Plasma treatment apparatus having a workpiece-side electrode grounding circuit

{
  "publication_number": "US5665167A",
  "country": "US",
  "kind": "A",
  "title": "Plasma treatment apparatus having a workpiece-side electrode grounding circuit",
  "abstract": "A static chuck and a workpiece push-up pin are disposed on a susceptor which is one of opposed electrodes generating plasma. The push-up pin and the susceptor are electrically connected. A grounding circuit which discharges electric charges remaining on the susceptor is disposed in parallel with an RF power supply circuit which supplies RF power to the susceptor. Thus, electric charges remaining in the power supply circuit can be discharged and an abnormal discharging between the push-up pin and the susceptor can be prevented.",
  "claims": [
    "1. A plasma treatment apparatus, comprising: a chamber; plasma generating means for generating plasma in said chamber; a workpiece-side electrode disposed in said chamber, for holding a workpiece; a pin straightly penetrating said workpiece-side electrode, after a treatment is completed, said pin being in contact with said workpiece so as to detach said workpiece from said workpiece-side electrode; and a conductive rubber member disposed at the distal end of said pin, said conductive rubber member having a lower hardness than said workpiece.",
    "2. The plasma treatment apparatus as set forth in claim 1, wherein said conductive rubber member is made of silicon rubber.",
    "3. A plasma treatment apparatus, comprising: a chamber; plasma generating means for generating plasma in said chamber; a workpiece-side electrode, disposed in said chamber, for holding a workpiece; a conductive pin straightly penetrating said workpiece-side electrode, after a treatment is completed, said pin being in contact with said workpiece so as to detach said workpiece from said workpiece-side electrode; a connecting circuit electrically connecting said pin to said workpiece-side electrode; a grounding circuit electrically connected to said workpiece-side electrode; and a conductive rubber member fixed to an end of said pin, said conductive rubber member having a lower hardness than said workpiece.",
    "4. The plasma treatment apparatus as set forth in claim 3, wherein: said conductive rubber member is made of silicon rubber.",
    "5. The plasma treatment apparatus as set forth in claim 3, further comprising: a switch disposed between said workpiece-side electrode and said grounding circuit.",
    "6. The plasma treatment as set forth in claim 3, further comprising: a power supply circuit connected to said workpiece-side electrode, wherein the impedance of said grounding circuit is at least 10 times as high as the impedance of said power supply circuit.",
    "7. The plasma treatment apparatus as set forth in claim 3, further comprising: a static chuck disposed on said workpiece-side electrode, for electrically attracting and holding said workpiece.",
    "8. The plasma treatment apparatus as set forth in claim 3, further comprising: a mechanical chuck disposed on said workpiece-side electrode, for mechanically holding said workpiece.",
    "9. The plasma treatment apparatus as set forth in claim 3, wherein: said plasma generating means has opposed electrodes, and said workpiece-side electrode is one of said opposed electrodes.",
    "10. The plasma treatment apparatus as set forth in claim 3, further comprising: magnetic field generating means disposed outside said chamber, for generating a rotating magnetic field.",
    "11. The plasma treatment apparatus as set forth in claim 3, wherein: said plasma generating means is a transformer coupled plasma type having a transformer coupled plasma type coil.",
    "12. The plasma treatment apparatus as set forth in claim 3, wherein: said plasma generating means is an inductively coupled type having a inductively coupled plasma type coil.",
    "13. A plasma treatment method for discharging electric charges remaining in a workpiece by using a plasma treatment apparatus comprising: providing a chamber; generating plasma in said chamber by a plasma generating means; holding a workpiece with a workpiece-side electrode disposed in said chamber; and penetrating straightly said workpiece-side electrode with a conductive pin, after a treatment is completed, said conductive pin being in contact with said workpiece so as to detach said workpiece from said workpiece-side electrode, wherein said conductive pin is electrically connected to said workpiece-side electrode, wherein said workpiece-side electrode is connected to a grounding circuit, and wherein a conductive rubber member is disposed at a forward end of said pin, said conductive rubber member having a lower hardness than said workpiece."
  ],
  "description_excerpt": "1. Field of the Invention\n\nThe present invention relates to a plasma treatment apparatus for accurately treating a workpiece such as a semiconductor wafer with plasma.\n\n2. Description of the Related Art\n\nIn a semiconductor device manufacturing process using a plasma treatment apparatus that performs a plasma-etching treatment, a workpiece such as a semiconductor wafer to be treated with plasma should be kept at a predetermined position. For example, in the case of a planar plasma treatment apparatus that performs a plasma etching treatment in vacuum atmosphere, a workpiece is secured to a static chuck on a susceptor disposed on one of opposed electrodes.\n\nA voltage is applied between a workpiece and an electrode which are opposed to each other with an insulation layer, positive and negative electric charges take place between the workpiece and the electrode and thereby Coulomb' force works therebetween. Thus, with the Coulomb' force, the static chuck attracts and holds the workpiece.\n\nAs such a static chuck, an insulating static attracting sheet may be disposed between a metal chuck and a workpiece. The static attracting sheet may be constructed by sandwiching a conductor such as copper with two sheets of insulating material such as polyimide.\n\nIn such a static chuck, when plasma generation is turned off after plasma treatment is completed, electric charges do not flow from the static chuck. Thus, a so-called float electrode is formed on the static chuck side. Consequently, electric charges stop flowing to the opposed electrode through plasma. As a result, the static chuck side is charged with residual electric charges.",
  "cpc": [
    "H01J 37/32082",
    "C23C 14/50",
    "C23C 16/4586",
    "H01J 2237/0044",
    "H10P 50/00",
    "H10P 72/722"
  ],
  "ipc": [
    "C23C 14/50",
    "C23C 16/458",
    "H01L 21/683"
  ],
  "assignees": [
    "Tokyo Electron Ltd"
  ],
  "inventors": [
    "Yoichi Deguchi",
    "Satoru Kawakami",
    "Shiro Koyama",
    "Kenji Ishikawa"
  ],
  "filing_date": "1994-02-14",
  "publication_date": "1997-09-09",
  "grant_date": "1997-09-09",
  "priority_date": "1993-02-16",
  "application_number": "US-19466594-A",
  "family_id": "27293798",
  "cited_by_count": 134,
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}