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：US11114491B2

公开(公告)日：2021-09-07

申请号：US16562396

申请日：2019-09-05

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Jehn-Huar Chern ,  John Fielden ,  Jingjing Zhang ,  David L. Brown ,  Sisir Yalamanchili

IPC: H01L27/146 ,  H01L27/148

Abstract: An image sensor utilizes a pure boron layer and a second epitaxial layer having a p-type dopant concentration gradient to enhance sensing DUV, VUV or EUV radiation. Sensing (circuit) elements and associated metal interconnects are fabricated on an upper surface of a first epitaxial layer, then the second epitaxial layer is formed on a lower surface of the first epitaxial layer, and then a pure boron layer is formed on the second epitaxial layer. The p-type dopant concentration gradient is generated by systematically increasing a concentration of p-type dopant in the gas used during deposition/growth of the second epitaxial layer such that a lowest p-type dopant concentration of the second epitaxial layer occurs immediately adjacent to the interface with the first epitaxial layer, and such that a highest p-type dopant concentration of the second epitaxial layer occurs immediately adjacent to the interface with pure boron layer.

公开(公告)号：US11011366B2

公开(公告)日：2021-05-18

申请号：US16879310

申请日：2020-05-20

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-Li ,  Edgardo Garcia-Berrios ,  John Fielden

IPC: H01J61/067 ,  G01N21/88 ,  H01J61/10 ,  G01N21/95

Abstract: A broadband ultraviolet illumination source for a characterization system is disclosed. The broadband ultraviolet illumination source includes an enclosure having one or more walls, the enclosure configured to contain a gas, and a plasma discharge device based on a graphene-dielectric-semiconductor (GOS) planar-type structure. The GOS structure includes a silicon substrate having a top surface, a dielectric layer disposed on the top surface of the silicon substrate, and at least one layer of graphene disposed on a top surface of the dielectric layer. A metal contact may be formed on the top surface of the graphene layer. The GOS structure has several advantages for use in an illumination source, such as low operating voltage (below 50 V), planar surface electron emission, and compatibility with standard semiconductor processes. The broadband ultraviolet illumination source further includes electrodes placed inside the enclosure or magnets placed outside the enclosure to increase the current density.

公开(公告)号：US10948423B2

公开(公告)日：2021-03-16

申请号：US16577326

申请日：2019-09-20

Applicant: KLA Corporation

Inventor： Xuefeng Liu ,  Jenn-Kuen Leong ,  Daniel Kavaldjiev ,  John Fielden

IPC: G01N21/95 ,  H01L21/66 ,  G01N21/21 ,  G01N21/956 ,  G01N21/88

Abstract: A dark-field inspection system may include an illumination source to generate an illumination beam, illumination optics configured to direct the illumination beam to a sample at an off-axis angle along an illumination direction, collection optics to collect scattered light from the sample in response to the illumination beam in a dark-field mode, a polarization rotator located at a pupil plane of the one or more collection optics, where the polarization rotator provides a spatially-varying polarization rotation angle selected to rotate light scattered from a surface of the sample to a selected polarization angle, a polarizer aligned to reject light polarized along the selected polarization angle to reject the light scattered from a surface of the sample, and a detector to generate a dark-field image of the sample based on scattered light from the sample passed by the polarizer.

公开(公告)号：US10921261B2

公开(公告)日：2021-02-16

申请号：US16819991

申请日：2020-03-16

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-Li ,  Elena Loginova ,  John Fielden

IPC: G03F1/36 ,  G03F7/20 ,  G01N21/95 ,  G02F1/35 ,  G02F1/355 ,  G02B21/00 ,  G02B5/28 ,  G02B21/06 ,  G01N21/33 ,  G02B21/16 ,  H01L21/66

Abstract: Strontium tetraborate is used as an optical coating material for optical components utilized in semiconductor inspection and metrology systems to take advantage of its high refractive indices, high optical damage threshold and high microhardness in comparison to conventional optical materials. At least one layer of strontium tetraborate is formed on the light receiving surface of an optical component's substrate such that its thickness serves to increase or decrease the reflectance of the optical component. One or multiple additional coating layers may be placed on top of or below the strontium tetraborate layer, with the additional coating layers consisting of conventional optical materials. The thicknesses of the additional layers may be selected to achieve a desired reflectance of the optical component at specific wavelengths. The coated optical component is used in an illumination source or optical system utilized in a semiconductor inspection system, a metrology system or a lithography system.

公开(公告)号：US20200264109A1

公开(公告)日：2020-08-20

申请号：US16577326

申请日：2019-09-20

Applicant: KLA Corporation

Inventor： Xuefeng Liu ,  Jenn-Kuen Leong ,  Daniel Kavaldjiev ,  John Fielden

IPC: G01N21/95 ,  G01N21/956 ,  G01N21/21 ,  H01L21/66

Abstract: A dark-field inspection system may include an illumination source to generate an illumination beam, illumination optics configured to direct the illumination beam to a sample at an off-axis angle along an illumination direction, collection optics to collect scattered light from the sample in response to the illumination beam in a dark-field mode, a polarization rotator located at a pupil plane of the one or more collection optics, where the polarization rotator provides a spatially-varying polarization rotation angle selected to rotate light scattered from a surface of the sample to a selected polarization angle, a polarizer aligned to reject light polarized along the selected polarization angle to reject the light scattered from a surface of the sample, and a detector to generate a dark-field image of the sample based on scattered light from the sample passed by the polarizer.

公开(公告)号：US20240250110A1

公开(公告)日：2024-07-25

申请号：US18404530

申请日：2024-01-04

Applicant: KLA Corporation

Inventor： Abbas Haddadi ,  Devis Contarato ,  John Fielden ,  Yung-Ho Alex Chuang

IPC: H01L27/148

CPC classification number: H01L27/14856

Abstract: Image sensors with a tunable floating diffusion (FD) structure for applications such as inspection and metrology are provided. One image sensor includes a sensing node electrically connected to circuits of the image sensor, formed on a first side of a silicon layer adjacent to the circuits, and formed by a Voltage-Controlled Variable Floating Diffusion (VCVFD) structure. The VCVFD structure includes a gate electrode configured to control a variable capacitance of the VCVFD structure via voltage applied to the gate electrode by an electrical connection to the gate electrode. The VCVFD structure converts a charge responsive to electron accumulation in the channel of the circuits to a voltage proportional to an amount of the charge and dependent on the variable capacitance. The VCVFD may also be implemented in an electron-sensor pixel configured for detecting electrons or x-rays as described further herein.

公开(公告)号：US20240063248A1

公开(公告)日：2024-02-22

申请号：US18502059

申请日：2023-11-05

Applicant: KLA Corporation

Inventor： Abbas Haddadi ,  Sisir Yalamanchili ,  John Fielden ,  Yung-Ho Alex Chuang

IPC: H01L27/146 ,  H01L27/148

CPC classification number: H01L27/14687 ,  H01L27/1464 ,  H01L27/14806

Abstract: An image sensor is fabricated by first heavily p-type doping the thin top monocrystalline silicon substrate of an SOI wafer, then forming a relatively lightly p-doped epitaxial layer on a top surface of the top silicon substrate, where p-type doping levels during these two processes are controlled to produce a p-type dopant concentration gradient in the top silicon substrate. Sensing (circuit) elements and associated metal interconnects are fabricated on the epitaxial layer, then the handling substrate and oxide layer of the SOI wafer are at least partially removed to expose a lower surface of either the top silicon substrate or the epitaxial layer, and then a pure boron layer is formed on the exposed lower surface. The p-type dopant concentration gradient monotonically decreases from a maximum level near the top-silicon/epitaxial-layer interface to a minimum concentration level at the epitaxial layer's upper surface.

公开(公告)号：US11815784B2

公开(公告)日：2023-11-14

申请号：US18087236

申请日：2022-12-22

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-Li ,  Elena Loginova ,  John Fielden ,  Baigang Zhang ,  Xuefeng Liu ,  Kelly Ann Weekley Mauser

IPC: G02F1/35 ,  G02F1/355

CPC classification number: G02F1/354 ,  G02F1/3503 ,  G02F1/3507 ,  G02F1/3548 ,  G02F1/3551

Abstract: A nonlinear crystal grating assembly including two integral nonlinear crystal grating structures having inverted crystal axes and having parallel spaced-apart mesas with predetermined mesa widths arranged such that, when assembled in an interdigitated configuration, the mesas of the two grating structures form an alternating grating pattern that is aligned with a propagation direction of input light, thereby creating a periodic structure for quasi-phase-matching (QPM). The nonlinear crystal grating structures are formed using strontium tetraborate, lithium triborate or another nonlinear crystal material. The nonlinear crystal grating assembly is utilized in a laser assembly in which fundamental wavelengths are doubled and/or summed using intermediate frequency conversion stages, and then a final frequency converting stage utilizes the nonlinear crystal grating assembly to double or sum one or more intermediate light beam frequencies to generate laser output light at high power and photon energy levels. A method and inspection system are also described.

公开(公告)号：US11567391B1

公开(公告)日：2023-01-31

申请号：US17555404

申请日：2021-12-18

Applicant: KLA Corporation

Inventor： Yung-Ho Alex Chuang ,  Yinying Xiao-Li ,  Elena Loginova ,  John Fielden ,  Baigang Zhang ,  Xuefeng Liu ,  Kelly Ann Weekley Mauser

IPC: G02F1/35 ,  G02F1/355

Abstract: A nonlinear crystal grating assembly including two integral nonlinear crystal grating structures having inverted crystal axes and having parallel spaced-apart mesas with predetermined mesa widths arranged such that, when assembled in an interdigitated configuration, the mesas of the two grating structures form an alternating grating pattern that is aligned with a propagation direction of input light, thereby creating a periodic structure for quasi-phase-matching (QPM). The nonlinear crystal grating structures are formed using strontium tetraborate, lithium triborate or another nonlinear crystal material. The nonlinear crystal grating assembly is utilized in a laser assembly in which fundamental wavelengths are doubled and/or summed using intermediate frequency conversion stages, and then a final frequency converting stage utilizes the nonlinear crystal grating assembly to double or sum one or more intermediate light beam frequencies to generate laser output light at high power and photon energy levels. A method and inspection system are also described.