一种集成超声传感器新结构

A Novel Structure for Integrated Ultrasonic Transducer

设计了一种具有片上读出电路的集成超声传感器新结构，并用PI膜来垫高扩展栅电极。和典型POSFET结构相比，所制作样品的灵敏度提高14dB以上，带宽可达7MHz，满足超声传感器需要。

A novel integrated polyvinylidene difluoride (PVDF ) ultrasonictransducer structure which contains a on-chip readout amplifier is presented. Theextended gate electrode of the MOSFET is placed over the epitaxial region isolatedfrom the substrate and is padded up with a polyimide (PI) layer, which significantly reduces the extended gate capacitance and therefore increases the sensitivity ofthe transducer. The operating band of about 7 MHz was measured for the amplifieron the chip. With a 5. 2 μm PI, sensitivity improvement of over 14 dB was achievedwhen compared with the normal POSFET.