感应耦合等离子体刻蚀InSb时偏压射频源功率的选取

摘要

N -type InSb with SiO2 mask is etched by inductively coupled plasma （ICP） in CH4/ H2/Ar. Effects of bias radio frequency （RF） power on etch rate, roughness of etched surface and etch selectivity are investigated and optimized bias RF power is obtained. Etch rate of 90 nm/min, roughness of etched surface of 6.1 nm and etch selectivity of InSb with respect to SiO2 of 6 are obtained when InSb is etched with following working parameters： bias RF power of 150 W, ICP power of 800 W, chamber pressure of 1.0 Pa and ratio of CHJH~/Ar kept at 3/10/1.%以CH4／H2／Ar为刻蚀气体，对带有SiO2掩膜图形的N型InSb晶片进行了感应耦合等离子体（ICP，inductivelycoupledplasma）刻蚀。研究了不同偏压射频源（RF）功率对InSb的刻蚀速率、刻蚀表面粗糙度以及InSb与SiO2的刻蚀选择比的影响，得到了ICP刻蚀InSb时的一个优选的偏压射频源功率值。结果表明：当偏压射频源功率为150W，ICP功率为800W，反应室压力为1．0Pa，CH4／H2／Ar的体积流量比为3／10／1时，InSb的刻蚀速率可达90nm／min，刻蚀表面的平均粗糙度（Ha）约为6．1nm，InSb与Si0：的刻蚀选择比约为6。