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This thesis presents a new silicon (Si) field emission devices (FE) fabrication process based on the potential of the HI-PS (Hydrogen Ion – Porous Silicon) micromachining technique, which is a combination of hydrogen implantation and porous silicon. Devices with 2500 emitters (Si microtips), integrated and non-integrated to the anode, enclosed in an area of 2.8 x 2.8 mm (3.2 x 10 tips/cm), were obtained from the proposed technique. The fabricated Si microtips show 10 μm in height, with apex diameter of about 150 nm. The separation distance between emitters (50 μm), considering the non-integrated devices design, was limited by the resolution of the lithographic mask applied. Microtips structural improvement process steps were proposed and applied in both anode-cathode design (integrated and non-integrated). As a result, a reduction in tip apex diameter to dimensions lower than 100 nm was verified. The integrated FE devices were obtained with an anode-cathode separation of about 12 μm, which distance was defined by lithographic mask dimensions, but not limited by the process applied. The outstanding advantages of the HI-PS technique in comparison with usual technologies for FE devices fabrication are the low complexity of the process proposed and the use of a single lithographic step to obtain a selfaligned and integrated anode-cathode system. A dedicated vacuum chamber, which allows the changing of the separation distance between non-integrated anodecathode structures without the need of removing the sample out the chamber, and three systems for electrical test, being one of them developed specifically for FE devices electrical characterization, were implemented. The electrical characterizations were performed by means of I-V, I-t and V-d curves, being the last one used to extract the macroscopic electrical field E, which was applied as comparison parameter between samples obtained from distinct structural improvement process and samples with emitters surface coated with Al. All samples characterized showed exponential-like behavior of current with the potential applied, as expected from theory proposed by Fowler-Nordheim (F-N). Devices with structural improvement or Al coating showed better emission characteristics (lower E value), according with the modified F-N model suggested in the literature for optimized surfaces. From the F-N plots, the distinct behavior of p type Si emitters was verified in comparison with different materials, establishing a relationship between the slope variations of the curve obtained and the electrons source of the Si. Based on the results obtained, the HI-PS technique is very promising to fabricate Si micromachined emitters for use in FE devices.

Desenvolvimento de dispositivos de emissão por efeito de campo elétrico fabricados pela técnica HI-PS.