Electron energy distribution control by fiat: breaking from the conventional flux ratio scaling rules in etch

摘要: With shrinking critical dimensions, minimizing each of aspect ratio dependent etching (ARDE), bowing, undercut, selectivity, and within die uniformly across a wafer is met by trading off one requirement against another. The problem trade-offs especially critical. At the root that roles radical flux, ion flux energy play may be both good bad. Increasing parameter helps meeting but hinders other. Managing process managing ratios alone with conventional sources not adequate because surface chemistry uncontrollable. lack control electron distribution function ( eedf ) has been controlled. Fortunately high density wave fiat. High are characterized distinct plasma regions: an active generation region temperature (T e ionization free rich diffusive (low T region). Pressure aids segregating regions proving means for momentum relaxation between source downstream region. “Spatial pulsing” allows access to reasonably from region, just above wafer. Low potential enables precise passivation surfaces which atomic layer etch (ALE) or precision where species can limited their purposed roles. need at cost speed manufacturability. Large precisely controlled RLSATM realizes fast desorption steps ALE without compromising throughput precision.