All types of alloy-junction transistors became obsolete in the early 1960s, with the introduction of the planar transistor which could be mass-produced easily while alloy-junction transistors had to be made individually. The first germanium planar transistors had much worse characteristics than alloy-junction germanium transistors of the period, but they cost much less, and the characteristics of planar transistors improved very rapidly, quickly exceeding those of all earlier germanium transistors.