GaAs材料ICP刻蚀中光刻胶厚度及刻蚀条件对侧壁倾斜度的影响

The influence of photopersist thickness and etching condition on the slope angle during the ICP etching process of GaAs

使用感应耦合等离子体(ICP)刻蚀技术刻蚀GaAs材料,在光刻过程中采用不同厚度的光刻胶,研究在同一刻蚀条件下不同光刻胶厚度对刻蚀图形侧壁倾斜度的影响,并研究了光刻胶厚度对侧壁倾角影响在不同大小图形刻蚀中的尺寸效应,提出了关于刻蚀机理的尺寸增益现象及可能发生的刻蚀离子的散射模型,解释了光刻胶厚度较大时小线宽图形侧壁倾角变化明显的现象。在研究光刻胶厚度对侧壁倾角影响的基础上,研究了不同ICP刻蚀选择比对GaAs样品刻蚀后侧壁倾角的变化的影响,并从GaAs干法刻蚀机理及刻蚀条件对ICP刻蚀过程中的化学、物理反应的影响来解释这一现象。

ICP etching technology was used to etching GaAs material which was coated with photoresist of different thicknesses and the slope angle of different patterns was studied. The dimensional effect of the GaAs material with small graphics in the etching process was discussed, the size gain and particle scatter- ing model was also proposed to explain the fact that the slope angle of GaAs material coated with large photopersist thickness varies apparently. On the basis of the above research on the influence of the pho- topersist thickness to the slope angle, the influence of different etching selectivity was also studied. The fact was explained on two aspects, which contains GaAs dry etching mechanism and the effect of ICP etch- ing parameters to the physical and chemical processes.