Development of the thermally induced crystallization lithography process.

摘要

The objective of this research is to develop an inexpensive pattern transfer process that is capable of patterning sub-micron features on a non-planar surface. To allow for patterning on non-planar surfaces, a pattern transfer process that does not require the focusing of an electromagnetic source is used. This process, Thermally Induced Crystallization Lithography (TICL), is a thermally driven process that transfers the pattern from a heated printhead to the underlying substrate by making intimate contact with an amorphous film and crystallizing selected areas; then a chemical solution etches away only the remaining amorphous material.;The design of the TILL process shows that it can be used on non-planar surfaces, and as a demonstration that the TICL process is a suitable pattern transfer process, sub-micron features are transferred on a planar surface. To achieve this level of resolution, all aspects of the TICL process must be investigated. A ‘clean’ thermal printhead is fabricated through anisotropic etching and focused ion beam deposition, yielding a printhead that can be used without requiring a special environment, such as a cleanroom. In addition to their influence on the TICL process, the sputtering parameters used for depositing the amorphous film, Indium Tin Oxide (ITO), are also investigated for their effect on the physical and electrical properties of the film. Varying the concentration and temperature of the selective etch, dilute hydrochloric acid, is performed to determine the conditions that result in the highest selectivity between the amorphous film and crystallized features.;For a given amorphous film, the temperature of the printhead, the applied force of the printhead, and the amount of time that the printhead is in contact with the amorphous film all contribute to whether the amorphous film crystallizes. Isolating the effect of each of these parameters shows how much of an effect each has on the TICL process. The investigation of the printing parameters also shows that there is a highly non-linear response by the amorphous film. That is, for a relatively small change in the printing parameters, the film transforms from amorphous to crystalline. This non-linear response, in conjunction with the successful transfer of sub-micron features, shows that the TICL process is indeed a viable pattern transfer technology.