Plasma texturing of low-defect epitaxial layers

In this paper new texturing processes for epitaxial Si layers and float zone (FZ) Si wafers are presented. The texturing was performed in an in-line plasma etching process. With the introduction of ammonia as a new process gas, smooth surfaces with low defect concentration have been homogeneously structured. The results were half spherical structures. On FZ-Si, a halving of the measured spectral reflectance was achieved and the percentage of diffuse reflected light was drastically increased. On surfaces with different crystalline orientations such as the Recrystallized Wafer-Equivalent, a uniformly distributed texture was achieved.