Verfahren zur Vorbehandlung von Halbleitern, auf denen mittels Bleilegierungen p-n-Zonen erzeugt worden sind, vor dem AEtzen

摘要

A PN or NI junction formed by fusing an alloy of lead with one or more donor or acceptor impurities to a germanium wafer is prepared for a subsequent conventional cleaning process by dipping in boiling concentrated chromic acid, rinsing in warm distilled water and drying. The dried junction may be cleaned by electrolytic etching in potash or glycol borate or by a jet etching treatment with "CP4" solution i.e. a mixture of nitric, hydrofluoric and acetic acids with bromine. In an embodiment a PN junction formed by fusing a dot of lead arsenic alloy to an indium doped germanium wafer is prepared for the above cleaning processes by immersion for 5 minutes in a boiling saturated solution of chromic acid, rinsing, and drying.