AVS 51st International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeM

Paper PS2-WeM2
Modeling of a Commercial Dual Frequency Magnetically Enhanced Capacitively Coupled Plasma Reactor with Rotating Static Magnetic Field

Wednesday, November 17, 2004, 8:40 am, Room 213B

Session: Plasma Sources
Presenter: T. Panagopoulos, Applied Materials, Inc.
Authors: T. Panagopoulos, Applied Materials, Inc.
A.M. Paterson, Applied Materials Inc.
J.P. Holland, Applied Materials Inc.
Correspondent: Click to Email
Magnetically enhanced reactive ion etching (MERIE) reactors have recently been modeled for 200mm wafer processing chambers with single frequency and uniform static magnetic field. An extension of this work is presented for a commercial 300mm dual frequency MERIE reactor with rotating static magnetic field for an argon discharge. The magnetic field is modeled in the 3D space (CFD-ACE) and it is used as an input in a 2D computational model (HPEM). The different moments of the static magnetic field are solved independently and the species spatial profiles are compared for different magnetic field intensities and operating pressures. The use of magnetic field results in more confinement of the ion density within the area of the two electrodes. This confinement is more effective for lower pressures (10s of mTorrs) and tends to confine the plasma at the wafer center. On the other hand, when the pressure increases to a few hundreds of mTorrs, the plasma density is confined close to wafer edge. The density profiles are affected by the time averaged ionization source by bulk electrons. When no magnetic field is applied in the chamber, the ionization source is located near the wafer edge and in the middle of the inter-electrode spacing. As the magnetic field increases in a high pressure regime, the ionization sources move closer to the bottom electrode, and for even higher magnetic field (~100G) most of the ionization takes place at the edge of the bottom electrode with a lessened contribution from the top electrode. For lower operating pressures (~30 mTorr), the ionization patterns are different with a substantial contribution from the top electrode and bulk of the plasma, for average magnetic fields. In a similar way the dc bias is affected by the operating pressure regime; it becomes less negative as the magnetic field increases at low pressures, while it becomes more negative for the high pressure regime. Experimental wafer results agree with the simulation trends.