InAs/GaSb II类超晶格红外焦平面台面的 ICP 刻蚀研究

本文报道了采用Cl2/N2电感耦合等离子（ICP）组合体刻蚀工艺在InAs/GaSb II类超晶格红外焦平面台面加工过程中的研究结果，实验采用分子束外延技术在GaSb衬底上生长的PIN型超晶格材料。结果表明，气体流量比例直接对刻蚀速率和刻蚀形貌产生影响，氯气含量越高，刻蚀速率越大，当氮气含量增加，刻蚀速率降低并趋于一定值。当氯气和氮气的流量比例和等离子腔体内压力等参数一定时，随着温度升高，刻蚀速率和选择比在有限范围内同时线性增大，台面的倾角趋于直角，台面轮廓层状纹理逐渐消失，但沟道内变得粗糙不平，并出现坑点。在实验研究范围内，电感耦合等离子源的ICP功率和RF功率对刻蚀结果产生的影响较小。

Study on ICP dry etching of type II InAs/GaSb superlattices infrared focal plane arrays

The results of a Cl2/ N2 inductively coupled plasma (ICP) reactive ion etching process on InAs/GaSb superlattices infrared focal plane arrays were reported. A standard PIN device structure based on GaSb substrate was applied in all samples grown by molecular beam epitaxy. The etching results including etching rate and mesa sidewall profile were affected by gas flow directly, The higher the chlorine content, the higher the etching rate, when the argon content increased, the etching rate decreased and tended to a certain value. When other parameters such as chamber pressure et al. were fixed, the etching rate and selection ratio increased linearly with temperature, and the mesa tended to be right angle, layered texture profile gradually disappeared, but the channel became rough and even pitted. Within the scope of the experimental study, the ICP power and RF power had little effect on the etching results.