Abstract: A solenoidal magnetic field generated by a coil around the upper chamber A acts as a magnetic plasma attenuator. By judicious adjustment of the magnetic field strength, a dense plasma region forms inside the tube and adjacent to an antenna and is at least partially trapped by the field lines. These field lines intersect the wall of the upper chamber near or on the lid, and either on the upper chamber wall near its base, or on the lid or upper walls of the lower chamber. Significant numbers of radicals can be created in the upper chamber, which then diffuse into the lower chamber. The associated ion flux is reduced, however, because of losses where the field lines intersect the walls, thereby ensuring that the ratio of ion numbers to radical numbers reaching the wafer is reduced.

Abstract: A sidewall passivation layer is deposited on an etched feature in a semiconductor substrate with a hydrocarbon deposition gas by introducing H2, determining certain mixture percentages for the hydrocarbon gas/H2 mix at which the etch rate for the substrate peaks, the etch rate begins to rise from a generally steady state, and/or the etch rate falls to zero, and then maintaining the mixture percentage within a selected range. Where the hydrocarbon gas/H2 mix is maintained at a percentage between the steady-state etch rate percentage and the peak etch rate percentage, then relatively high ion energies are used. Where the hydrocarbon gas/H2 mix is maintained at a percentage between the peak etch rate percentage and the percentage where the etch rate falls to zero, then relatively low ion energies are used.

Abstract: There is disclosed a method and apparatus for etching a substrate. The method comprises the steps of etching a substrate or alternately etching and depositing a passivation layer. A bias frequency, which may be pulsed, may be applied to the substrate and may be at or below the ion plasma frequency.

Abstract: This invention relates to methods for treatment of semiconductor substrates and in particular a method of etching a trench in a semiconductor substrate in a reactor chamber using alternatively reactive ion etching and depositing a passivation layer by chemical vapour deposition, wherein one or more of the following parameters: gas flow rates, chamber pressure, plasma power, substrate bias, etch rate, deposition rate, cycle time and etching/deposition ratio vary with time.