Microelectronic Fabrication

My team of three engineers fabricated and tested semiconductor components on a blank silicon wafer. Over the course of a semester, each of us participated in many common microelectronic fabrication techniques. The process began with RCA cleaning and wet and dry thermal oxidation. Then photolithography was conducted by applying photoresist to the wafer, exposing the appropriate portions of the resist to ultraviolet light through a mask, etching the corresponding areas of oxide, and removing the photoresist. The wafer next underwent processes of pre-deposition diffusion, etching of the phosphosilicate glass, and drive-in diffusion. Many of the same techniques were repeated for a series of additional masks in order to build the necessary layers into and onto the substrate. Final conductive material was deposited onto the wafer by evaporating and condensing aluminum in a vacuuming camber and then etching away all but the desired metal contacts and pathways.

The final devices that were fabricated included transistors, diodes, CMOS capacitors, transmission lines, photodiodes, and resistors, as well as a large ground contact. The laboratory equipment used for the project included a 4-point probe, ellipsometer, microscope, furnace, hot plate, photoresist spinner, mask aligner and ultraviolet emitter, and vacuum chamber. All semiconductor devices were tested to prove functionality and their performance measured and compared to ideal components.