An integrated impedance matching circuit is disclosed using a flip chip process and a heterlithic microwave integrated circuit (HMIC). In a preferred embodiment, a silicon microwave power transistor is flip chip mounted on a glass substrate having a ground plane and silicon pedestals 404 selectively etched and having glass disposed about the silicon pedestals to form the substrate. The glass substrate of the present invention is finely ground and polished to enable VLSI techniques for mass production fabrication. To this end, photolithography and deposition techniques well-known in the art are utilized to effect impedance matching circuitry. Because the input impedance of the Si power transistor is relatively low, by using the flip chip technique the precision of the impedance matching circuit can be effected without the use of wire bonds which must be tuned in a labor intensive manner. Finally, the silicon pedestals of the present invention are used as an electrical ground for the common base as well and as a thermal sink for the system.