# US 7,608,821 B2 · Substrate inspection apparatus, substrate inspection method and semiconductor device manufacturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,821 B2 - Document ID: US7608821B2 - Status: Granted - Kind: B2 - Application number: 11/698,132 - Filed: 2007-01-26 - Published: 2007-08-23 - Granted: 2009-10-27 - Earliest claimed: 2006-02-13 - Assignees: Kabushiki Kaisha Toshiba - Inventors: Ichirota Nagahama; Yuichiro Yamazaki; Atsushi Onishi - Web page: https://patentgrep.com/patent/US7608821B2 ## CPC - H01J 37/026: {Means for avoiding or neutralising unwanted electrical charges on tube components} - H01J 37/26: Electron or ion microscopes; Electron or ion diffraction tubes - H01J 2237/0044: of objects being observed or treated - H01J 2237/0048: Charging arrangements - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A substrate inspection apparatus includes: an electron gun which generates an electron beam to irradiate the electron beam to a substrate; an electron detection unit which detects at least one of a secondary electron, a reflection electron and a back scattering electron generated from a surface of the substrate by the irradiation of the electron beam to output signals constituting an image showing a state of the substrate surface; and a surface potential uniformizing unit which generates ions, and irradiates the ions to the substrate before the irradiation of the electron beam to uniformize a surface potential of the substrate. ## Claims ### Claim 1 A substrate inspection apparatus comprising: an electron gun which generates an electron beam to irradiate the electron beam to a substrate; an electron detection unit which detects at least one of a secondary electron, a reflection electron and a back scattering electron generated from a surface of the substrate by the irradiation of the electron beam to output signals constituting an image showing a state of the substrate surface; and a uniform surface potential creating unit which generates ions, and irradiates the ions to the substrate prior to the irradiation of the electron beam to create a uniform surface potential of the substrate: wherein the uniform surface potential creating unit is configured to form a first electric field to guide the ions to the substrate until the surface potential of the substrate becomes a first potential having a preset value and is configured to form a second electric field whose direction is opposite to that of the first electric field to turn back the irradiated ions from the substrate in replacement of the first electric field, when an absolute value of the surface potential of the substrate becomes congruent with or exceeds an absolute value of the first potential. ### Claim 2 (depends on 1) The substrate inspection apparatus according to claim 1, further comprising: a controller which sets a polarity of the ions and an arbitrary value of the surface potential of the substrate in accordance with a charged state of the substrate surface estimated due to the irradiation of the electron beam. ### Claim 3 (depends on 2) The substrate inspection apparatus according to claim 2, wherein the uniform surface potential creating unit includes: a first electrode configured to generate the ions by application of a second voltage whose absolute value is more than that of the first voltage to generate, the second voltage having the same polarity as the polarity of the ions; and a second electrode which is disposed between the first electrode and the substrate and which is configured to generate the first or second electric field by application of the first voltage and to allow the passage of the ions by the first or second electric field. ### Claim 4 (depends on 1) The substrate inspection apparatus according to claim 1, wherein the uniform surface potential creating unit generates the ions by a gaseous discharge. ### Claim 5 (depends on 4) The substrate inspection apparatus according to claim 4, wherein the uniform surface potential creating unit includes a gas introduction unit which introduces a gas, and a gas controller which controls components and flow volume of the gas. ### Claim 6 (depends on 1) The substrate inspection apparatus according to claim 1, wherein the electron detection unit has a detection surface which detects at least one of the secondary electron, the reflection electron and the back scattering electron; and the substrate inspection apparatus further comprises a projection optics which projects at least one of the secondary electron, the reflection electron and the back scattering electron to image the electron on the detection surface. ### Claim 7 A substrate inspection method comprising: generating an electron beam to irradiate the electron beam to a substrate; detecting at least one of a secondary electron, a reflection electron and a back scattering electron generated from a surface of the substrate by the irradiation of the electron beam in order to acquire signals constituting an image showing a state of the substrate surface; and creating a uniform surface potential of the substrate by generating ions and irradiating the ions to the substrate prior to the irradiation of the electron beam; wherein creating the uniform surface potential of the substrate comprises: forming a first electric field to guide the ions to the substrate until a value of the surface potential of the substrate becomes a preset value; and forming a second electric field whose direction is opposite to that of the first electric field to turn back the irradiated ions from the substrate in replacement of the first electric field, when an absolute value of the surface potential of the substrate becomes congruent with or exceeds an absolute value of the preset value. ### Claim 8 (depends on 7) The substrate inspection method according to claim 7, further comprising: estimating a state in which the substrate surface is charged due to the irradiation of the electron beam; and setting a polarity of the ions and an arbitrary value of the surface potential of the substrate in accordance with the estimated charged state. ### Claim 9 (depends on 7) The substrate inspection method according to claim 7, wherein the ions are generated by a gaseous discharge. ### Claim 10 (depends on 9) The substrate inspection method according to claim 9, wherein the ions are generated by use of dehydrated air. ### Claim 11 (depends on 7) The substrate inspection method according to claim 7, further comprising: projecting at least one of the secondary electron, the reflection electron and the back scattering electron as a secondary beam, and imaging the secondary beam at a position where at least one of the secondary electron, the reflection electron and the back scattering electron is detected. ### Claim 12 A semiconductor device manufacturing method comprising implementing a manufacturing process onto a substrate which is passed through inspection by a substrate inspection method, the substrate inspection method comprising: generating an electron beam to irradiate the electron beam to a substrate; detecting at least one of a secondary electron, a reflection electron and a back scattering electron generated from the surface of the substrate by the irradiation of the electron beam in order to acquire signals constituting an image showing a state of the substrate surface; and creating a uniform surface potential of the substrate by generating ions and irradiating the ions to the substrate prior to the irradiation of the electron beam; wherein creating the uniform surface potential of the substrate comprises: forming a first electric field to guide the ions to the substrate until a value of the surface potential of the substrate becomes a preset value; and forming a second electric field whose direction is opposite to that of the first electric field to turn back the irradiated ions from the substrate, in replacement of the first electric field, when an absolute value of the surface potential of the substrate becomes congruent with or exceeds an absolute value of the preset value. ### Claim 13 (depends on 12) The semiconductor device manufacturing method according to claim 12, wherein the substrate inspection method further includes estimating a state in which the substrate surface is charged due to the irradiation of the electron beam; and setting a polarity of the ions and an arbitrary value of the surface potential of the substrate in accordance with the estimated charged state. ### Claim 14 (depends on 12) The semiconductor device manufacturing method according to claim 12, wherein the ions are generated by a gaseous discharge. ### Claim 15 (depends on 14) The semiconductor device manufacturing method according to claim 14, wherein the ions are generated by use of dehydrated air. ### Claim 16 (depends on 12) The semiconductor device manufacturing method according to claim 12, wherein the substrate inspection method further includes projecting at least one of the secondary electron, the reflection electron and the back scattering electron as a secondary beam, and imaging the secondary beam at a position where at least one of the secondary electron, the reflection electron and the back scattering electron is detected.