Design and Development of 1-D CMUT Array with Diamond Membrane

2022-1-25
Karacaer, Berkay
This thesis presents a new microfabrication method of 1-D capacitive micromachined ultrasonic transducer (CMUT) array featuring diamond membrane. This microfabrication method for diamond membrane CMUT array is based on the sacrificial etching of polysilicon in XeF2 plasma. The stiction problem of membranes due to capillary force in wet etching processes is avoided since the XeF2 is a gaseous chemical in plasma form that etches silicon and its derivatives with very high selectivity over silicon dioxide and diamond. The developed microfabrication process flow, the realization of the microfabrication process flow in the computer environment, and the design of the 64-element 1-D diamond membrane CMUT array are explained and demonstrated. In this thesis, in addition to the proposed microfabrication, a CMUT array structure named Faraday caged CMUT and a transmit and receive operation are proposed for electrical crosstalk and parasitic capacitance reduction. The finite element method (FEM) modeling of the regular 2-element 1-D CMUT array and the 2-element 1-D Faraday caged CMUT array are performed. The electrical properties and the electrical crosstalk of these CMUT arrays are examined and compared through computational analysis.

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Citation Formats
B. Karacaer, “Design and Development of 1-D CMUT Array with Diamond Membrane,” M.S. - Master of Science, Middle East Technical University, 2022.