Transmission Characteristic of CPW Structures on Surface Passivation Silicon Substrate

• Main Authors: Ru-Yu Lin, 林育儒
• Other Authors: Ruey-Lue Wang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/72582398834946885836

碩士 === 國立高雄師範大學 === 電子工程學系 === 100 === In this thesis, the transmission characteristics and crosstalk phenomena of coplanar waveguide structures on silicon substrates with a surface passivation layer of different thickness were studied. Related characteristics were measured and analyzed, moreover, characteristics of inductor on a surface-passivated high-resistivity silicon substrate was also studied. There exists a inversion layer between the silicon substrate and the oxide layer because positive charges in the oxide attract minority carriers to the substrate surface to form a carrier channel. Radio-frequency (RF) and microwave signals can transport through the channel and hence are attenuated. This will result in the increase of overall loss in a RF and microwave component. Therefore, how to suppress the formation of the channel is an important topic. In the study of surface passivation, amorphous silicon or polysilicon was used as a material for surface passivation. Amorphous silicon or polysilicon and oxide of different thickness were deposited on a low-resistivity silicon substrate. The transmission loss of coplanar waveguide transmission lines on these substrates was measured and compared. The experimental results show that transmission loss caused by substrate can be effectively decreased with the increase of total thickness of surface-passivation layer and oxide. Because of the native lossy property of low-resistivity silicon substrate, passive components have very high signal loss when operated at high frequencies, and hence device characteristic are unstable. Therefore, we have also fabricated inductors on surface-passivaton high-resistivity silicon substrates, which have the excellent nature of low loss. The measurement results show the inductors have higher inductance and higher quality factor.