A plasma etch reactor 20 includes a reactor chamber 22 with a grounded upper electrode 24, a lower electrode 28 which is attached to a high frequency power supply 30 and a low frequency power supply 32, and a peripheral electrode 26 which is located between the upper and lower electrode, and which is allowed to have a floating potential. Rare earth magnets 46, 47 are used to establish the magnetic field which confines the plasma developed within the reactor chamber 22. The plasma etch reactor 20 is capable of etching emerging films used with high density semiconductor devices.