Sacrificial layers for air gaps in NEMS using alucone molecular layer deposition

A molecular layer deposition approach is reported that produces a new class of hybrid organic–inorganic thin films. These films have very low densities, and display typical atomic layer deposition characteristics: controllable linear growth, conformality, low roughness, and uniform composition. Because of their aluminum content, the alucone films cannot be dry etched with oxygen plasma. In accordance with their molecular structure, the new materials are completely removed in hydrochloric acid solutions. Since they can be etched with accurate control in acidic solutions, these hybrid materials are promising for the fabrication of MEMS/NEMS (Micro/Nano Electro Mechanical Systems) devices. Doubly supported structures with 120 nm air gaps are demonstrated using alucone materials as sacrificial layers.