4H silicon carbide bipolar transistors were fabricated using a double-mesa process. The devices exhibit a maximum common emitter current gain of 17.4, a maximum current density of 42 kA/cm(2) and maximum DC power dissipation density of 1.67 MW/cm(2). The current gain was measured to decrease to 65% of its room temperature value at 300 degreesC. The record high current and power density of the devices makes them attractive for high-power RF applications. (C) 2002 Elsevier Science Ltd. All rights reserved.