Tsinghua University

Beijing U-Precision Tech Co., Ltd.

Shanghai Micro Electronics Equipment Co., Ltd.

Jinchun Hu

Yu Zhu

Ming Lei Zhang

Kaiming Yang

Wensheng Yin

Dengfeng Xu

Rong Cheng

Haihua Mu

Leijie Wang

Li Tian

Zhao Liu

Xin Li

Guanghong Duan

Weinan Ye

Chuxiong Hu

Li Ni Zhang

Jin Zhang

Jingsong Wang

Fan Zhi

Yanpo Zhao

Huichao Qin

Longmin Chen

Hao Liu

Feng Liu

Ming Zhang

Jinsong Wang

Anlin Chen

Jitao Xu

Fuzhong Yang

Jing Wang

Yi Shan Jiang

Yan Xu

Jing Yan Ma

Guang Cheng Li

Yujie Li

Dongdong Yu

Jiankun Hao

Yuting Sun

Guofeng Ji

Shengwu Du

Enyao Shang

Rujin Han

Chang Tian

Yujing Song

Kai Liao

An exposure light beam phase measurement method for laser interference photolithography comprises: separating a measurement light from an exposure light beam and inputting light into a laser phase measurement interferometer to carry out phase measurement on the exposure light beam; inputting a reference light beam homologous with the exposure light beam into the laser phase measurement interferometer; processing the reference light beam to form an interference measurement optical signal; calculating to obtain the phase of the exposure light beam. A laser interference photolithography system using the method comprises a laser phase measurement interferometer, a controller and phase modulators, the laser phase measurement interferometer measures whether the phase of an exposure light beam drifts, the controller controls phase modulators to carry out phase modulation, to achieve locking of exposure stripe phase drift and manufacturing of a high-precision variable-period optical grating.

Exposure light beam phase measurement method in laser interference photolithography, and photolithography system

A high-resolution phase detection method and system based on a plane grating laser interferometer. The method uses a dual-frequency interferometer to measure the displacement, and the measurement signal processing comprises an integral part and a decimal portion, a phase equation set of a displacement measurement signal is constructed according to a measurement optical path principle of a heterodyne plane grating laser interferometer; a non-linear equation set for which the unknowns are instantaneous phase, interval phase and signal amplitude is established; and the equation sets above are solved by using the least squares method, so as to realize phase discrimination, thereby realizing precise displacement measurement. The method can solve the problems in the traditional time measurement-based phase detection technology, such as low measurement accuracy, and failing to satisfy small measuring range measurement. The measurement method can be applied to systems such as precision manufacturing equipment and lithography machine.

High-resolution phase detection method and system based on plane grating laser interferometer

A laser interference photolithography system, comprising a laser device, a first reflector, a grating beam-splitter, a second reflector, a first universal reflector, a first lens, a second universal reflector, a second lens, a beam splitting prism, a control module, an angle measurement module, a third lens and a substrate. The control module comprises a signal processing terminal, a controller, and a driver. The signal processing terminal is connected to the angle measurement module, the controller is connected to both the signal processing terminal and the driver, and the driver is connected to both the first universal reflector and the second universal reflector. The laser emits a laser light that is split into two beams of light by the system, and the two beams of light are focused on the substrate for exposure.

Laser interference photolithography system

Disclosed is a plane grating calibration system, comprising an optical subsystem, a frame, first vibration isolator, a vacuum chuck, a workpiece stage, second vibration isolator, a base platform and a controller; the optical subsystem is mounted on the frame, and the frame is isolated from vibration by the first vibration isolator; the vacuum chuck is rotatably mounted on the workpiece stage, the workpiece stage is positioned on the base platform, and the base platform is isolated from vibration by the second vibration isolator. A displacement interferometer is integrated into the optical subsystem, and the entire optical subsystem adopts a method of sharing a light source, thereby avoiding the problems of low wavelength precision and poor coherence of separate light sources.

Plane grating calibration system

A five-degree-of-freedom heterodyne grating interferometry system comprises: a single-frequency laser for emitting single-frequency laser light, the single-frequency laser light can be split into a reference light beam and a measurement light beam; an interferometer lens set and a measurement grating for converting the reference light and the measurement light into a reference interference signal and a measurement interference signal; and multiple optical fiber bundles respectively receiving the measurement interference signal and the reference interference signal, wherein each optical fiber bundle has multiple multi-mode optical fibers respectively receiving interference signals at different positions on the same plane. The system is not over-sensitive to the environment, is small and light, and is easy to arrange. Six-degree-of-freedom ultra-precision measurement can be achieved by arranging multiple five-degree-of-freedom interferometry systems and using redundant information, thereby meeting the needs of a lithography machine worktable for six-degree-of-freedom position and orientation measurement.

Five-degree-of-freedom heterodyne grating interferometry system

A two-degree-of-freedom heterodyne grating interferometry measurement system, comprising: a single-frequency laser device for emitting a single-frequency laser, and the single-frequency laser can be split into a beam of reference light and a beam of measurement light; an interferometer mirror group and a measurement grating for forming a reference interference signal and a measurement interference signal from the reference light and the measurement light; and a receiving optical fiber for receiving the reference interference signal and the measurement interference signal, wherein a core diameter of the receiving optical fiber is smaller than a width of an interference fringe of the reference interference signal and the measurement interference signal, so that the receiving optical fiber receives a part of the reference interference signal and the measurement interference signal. The measurement system has advantages of insensitivity to grating rotation angle error, small volume, light weight, and a facilitating arrangement.

Two-degree-of-freedom heterodyne grating interferometry measurement system

Provided is a method for calibrating an error of installation of an interferometer in a multi-axis laser displacement measurement system, including: adding one or more redundant interferometers in a laser interferometer displacement measurement system; then establishing displacement calculating equations containing installation error of the laser interferometer and obtaining redundant measurement information by continuously measuring displacement information of multiple points, wherein the number of the combined displacement calculating equations is equal to the number of unknown quantities; and further solving the equation set to obtain the installation error of the interferometer. With a redundant arrangement of the laser interferometer, self-calibration of the installation error thereof can be achieved. A problem of difficulty in calibration of the installation error of the multi-axis interferometer in industrial application can be solved without assistance of other displacement sensors with higher precision.

Method for calibrating an error of installation of an interferometer in a multi-axis laser displacement measurement system

A magnetic levitation reaction sphere includes a spherical-housing-shaped rotor and three groups of stators. Each group includes two stators using the sphere center of the rotor as a symcenter. Axes of the three groups are mutually orthogonal. Each stator comprises a stator core and a coil array. An air gap is reserved between an inner surface of each stator core and the outer surface of the rotor. Through grooves are radially formed in the stator cores. The coil arrays are disc-type motor stator windings. Two effective sides of each coil in each coil array are respectively placed in two through grooves of the corresponding stator core. The magnetic levitation reaction sphere has low cost; levitation and rotation driving are integrated; the magnetic levitation reaction sphere has a simple and compact structure, a small size and a low mass, and relates to inherent stable levitation; and the levitation control is simple.

Magnetic levitation reaction sphere

A six-degree-of-freedom displacement measurement method for an exposure region on a wafer stage, the wafer stage comprises a coil array and a movable platform. A planar grating is fixed below a permanent magnet array of the movable platform. A reading head is fixed in a gap of the coil array. A measurement region is formed on the planar grating by an incident measurement light beam of the reading head. The reading head measures the six-degree-of-freedom displacement of the measurement region, so that the six-degree-of-freedom displacement of the exposure region is obtained through calculation. In the method, the six-degree-of-freedom displacement of the exposure region at any time is measured; the measurement complexity is reduced and the measurement precision is improved, and especially, the six-degree-of-freedom displacement of the exposure region can be precisely measured at any time even if the movable platform has high flexibility.

Six-degree-of-freedom displacement measurement method for exposure region on silicon wafer stage

A coarse motion and fine motion integrated reticle stage driven by a planar motor comprises a movable platform () of the reticle stage, a balance mass (), a drive motor, a mask plate (), a base (), a vibration isolation system (), and a measuring system, wherein, the vibration isolation system is located between the balance mass and the base, and the mask plate is mounted on the movable platform. The drive motor of the movable platform is a moving-iron type planar motor (). The reticle stage can lower the design complexity of the drive motor of the movable platform. Compared with a linear motor, the planar motor can provide push forces in more directions, the number of motors is reduced, the structure of the movable platform is more compact, the inherent frequency and the control bandwidth of the movable platform are improved, and thus control precision is improved.

Coarse motion and fine motion integrated reticle stage driven by planar motor

A three-DOF (Degree of Freedom) heterodyne grating interferometer displacement measurement system comprises a dual-frequency laser, a grating interferometer, a measurement grating, receivers and an electronic signal processing component; the grating interferometer comprises a polarizing beam splitter, a reference grating and dioptric elements; the measurement system realizes displacement measurement on the basis of grating diffraction, the optical Doppler Effect and the optical beat frequency principle. Three linear displacements can be output by the system when the grating interferometer and the measurement grating perform a three-DOF linear relative motion. The measurement system can reach sub-nanometer and higher resolution and precision, and can simultaneously measure three linear displacements. The measurement system has the advantages of being environmentally insensitive, high in measurement precision, small in size, light in weight, and is capable of improving the overall performances of an ultra-precision stage of a lithography machine as a position measurement system for this stage.

Three-DOF heterodyne grating interferometer displacement measurement system

A dual-frequency grating interferometer displacement measurement system, comprises a dual-frequency laser, an interferometer, a measurement grating and an electronic signal processing component. The measurement system realizes displacement measurement based on grating diffraction, optical Doppler effect and optical beat frequency theory. Dual-frequency laser light is emitted from the dual-frequency laser and split into reference light and measurement light via a polarization spectroscope. The measurement light is incident to the measurement grating to generate positive and negative first-order diffraction. The diffraction light and the reference light form a beat frequency signal containing displacement information about two directions at a photo-detection unit, and linear displacement output is realized after signal processing. The measurement system can realize sub-nanometer and even higher resolution and accuracy, and is able to measure long horizontal displacement and vertical displacement at the same time.

Dual-frequency grating interferometer displacement measurement system

A displacement measurement system of heterodyne grating interferometer, comprises a reading head, a measurement grating and an electronic signal processing component. Laser light emitted from the laser tube is collimated, passes through the first polarization spectroscope, and then emits two light beams with an orthogonal polarization direction and an orthogonal propagation direction; the two light beams pass through two acousto-optic modulators and respectively generate two first-order diffraction light beams with different frequencies, which are later divided into reference light and measurement light; two parallel reference light beams form a beat frequency electric signal with positive and negative first-order diffraction measurement light respectively after passing through a measurement signal photo-electric conversion unit; the beat frequency signals are transmitted to the electronic signal processing component for signal processing, thus the output of linear displacement in two directions is realized.

Heterodyne grating interferometer displacement measurement system

An optical grating phase modulator for a laser interference photoetching system is composed of a substrate, an optical grating, an electric motor and an optical grating positioner. The optical grating, the electric motor and the optical grating positioner are all mounted on the substrate. The optical grating is circular or rectangular, and adopt transmission or reflection type optical grating. A light beam is incident on the optical grating and generates diffraction, and when the electric motor drives the optical grating to continuously move relative to the incident light beam, diffracted light will generate a frequency shift, thereby realizing the phase modulation of the light beam. The optical grating phase modulator has the advantages of high phase modulation speed, high regulation precision and wide regulation range, thereby improving the whole performance of an interference photoetching system.

Optical grating phase modulator for laser interference photoetching system

A magnetically suspended coarse motion and fine motion integrated reticle stage driven by a planar motor comprises a movable platform (), a balance mass (), a drive motor, a mask plate (), a base (), a vibration isolation system (), and a measuring system, wherein, the vibration isolation system is located between the balance mass and the base, and the mask plate is mounted on the movable platform. The drive motor of the movable platform is a moving-iron type planar motor (). The reticle stage can lower the design complexity of the drive motor of the movable platform. Compared with a linear motor, the planar motor can provide push forces in more directions, the number of motors is reduced, the structure of the movable platform is more compact, the inherent frequency and the control bandwidth of the movable platform are improved, and thus control precision is improved.

Magnetically suspended coarse motion and fine motion integrated reticle stage driven by planar motor

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Beijing, China

Jinchun Hu