用于微放电器的聚酰亚胺绝缘层的工艺和性能研究

Fabrication and Performance of Insulating Polyimide Layers of Micro-Plasma Reactors

研究了一种应用于微放电器的聚酰亚胺绝缘材料的工艺及性能。分析了聚酰亚胺制备过程中亚胺化程度以及图形化过程中反应离子刻蚀功率、气体流量、气体成分、清洗等因素对于薄膜质量、刻蚀速率和残留物的影响,设计了用于测定聚酰亚胺介电常数和击穿强度的电路。实验表明,当聚酰亚胺热环化采用阶梯升温方式,反应离子刻蚀功率为60 W、O2流量为60 cm3/min(标准状态)、加入5%SF6或10%CHF3时,可保证较好的薄膜质量且获得较高的刻蚀速率。实验测得聚酰亚胺相对介电常数为2.8,介电击穿强度为125 V/μm,使用该聚酰亚胺作为绝缘层而制备的微放电器可在10 kPa SF6中稳定放电。

A novel technique was developed to fabricate the insulting polyimide（PI） thin film for micro-plasma reactor.The impacts of the PI imidization and the ion etching conditions,including the reactive ion etching rate,gas flow rate,gas compositions,and cleaning procedures,on the etching rate,film quality and etching residues were evaluated.A dedicated circuitry was developed to measure the dielectric coefficient and breakdown intensity of the PI films.The results show that the imidization mode and ion etching conditions strongly affects the film quality and the etching rate.For instance,high etching rate and good PI films could be obtained with the PI raw films imidized by stepped heating and etched under the following conditions：a reactive etching power of 60 W,an oxygen flow rate of 60 cm3/min（standard state）,in a solution of 5% SF6 or 10% CHF3.Its dielectric coefficient and breakdown intensity were found to be 2.8 and 125 V/μm,respectively.The fabricated micro-plasma reactor with PI insulation structure was capable of stably discharging at 10 kPa SF6.