COMPLEMENTARY NPN AND PNP TRANSISTORS ARE PREPARED SIMULTANEOUSLY WHICH HAVE PROPERTIES OF A HIGH FREQUENCY RESPONSE. SELECTED IMPURITY CONCENTRATIONS ARE EMPLOYED WHEREBY THE SECOND EMITTER DIFFUSION IS PERFORMED WITH THE FIRST EMITTER AREA UNMASKET. THIS ELIMINATES AND EMITTER CONTACT OPENING STEP SUCH THAT EACH CONTACT AREA AND EMITTER ARE CO-EXTENSIVE. OTHER CIRCUIT COMPONENTS SUCH AS RESISTORS AND DIODES ARE ALSO FORMED DURING THE FORMATION OF THE NPN AND PNP TRANSISTORS.