Design of the ultraprecision stage for lithography using VCM

Jung-Han Kim; Mun-Su Kim; Min-Taek Oh

doi:10.1117/12.784429

9 January 2008 Design of the ultraprecision stage for lithography using VCM

Jung-Han Kim, Mun-Su Kim, Min-Taek Oh

Proceedings Volume 6794, ICMIT 2007: Mechatronics, MEMS, and Smart Materials; 67941P (2008) https://doi.org/10.1117/12.784429
Event: ICMIT 2007: Mechatronics, MEMS, and Smart Materials, 2007, Gifu, Japan

Abstract

This paper presents a new design of precision stage for the reticle in lithography process and a low hunting control method for the stage. The stage has three axes for X,Y, θ_Z, those actuated by three voice coil motors individually. The proposed precision stage system has three gap sensors and voice coil motors, and supported by four air bearings, so it do not have any mechanical contact and nonlinear effect such as hysterisis which usually degrade performance in nano level movement. The reticle stage has cross coupled dynamics between X,Y,θ_Z, axes, so the forward and inverse kinematics were solved to get an accurate reference position. When the stage is in regulating control mode, there always exist small fluctuations (stage hunting) in the stage movement. Because the low stage hunting characteristic is very important in recent lithography and nano-level applications, the proposed stage has a special regulating controller composed of digital filter, adjustor and switching algorithm. Another importance factor that generates hunting noise is the system noise inside the lithography machine such as EMI from another motor and solenoids. For reducing such system noises, the proposed controller has a two-port transmission system that transfers torque command signal from the DSP board to the amplifier. The low hunting control algorithm and two-port transmission system reduced hunting noise as 35nm(rms) when a conventional PID generates 77nm(rms) in the same mechanical system. The experimental results showed that the reticle system has 100nm linear accuracy and 1μ rad rotation accuracy at the control frequency of 8 kHz.

Citation Download Citation

Jung-Han Kim, Mun-Su Kim, and Min-Taek Oh "Design of the ultraprecision stage for lithography using VCM", Proc. SPIE 6794, ICMIT 2007: Mechatronics, MEMS, and Smart Materials, 67941P (9 January 2008); https://doi.org/10.1117/12.784429

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available