Reactive ion etching of Si/sub 1-x/Ge/sub x/ alloy with hydrogen bromide

The reactive ion etching (RIE) of Si/sub 1-x/Ge/sub x/ alloy with hydrogen bromide is described. The technologies of producing Si/sub 1-x/Ge/sub x/ devices are compatible with those of producing silicon devices, which is the major reason why Si/sub 1-x/Ge/sub x/ technologies have been developed so fast in the past few years. One of the key technologies is the etching of Si/sub 1-x/Ge/sub x/ materials during the production of devices. The materials used were grown by SIVA32 MBE systems under 6.0/spl times/10/sup -10//spl sim/6.0/spl times/10/sup -11/ Torr. The experimental results showed that the etch rate of Si/sub 1-x/Ge/sub x/ RIE increased monotonically with increased Ge-content in Si/sub 1-x/Ge/sub x/. The higher Ge-content is, the higher the ratio of Si/sub 1-x/Ge/sub x/ etch rate to Si etch rate is. For instance, when x=0.1, the ratio is 1.12; but, when x=0.18, the ratio is 1.35. The RIE rate of Ge epitaxial layers is higher than that of Si/sub 1-x/Ge/sub x/, and is almost four times as high as that of monocrystalline Si.