4H-SiC材料干法刻蚀工艺的研究

鉴于SiC材料具有很强的稳定性以及湿法刻蚀的种种缺点,目前主要使用干法刻蚀来刻蚀SiC材料。但是干法刻蚀后样品表面的粗糙度对器件的性能有一定的影响。针对这一问题,采用电感耦合等离子体-反应离子刻蚀技术,对SiC材料进行SF₆/O₂混合气体和SF₆/CF₄/O₂混合气体的刻蚀,并且探究了压强、ICP功率和混合气体比例对样品表面粗糙度的影响。实验结果表明使用SF₆/O₂混合气体刻蚀后,样品的表面平整度较好。在一定RIE功率条件下,当ICP功率为700 W、压强为20 mT和SF₆/O₂为50/40 sccm时,样品表面的粗糙度最小。

Study of Dry Etching in 4H-SiC Material

Due to the stability of SiC material and the disadvantages of wet etching, dry etching is generally used to etch SiC material. However,the roughness of the etched sample surface caused by dry etching will have a certain impact on the performance of the device. In order to solve the problem, inductively coupled plasma-reactive ion etching (ICP-RIE) was applied to etch SiC material with the mixture of SF₆/O₂ and SF₆/CF₄/O₂. The effects of pressure, ICP power and gas mixture ratio on the surface roughness of the samples were investigated respectively. The experimental results showed that with use of the mixture of SF₆/O₂ , the surface roughness was improved. Under certain RIE power, when the ICP power was 700 W, the pressure was 20 mT and SF₆/O₂ was 50/40 sccm. Meanwhile, the roughness of the sample surface was the minimum.