We studied the drying process of polymer solution drops placed on a substrate having a large contact angle with the drop. The drying process takes place in three stages. First, the droplet evaporates keeping the contact line fixed. Second, the droplet shrinks uniformly with receding contact line. Finally the contact line is pinned again, and the droplet starts to be deformed. The shape of the final polymer deposit changes from concave dot, to flat dot, and then to concave dot again with the increase of the initial polymer concentration. This shape change is caused by the gradual transition from the solute piling mechanism proposed by Deegan to the crust buckling mechanism proposed by de Gennes and Pauchard.

The drying process of thin films of polymer solutions or colloidal suspensions with a pinned contact line is investigated theoretically. The time evolution of the surface shape is calculated by taking into account of the solvent evaporation, the internal flow driven by surface tension, and the gelation (or solidification) of the fluid. It is shown that the final shape of the solidified film changes from dot-type to ring-type as the initial concentration of solute increases, or the evaporation rate decreases, but this is due to a rather intricate balance of the change of the solvent evaporation rate and the change of viscosity.

Photochemical vapor deposition technique using an ArF excimer laser has been employed to deposit W films on SiO2 and Si from a WF6 and H2 system. Adhesion characteristics of the film to SiO2 are found to depend both on substrate temperature and on H2/WF6 gas flow ratio: good adhesion is obtained with an increase in the temperature or the ratio. Film formation has reaction orders of 1, 1/2 , and 1 with respect to deposition time, and WF6 and H2 partial pressures, respectively. An activation energy of 0.36 eV is estimated for this film formation on both SiO2 and Si; this energy is plausibly due to H atom diffusion on the W surface. These findings are different from conventional thermal chemical vapor deposition. Film resistivities as low as about 2× the value of bulk W have been observed in the substrate temperature range 250–500 °C. The crystalline structure of the film deposited in this temperature range is uniquely of the α phase. The crystal orientation of the film depends both on substrate temperature and on H2/WF6 gas flow ratio: at low ratios, the dominant crystal orientation varies from (110) to (200) with an increase in temperature. With an increase in H2/WF6 gas flow ratio, the dominant crystal orientation is changed from (200) to (110).

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