), and each pulse waveform can achieve a single step step displacement. If the pulse voltage waveform is continuously input, continuous operation is possible. Stepping motion to achieve the desired long-stroke positioning goal. As shown above, the design of the X and Y axis friction drive platforms (7, 8) can be improved = the shortcomings of the system stroke limitation, providing-a kind of precise long stroke setting that achieves long strokes without affecting its positioning accuracy at all = Simple manufacturing, easy to use, not easy to use and quite streamlined, so it is not easy to be damaged, and it is easy to be damaged. It can be used in the field of precision machinery, optics, and long life, regardless of the application of semiconductor AFM and other instruments. , Or STM, SPM,% LS has very good performance.

2. The composition structure of the Z-axis piezoelectric platform (9) is shown in Figure 1. It contains the pressure 552613. V. Creation instructions (13) Electric actuator (91), flat leaf spring (92), penetrating slot Working platform (94) and test fixture (95). Z-axis piezoelectric platform (= mobile actuation 1§ (9 1) as a driving device, and using a flat leaf spring (, variable motion mode (that is, elastic deformation of the material) to analyze (target. Z-axis piezoelectric type Platform (9) ㈣ more (two ϊ) analog linear controller for closed-loop setting; control: = the purpose of Nan Jingli, 的 position. The test fixture (95) is mainly used to hold the test: shaking: to avoid the cause of the test piece X, γ axis friction drive platform (7, 8) stepping motion scale = device: the end is connected to the fixed base, the other end of the actuator is connected to the displacement end: one end of the plate blade elastic Jing and the fixed base are selected, flat The blade 2 is connected to a displacement table. There is a capacitor ^ 4 vertical displacement sensor inside the displacement table. When the actuator is driven, it provides displacement and force. It moves through the guide of the plate η spring. Induced, produced-displacement effect in position + σ, resulting in relative movement of the working platform and the fixed base, the relative two movements are measured by a capacitive displacement sensor, and closed-loop positioning control is performed via a linear analog controller. Ζ Axial pressure The electric platform (9) uses multilayer piezoelectric ceramics, which has a small volume, fast response, The lowest heat, the advantages of the control surface, coupled with the large axial thrust and high resolution of the displacement, and the excellent dynamic characteristics caused by the electric f: & it can make a small amount of dynamic displacement with the periodic voltage signal, so Very suitable as z-axis electric platform actuation page 17 552613 V. Creative Instructions (14) " ~ '~ f device', although the piezoelectric actuator (9 1) is affected by its own material hysteresis, in The displacement and input voltage are not completely linear, but the closed-loop control can improve the positioning accuracy of the Z-axis piezoelectric platform (9). The actuation mechanism of the Z-axis piezoelectric platform (9) is not The traditional link mechanism manufacturing method is adopted, but the wire actuator (wire Electro-Discharge-Machine) is used to integrate the platform's actuation mechanism into a complete cut, and the flat leaf spring (92) manufactured by cutting is used to simulate the traditional link The movement of the machine g makes the displacement work platform (94) perform extremely well in the category of micro-displacement. Since the deformation of the mechanism occurs at the flat leaf spring (92), there is no gap, only the intermolecular Internal friction Therefore, the energy consumption is also very small, and it can reach a very high resolution. The processing accuracy of the wire cutting machine is up to 10 // m, so the linear movement of the Z-axis piezoelectric platform (9) and the traditional mechanism in assembly Assembly error caused by its straightness of movement

The optical auto-focusing system in this creative wafer stepper includes a laser light reading head; a focus error signal processing circuit; an analog controller; etc .; a linear range focusing error laser light reading in a polarizing beam splitter, chirp, etc. The pick-up head includes a laser light source, an objective lens, and an optical element; the laser head is used to read the s-curve of the head

Page 18552613 V. Creative Instructions (15) n (Focus Error Signai), after processing the focus error signal: circuit) It is the error signal of the analog controller control loop at first, in order to control the displacement of the 2-axis positioning platform to maintain the thunder Within the focusing range of the light reading head; in order to keep the Z-axis platform to drive the wafer within the optical focusing working range. this

Right: Observing tiny structures and t • 'usually use optical systems to assist ordinary microscopes, but the disadvantage of microscopes is that high resolution is difficult to achieve. With the development of optoelectronic technology, it is possible to display images with electronic technology The Junr process has been further developed on the glorious screen. Optical autofocus = higher resolution of the microscope 'so it becomes a fine disc for observation; ΐ On a fast-rotating disc, use the information received by its servo system. On the disc drive Laser light reading = upper == on-board laser light reading head core platform (9 acre r & lgIlal) S-curve, combined with the Z-axis piezoelectric test specimen to form an optical autofocus system, as Measuring table (7 heights) and simultaneous scanning of thousands and thousands of planes with X and Y axis friction drive. Part of the laser light reading head (11) is the most important in the focus servo system. Page 19 552613

It contains optical elements, objective lenses, actuators that drive objective lenses, quad-segment photodetectors, etc. Due to different focusing error principles used by different laser light reading heads (1 1), this case uses the most commonly used on the market. Astigmatism focusing error correction system as an example, its working principle is shown in Figure 6. It can be seen from the figure that the point light source is emitted by a laser diode, and processed by the collimating lenses to turn the point light source into a parallel beam, and passes through the beam splitter lens and the objective lens to reach the optical disc or test. The reflected surface of the component passes through the objective lens and beam splitter lens to reach the astigmatic lens (Astigmatic Lens). After the astigmatic lens is processed, it enters the photosensitive surface of the Quad Detect or. An astigmatic lens is a special lens with two focusing planes. The most common geometric shape is a semi-cylindrical shape. Please refer to Figure 7. When the position of the test piece is on the focal plane of the objective lens, the reflected light is processed by the astigmatic lens to form a circular light area on the photodetector. Area, the shape of the reflected light processed by the astigmatic lens on the photodetector is elliptical.

When the surface of the test piece is located at the unfocused position in Figure 6A, the reflected light processed by the astigmatic lens will form a vertical elliptical aperture in the photodetector. As shown in Figure 7A, the photodetector signal passes through the homemade focus. The error processing circuit (84) produces a positive voltage output, as shown in area a of Figure 8; when the surface of the test piece is located at the focus position of Figure 6B, the reflected light forms a positive circular aperture on the photodetector, such as As shown in Figure 7B, the focus error of the photodetector signal

Page 20 552613 V. Creation instructions (17) ί 理 = (: ί) is treated as a zero voltage output, as shown in the figure: The surface of the test piece is formed on the device of the β point of c❸ 非 聚 隹 ^ 八 之 in Figure 6 The horizontal elliptical aperture is set as shown in Figure tc. The reflected light passes through the focus error processing circuit (84: shown in Figure 8). The light detection is shown in area c of Figure 8. After that, it is a negative voltage output. The curve shown in Figure 8 Optical self

Curves. The areas A, 3, and 0 in the figure correspond to the most important S signal processing graphics in the figure and the seven series 1. I 隹 # of Α, β and C three%; The linear area in the focus difference curve can be used for A # # θ measurement. It is excellent in both dynamic and static characteristics as a displacement displacement component. Good characteristics of beautiful straight line 5 = middle area controlled by servo (feeding, can be used = for reading and writing heads, its feeding control :: 致 围 二 ^^^ The position of the mirror 'keeps the laser light focused on] ί:;! The design method is to fix the objective lens with ζ-axis piezoelectric ί * two () as the carrier of the test piece (10), move the surface of the test piece (10): = reading head (The objective lens on the focusing plane constitutes a set: The displacement amount of the autofocus system 'test piece (10) is read by a capacitive displacement sensor (9 6) on a 2-axis piezoelectric type ^. The wafer stepper designed by the creative consists of three subsystems. The X-axis and Z-axis friction drive platforms (7, 8), the ζ-axis piezoelectric platform (9), and: The functions of the chip stepper can be pinched together after the system is integrated. The integrated architecture is shown in Figure 9 and the &

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552613

Two closed-loop control systems are vertical optical automatic systems ’and one is a horizontal two-dimensional positioning control system. A focus positioning control system. Another 8>, horizontal two-dimensional positioning control system including X, Y-axis friction drive platform (7, f optical encoder (5), analog to digital / digital to analog (⑽ / 程 十 t personal computer and power amplifier And other components. Written by a personal computer and control the waveform, amplitude, and frequency of the output voltage through the DA card. This round of input signal is amplified by the power amplifier and input into the piezoelectric actuator 0 2), The X and γ-axis friction drive platforms (7, 8) will achieve stepping displacements according to the principle of two forces. The linear optical encoder (5) installed on the χ and γ-axis friction drive platforms (7,) can measure the platform at X The direction and γ = li 'are transmitted to the personal computer in the form of digital data, and the next input signal is determined by the numerical operation and logical judgment of the program. This closed-loop control can accurately achieve the X and γ axis friction drive platform (7, 8) Two-dimensional (2-position target. Straight-line optical auto-focus positioning control system includes Z-axis piezoelectric stage (9), laser light reading head (11), focus error signal processing circuit (84), Differential controller (PID), or pseudo-differential controller PDF) Analog linear control | device (85) and power amplifier (81) and other components. The laser zero light source of the laser light reading head (11) hits the surface of the test piece (10), and the reflected light returned by the optical head Received by the light sensor, through the signal processing of the focus error signal processing circuit (8 4), it can be known whether the surface of the test piece (10) is in the focus position. This signal is input to the differential controller (PID) or pseudo-differential controller. (PDF) Analog Linear Control Circuit

552613 V. Creative Instructions (19) In the road, 'The voltage is amplified by the power amplifier and input into the piezoelectric actuator (91)'. The test piece (1〇) is made by the movement of the Z-axis piezoelectric platform (9). The surface is always in focus, which constitutes a complete closed-loop control system. Capacitive displacement sensor (96) built in Z-axis piezoelectric platform (9) can measure the displacement of the displacement working platform (94) during focusing movement. This displacement measurement is analogous to voltage. The signal is digitally transmitted back to the personal computer through the conversion of the AD card, and the displacement value is recorded.

When used as a wafer stepper for deep ultraviolet optical lithography (DUV Lithography), in order to match the alignment of Wafer and Mask and multiple repeated exposures, it is used as a repeating step projection (Step —Repeat PrOje ( ? ti〇n) * Use of Step-Scan Projection, X, γ axis rubbing

The planar positioning capability of the wiper driving platform (7, 8) can be used as a wafer stepper with excellent performance. As Excimer Laser focuses on the photoresist layer on the wafer surface, the working range is only 丨 # m, but X, The γ-axis friction drive platform (7, 8) does not guarantee that the displacement of the wafer in 2 directions will be less than 1 # π when the distance is long. Therefore, the Z-axis piezoelectric platform (9) and the laser light reading head (Π The optical autofocus system formed by) can precisely locate the photoresist layer on the surface of the wafer within the working range of Excimer Laser for a long time. ^ Experimental results:

Page 23 552613 V. Creation Instructions (20) ---- Using a precision capacitive micrometer as the χ and γ axis friction drive platform (7, H 彳 position = measuring tool, when the pulse waveform is input to the Υ, Υ friction The displacement response of the drive port is shown in Figure 10. The upper half of the figure is the pulse voltage waveform of the wheel in, and the lower half is the step displacement curve of the platform. The single step of the platform can be observed from the figure. The displacement is 25nm, and its step displacement is equivalent to -I. It can be seen that the repeatability of each step of the platform is relatively high, so it can be predicted that the displacement performance of the platform is very good. From the experimental results, the resolution of the southernmost displacement is 7.5 nm. If the voltage signals of the χ and γ-axis friction drive platforms & 8) are sawtooth waveforms, the displacement curve of the platform is shown in Figure 11, and the upper part of the graph is the sawtooth waveform voltage input. The half is the step displacement curve of the platform, and the single-step step displacement is 100. Figure 12 shows the displacement response (bottom half of the graph) measured by inputting the z-axis piezoelectric platform (9) with the step voltage waveform (top half of the graph), and measured by a capacitive displacement sensor (96). The displacement of the displacement working platform (94), its displacement curve is 12 nm / step. It can be seen from the figure that the displacement working platform (the displacement curve of 94 ^ has almost no backlash, so the platform has excellent displacement performance in the open-loop positioning control. To achieve a higher displacement resolution, = The experimental environment and the interference of electronic signals must be controlled more strictly. From the experimental measurement results, it is known that the maximum displacement resolution of the Z-axis piezoelectric platform is 3 nm / step ° in the wafer grating (Grati stepper's In the verification of the working performance, a test piece with a period of 2 (ng) was used as the test optical autofocus system and the χ and γ axes.

Page 24 552613 V. Creative Note (21) Performance of Friction Driven Platform u, 8). : When the stage (7) is performing stepwise displacement, the displacement of the X-axis friction-driven flat-electric platform (9) in the optical diagram of the ellipse is not affected by: It is exactly 2 p, and the depth of the circumference of the displacement curve is the same as that of the horizontal displacement curve. The film is straight; \ degree ^ dagger and G are called test coupons. The working performance of the day-to-day film stepper has been verified in this case. Resolution ceramics have been designed, and the feedback is best on the disc used for feedback. The design of the previous stepper stepper is used as a feedback for this design. There are many, but the performance of the wafer is continuously encoded. The XY axis is stored in degree (Z axis). The high-level device is a multi-layer type, which is easy to control. The effect of focusing is on the sensing laser light. The linear optical method generated by the platform is used to perform the positioning capability and the single-free piezoelectric platform used in the f auto-focusing mechanism. Because of the piezoelectric actuation, it has a small volume, fast response, and the lowest temperature rise. After being controlled by its own material hysteresis, it can achieve excellent improvement. The laser read head of the automatic machine directly projects the adjustment of the equal distance between the He-N〆 wafer and the light source, which is superior. In this case, the transmission mechanism phenomenon (Stick-SI ip Ef fect) on the χγ axis makes the work displacement, and installs an ultra-high-resolution displacement sensor on the platform, and uses computer programs to control the positioning control. The biggest feature of long stroke. The wafer stepper of this creation has not seen similar or similar products exposed to the world, so it meets the requirements for patent applications that are novel and practical. Apply for the application in accordance with the law, and ask your reviewing committee to review it and give you a sense of quasi-patent To

Page 25 552613 V. Creation Instructions (22). However, the above is only one of the preferred embodiments of this creation. Therefore, any equivalent structural changes applied to the description of this creation and the scope of patent application should be included in the scope of patent protection of this creation.

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Claims (1)

552613 MM 88112238 6. Scope of patent application a. Actuator-moving a flat platform; leaf spring fixed base; type roller sliding optical plummeting mechanism; etc .; one end of a cross-linear-friction seat actuator is connected to the motion platform. At the other end of the actuator, one end of the spring, the motion platform, the motion platform is connected to the moving flat friction mechanism, and the other end is connected, and the linear motion platform is the driving point). Fixed bottom movement, if it can, according to the system, the lapping blade and the quality optical ion friction actuator make the actuation force friction, movement, when the movement block connection < knitting device mounting mechanism connection The driving source uses the force quickly. When the motion is flat, the driving parameter is used to make the inertial action platform pass through the seat. This motion and this motion program are constantly rubbing. The principle is set to have a long stroke. There is a differential motion in high precision. The mass of the force block and the fixed bottom can be achieved by the cross-type rolling actuator. Line, that is, the platform, its linear light connection, the reciprocating roller table and the fixed and fixed bottom discontinuity point and the movement level is larger than the friction seat. The platform's single-stroke continuous motion encoder is connected to the mass block plate and leaf spring spring slide seat connected to the base, and the carriage is connected; (that is, the broken and broken platform all bears the most sliding friction guide of the interface, which becomes a length; Is the static friction and friction static at the stepwise displacement? There is no limit. Page 28 2002, 10 · 〇7 · 007 552613 —- ^ _ Case No. 88112238 _Year S Chromium _ VI. Patent Application Fan® Measure its position stroke; its main function is to achieve a straight line with long stroke and high displacement resolution The goal of step motion for the application of optically etched wafersZero 3. The wafer stepper according to the second item of the patent application, wherein the in-round waveform provided by the driving source has a differential discontinuity point (ie, a breakpoint), and the slopes on both sides of this point have extremely large slopes. The difference is that the platform has the movement with the maximum displacement at the point of the waveform. If you input the driving waveform in this way, you can achieve continuous step motion. For the input waveform, it can be selected from the pulse waveform (Impulse Waveform) and the transcendental function waveform (Transcendental Waveform) and Cycloidal Waveform. 4. The wafer stepper as described in the first item of the patent application, wherein the X-Y-axis friction drive stage is included, and the actuators included may be selected from the materials of electric power generation, and the magnetostrictive materials and Electromagnetic motors, shape memory alloys, and other actuators driven by light, electricity, heat, and magnetic energy ° 5. As described in the patent application for the first stepper of the wafer park, the Z-axis actuation platform includes: Actuator:-almost leaf spring; a displacement table; a fixed base; a capacitive position sensor, etc .; 552613 --- ~~ 12238 VI. Patent Application Fan t one side of the positive actuator is connected to the fixed base, the other end of the actuator is in position ^ connection, one end of the flat leaf spring is connected to the fixed base, "flat leaf spring The other end is connected to a displacement table. There is a capacitive displacement sensor inside the displacement 7 σ. When the actuator is driven, it provides displacement and force. The displacement generated is guided by the flat leaf spring to produce a displacement effect. Displacement of the workbench results in relative movement of the fixed base of the work platform, which is measured by a capacitive displacement sensor and controlled by closed-loop positioning via a linear analog controller. Machine, wherein the Z-axis actuation platform, the actuators included may be selected from piezoelectric materials, and magnetostrictive materials, electromagnetic motors, shape memory alloys, and other optical, electrical, thermal, and magnetic energy Actuator to achieve the purpose of high-precision home. As the first step of the patent application of the wafer stepper, the optical autofocus system, including : A laser light reading head: a focus error signal processing circuit; an analog controller, etc .; the laser light reading head contains laser light sources, objective lenses, polarizing beam splitters, chirps and other optical elements 4; using a laser light reading head The focus error signal in the linear range of the s-curve (Foous Error Signal) is processed by the focus error signal processing circuit as an error signal of the analog controller control loop to control the displacement of the Z-axis micro-positioning platform at the focal range of the laser light reading head. Page 30 2002.10.07. 009 552613 _ Case No. 88112238 Amendment VI. Within the scope of patent application 丨 Its function is to maintain the Z-axis platform moving chip within the optical focus working range. Page 31 2002.10.0Ϋ. 010