The Design and Fabrication of Pentacene Acoustic Charge Transfer Devices

• Main Author: Shao, Hua
• Other Authors: DooYoung Hah
• Format: Others
• Language: en
• Published: LSU 2008
• Subjects: Electrical & Computer Engineering
• Online Access: http://etd.lsu.edu/docs/available/etd-04012008-101702/

Acoustic charge transport (ACT) devices are used to transfer electrical signals by surface acoustic waves (SAW), which are generated by interdigital transducers (IDT) on piezoelectric crystal substrates. In order to reduce fabrication cost, pentacene ACT is desired to transfer charge packages because of its reduced cost in. As some researchers reported, pentacene is a p type organic semiconductor, and can get high carrier mobility by growing in very pure crystalline structure under some specified growing conditions. In this project, charge transfer channel was made of crystal pentacene to form and carry the charge packages following SAW propagation. The pentacene ACT consists of IDT, input/output probes, metallic parabolic horns, and pentacene charge channel which are deposited on lithium niobate (LiNbO3) piezoelectric substrate. In addition, the frequency of SAW in this device was designed to be 284 MHz. IDT and probes were made by bilayer lift-off process, and the resolution is 3 ìm. The pentacene channel was deposited through a silicon shadow mask in thermal evaporator. Some facilities were designed for the above process, such as chromium glass masks, print out film mask, and LiNbO3 wafer holder. Semiconductor fabrication techniques such as photolithography and wet/dry etch were also involved in making this device. Another project, Gallium arsenide epitaxial film is also under consideration to be charge transfer channel in ACT. This project involved epitaxial film lift-off and wafer or film bonding technique. Further work will be required to produce this device.