# US 2013/0153147 A1 · Dechuck control method and plasma processing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153147 A1 - Document ID: US20130153147A1 - Status: Published application - Kind: A1 - Application number: 13/719,509 - Filed: 2012-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Tokyo Electron Limited - Inventors: Shigeru SENZAKI; Shunichi Mikami; Toshikatsu Tobana - Web page: https://patentgrep.com/patent/US20130153147A1 ## CPC - H02N 13/00: Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect - C23F 1/08: Apparatus, e.g. for photomechanical printing surfaces (photo- mechanical reproduction G03F) - H01J 37/32715: {Workpiece holder} - H10P 72/72: using electrostatic chucks - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A dechuck control method includes performing a discharge process by introducing an inert gas into a processing chamber and maintaining the pressure within the processing chamber at a first pressure; monitoring the pressure of a heat transmitting gas supplied to the processing object rear face and/or the leakage flow rate of the heat transmitting gas; obtaining the amount and polarity of the residual electric charge of the electrostatic chuck surface and applying a voltage for supplying an electric charge that is of the same amount as the residual electric charge but of the opposite polarity to a chuck electrode; evacuating the inert gas from the processing chamber while applying the voltage to the chuck electrode and reducing the pressure within the processing chamber to a second pressure; and turning off the voltage applied to the electrostatic chuck and dechucking the processing object from the electrostatic chuck. ## Claims ### Claim 1 A dechuck control method for dechucking a processing object from an electrostatic chuck that electrostatically attracts the processing object and includes a chuck electrode, the method comprising the steps of: performing a discharge process after a plasma process by introducing an inert gas into a processing chamber and maintaining a pressure within the processing chamber at a first pressure; monitoring at least one of a pressure of a heat transmitting gas supplied to a rear face of the processing object that is placed on the electrostatic chuck and a leakage flow rate of the heat transmitting gas leaking from the rear face of the processing object; obtaining an amount of residual electric charge of a surface of the electrostatic chuck and a polarity of the residual electric charge based on a monitoring result of the monitoring step, obtaining a voltage for supplying to the chuck electrode an electric charge that is of the same amount as the residual electric charge and of the opposite polarity with respect to the polarity of the residual electric charge, and applying the obtained voltage to the chuck electrode; evacuating the inert gas within the processing chamber while applying the obtained voltage to the chuck electrode and reducing the pressure within the processing chamber to a second pressure; and turning off the obtained voltage applied to the electrostatic chuck and dechucking the processing object from the electrostatic chuck using a support pin. ### Claim 2 (depends on 1) The dechuck control method as claimed in claim 1, wherein the second pressure is achieved by vacuuming the inert gas until the pressure within the processing chamber is reduced to a pressure at which movement of an electric charge of the processing object through gas within the processing chamber ceases to occur according to Paschen's Law. ### Claim 3 (depends on 2) The dechuck control method as claimed in claim 2, wherein the evacuating step includes vacuuming the inert gas such that an order of magnitude of the pressure within the processing chamber after evacuation is reduced by at least one digit compared to an order of magnitude of the pressure within the processing chamber before evacuation. ### Claim 4 (depends on 1) The dechuck control method as claimed in claim 1, wherein a pressure within the processing chamber during the monitoring step is greater than or equal to the first pressure. ### Claim 5 (depends on 4) The dechuck control method as claimed in claim 4, further comprising the steps of raising the processing object from the electrostatic chuck using the support pin after turning off the obtained voltage applied to the chuck electrode and reintroducing gas into the processing chamber. ### Claim 6 (depends on 1) The dechuck control method as claimed in claim 1, wherein the surface of the electrostatic chuck includes a dielectric member that covers the chuck electrode; and a volume resistivity of the dielectric member is greater than or equal to 1×1014 Ωcm. ### Claim 7 (depends on 1) The dechuck control method as claimed in claim 1, wherein the dechuck control method is automatically implemented upon dechucking the processing object from the electrostatic chuck that has been in use for at least a predetermined period of time. ### Claim 8 (depends on 1) The dechuck control method as claimed in claim 1, wherein the monitoring step includes detecting at least one pressure value of the heat transmitting gas within a time period after stopping the supply of the heat transmitting gas during which time period the pressure of the heat transmitting gas changes by at least 50%; and stopping the dechucking step of dechucking the processing object from the electrostatic chuck when the detected pressure value of the heat transmitting gas is greater than 2.6 Torr (346.6 Pa). ### Claim 9 (depends on 8) The dechuck control method as claimed in claim 8, wherein the time period during which the pressure of the heat transmitting gas changes by at least 50% is within one second. ### Claim 10 (depends on 8) The dechuck control method as claimed in claim 8, wherein the monitoring step includes repeating the detecting step of detecting at least one pressure value of the heat transmitting gas within the time period during which the pressure of the heat transmitting gas changes by at least 50%, the detecting step being repeated up to a predetermined number of times while the detected pressure value is greater than 2.6 Torr (346.6 Pa); and stopping the dechucking step of dechucking the processing object from the electrostatic chuck using the support pin when the detected pressure value continues to be greater than 2.6 Torr (346.6 Pa) after repeating the detecting process the predetermined number of times. ### Claim 11 (depends on 7) The dechuck control method as claimed in claim 7, wherein the dechuck control method is automatically implemented upon dechucking the processing object from the electrostatic chuck in at least one of a first case where the detected pressure value of the heat transmitting gas is greater than or equal to 2.6 Torr (346.6 Pa) and a second case where the leakage flow rate of the heat transmitting gas leaking from the rear face of the processing object is less than or equal to 0.3 sccm. ### Claim 12 (depends on 1) The dechuck control method as claimed in claim 1, wherein when the heat transmitting gas is supplied from plural heat transmitting gas supply ports, the monitoring step includes monitoring at least one of a pressure of the heat transmitting gas supplied from an outermost heat transmitting gas supply port of the heat transmitting gas supply ports and the leakage flow rate of the heat transmitting gas leaking from the rear face of the processing object. ### Claim 13 A plasma processing apparatus comprising: an electrostatic chuck that electrostatically attracts a processing object and includes a chuck electrode; a control unit that performs a discharge process after a plasma process by introducing an inert gas into a processing chamber and maintaining a pressure within the processing chamber to a first pressure; and a monitor that detects at least one of a pressure of a heat transmitting gas supplied to a rear face of the processing object that is placed on the electrostatic chuck and a leakage flow rate of the heat transmitting gas leaking from the rear face of the processing object; wherein the control unit performs the steps of applying a voltage obtained based on a monitoring result of the monitor to the chuck electrode, evacuating the inert gas within the processing chamber, and reducing the pressure within the processing chamber to a second pressure; and turning off the voltage applied to the chuck electrode and dechucking the processing object from the electrostatic chuck using a support pin.