公开(公告)号：US20210389643A1

公开(公告)日：2021-12-16

申请号：US17239561

申请日：2021-04-24

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-li ,  Elena Loginova ,  John Fielden ,  Baigang Zhang

IPC: G02F1/355 ,  G02F1/35

Abstract: A nonlinear crystal including stacked Strontium tetraborate SrB4O7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency converting stage of a laser assembly to generate laser output light having a wavelength in the range of 125 nm to 183 nm. One or more fundamental light beams having fundamental wavelengths between 1 and 1.1 μm are doubled and/or summed using multiple intermediate frequency conversion stages to generate one or more intermediate light beam frequencies (e.g., second through eighth harmonics, or sums thereof), and then the final frequency converting stage utilizes the nonlinear crystal to either double a single intermediate light beam frequency or to sum two intermediate light beam frequencies to generate the desired laser output light at high power and photon energy levels. A method and inspection system incorporating the laser assembly is also described.

公开(公告)号：US11237455B2

公开(公告)日：2022-02-01

申请号：US17239561

申请日：2021-04-24

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-li ,  Elena Loginova ,  John Fielden ,  Baigang Zhang

IPC: G02F1/355 ,  G02F1/35

Abstract: A nonlinear crystal including stacked Strontium tetraborate SrB4O7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency converting stage of a laser assembly to generate laser output light having a wavelength in the range of 125 nm to 183 nm. One or more fundamental light beams having fundamental wavelengths between 1 and 1.1 μm are doubled and/or summed using multiple intermediate frequency conversion stages to generate one or more intermediate light beam frequencies (e.g., second through eighth harmonics, or sums thereof), and then the final frequency converting stage utilizes the nonlinear crystal to either double a single intermediate light beam frequency or to sum two intermediate light beam frequencies to generate the desired laser output light at high power and photon energy levels. A method and inspection system incorporating the laser assembly is also described.