Fabrication Technology Design And Characters Measurements Of GaAs Vector Hydrophone

Micro/nano-electro-mechanic System (MEMS) has many merits, such as extreme miniaturization, low power consumption, high integrated level and so on. They can complete tasks that large-dimension electro-mechanic system can not achieve, and raise automatization, intelligentized ability and reliability to a new level by embedding in large system. The study of MEMS devices based on the piezoresistive effect of doped silicon has several ten years history with widely applications. Because of the relative low sensitivity and resistance variety dependency on temperature et al of the piezoresistive effect based on doped silicon, the uses of it are restrained under conditions such as accurate precision and high sensitivity.Based on the piezo-resistive effect of resonant tunneling structure (RTS), design, process methods and measurement et al of GaAs vector hydrophone are studied in this paper. The works mainly contain three targets: calibration of the piezoresistive coefficient of RTS, GaAs bulk process methods and design, measurements of the hydrophone. By molecular beam epitaxy (MBE) technology, the GaAs/AlAs/InGaAs double barrier RTS is grown on semi-insulating GaAs substrate, and the resonant tunneling devices are fabricated with obvious negative differential resistance (NDR) effect. The meso-piezoresistive phenomena of RTS is measured, either by micro Raman-probe stress system, centrifugal machine-Agilent4156C semiconductor characteristic analyzer system and/or jarring table-Wheatstone bridge solution circuit system, and the consistent largest piezoresistive coefficients: 10-9Pa-1 are discovered (NDR region); The control-hole technology and etch-stop technology of GaAs bulk process methods are studied too, and by control-hole technology, the basic hydrophone structure with four beam-block is designed and fabricated; At last, In Hangzhou Applied Acoustics Research Institute (715 institute), the directivity, frequency response and sensitivity et al of the packaged vector hydrophone are measured primarily. The good"8"cosine vector directivity and frequency response curves are obtained, and the sensor's sensitivity reaches -184.6dB at 1 KHz.The innovations of this paper are the combination of quantum well resonant tunneling materials and M/NEMS, the study of the electro-mechanic coupling phenomena in nano-dimension, and its application in vector hydrophone structure. Others contain optimizing GaAs process steps, perfecting series of GaAs fabrication technology, and processing the meso-piezoresistive M/NEMS devices.