Film thickness planarization

As expected, the degree of leveling was superior to that achieved by 2 nm thick films, and the poly(a-methylstyrene) film achieved better planarization over the wider holes. The improvement in the planarity of the film profiles was extended to holes as wide as 500 /zm by doubling the film thickness. 

The decreased contribution of film resistance for the microtubular electrode makes sense because the effective film thickness for the microtubular system is less than for the thin film control electrode. This is because the surface area of the microtubular current collector is eight times higher than the surface area of the planar current collector. (This factor is calculated from the membrane thickness and the density and diameter of the pores in the membrane.) Since the control and microtubular electrodes contain the same amount of TiS2, the eight times higher underlying surface area of the microtubular electrode means that the TiS2 film is effectively a factor of 8 thinner, relative to the control electrode. 

For nondeformable particles, the theories describing the interaction forces are well advanced. So far, most of the surface force measnrements between planar liquid surfaces (TFB) have been conducted under conditions such that the film thickness is always at equilibrium. In the absence of hydrodynamics effects, the forces are correctly accounted considering classical theories valid for planar solid surfaces. When approached at high rate, droplets may deform, which considerably complicates the description it is well known that when the two droplets are sufficiently large, hydrodynamic forces result in the formation of a dimple that flattens prior to film thinning. Along with the hydrodynamic interactions, the direct... 

Before local planarity is achieved (i.e., while local step height still exists), the final film thickness is inversely proportional to the effective local density. The film is assumed to polish linearly at the blanket rate afterward. The key... 

We describe this situation of a reacting film in Figure 9-12. The unreacted solid forms a planar film of thickness on an impermeable substrate, and the reacted layer Cs forms another film over B,. We shall assume that, as the reaction occurs, the total film thickness remains unchanged, so that, as the reaction proceeds, the position c moves from the substrate at x = 0 initially to the position X= q when the reaction has gone to completion. 

In the preceding expression we include an effectiveness factor r to account for pore diffusion limitations of A. Hi fact, if the catalyst film thickness on the wall of the reactor is small enough that we can assume it planar, then the effectiveness factor becomes... 

In this section we return to the situation sketched in Fig. Id, namely a polymer mixture (A,B) confined between two different planar surfaces, such that the lower surface prefers species A, and the upper surface prefers species B. We are interested in the temperature region in between the critical temperature of phase separation in the bulk and the wetting transition temperatures of the two surfaces (i.e., yw < % < in Fig 6 in principle, one must for film thicknesses D—... 

In the initial state the film surface is planar until a contact with a solid particle occurs. At the moment of rupture when the menisci tips come into contact, the film thickness becomes h = 2h. The rate of mutual approach of the menisci depends on the volume rate of film thinning and on the excess liquid volume (V + Vy. 

Thin solid films of polymeric materials used in various microelectronic applications are usually commercially produced the spin coating deposition (SCD) process. This paper reports on a comprehensive theoretical study of the fundamental physical mechanisms of polymer thin film formation onto substrates by the SCD process. A mathematical model was used to predict the film thickness and film thickness uniformity as well as the effects of rheological properties, solvent evaporation, substrate surface topography and planarization phenomena. A theoretical expression is shown to provide a universal dimensionless correlation of dry film thickness data in terms of initial viscosity, angular speed, initial volume dispensed, time and two solvent evaporation parameters. 

---