Micro-mechanical devices, such as MEMS, having layers thereon, and methods of forming the layers, are disclosed. In one aspect, a method may include forming a layer including an oxide of aluminum over at least a portion of a micro-mechanical device, and coating the layer by bonding material to surface hydroxyl groups of the layer. In another aspect, a method may include introducing a micro-mechanical device into an atomic layer deposition chamber, and substantially filling nanometer sized voids of the micro-mechanical device by using atomic layer deposition to introduce material into the voids. In a still further aspect, a method may include introducing an alkylaminosilane to a micro-mechanical device having a surface hydroxyl group, and bonding a silane to the micro-mechanical device by reacting the alkylaminosilane with the surface hydroxyl group.