Engineering Research Equipment Grant: Reactive Ion Etching System

GaAs和其他化合物半导体的蚀刻是 用湿化学技术进行。 湿法化学蚀刻 存在一些局限性，因此P.I.的愿望 以获得反应离子蚀刻（RIE）系统。 Rie 提供了高度各向异性的蚀刻， 辅助化学过程。 这种各向异性蚀刻将 允许定义比当前更小的几何图形 可能具有湿法化学蚀刻能力， 减少掩模图案的底切。 通过适当 在这种条件下，接近于零的横向蚀刻速率可以是 通过RIE获得。 这一点对以下方面尤为重要： 处理GaAs，因为与硅不同，GaAs没有液体 蚀刻剂将导致很少或没有底切 掩模图案。 RIE的另一个优点是 选择性蚀刻层的能力。 这是由于 所用蚀刻剂的高选择性。 即使当 这种蚀刻剂选择性是不可能的， 选择性地去除层与RIE由于容易 结合终点检测。 终点检测 是通过光谱方法监测一种或多种 反应物或流出物，以确定何时层具有 被移除了

Etching of GaAs and other compound semiconductors is performed with wet chemical techniques. Wet chemical etching present several limitations, and therefore the P.I.'s wish to acquire a reactive ion etching (RIE) system. RIE provides highly anisotropic etching due to kinetically assisted chemical processes. This anisotropic etching will allow definition of smaller geometries than are currently possible with wet chemical etching capabilities due to a reduction in undercutting of masking patterns. With proper conditions, lateral etch rates close to zero can be obtained with RIE. This is particularly important for processing GaAs because unlike silicon, GaAs has no liquid etchants which will result in little or no undercutting of the masking pattern. Another advantage of RIE is the ability to selectively etch layers. This is due to the high selectivity of the etchants used. Howevern even when this etchant selectivity is not possible, one can still selectively remove layers with RIE due to the easy incorporation of end point detection. End point detection is the monitoring by spectrometric methods of one or more of the reactants or effluent to determine when a layer has been removed.