High-speed InGaAs(P)/InP double-heterostructure bipolar transistors

Double-heterostructure InGaAs(P)/InP bipolar transistors ranging in emitter size from 5 × 10 to 100 × 150 µm
²
have been fabricated using a non-self-aligned technology. These transistors exhibit current gains as high as 275 independent of emitter perimeter-to-area ratio. The best frequency of unity current gain was measured in the smallest devices to be 18 GHz. The high-frequency operation was mainly limited by the emitter charging time.