Tsinghua University

Beijing U-precision Tech Co., Ltd.

Other

Wuxi Hisky Medical Technologies Co., Ltd.

Leijie Wang

Yu Zhu

Rong Cheng

Ming Lei Zhang

Jinchun Hu

Kaiming Yang

Xin Li

Weinan Ye

Wensheng Yin

Dengfeng Xu

Ming Zhang

Haihua Mu

Fuzhong Yang

Jitao Xu

Zhao Liu

Longmin Chen

Jiankun Hao

Li Ni Zhang

Jin Zhang

Li Tian

Jin Sun

Jinhua Shao

Houli Duan

Chuxiong Hu

Yanpo Zhao

Huichao Qin

Zhaokui Cheng

Siqi Gao

Yizhou Xia

Mingjie Yao

Fengmin Lu

Ziwen Guo

Yuezhu Yang

Yujiao Fan

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 device and a method for regulating and controlling an incident angle of a light beam in a laser interference lithography process are disclosed. The device comprises: a beam splitter prism between a first lens and a second lens, a first position detector, a first decoupling lens between the first position detector and the beam splitter prism, a feedback control system connected to the first position detector and a first universal reflecting mirror. The beam splitter prism reflects first incident light passing through the first universal reflecting mirror, the first decoupling lens enables a first reflected light enter into the first position detector, the first position detector measures the light beam position, the feedback control system outputs a control command according to the measurement result to regulate a mirror base of the first universal reflecting mirror, thereby regulating and controlling an incident angle of an exposure light beam.

Device and method for regulating and controlling incident angle of light beam in laser interference lithography

Disclosed is a heterodyne grating interferometry system based on secondary diffraction, including a single-frequency laser, an input optical fiber, an acousto-optic modulator, a reading head, and a measurement grating, an output optical fiber, a photoelectric conversion unit and an electronic signal processing unit, wherein the single-frequency laser emits a single-frequency laser, which enters the acousto-optic modulator through the input optical fiber, and is divided into a reference light and measurement light to be input to the reading head, wherein the reading head and the measurement grating convert the reference light and measurement light into a reference interference optical signal and a measurement interference optical signal and send them to the photoelectric conversion unit through the output optical fiber and wherein the photoelectric conversion unit converts the measurement interference optical signal and the reference interference optical signal into a measurement interference electrical signal and a reference interference electrical signal.

Heterodyne grating interferometry system based on secondary diffraction

Disclosed is a scanning interference photolithography system, comprising a heterodyne optical path, a first interference optical path, a second interference optical path, a motion platform and a control subsystem, wherein a substrate is carried on the motion platform, a displacement measurement interferometer is used to measure the displacement of the motion platform, a first light beam and a second light beam are focused on the substrate for interference exposure; the control subsystem generates instructions according to various measurement information, adjusts angles of corresponding devices or the phase of a light beam, and locks the phase shift of interference exposure fringes of the first light beam and the second light beam. The system has a high precision of fringe pattern locking and a high laser utilization rate, and can be used for producing a large-area high-precision dense grating line gradient periodic grating.

Scanning interference lithographic system

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 method and device for detecting inflammation activity of a tissue. The method includes: determining whether there is a possibility for tissue inflammation; and when there is a possibility for tissue inflammation, determining the inflammation activity of a tissue according to tissue stiffness or a parameter reflecting tissue stiffness. The tissue stiffness or the parameter reflecting tissue stiffness can be detected by means of a non-invasive quantitative detection technique of tissue elastic modulus, avoiding defects caused by tissue biopsy, and can detect inflammation activity of a tissue non-invasively, continuously and accurately.

Method and device for detecting inflammation activity of tissue

A five-degree-of-freedom heterodyne grating interferometry system, comprising a single frequency laser device () and an acousto-optic modulator (); the single frequency laser device () emits a single frequency laser, and the single frequency laser is coupled by optical fiber and, after being split, enters the acousto-optic modulator () to obtain two linearly polarized lights of different frequencies, one being a reference light, and one being a measurement light; an interferometer lens group () and a measurement grating (), used for forming the reference light and the measurement light into a measurement interference signal and a compensation interference signal; and multiple optical fiber bundles (), respectively receiving the measurement interference signal and the compensation interference signal, each optical fiber bundle () having multiple multimode optical fibers respectively receiving signals at different positions on the same plane. The present measurement system has the advantages of high measurement precision, a large measurement range, not being sensitive to temperature drift, and small overall size, and can be used as a photoetching machine ultra-precision workpiece table position measurement 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

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.

Growing community of inventors

Beijing, China

Leijie Wang