Assessment and Development of Process Procedures for Thermal Evaporation Within an Undergraduate Context
School of Engineering
Padnos College of Engineering and Computing
The physical vapor deposition of metal thin films by means of evaporation at low pressure was investigated as part of an undergraduate research effort to improve process efficiency and outcomes utilizing in-place equipment. The overarching intent of the study was to develop procedures for use by students in laboratory courses focused on the design and production of solid state devices. Three specific objectives were targeted: consistency in achieving required layer thicknesses; stable deposition rates; final process procedures to remain within tungsten filament tolerances in order to maximize usable life. Several process variations were explored and conclusions were drawn as to the selection of filament configurations and process parameters, ultimately settling on a semiautomatic power sequence using filaments shaped in a coil configuration. A power sequence that began with an automatically controlled ramp-up in the current delivered to the tungsten filament led to a higher degree of control and reproducibility of deposition parameters while also extending the life of the filament by reducing thermal wear. Coil filaments were preferred due to their comparably high current and voltage tolerances, carrying capacity, and moderate cost. Consideration was also given to the surface topography resulting from varying deposition rates. A complete process procedure was developed based on the work carried out in this study. It was found that some variability in processing results was unavoidable given the nature of the equipment but a higher probability of successful outcomes was achieved through employment of the developed procedures.
119th American Society for Engineering Education Annual Conference and Exposition
San Antonio, Texas
Jiao, Lihong; Johnson, Jeffery; and Barakat, Nael, "Assessment and Development of Process Procedures for Thermal Evaporation Within an Undergraduate Context" (2011). Faculty Scholarly Dissemination Grants. 393.