GaAs can be used for various transistor types:
* Metal–semiconductor field-effect transistor (MESFET)
* High-electron-mobility transistor (HEMT)
* Junction field-effect transistor (JFET)
* Heterojunction bipolar transistor (HBT)
* Metal–oxide–semiconductor field-effect transistor (MOSFET)
The HBT can be used in integrated injection logic (IL).
The earliest GaAs logic gate used Buffered FET Logic (BFL).
From  to 1995 the main logic families used were:
* Source-coupled FET logic (SCFL) fastest and most complex, (used by TriQuint & Vitesse)
* Capacitor–diode FET logic (CDFL) (used by Cray for Cray-3)
* Direct-coupled FET logic (DCFL) simplest and lowest power (used by Vitesse for VLSI gate arrays)