NaOH对硅基薄膜体声波谐振器的背腔刻蚀研究

摘要

Thin film bulk acoustic resonator(FBAR)has promising prospects of development and application in the field of wireless communications.In this thesis,the wet etching process of thin film bulk acoustic resonator was mainly studied.The etching rate of silicon and the roughness of etched surface were studied by changing the concentration of NaOH and etching temperature. The results indicate that the etching rate of silicon and temperature shows a exponential relationship.And the etching rate meets the maximum at NaOH concentration of 33%,while the surface roughness reaches the minimum.Under this condition,the etching rate is up to 1 μm/min,and the surface roughness is less than 5 nm.The etching process can meet the requirement of the silicon and the surface quality of the support layer in the etching process of the resonator.%薄膜体声波谐振器(FBAR)在无线通信领域具有十分广阔的发展和应用前景.该文主要针对薄膜体声波谐振器背腔湿法刻蚀工艺进行了研究.通过改变NaOH浓度以及刻蚀温度对硅进行了湿法刻蚀,研究了硅的刻蚀速率以及刻蚀表面的粗糙度Ra.研究表明硅刻蚀速率随温度呈指数变化,在NaOH质量分数为33%时刻蚀速率最快,同时刻蚀表面粗糙度最小.在此质量分数条件下,刻蚀速率可达1 μm/min,刻蚀表面粗糙度小于5 nm.该刻蚀工艺可以满足谐振器背腔刻蚀过程中对硅以及支撑层表面质量的要求.