Induction plasma source
First Claim
1. A plasma process apparatus for integrated circuit fabrication having a chamber and a platen for supporting on a surface thereof a substrate in the chamber, comprising:
- a hemispherically shaped induction coil having multiple helical windings, a base winding thereof being generally parallel to and coplanar with the support surface of the platen, and each of the other windings being generally parallel to the support surface of the platen, the chamber being disposed inside the induction coil;
a low frequency radio frequency power source coupled to the induction coil; and
a bias power source coupled to the platen for biasing the substrate.
1 Assignment
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Accused Products
Abstract
An induction plasma source for integrated circuit fabrication includes a hemispherically shaped induction coil in an expanding spiral pattern about the vacuum chamber containing a semiconductor wafer supported by a platen. The windings of the induction coil follow the contour of a hemispherically shaped quartz bell jar, which holds the vacuum. The power source is a low frequency rf source having a frequency of about 450 KHz and a power in the range of 200-2000 watts, and the pressure is a low pressure of about 0.1-100 mTorr. A high frequency rf source independently adjusts the bias voltage on the wafer.
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Citations
25 Claims
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1. A plasma process apparatus for integrated circuit fabrication having a chamber and a platen for supporting on a surface thereof a substrate in the chamber, comprising:
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a hemispherically shaped induction coil having multiple helical windings, a base winding thereof being generally parallel to and coplanar with the support surface of the platen, and each of the other windings being generally parallel to the support surface of the platen, the chamber being disposed inside the induction coil; a low frequency radio frequency power source coupled to the induction coil; and a bias power source coupled to the platen for biasing the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A plasma process apparatus for integrated circuit fabrication having a chamber and a platen for supporting on a surface thereof a substrate in the chamber, comprising:
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a vessel having a hemispherical quartz wall for containing the chamber; means for inducing a low frequency oscillating azimuthal electric field in a region near the quartz wall so that electrons entering the region within the plasma boundary are accelerated and cancel an axial magnetic field in the interior of the plasma discharge; and means for imposing a biasing voltage on the wafer independently of the inducing means.
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9. A plasma process apparatus for integrated circuit wafer fabrication, comprising:
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a housing having a top plate; a bell jar having a hemispherical quartz wall, the bell jar being mounted on the top plate for containing a vacuum chamber; a platen having a top surface for supporting a semiconductor wafer in the vacuum chamber; a hemispherical induction coil conformal with the quartz wall of the bell jar, the induction coil having a plurality of windings which are generally parallel to the platen, one of the windings being at the base of the induction coil and generally coplanar with the top surface of the platen; a gas system for delivering gas to the process chamber; a low frequency radio frequency power source connected to one end of the induction coil through a matching network for inducing an oscillatory azimuthal electric field within the process chamber near the bell jar wall, the other end of the induction coil being connected to the housing; and a high frequency radio frequency power source connected to the platen through a matching network for biasing the wafer; wherein a plasma is operably sustainable in the vacuum chamber at a gas pressure therein as low as 1.0 milliTorr. - View Dependent Claims (10, 11, 12, 13)
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14. A method of generating a plasma for processing an integrated circuit substrate, comprising the steps of:
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placing the substrate in a chamber contained within a hemispherical vessel, the vessel having a hemispherical induction coil conformal with a surface of the vessel; delivering a gas to the chamber; applying an oscillating current to the induction coil so that a plasma is formed by excitation of the gas; and imposing a biasing voltage on the substrate. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A plasma process apparatus for integrated circuit fabrication having a chamber and a supporting member for supporting a substrate in a plane within the chamber, comprising:
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a hemispherically shaped induction coil having multiple helical windings, each of the windings being generally parallel to the plane; an alternating current source coupled to the induction coil; and a bias source coupled to the supporting member for biasing the substrate. - View Dependent Claims (22, 23, 24)
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25. A plasma process for integrated circuit wafer fabrication, comprising the steps of:
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sustaining a plasma within a hemispherical region of a process chamber; inducing a low frequency oscillating azimuthal electrical field in the periphery of the hemispherical region so that electrons in a plasma entering the periphery are accelerated and cancel an axial magnetic field in the interior of the plasma; and imposing a biasing voltage on the wafer.
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Specification