Acta Optica Sinica, Volume. 35, Issue 10, 1011003(2015)
Compensation Method of Thermal Aberration for On-Axis Two-Mirror High NA lithographic Lens
Thermal aberration is one of the main reasons for imaging quality degradation of lithographic lens in working status. According to the structure feature of on-axis two-mirror high numerical aperture (NA)lithographic lens, a combination of element position shift and district heating method is proposed to compensate thermal aberration. The element position shift method takes advantage of element space, decentration and tilt to adjust the imaging quality; the district heating method takes advantage of the feature that the refractive index of optical material changes along with the temperature to control the temperature distribution on the lens and generate a controllable wavefront. The thermal aberration under dipole illumination model is compensated by the proposed method, and the wavefront aberration and distortion are recovered from 129.78 nm and 12.24 nm to 1.69 nm and 1.31 nm, respectively. The proposed method can basically recover the imaging quality of lens to design level.
Get Citation
Copy Citation Text
Xu Xiangru, Huang Wei, Jia Shuqiang, Xu Mingfei. Compensation Method of Thermal Aberration for On-Axis Two-Mirror High NA lithographic Lens[J]. Acta Optica Sinica, 2015, 35(10): 1011003
Category: Reviews
Received: Apr. 20, 2015
Accepted: --
Published Online: Oct. 8, 2015
The Author Email: Xiangru Xu (xuxiangru@foxmail.com)