The Design and Characterisation of Thin-film Capacitors

Abstract

Capacitors are an essential component of almost every electronic circuit. In this project, several capacitance measurement techniques were implemented to measure capacitance, ranging from 1 pF to 100 nF. The first method is based on charging time using an RC circuit. The second method calculates capacitance by measuring the resonance frequency of an LC circuit. The last method is based on measuring the number of pulses generated using the IC-555 timer method. This project also analyses and compares the performance of commercial capacitors and those made in-house in the Leeds University nanotechnology cleanroom. Finally, changes in the capacitor characteristics were examined by varying its properties, such as capacitor size, dielectric thickness and dielectric material, and analysing how these changes affected each capacitor’s performance. The results showed that each measurement technique had a certain range in which the measurement was most accurate. The RC charging method worked optimally at 100 pF–1 nF, the resonance method worked best at 1 nF–10 nF, and the IC 555 timer was optimal at 10 nF–100 nF. The results also demonstrated increased measurement accuracy when more precise capacitors were used.