Title :
High-gain, low-leakage GaAs pseudo-HBT´s for operation in reduced temperature environments
Author :
Dodd, P.E. ; Melloch, Michael R. ; Lundstrom, Mark S.
Author_Institution :
Sch. of Electr. Eng., Purdue Univ., West Lafayette, IN, USA
Abstract :
GaAs pseudo-heterojunction bipolar transistors (HBTs) that make use of the difference in effective bandgap narrowing in n- and p-type GaAs have been fabricated and characterized. A current gain enhancement by a factor greater than 20 is observed as the transistors are cooled to 35 K. Current gains of over 100 at a current density of 2.5*10/sup 3/ A/cm/sup 2/ were observed in transistors with a base doping 10 times the emitter doping. Tunneling currents, which previously dominated the low-temperature base current, were eliminated by the use of a spacer layer between the base and the emitter.<>
Keywords :
III-V semiconductors; gallium arsenide; heterojunction bipolar transistors; 35 K; GaAs; base doping; cryogenic characteristics; current density; current gain; current gain enhancement; difference in effective bandgap narrowing; emitter doping; high gain; low-leakage; low-temperature base current; n-type GaAs; operation; p-type GaAs; pseudo HBT; pseudo-heterojunction bipolar transistors; reduced temperature environments; semiconductors; spacer layer; tunneling currents elimination; Bipolar transistors; Cryogenics; Current density; Degradation; Gallium arsenide; Helium; Photonic band gap; Semiconductor device doping; Temperature; Tunneling;
Journal_Title :
Electron Device Letters, IEEE
