Patents by Inventor Zhaohui Cheng

Zhaohui Cheng has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8309923
    Abstract: Provided is a sample observing method wherein the effect on throughput is minimized, and a pattern profile can be obtained at high accuracy even in a complicated LSI pattern, regardless of the scanning direction of an electron beam. In the sample observing method, the presence or absence of an edge parallel to a scanning direction (707) of an electron beam is judged regarding an edge (708) of a pattern to be observed (S702); if the edge is present, an area in the vicinity of the pattern edge is designated as a local pre-dose area (709) (S703); a local pre-dose of an electron beam is performed, so that the initial charged state is controlled not to return secondary electrons generated by irradiation of an electron beam when an image is captured, to the surface of a sample.
    Type: Grant
    Filed: February 9, 2010
    Date of Patent: November 13, 2012
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Seiko Omori, Zhaohui Cheng, Hideyuki Kazumi
  • Patent number: 8207513
    Abstract: A charged particle beam apparatus is provided which has high resolving power and a wide scanning region (observation field of view). The apparatus has a unit for adjusting the focus, a unit for adjusting astigmatism, a unit for controlling and detecting scanning positions and a controller operative to control the focus adjustment and astigmatism adjustment at a time in interlocked relation to the scanning positions, thereby assuring compatibility between the high resolving power and the observation view field of a wide area.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: June 26, 2012
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yuko Sasaki, Yasuhiro Gunji, Zhaohui Cheng
  • Publication number: 20120153145
    Abstract: A scanning electron microscope of the present invention performs scanning by changing a scanning line density in accordance with a sample when an image of a scanned region is formed by scanning a two-dimensional region on the sample with an electron beam or is provided with a GUI having sample information input means which inputs information relating to the sample and display means which displays a recommended scanning condition according to the input and performs scanning with a scanning line density according to the sample by selecting the recommended scanning condition. As a result, in observation using a scanning electron microscope, a suitable scanning device which can improve contrast of a profile of a two-dimensional pattern and suppress shading by suppressing the influence of charging caused by primary charged particle radiation and by improving a detection rate of secondary electrons and a scanning method are provided.
    Type: Application
    Filed: July 30, 2010
    Publication date: June 21, 2012
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Zhaohui Cheng, Hikaru Koyama, Yoshinobu Kimura, Hiroyuki Shinada, Osamu Komuro
  • Publication number: 20110303843
    Abstract: Provided is a sample observing method wherein the effect on throughput is minimized, and a pattern profile can be obtained at high accuracy even in a complicated LSI pattern, regardless of the scanning direction of an electron beam. In the sample observing method, the presence or absence of an edge parallel to a scanning direction (707) of an electron beam is judged regarding an edge (708) of a pattern to be observed (S702); if the edge is present, an area in the vicinity of the pattern edge is designated as a local pre-dose area (709) (S703); a local pre-dose of an electron beam is performed, so that the initial charged state is controlled not to return secondary electrons generated by irradiation of an electron beam when an image is captured, to the surface of a sample.
    Type: Application
    Filed: February 9, 2010
    Publication date: December 15, 2011
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Seiko Omori, Zhaohui Cheng, Hideyuki Kazumi
  • Patent number: 7928384
    Abstract: A charged particle beam device including a function for measuring localized static charges on a sample. A primary charged particle beam scans a sample positioned in a mirror state to acquire an image. The acquired image may be an image of the sample or may be an image of a structural component in the charged particle optical system. The acquired image is compared with a standard sample image and the localized static charge is measured.
    Type: Grant
    Filed: August 12, 2008
    Date of Patent: April 19, 2011
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Zhaohui Cheng, Tasuku Yano, Seiko Omori
  • Patent number: 7910884
    Abstract: An electrification control electrode B is installed at a measured or inspected specimen side of an electrification control electrode A, and a constant voltage is applied from an electrification control electrode control portion of an electrification control electrode B according to an electrification state of a specimen, whereby a variation of an electrification state and a potential barrier of a specimen surface formed before an inspection is suppressed. A retarding potential is applied by an electrification control electrode, and the electrification control electrode B is disposed below the electrification control electrode A adjusted to equal potential to a specimen. As a result, it is possible to adjust the amount that secondary electrons emitted from a specimen such as a wafer to which a primary electron beam is irradiated return to a specimen, and thus it is possible to stably maintain an inspection condition of high sensitivity during an inspection.
    Type: Grant
    Filed: January 6, 2009
    Date of Patent: March 22, 2011
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Zhaohui Cheng, Natsuki Tsuno
  • Patent number: 7714288
    Abstract: Electrification affected on a surface of a sample which is caused by irradiation of a primary charged particle beam is prevented when plural frames are integrated to obtain an image of a predetermined area of the sample in a charged particle beam apparatus. The predetermined area of the sample is scanned with a primary electron beam from an electron gun, and plural frames are generated and integrated while detecting generated secondary electrons with a detector to obtain the image of the predetermined area. If it is determined by a detection signal of the detector that an electrification amount at the predetermined area becomes a specified value when generating plural frames, an electricity removal voltage is applied to a boosting electrode to remove or reduce the electrification, prior to generation of the next frame. Accordingly, the signal-to-noise ratio of the image obtained by integrating plural frames can be improved.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: May 11, 2010
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Tasuku Yano, Zhaohui Cheng, Takashi Furukawa, Osamu Nasu
  • Patent number: 7683319
    Abstract: The invention solves charge nonuniformity of a specimen surface resulting from emission variation of a carbon nanotube electron source and individual difference of emission characteristics. During charge control processing, charge of the specimen surface is measured in real time. As means for solving charge nonuniformity resulting from nonuniformity of electron illumination density, electrons illuminating the specimen and the specimen are moved relatively to average electron illumination density. Moreover, an absorption current flowing into the specimen and the numbers of secondary electrons emitted from the specimen and of backscattered electrons are measured as means for monitoring charge of the specimen surface in real time.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: March 23, 2010
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Hiroshi Makino, Zhaohui Cheng, Kenji Tanimoto, Hideo Todokoro
  • Publication number: 20100051806
    Abstract: A charged particle beam apparatus is provided which has high resolving power and a wide scanning region (observation field of view). The apparatus has a unit for adjusting the focus, a unit for adjusting astigmatism, a unit for controlling and detecting scanning positions and a controller operative to control the focus adjustment and astigmatism adjustment at a time in interlocked relation to the scanning positions, thereby assuring compatibility between the high resolving power and the observation view field of a wide area.
    Type: Application
    Filed: November 10, 2009
    Publication date: March 4, 2010
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Yuko Sasaki, Yasuhiro Gunji, Zhaohui Cheng
  • Patent number: 7655906
    Abstract: An inspection and measurement method and apparatus for semiconductor devices and patterns such as photomasks using an electron beam capable of measuring the potential of a sample with higher precision than conventional systems. When an S curve is observed in a semiconductor device to be inspected, fluctuations of the potential of the inspection sample surface are suppressed by optimizing the energy of a primary electron beam used for irradiation. When the surface potential of the semiconductor device is measured, a more precise measurement can be obtained without adverse effects from an insulation film surface. Further, the surface potential can be measured without installing a special apparatus for wafer surface potential measurement such as an energy filter, so the cost of the apparatus can be reduced.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: February 2, 2010
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Zhaohui Cheng, Hiroshi Makino, Hikaru Koyama, Mitsugu Sato
  • Patent number: 7652248
    Abstract: When performing an inspection using a charge control function in a SEM wafer inspection apparatus, acceleration voltage, control voltage and deceleration voltage are changed in conjunction so that incident energy determined by “acceleration voltage?deceleration voltage” and bias voltage determined by “deceleration voltage?control voltage” do not change. By this means, charge of a wafer can be controlled, while restraining electrostatic lens effect generated near a control electrode. As a result, an inspection using a charge control function at low incident energy and in a wide viewing field can be performed, and a highly sensitive inspection of semiconductor patterns subject to damages due to electron beam irradiation can be realized. Acceleration voltage, control voltage and deceleration voltage are changed in conjunction so that incident energy determined by “acceleration voltage?deceleration voltage” and bias voltage determined by “deceleration voltage?control voltage” do not change.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: January 26, 2010
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Hiroshi Makino, Kenji Tanimoto, Zhaohui Cheng, Hikaru Koyama
  • Patent number: 7633303
    Abstract: Efficiency of a charging processing of an insulator sample is improved. And, an electron optical system is adjusted according to a contact resistance value of the insulator sample. Breakdown of a sample is performed before the charging processing, and then, the charging processing is performed. A control parameter of the electron optical system is selected using a result of a resistance value of the sample for checking the breakdown.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: December 15, 2009
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Takashi Furukawa, Natsuki Tsuno, Zhaohui Cheng
  • Publication number: 20090179151
    Abstract: An electrification control electrode B is installed at a measured or inspected specimen side of an electrification control electrode A, and a constant voltage is applied from an electrification control electrode control portion of an electrification control electrode B according to an electrification state of a specimen, whereby a variation of an electrification state and a potential barrier of a specimen surface formed before an inspection is suppressed. A retarding potential is applied by an electrification control electrode, and the electrification control electrode B is disposed below the electrification control electrode A adjusted to equal potential to a specimen. As a result, it is possible to adjust the amount that secondary electrons emitted from a specimen such as a wafer to which a primary electron beam is irradiated return to a specimen, and thus it is possible to stably maintain an inspection condition of high sensitivity during an inspection.
    Type: Application
    Filed: January 6, 2009
    Publication date: July 16, 2009
    Inventors: Zhaohui CHENG, Natsuki TSUNO
  • Publication number: 20090166557
    Abstract: The invention solves charge nonuniformity of a specimen surface resulting from emission variation of a carbon nanotube electron source and individual difference of emission characteristics. During charge control processing, charge of the specimen surface is measured in real time. As means for solving charge nonuniformity resulting from nonuniformity of electron illumination density, electrons illuminating the specimen and the specimen are moved relatively to average electron illumination density. Moreover, an absorption current flowing into the specimen and the numbers of secondary electrons emitted from the specimen and of backscattered electrons are measured as means for monitoring charge of the specimen surface in real time.
    Type: Application
    Filed: January 25, 2006
    Publication date: July 2, 2009
    Inventors: Hiroshi Makino, Zhaohui Cheng, Kenji Tanimoto, Hideo Todokoro
  • Patent number: 7547884
    Abstract: In the present invention, the structure of an electrification control electrode is changed from a grid type to a slit type and thereby shadows are not formed when a wafer is irradiated with a beam. Further, a beam forming slit is disposed ahead of an electrification control slit, thus the electrification control slit is prevented from being irradiated with an electron beam for preliminary electrification, and thereby secondary electrons which disturb the control of the electrification are inhibited from being generated. The shape of the slit is designed so that the strength of an electron beam may gradually decrease toward both the ends of an electron beam irradiation region in the longitudinal direction thereof. Furthermore, a preliminary static eliminator to remove or reduce the unevenness in an electrification potential distribution which has undesirably been formed earlier is disposed.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: June 16, 2009
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Masaki Hasegawa, Hiroshi Makino, Hikaru Koyama, Zhaohui Cheng, Hisaya Murakoshi
  • Publication number: 20090057557
    Abstract: A charged particle beam device including a function for measuring localized static charges on a sample. A primary charged particle beam scans a sample positioned in a mirror state to acquire an image. The acquired image may be an image of the sample or may be an image of a structural component in the charged particle optical system. The acquired image is compared with a standard sample image and the localized static charge is measured.
    Type: Application
    Filed: August 12, 2008
    Publication date: March 5, 2009
    Inventors: Zhaohui Cheng, Tasuku Yano, Seiko Omori
  • Publication number: 20080277583
    Abstract: Electrification affected on a surface of a sample which is caused by irradiation of a primary charged particle beam is prevented when plural frames are integrated to obtain an image of a predetermined area of the sample in a charged particle beam apparatus. The predetermined area of the sample is scanned with a primary electron beam from an electron gun, and plural frames are generated and integrated while detecting generated secondary electrons with a detector to obtain the image of the predetermined area. If it is determined by a detection signal of the detector that an electrification amount at the predetermined area becomes a specified value when generating plural frames, an electricity removal voltage is applied to a boosting electrode to remove or reduce the electrification, prior to generation of the next frame. Accordingly, the signal-to-noise ratio of the image obtained by integrating plural frames can be improved.
    Type: Application
    Filed: April 29, 2008
    Publication date: November 13, 2008
    Inventors: Tasuku Yano, Zhaohui Cheng, Takashi Furukawa, Osamu Nasu
  • Publication number: 20080246497
    Abstract: Efficiency of a charging processing of an insulator sample is improved. And, an electron optical system is adjusted according to a contact resistance value of the insulator sample. Breakdown of a sample is performed before the charging processing, and then, the charging processing is performed. A control parameter of the electron optical system is selected using a result of a resistance value of the sample for checking the breakdown.
    Type: Application
    Filed: April 4, 2008
    Publication date: October 9, 2008
    Inventors: Takashi Furukawa, Natsuki Tsuno, Zhaohui Cheng
  • Patent number: 7394070
    Abstract: When the electrode potential of a charge control electrode above a wafer is reduced, image brightness is reduced. A point of change in the image brightness is a switching point between a positively charged state of the image and a negatively charged state of the image, showing the weakly charged state of the image. By setting this point of change as an inspecting condition, the amount of electric charges on the surface of the wafer can be reduced, and stable wafer inspection can be performed. It is estimated that an applied voltage V1 in FIG. 14 corresponds to the point of the change and is roughly included in the voltage range of a region enclosed by a broken line in the vicinity of the applied voltage V1. Within this voltage range, the influence of charge on an inspection under the inspecting condition can be reduced.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: July 1, 2008
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Mari Nozoe, Yasunori Goto, Zhaohui Cheng
  • Publication number: 20080017797
    Abstract: Pattern inspection and measurement technique where the failure of the detection of a secondary signal due to the variation of an optical condition of a primary electron beam or the occurrence of an electric field perpendicular to a traveling direction of the primary electron beam in a surface of a wafer is minimized, an SEM image the SN ratio of which is high and which hardly has shading in a field of view can be acquired and measurement such as measuring the dimensions and configuration of a measured object and inspecting a defect is enabled at high precision and high repeatability. A lens for converging a secondary signal is installed in a position which a traveling direction of the primary electron beam crosses or on a course of the secondary signal spatially separated from the primary electron beam by Wien filter.
    Type: Application
    Filed: July 17, 2007
    Publication date: January 24, 2008
    Inventors: Zhaohui CHENG, Hiroshi Makino, Kenji Tanimoto, Seiko Omori