具有自由悬浮敏感膜的硅微机械电容式麦克风的设计与-传感技术学报.PDF

第 22 卷 　第 11 期 传 感 技 术 学 报 Vol . 22 　N o . 11 2009 年 11 月 CHIN ES E J OU RNAL OF S EN SORS AND AC TUA TORS N ov . 2009 Design and Simulation of Micromachined Sil icon Condenser Microphone with Free Floating Diaphragm WA N G Wei , D ON G J i an , J I S h i m i ng 1 The M O E Key L aboratory of S p eci al P u rp ose Equip ment an d A d v ance d P rocess i ng Technology , Z hej i ang Uni vers i ty of Technology , H ang z hou 3 100 14 , Chi na Abstract :A micro machined conden ser microp hone wit h a f ree floating sen sin g diap hragm and a p erforat ed t hick copp er backp lat e i s p re sent ed . The san dwich diap hragm i s f abricat ed by u sin g lowp re ssure chemical vapor dep o sition (L PCVD) . One end of sen sing diap hragm stick s on silicon sub st rat e w hile t he ot her p art s float f ro m sub st rat e ,so t hat t he int rin sic st re ss of diap hragm can be relea sed . The backp lat e i s f abricat ed by u sing a copp er elect rop latin g t echnolo gy an d p erforat ed wit h circular vent hole s. Perforat ed circular hole s on backp lat e are laid o ut a s hexagon to adj u st air squeezefilm damping bet ween diap hragm an d backp lat e . Simulation show t hat t he microp hone ha s t he sen sitivit y of 1062 mv/ Pa at 5 V bia s volt age ,t he p ullin volt age of 97 V and t he f requency bandwidt h ran ging f ro m 0 to 1057 k Hz . All t he se p erfor mance s of mi crop ho ne can meet wit h t he requirement s of con sumer s. Key words :silicon co nden ser micro machined microp hone ;a f ree floatin g sen sing diap hragm ;air